Merge branch 'support-global-data'

Daniel Borkmann says:

====================
This series is a major rework of previously submitted libbpf
patches [0] in order to add global data support for BPF. The
kernel has been extended to add proper infrastructure that allows
for full .bss/.data/.rodata sections on BPF loader side based
upon feedback from LPC discussions [1]. Latter support is then
also added into libbpf in this series which allows for more
natural C-like programming of BPF programs. For more information
on loader, please refer to 'bpf, libbpf: support global data/bss/
rodata sections' patch in this series.

Thanks a lot!

  v5 -> v6:
   - Removed synchronize_rcu() from map freeze (Jann)
   - Rest as-is
  v4 -> v5:
   - Removed index selection again for ldimm64 (Alexei)
   - Adapted related test cases and added new ones to test
     rejection of off != 0
  v3 -> v4:
   - Various fixes in BTF verification e.g. to disallow
     Var and DataSec to be an intermediate type during resolve (Martin)
   - More BTF test cases added
   - Few cleanups in key-less BTF commit (Martin)
   - Bump libbpf minor version from 2 to 3
   - Renamed and simplified read-only locking
   - Various minor improvements all over the place
  v2 -> v3:
   - Implement BTF support in kernel, libbpf, bpftool, add tests
   - Fix idx + off conversion (Andrii)
   - Document lower / higher bits for direct value access (Andrii)
   - Add tests with small value size (Andrii)
   - Add index selection into ldimm64 (Andrii)
   - Fix missing fdput() (Jann)
   - Reject invalid flags in BPF_F_*_PROG (Jakub)
   - Complete rework of libbpf support, includes:
    - Add objname to map name (Stanislav)
    - Make .rodata map full read-only after setup (Andrii)
    - Merge relocation handling into single one (Andrii)
    - Store global maps into obj->maps array (Andrii, Alexei)
    - Debug message when skipping section (Andrii)
    - Reject non-static global data till we have
      semantics for sharing them (Yonghong, Andrii, Alexei)
    - More test cases and completely reworked prog test (Alexei)
   - Fixes, cleanups, etc all over the set
   - Not yet addressed:
    - Make BTF mandatory for these maps (Alexei)
    -> Waiting till BTF support for these lands first
  v1 -> v2:
    - Instead of 32-bit static data, implement full global
      data support (Alexei)

  [0] https://patchwork.ozlabs.org/cover/1040290/
  [1] http://vger.kernel.org/lpc-bpf2018.html#session-3
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Documentation/bpf/btf.rst

@@ -82,6 +82,8 @@ sequentially and type id is assigned to each recognized type starting from id
     #define BTF_KIND_RESTRICT       11      /* Restrict     */
     #define BTF_KIND_FUNC           12      /* Function     */
     #define BTF_KIND_FUNC_PROTO     13      /* Function Proto       */
+    #define BTF_KIND_VAR            14      /* Variable     */
+    #define BTF_KIND_DATASEC        15      /* Section      */
 
 Note that the type section encodes debug info, not just pure types.
 ``BTF_KIND_FUNC`` is not a type, and it represents a defined subprogram.
@@ -393,6 +395,61 @@ refers to parameter type.
 If the function has variable arguments, the last parameter is encoded with
 ``name_off = 0`` and ``type = 0``.
 
+2.2.14 BTF_KIND_VAR
+~~~~~~~~~~~~~~~~~~~
+
+``struct btf_type`` encoding requirement:
+  * ``name_off``: offset to a valid C identifier
+  * ``info.kind_flag``: 0
+  * ``info.kind``: BTF_KIND_VAR
+  * ``info.vlen``: 0
+  * ``type``: the type of the variable
+
+``btf_type`` is followed by a single ``struct btf_variable`` with the
+following data::
+
+    struct btf_var {
+        __u32   linkage;
+    };
+
+``struct btf_var`` encoding:
+  * ``linkage``: currently only static variable 0, or globally allocated
+                 variable in ELF sections 1
+
+Not all type of global variables are supported by LLVM at this point.
+The following is currently available:
+
+  * static variables with or without section attributes
+  * global variables with section attributes
+
+The latter is for future extraction of map key/value type id's from a
+map definition.
+
+2.2.15 BTF_KIND_DATASEC
+~~~~~~~~~~~~~~~~~~~~~~~
+
+``struct btf_type`` encoding requirement:
+  * ``name_off``: offset to a valid name associated with a variable or
+                  one of .data/.bss/.rodata
+  * ``info.kind_flag``: 0
+  * ``info.kind``: BTF_KIND_DATASEC
+  * ``info.vlen``: # of variables
+  * ``size``: total section size in bytes (0 at compilation time, patched
+              to actual size by BPF loaders such as libbpf)
+
+``btf_type`` is followed by ``info.vlen`` number of ``struct btf_var_secinfo``.::
+
+    struct btf_var_secinfo {
+        __u32   type;
+        __u32   offset;
+        __u32   size;
+    };
+
+``struct btf_var_secinfo`` encoding:
+  * ``type``: the type of the BTF_KIND_VAR variable
+  * ``offset``: the in-section offset of the variable
+  * ``size``: the size of the variable in bytes
+
 3. BTF Kernel API
 *****************
 

include/linux/bpf.h

@@ -57,6 +57,12 @@ struct bpf_map_ops {
 			     const struct btf *btf,
 			     const struct btf_type *key_type,
 			     const struct btf_type *value_type);
+
+	/* Direct value access helpers. */
+	int (*map_direct_value_addr)(const struct bpf_map *map,
+				     u64 *imm, u32 off);
+	int (*map_direct_value_meta)(const struct bpf_map *map,
+				     u64 imm, u32 *off);
 };
 
 struct bpf_map {
@@ -81,7 +87,8 @@ struct bpf_map {
 	struct btf *btf;
 	u32 pages;
 	bool unpriv_array;
-	/* 51 bytes hole */
+	bool frozen; /* write-once */
+	/* 48 bytes hole */
 
 	/* The 3rd and 4th cacheline with misc members to avoid false sharing
 	 * particularly with refcounting.
@@ -424,6 +431,35 @@ struct bpf_array {
 #define BPF_COMPLEXITY_LIMIT_INSNS      1000000 /* yes. 1M insns */
 #define MAX_TAIL_CALL_CNT 32
 
+#define BPF_F_ACCESS_MASK	(BPF_F_RDONLY |		\
+				 BPF_F_RDONLY_PROG |	\
+				 BPF_F_WRONLY |		\
+				 BPF_F_WRONLY_PROG)
+
+#define BPF_MAP_CAN_READ	BIT(0)
+#define BPF_MAP_CAN_WRITE	BIT(1)
+
+static inline u32 bpf_map_flags_to_cap(struct bpf_map *map)
+{
+	u32 access_flags = map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG);
+
+	/* Combination of BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG is
+	 * not possible.
+	 */
+	if (access_flags & BPF_F_RDONLY_PROG)
+		return BPF_MAP_CAN_READ;
+	else if (access_flags & BPF_F_WRONLY_PROG)
+		return BPF_MAP_CAN_WRITE;
+	else
+		return BPF_MAP_CAN_READ | BPF_MAP_CAN_WRITE;
+}
+
+static inline bool bpf_map_flags_access_ok(u32 access_flags)
+{
+	return (access_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) !=
+	       (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG);
+}
+
 struct bpf_event_entry {
 	struct perf_event *event;
 	struct file *perf_file;

include/linux/bpf_verifier.h

@@ -224,6 +224,10 @@ struct bpf_insn_aux_data {
 		unsigned long map_state;	/* pointer/poison value for maps */
 		s32 call_imm;			/* saved imm field of call insn */
 		u32 alu_limit;			/* limit for add/sub register with pointer */
+		struct {
+			u32 map_index;		/* index into used_maps[] */
+			u32 map_off;		/* offset from value base address */
+		};
 	};
 	int ctx_field_size; /* the ctx field size for load insn, maybe 0 */
 	int sanitize_stack_off; /* stack slot to be cleared */

include/linux/btf.h

@@ -51,6 +51,7 @@ bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
 			   const struct btf_member *m,
 			   u32 expected_offset, u32 expected_size);
 int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t);
+bool btf_type_is_void(const struct btf_type *t);
 
 #ifdef CONFIG_BPF_SYSCALL
 const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);

include/uapi/linux/bpf.h

@@ -105,6 +105,7 @@ enum bpf_cmd {
 	BPF_BTF_GET_FD_BY_ID,
 	BPF_TASK_FD_QUERY,
 	BPF_MAP_LOOKUP_AND_DELETE_ELEM,
+	BPF_MAP_FREEZE,
 };
 
 enum bpf_map_type {
@@ -255,8 +256,19 @@ enum bpf_attach_type {
  */
 #define BPF_F_ANY_ALIGNMENT	(1U << 1)
 
-/* when bpf_ldimm64->src_reg == BPF_PSEUDO_MAP_FD, bpf_ldimm64->imm == fd */
+/* When BPF ldimm64's insn[0].src_reg != 0 then this can have
+ * two extensions:
+ *
+ * insn[0].src_reg:  BPF_PSEUDO_MAP_FD   BPF_PSEUDO_MAP_VALUE
+ * insn[0].imm:      map fd              map fd
+ * insn[1].imm:      0                   offset into value
+ * insn[0].off:      0                   0
+ * insn[1].off:      0                   0
+ * ldimm64 rewrite:  address of map      address of map[0]+offset
+ * verifier type:    CONST_PTR_TO_MAP    PTR_TO_MAP_VALUE
+ */
 #define BPF_PSEUDO_MAP_FD	1
+#define BPF_PSEUDO_MAP_VALUE	2
 
 /* when bpf_call->src_reg == BPF_PSEUDO_CALL, bpf_call->imm == pc-relative
  * offset to another bpf function
@@ -283,7 +295,7 @@ enum bpf_attach_type {
 
 #define BPF_OBJ_NAME_LEN 16U
 
-/* Flags for accessing BPF object */
+/* Flags for accessing BPF object from syscall side. */
 #define BPF_F_RDONLY		(1U << 3)
 #define BPF_F_WRONLY		(1U << 4)
 
@@ -293,6 +305,10 @@ enum bpf_attach_type {
 /* Zero-initialize hash function seed. This should only be used for testing. */
 #define BPF_F_ZERO_SEED		(1U << 6)
 
+/* Flags for accessing BPF object from program side. */
+#define BPF_F_RDONLY_PROG	(1U << 7)
+#define BPF_F_WRONLY_PROG	(1U << 8)
+
 /* flags for BPF_PROG_QUERY */
 #define BPF_F_QUERY_EFFECTIVE	(1U << 0)
 

include/uapi/linux/btf.h

@@ -39,11 +39,11 @@ struct btf_type {
 	 *             struct, union and fwd
 	 */
 	__u32 info;
-	/* "size" is used by INT, ENUM, STRUCT and UNION.
+	/* "size" is used by INT, ENUM, STRUCT, UNION and DATASEC.
 	 * "size" tells the size of the type it is describing.
 	 *
 	 * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT,
-	 * FUNC and FUNC_PROTO.
+	 * FUNC, FUNC_PROTO and VAR.
 	 * "type" is a type_id referring to another type.
 	 */
 	union {
@@ -70,8 +70,10 @@ struct btf_type {
 #define BTF_KIND_RESTRICT	11	/* Restrict	*/
 #define BTF_KIND_FUNC		12	/* Function	*/
 #define BTF_KIND_FUNC_PROTO	13	/* Function Proto	*/
-#define BTF_KIND_MAX		13
-#define NR_BTF_KINDS		14
+#define BTF_KIND_VAR		14	/* Variable	*/
+#define BTF_KIND_DATASEC	15	/* Section	*/
+#define BTF_KIND_MAX		BTF_KIND_DATASEC
+#define NR_BTF_KINDS		(BTF_KIND_MAX + 1)
 
 /* For some specific BTF_KIND, "struct btf_type" is immediately
  * followed by extra data.
@@ -138,4 +140,26 @@ struct btf_param {
 	__u32	type;
 };
 
+enum {
+	BTF_VAR_STATIC = 0,
+	BTF_VAR_GLOBAL_ALLOCATED,
+};
+
+/* BTF_KIND_VAR is followed by a single "struct btf_var" to describe
+ * additional information related to the variable such as its linkage.
+ */
+struct btf_var {
+	__u32	linkage;
+};
+
+/* BTF_KIND_DATASEC is followed by multiple "struct btf_var_secinfo"
+ * to describe all BTF_KIND_VAR types it contains along with it's
+ * in-section offset as well as size.
+ */
+struct btf_var_secinfo {
+	__u32	type;
+	__u32	offset;
+	__u32	size;
+};
+
 #endif /* _UAPI__LINUX_BTF_H__ */

kernel/bpf/arraymap.c

@@ -22,7 +22,7 @@
 #include "map_in_map.h"
 
 #define ARRAY_CREATE_FLAG_MASK \
-	(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
+	(BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
 
 static void bpf_array_free_percpu(struct bpf_array *array)
 {
@@ -63,6 +63,7 @@ int array_map_alloc_check(union bpf_attr *attr)
 	if (attr->max_entries == 0 || attr->key_size != 4 ||
 	    attr->value_size == 0 ||
 	    attr->map_flags & ~ARRAY_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags) ||
 	    (percpu && numa_node != NUMA_NO_NODE))
 		return -EINVAL;
 
@@ -160,6 +161,36 @@ static void *array_map_lookup_elem(struct bpf_map *map, void *key)
 	return array->value + array->elem_size * (index & array->index_mask);
 }
 
+static int array_map_direct_value_addr(const struct bpf_map *map, u64 *imm,
+				       u32 off)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+
+	if (map->max_entries != 1)
+		return -ENOTSUPP;
+	if (off >= map->value_size)
+		return -EINVAL;
+
+	*imm = (unsigned long)array->value;
+	return 0;
+}
+
+static int array_map_direct_value_meta(const struct bpf_map *map, u64 imm,
+				       u32 *off)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	u64 base = (unsigned long)array->value;
+	u64 range = array->elem_size;
+
+	if (map->max_entries != 1)
+		return -ENOTSUPP;
+	if (imm < base || imm >= base + range)
+		return -ENOENT;
+
+	*off = imm - base;
+	return 0;
+}
+
 /* emit BPF instructions equivalent to C code of array_map_lookup_elem() */
 static u32 array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
 {
@@ -360,7 +391,8 @@ static void array_map_seq_show_elem(struct bpf_map *map, void *key,
 		return;
 	}
 
-	seq_printf(m, "%u: ", *(u32 *)key);
+	if (map->btf_key_type_id)
+		seq_printf(m, "%u: ", *(u32 *)key);
 	btf_type_seq_show(map->btf, map->btf_value_type_id, value, m);
 	seq_puts(m, "\n");
 
@@ -397,6 +429,18 @@ static int array_map_check_btf(const struct bpf_map *map,
 {
 	u32 int_data;
 
+	/* One exception for keyless BTF: .bss/.data/.rodata map */
+	if (btf_type_is_void(key_type)) {
+		if (map->map_type != BPF_MAP_TYPE_ARRAY ||
+		    map->max_entries != 1)
+			return -EINVAL;
+
+		if (BTF_INFO_KIND(value_type->info) != BTF_KIND_DATASEC)
+			return -EINVAL;
+
+		return 0;
+	}
+
 	if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
 		return -EINVAL;
 
@@ -419,6 +463,8 @@ const struct bpf_map_ops array_map_ops = {
 	.map_update_elem = array_map_update_elem,
 	.map_delete_elem = array_map_delete_elem,
 	.map_gen_lookup = array_map_gen_lookup,
+	.map_direct_value_addr = array_map_direct_value_addr,
+	.map_direct_value_meta = array_map_direct_value_meta,
 	.map_seq_show_elem = array_map_seq_show_elem,
 	.map_check_btf = array_map_check_btf,
 };
@@ -440,6 +486,9 @@ static int fd_array_map_alloc_check(union bpf_attr *attr)
 	/* only file descriptors can be stored in this type of map */
 	if (attr->value_size != sizeof(u32))
 		return -EINVAL;
+	/* Program read-only/write-only not supported for special maps yet. */
+	if (attr->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG))
+		return -EINVAL;
 	return array_map_alloc_check(attr);
 }
 

kernel/bpf/btf.c

@@ -185,6 +185,16 @@
 	     i < btf_type_vlen(struct_type);				\
 	     i++, member++)
 
+#define for_each_vsi(i, struct_type, member)			\
+	for (i = 0, member = btf_type_var_secinfo(struct_type);	\
+	     i < btf_type_vlen(struct_type);			\
+	     i++, member++)
+
+#define for_each_vsi_from(i, from, struct_type, member)				\
+	for (i = from, member = btf_type_var_secinfo(struct_type) + from;	\
+	     i < btf_type_vlen(struct_type);					\
+	     i++, member++)
+
 static DEFINE_IDR(btf_idr);
 static DEFINE_SPINLOCK(btf_idr_lock);
 
@@ -262,6 +272,8 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
 	[BTF_KIND_RESTRICT]	= "RESTRICT",
 	[BTF_KIND_FUNC]		= "FUNC",
 	[BTF_KIND_FUNC_PROTO]	= "FUNC_PROTO",
+	[BTF_KIND_VAR]		= "VAR",
+	[BTF_KIND_DATASEC]	= "DATASEC",
 };
 
 struct btf_kind_operations {
@@ -314,7 +326,7 @@ static bool btf_type_is_modifier(const struct btf_type *t)
 	return false;
 }
 
-static bool btf_type_is_void(const struct btf_type *t)
+bool btf_type_is_void(const struct btf_type *t)
 {
 	return t == &btf_void;
 }
@@ -375,13 +387,36 @@ static bool btf_type_is_int(const struct btf_type *t)
 	return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
 }
 
+static bool btf_type_is_var(const struct btf_type *t)
+{
+	return BTF_INFO_KIND(t->info) == BTF_KIND_VAR;
+}
+
+static bool btf_type_is_datasec(const struct btf_type *t)
+{
+	return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
+}
+
+/* Types that act only as a source, not sink or intermediate
+ * type when resolving.
+ */
+static bool btf_type_is_resolve_source_only(const struct btf_type *t)
+{
+	return btf_type_is_var(t) ||
+	       btf_type_is_datasec(t);
+}
+
 /* What types need to be resolved?
  *
  * btf_type_is_modifier() is an obvious one.
  *
  * btf_type_is_struct() because its member refers to
  * another type (through member->type).
-
+ *
+ * btf_type_is_var() because the variable refers to
+ * another type. btf_type_is_datasec() holds multiple
+ * btf_type_is_var() types that need resolving.
+ *
  * btf_type_is_array() because its element (array->type)
  * refers to another type.  Array can be thought of a
  * special case of struct while array just has the same
@@ -390,9 +425,11 @@ static bool btf_type_is_int(const struct btf_type *t)
 static bool btf_type_needs_resolve(const struct btf_type *t)
 {
 	return btf_type_is_modifier(t) ||
-		btf_type_is_ptr(t) ||
-		btf_type_is_struct(t) ||
-		btf_type_is_array(t);
+	       btf_type_is_ptr(t) ||
+	       btf_type_is_struct(t) ||
+	       btf_type_is_array(t) ||
+	       btf_type_is_var(t) ||
+	       btf_type_is_datasec(t);
 }
 
 /* t->size can be used */
@@ -403,6 +440,7 @@ static bool btf_type_has_size(const struct btf_type *t)
 	case BTF_KIND_STRUCT:
 	case BTF_KIND_UNION:
 	case BTF_KIND_ENUM:
+	case BTF_KIND_DATASEC:
 		return true;
 	}
 
@@ -467,6 +505,16 @@ static const struct btf_enum *btf_type_enum(const struct btf_type *t)
 	return (const struct btf_enum *)(t + 1);
 }
 
+static const struct btf_var *btf_type_var(const struct btf_type *t)
+{
+	return (const struct btf_var *)(t + 1);
+}
+
+static const struct btf_var_secinfo *btf_type_var_secinfo(const struct btf_type *t)
+{
+	return (const struct btf_var_secinfo *)(t + 1);
+}
+
 static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t)
 {
 	return kind_ops[BTF_INFO_KIND(t->info)];
@@ -478,23 +526,31 @@ static bool btf_name_offset_valid(const struct btf *btf, u32 offset)
 		offset < btf->hdr.str_len;
 }
 
-/* Only C-style identifier is permitted. This can be relaxed if
- * necessary.
- */
-static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
+static bool __btf_name_char_ok(char c, bool first, bool dot_ok)
+{
+	if ((first ? !isalpha(c) :
+		     !isalnum(c)) &&
+	    c != '_' &&
+	    ((c == '.' && !dot_ok) ||
+	      c != '.'))
+		return false;
+	return true;
+}
+
+static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok)
 {
 	/* offset must be valid */
 	const char *src = &btf->strings[offset];
 	const char *src_limit;
 
-	if (!isalpha(*src) && *src != '_')
+	if (!__btf_name_char_ok(*src, true, dot_ok))
 		return false;
 
 	/* set a limit on identifier length */
 	src_limit = src + KSYM_NAME_LEN;
 	src++;
 	while (*src && src < src_limit) {
-		if (!isalnum(*src) && *src != '_')
+		if (!__btf_name_char_ok(*src, false, dot_ok))
 			return false;
 		src++;
 	}
@@ -502,6 +558,19 @@ static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
 	return !*src;
 }
 
+/* Only C-style identifier is permitted. This can be relaxed if
+ * necessary.
+ */
+static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
+{
+	return __btf_name_valid(btf, offset, false);
+}
+
+static bool btf_name_valid_section(const struct btf *btf, u32 offset)
+{
+	return __btf_name_valid(btf, offset, true);
+}
+
 static const char *__btf_name_by_offset(const struct btf *btf, u32 offset)
 {
 	if (!offset)
@@ -697,6 +766,32 @@ static void btf_verifier_log_member(struct btf_verifier_env *env,
 	__btf_verifier_log(log, "\n");
 }
 
+__printf(4, 5)
+static void btf_verifier_log_vsi(struct btf_verifier_env *env,
+				 const struct btf_type *datasec_type,
+				 const struct btf_var_secinfo *vsi,
+				 const char *fmt, ...)
+{
+	struct bpf_verifier_log *log = &env->log;
+	va_list args;
+
+	if (!bpf_verifier_log_needed(log))
+		return;
+	if (env->phase != CHECK_META)
+		btf_verifier_log_type(env, datasec_type, NULL);
+
+	__btf_verifier_log(log, "\t type_id=%u offset=%u size=%u",
+			   vsi->type, vsi->offset, vsi->size);
+	if (fmt && *fmt) {
+		__btf_verifier_log(log, " ");
+		va_start(args, fmt);
+		bpf_verifier_vlog(log, fmt, args);
+		va_end(args);
+	}
+
+	__btf_verifier_log(log, "\n");
+}
+
 static void btf_verifier_log_hdr(struct btf_verifier_env *env,
 				 u32 btf_data_size)
 {
@@ -974,7 +1069,8 @@ const struct btf_type *btf_type_id_size(const struct btf *btf,
 	} else if (btf_type_is_ptr(size_type)) {
 		size = sizeof(void *);
 	} else {
-		if (WARN_ON_ONCE(!btf_type_is_modifier(size_type)))
+		if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) &&
+				 !btf_type_is_var(size_type)))
 			return NULL;
 
 		size = btf->resolved_sizes[size_type_id];
@@ -1509,7 +1605,7 @@ static int btf_modifier_resolve(struct btf_verifier_env *env,
 	u32 next_type_size = 0;
 
 	next_type = btf_type_by_id(btf, next_type_id);
-	if (!next_type) {
+	if (!next_type || btf_type_is_resolve_source_only(next_type)) {
 		btf_verifier_log_type(env, v->t, "Invalid type_id");
 		return -EINVAL;
 	}
@@ -1542,6 +1638,53 @@ static int btf_modifier_resolve(struct btf_verifier_env *env,
 	return 0;
 }
 
+static int btf_var_resolve(struct btf_verifier_env *env,
+			   const struct resolve_vertex *v)
+{
+	const struct btf_type *next_type;
+	const struct btf_type *t = v->t;
+	u32 next_type_id = t->type;
+	struct btf *btf = env->btf;
+	u32 next_type_size;
+
+	next_type = btf_type_by_id(btf, next_type_id);
+	if (!next_type || btf_type_is_resolve_source_only(next_type)) {
+		btf_verifier_log_type(env, v->t, "Invalid type_id");
+		return -EINVAL;
+	}
+
+	if (!env_type_is_resolve_sink(env, next_type) &&
+	    !env_type_is_resolved(env, next_type_id))
+		return env_stack_push(env, next_type, next_type_id);
+
+	if (btf_type_is_modifier(next_type)) {
+		const struct btf_type *resolved_type;
+		u32 resolved_type_id;
+
+		resolved_type_id = next_type_id;
+		resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
+
+		if (btf_type_is_ptr(resolved_type) &&
+		    !env_type_is_resolve_sink(env, resolved_type) &&
+		    !env_type_is_resolved(env, resolved_type_id))
+			return env_stack_push(env, resolved_type,
+					      resolved_type_id);
+	}
+
+	/* We must resolve to something concrete at this point, no
+	 * forward types or similar that would resolve to size of
+	 * zero is allowed.
+	 */
+	if (!btf_type_id_size(btf, &next_type_id, &next_type_size)) {
+		btf_verifier_log_type(env, v->t, "Invalid type_id");
+		return -EINVAL;
+	}
+
+	env_stack_pop_resolved(env, next_type_id, next_type_size);
+
+	return 0;
+}
+
 static int btf_ptr_resolve(struct btf_verifier_env *env,
 			   const struct resolve_vertex *v)
 {
@@ -1551,7 +1694,7 @@ static int btf_ptr_resolve(struct btf_verifier_env *env,
 	struct btf *btf = env->btf;
 
 	next_type = btf_type_by_id(btf, next_type_id);
-	if (!next_type) {
+	if (!next_type || btf_type_is_resolve_source_only(next_type)) {
 		btf_verifier_log_type(env, v->t, "Invalid type_id");
 		return -EINVAL;
 	}
@@ -1609,6 +1752,15 @@ static void btf_modifier_seq_show(const struct btf *btf,
 	btf_type_ops(t)->seq_show(btf, t, type_id, data, bits_offset, m);
 }
 
+static void btf_var_seq_show(const struct btf *btf, const struct btf_type *t,
+			     u32 type_id, void *data, u8 bits_offset,
+			     struct seq_file *m)
+{
+	t = btf_type_id_resolve(btf, &type_id);
+
+	btf_type_ops(t)->seq_show(btf, t, type_id, data, bits_offset, m);
+}
+
 static void btf_ptr_seq_show(const struct btf *btf, const struct btf_type *t,
 			     u32 type_id, void *data, u8 bits_offset,
 			     struct seq_file *m)
@@ -1776,7 +1928,8 @@ static int btf_array_resolve(struct btf_verifier_env *env,
 	/* Check array->index_type */
 	index_type_id = array->index_type;
 	index_type = btf_type_by_id(btf, index_type_id);
-	if (btf_type_nosize_or_null(index_type)) {
+	if (btf_type_is_resolve_source_only(index_type) ||
+	    btf_type_nosize_or_null(index_type)) {
 		btf_verifier_log_type(env, v->t, "Invalid index");
 		return -EINVAL;
 	}
@@ -1795,7 +1948,8 @@ static int btf_array_resolve(struct btf_verifier_env *env,
 	/* Check array->type */
 	elem_type_id = array->type;
 	elem_type = btf_type_by_id(btf, elem_type_id);
-	if (btf_type_nosize_or_null(elem_type)) {
+	if (btf_type_is_resolve_source_only(elem_type) ||
+	    btf_type_nosize_or_null(elem_type)) {
 		btf_verifier_log_type(env, v->t,
 				      "Invalid elem");
 		return -EINVAL;
@@ -2016,7 +2170,8 @@ static int btf_struct_resolve(struct btf_verifier_env *env,
 		const struct btf_type *member_type = btf_type_by_id(env->btf,
 								member_type_id);
 
-		if (btf_type_nosize_or_null(member_type)) {
+		if (btf_type_is_resolve_source_only(member_type) ||
+		    btf_type_nosize_or_null(member_type)) {
 			btf_verifier_log_member(env, v->t, member,
 						"Invalid member");
 			return -EINVAL;
@@ -2411,6 +2566,222 @@ static struct btf_kind_operations func_ops = {
 	.seq_show = btf_df_seq_show,
 };
 
+static s32 btf_var_check_meta(struct btf_verifier_env *env,
+			      const struct btf_type *t,
+			      u32 meta_left)
+{
+	const struct btf_var *var;
+	u32 meta_needed = sizeof(*var);
+
+	if (meta_left < meta_needed) {
+		btf_verifier_log_basic(env, t,
+				       "meta_left:%u meta_needed:%u",
+				       meta_left, meta_needed);
+		return -EINVAL;
+	}
+
+	if (btf_type_vlen(t)) {
+		btf_verifier_log_type(env, t, "vlen != 0");
+		return -EINVAL;
+	}
+
+	if (btf_type_kflag(t)) {
+		btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+		return -EINVAL;
+	}
+
+	if (!t->name_off ||
+	    !__btf_name_valid(env->btf, t->name_off, true)) {
+		btf_verifier_log_type(env, t, "Invalid name");
+		return -EINVAL;
+	}
+
+	/* A var cannot be in type void */
+	if (!t->type || !BTF_TYPE_ID_VALID(t->type)) {
+		btf_verifier_log_type(env, t, "Invalid type_id");
+		return -EINVAL;
+	}
+
+	var = btf_type_var(t);
+	if (var->linkage != BTF_VAR_STATIC &&
+	    var->linkage != BTF_VAR_GLOBAL_ALLOCATED) {
+		btf_verifier_log_type(env, t, "Linkage not supported");
+		return -EINVAL;
+	}
+
+	btf_verifier_log_type(env, t, NULL);
+
+	return meta_needed;
+}
+
+static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t)
+{
+	const struct btf_var *var = btf_type_var(t);
+
+	btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage);
+}
+
+static const struct btf_kind_operations var_ops = {
+	.check_meta		= btf_var_check_meta,
+	.resolve		= btf_var_resolve,
+	.check_member		= btf_df_check_member,
+	.check_kflag_member	= btf_df_check_kflag_member,
+	.log_details		= btf_var_log,
+	.seq_show		= btf_var_seq_show,
+};
+
+static s32 btf_datasec_check_meta(struct btf_verifier_env *env,
+				  const struct btf_type *t,
+				  u32 meta_left)
+{
+	const struct btf_var_secinfo *vsi;
+	u64 last_vsi_end_off = 0, sum = 0;
+	u32 i, meta_needed;
+
+	meta_needed = btf_type_vlen(t) * sizeof(*vsi);
+	if (meta_left < meta_needed) {
+		btf_verifier_log_basic(env, t,
+				       "meta_left:%u meta_needed:%u",
+				       meta_left, meta_needed);
+		return -EINVAL;
+	}
+
+	if (!btf_type_vlen(t)) {
+		btf_verifier_log_type(env, t, "vlen == 0");
+		return -EINVAL;
+	}
+
+	if (!t->size) {
+		btf_verifier_log_type(env, t, "size == 0");
+		return -EINVAL;
+	}
+
+	if (btf_type_kflag(t)) {
+		btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+		return -EINVAL;
+	}
+
+	if (!t->name_off ||
+	    !btf_name_valid_section(env->btf, t->name_off)) {
+		btf_verifier_log_type(env, t, "Invalid name");
+		return -EINVAL;
+	}
+
+	btf_verifier_log_type(env, t, NULL);
+
+	for_each_vsi(i, t, vsi) {
+		/* A var cannot be in type void */
+		if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) {
+			btf_verifier_log_vsi(env, t, vsi,
+					     "Invalid type_id");
+			return -EINVAL;
+		}
+
+		if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) {
+			btf_verifier_log_vsi(env, t, vsi,
+					     "Invalid offset");
+			return -EINVAL;
+		}
+
+		if (!vsi->size || vsi->size > t->size) {
+			btf_verifier_log_vsi(env, t, vsi,
+					     "Invalid size");
+			return -EINVAL;
+		}
+
+		last_vsi_end_off = vsi->offset + vsi->size;
+		if (last_vsi_end_off > t->size) {
+			btf_verifier_log_vsi(env, t, vsi,
+					     "Invalid offset+size");
+			return -EINVAL;
+		}
+
+		btf_verifier_log_vsi(env, t, vsi, NULL);
+		sum += vsi->size;
+	}
+
+	if (t->size < sum) {
+		btf_verifier_log_type(env, t, "Invalid btf_info size");
+		return -EINVAL;
+	}
+
+	return meta_needed;
+}
+
+static int btf_datasec_resolve(struct btf_verifier_env *env,
+			       const struct resolve_vertex *v)
+{
+	const struct btf_var_secinfo *vsi;
+	struct btf *btf = env->btf;
+	u16 i;
+
+	for_each_vsi_from(i, v->next_member, v->t, vsi) {
+		u32 var_type_id = vsi->type, type_id, type_size = 0;
+		const struct btf_type *var_type = btf_type_by_id(env->btf,
+								 var_type_id);
+		if (!var_type || !btf_type_is_var(var_type)) {
+			btf_verifier_log_vsi(env, v->t, vsi,
+					     "Not a VAR kind member");
+			return -EINVAL;
+		}
+
+		if (!env_type_is_resolve_sink(env, var_type) &&
+		    !env_type_is_resolved(env, var_type_id)) {
+			env_stack_set_next_member(env, i + 1);
+			return env_stack_push(env, var_type, var_type_id);
+		}
+
+		type_id = var_type->type;
+		if (!btf_type_id_size(btf, &type_id, &type_size)) {
+			btf_verifier_log_vsi(env, v->t, vsi, "Invalid type");
+			return -EINVAL;
+		}
+
+		if (vsi->size < type_size) {
+			btf_verifier_log_vsi(env, v->t, vsi, "Invalid size");
+			return -EINVAL;
+		}
+	}
+
+	env_stack_pop_resolved(env, 0, 0);
+	return 0;
+}
+
+static void btf_datasec_log(struct btf_verifier_env *env,
+			    const struct btf_type *t)
+{
+	btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
+}
+
+static void btf_datasec_seq_show(const struct btf *btf,
+				 const struct btf_type *t, u32 type_id,
+				 void *data, u8 bits_offset,
+				 struct seq_file *m)
+{
+	const struct btf_var_secinfo *vsi;
+	const struct btf_type *var;
+	u32 i;
+
+	seq_printf(m, "section (\"%s\") = {", __btf_name_by_offset(btf, t->name_off));
+	for_each_vsi(i, t, vsi) {
+		var = btf_type_by_id(btf, vsi->type);
+		if (i)
+			seq_puts(m, ",");
+		btf_type_ops(var)->seq_show(btf, var, vsi->type,
+					    data + vsi->offset, bits_offset, m);
+	}
+	seq_puts(m, "}");
+}
+
+static const struct btf_kind_operations datasec_ops = {
+	.check_meta		= btf_datasec_check_meta,
+	.resolve		= btf_datasec_resolve,
+	.check_member		= btf_df_check_member,
+	.check_kflag_member	= btf_df_check_kflag_member,
+	.log_details		= btf_datasec_log,
+	.seq_show		= btf_datasec_seq_show,
+};
+
 static int btf_func_proto_check(struct btf_verifier_env *env,
 				const struct btf_type *t)
 {
@@ -2542,6 +2913,8 @@ static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
 	[BTF_KIND_RESTRICT] = &modifier_ops,
 	[BTF_KIND_FUNC] = &func_ops,
 	[BTF_KIND_FUNC_PROTO] = &func_proto_ops,
+	[BTF_KIND_VAR] = &var_ops,
+	[BTF_KIND_DATASEC] = &datasec_ops,
 };
 
 static s32 btf_check_meta(struct btf_verifier_env *env,
@@ -2622,13 +2995,17 @@ static bool btf_resolve_valid(struct btf_verifier_env *env,
 	if (!env_type_is_resolved(env, type_id))
 		return false;
 
-	if (btf_type_is_struct(t))
+	if (btf_type_is_struct(t) || btf_type_is_datasec(t))
 		return !btf->resolved_ids[type_id] &&
-			!btf->resolved_sizes[type_id];
+		       !btf->resolved_sizes[type_id];
 
-	if (btf_type_is_modifier(t) || btf_type_is_ptr(t)) {
+	if (btf_type_is_modifier(t) || btf_type_is_ptr(t) ||
+	    btf_type_is_var(t)) {
 		t = btf_type_id_resolve(btf, &type_id);
-		return t && !btf_type_is_modifier(t);
+		return t &&
+		       !btf_type_is_modifier(t) &&
+		       !btf_type_is_var(t) &&
+		       !btf_type_is_datasec(t);
 	}
 
 	if (btf_type_is_array(t)) {

kernel/bpf/core.c

@@ -292,7 +292,8 @@ int bpf_prog_calc_tag(struct bpf_prog *fp)
 		dst[i] = fp->insnsi[i];
 		if (!was_ld_map &&
 		    dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
-		    dst[i].src_reg == BPF_PSEUDO_MAP_FD) {
+		    (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
+		     dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
 			was_ld_map = true;
 			dst[i].imm = 0;
 		} else if (was_ld_map &&

kernel/bpf/disasm.c

@@ -205,10 +205,11 @@ void print_bpf_insn(const struct bpf_insn_cbs *cbs,
 			 * part of the ldimm64 insn is accessible.
 			 */
 			u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm;
-			bool map_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD;
+			bool is_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD ||
+				      insn->src_reg == BPF_PSEUDO_MAP_VALUE;
 			char tmp[64];
 
-			if (map_ptr && !allow_ptr_leaks)
+			if (is_ptr && !allow_ptr_leaks)
 				imm = 0;
 
 			verbose(cbs->private_data, "(%02x) r%d = %s\n",

kernel/bpf/hashtab.c

@@ -23,7 +23,7 @@
 
 #define HTAB_CREATE_FLAG_MASK						\
 	(BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU | BPF_F_NUMA_NODE |	\
-	 BPF_F_RDONLY | BPF_F_WRONLY | BPF_F_ZERO_SEED)
+	 BPF_F_ACCESS_MASK | BPF_F_ZERO_SEED)
 
 struct bucket {
 	struct hlist_nulls_head head;
@@ -262,8 +262,8 @@ static int htab_map_alloc_check(union bpf_attr *attr)
 		/* Guard against local DoS, and discourage production use. */
 		return -EPERM;
 
-	if (attr->map_flags & ~HTAB_CREATE_FLAG_MASK)
-		/* reserved bits should not be used */
+	if (attr->map_flags & ~HTAB_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags))
 		return -EINVAL;
 
 	if (!lru && percpu_lru)

kernel/bpf/local_storage.c

@@ -14,7 +14,7 @@ DEFINE_PER_CPU(struct bpf_cgroup_storage*, bpf_cgroup_storage[MAX_BPF_CGROUP_STO
 #ifdef CONFIG_CGROUP_BPF
 
 #define LOCAL_STORAGE_CREATE_FLAG_MASK					\
-	(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
+	(BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
 
 struct bpf_cgroup_storage_map {
 	struct bpf_map map;
@@ -282,8 +282,8 @@ static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
 	if (attr->value_size > PAGE_SIZE)
 		return ERR_PTR(-E2BIG);
 
-	if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK)
-		/* reserved bits should not be used */
+	if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags))
 		return ERR_PTR(-EINVAL);
 
 	if (attr->max_entries)

kernel/bpf/lpm_trie.c

@@ -538,7 +538,7 @@ out:
 #define LPM_KEY_SIZE_MIN	LPM_KEY_SIZE(LPM_DATA_SIZE_MIN)
 
 #define LPM_CREATE_FLAG_MASK	(BPF_F_NO_PREALLOC | BPF_F_NUMA_NODE |	\
-				 BPF_F_RDONLY | BPF_F_WRONLY)
+				 BPF_F_ACCESS_MASK)
 
 static struct bpf_map *trie_alloc(union bpf_attr *attr)
 {
@@ -553,6 +553,7 @@ static struct bpf_map *trie_alloc(union bpf_attr *attr)
 	if (attr->max_entries == 0 ||
 	    !(attr->map_flags & BPF_F_NO_PREALLOC) ||
 	    attr->map_flags & ~LPM_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags) ||
 	    attr->key_size < LPM_KEY_SIZE_MIN ||
 	    attr->key_size > LPM_KEY_SIZE_MAX ||
 	    attr->value_size < LPM_VAL_SIZE_MIN ||

kernel/bpf/queue_stack_maps.c

@@ -11,8 +11,7 @@
 #include "percpu_freelist.h"
 
 #define QUEUE_STACK_CREATE_FLAG_MASK \
-	(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
-
+	(BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
 
 struct bpf_queue_stack {
 	struct bpf_map map;
@@ -52,7 +51,8 @@ static int queue_stack_map_alloc_check(union bpf_attr *attr)
 	/* check sanity of attributes */
 	if (attr->max_entries == 0 || attr->key_size != 0 ||
 	    attr->value_size == 0 ||
-	    attr->map_flags & ~QUEUE_STACK_CREATE_FLAG_MASK)
+	    attr->map_flags & ~QUEUE_STACK_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags))
 		return -EINVAL;
 
 	if (attr->value_size > KMALLOC_MAX_SIZE)

kernel/bpf/syscall.c

@@ -166,13 +166,25 @@ void bpf_map_area_free(void *area)
 	kvfree(area);
 }
 
+static u32 bpf_map_flags_retain_permanent(u32 flags)
+{
+	/* Some map creation flags are not tied to the map object but
+	 * rather to the map fd instead, so they have no meaning upon
+	 * map object inspection since multiple file descriptors with
+	 * different (access) properties can exist here. Thus, given
+	 * this has zero meaning for the map itself, lets clear these
+	 * from here.
+	 */
+	return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
+}
+
 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
 {
 	map->map_type = attr->map_type;
 	map->key_size = attr->key_size;
 	map->value_size = attr->value_size;
 	map->max_entries = attr->max_entries;
-	map->map_flags = attr->map_flags;
+	map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
 	map->numa_node = bpf_map_attr_numa_node(attr);
 }
 
@@ -343,6 +355,18 @@ static int bpf_map_release(struct inode *inode, struct file *filp)
 	return 0;
 }
 
+static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
+{
+	fmode_t mode = f.file->f_mode;
+
+	/* Our file permissions may have been overridden by global
+	 * map permissions facing syscall side.
+	 */
+	if (READ_ONCE(map->frozen))
+		mode &= ~FMODE_CAN_WRITE;
+	return mode;
+}
+
 #ifdef CONFIG_PROC_FS
 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
 {
@@ -364,14 +388,16 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
 		   "max_entries:\t%u\n"
 		   "map_flags:\t%#x\n"
 		   "memlock:\t%llu\n"
-		   "map_id:\t%u\n",
+		   "map_id:\t%u\n"
+		   "frozen:\t%u\n",
 		   map->map_type,
 		   map->key_size,
 		   map->value_size,
 		   map->max_entries,
 		   map->map_flags,
 		   map->pages * 1ULL << PAGE_SHIFT,
-		   map->id);
+		   map->id,
+		   READ_ONCE(map->frozen));
 
 	if (owner_prog_type) {
 		seq_printf(m, "owner_prog_type:\t%u\n",
@@ -448,10 +474,10 @@ static int bpf_obj_name_cpy(char *dst, const char *src)
 	const char *end = src + BPF_OBJ_NAME_LEN;
 
 	memset(dst, 0, BPF_OBJ_NAME_LEN);
-
-	/* Copy all isalnum() and '_' char */
+	/* Copy all isalnum(), '_' and '.' chars. */
 	while (src < end && *src) {
-		if (!isalnum(*src) && *src != '_')
+		if (!isalnum(*src) &&
+		    *src != '_' && *src != '.')
 			return -EINVAL;
 		*dst++ = *src++;
 	}
@@ -478,9 +504,16 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
 	u32 key_size, value_size;
 	int ret = 0;
 
-	key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
-	if (!key_type || key_size != map->key_size)
-		return -EINVAL;
+	/* Some maps allow key to be unspecified. */
+	if (btf_key_id) {
+		key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
+		if (!key_type || key_size != map->key_size)
+			return -EINVAL;
+	} else {
+		key_type = btf_type_by_id(btf, 0);
+		if (!map->ops->map_check_btf)
+			return -EINVAL;
+	}
 
 	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
 	if (!value_type || value_size != map->value_size)
@@ -489,6 +522,8 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
 	map->spin_lock_off = btf_find_spin_lock(btf, value_type);
 
 	if (map_value_has_spin_lock(map)) {
+		if (map->map_flags & BPF_F_RDONLY_PROG)
+			return -EACCES;
 		if (map->map_type != BPF_MAP_TYPE_HASH &&
 		    map->map_type != BPF_MAP_TYPE_ARRAY &&
 		    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE)
@@ -545,7 +580,7 @@ static int map_create(union bpf_attr *attr)
 	if (attr->btf_key_type_id || attr->btf_value_type_id) {
 		struct btf *btf;
 
-		if (!attr->btf_key_type_id || !attr->btf_value_type_id) {
+		if (!attr->btf_value_type_id) {
 			err = -EINVAL;
 			goto free_map_nouncharge;
 		}
@@ -713,8 +748,7 @@ static int map_lookup_elem(union bpf_attr *attr)
 	map = __bpf_map_get(f);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
-
-	if (!(f.file->f_mode & FMODE_CAN_READ)) {
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
 		err = -EPERM;
 		goto err_put;
 	}
@@ -843,8 +877,7 @@ static int map_update_elem(union bpf_attr *attr)
 	map = __bpf_map_get(f);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
-
-	if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
 		err = -EPERM;
 		goto err_put;
 	}
@@ -955,8 +988,7 @@ static int map_delete_elem(union bpf_attr *attr)
 	map = __bpf_map_get(f);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
-
-	if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
 		err = -EPERM;
 		goto err_put;
 	}
@@ -1007,8 +1039,7 @@ static int map_get_next_key(union bpf_attr *attr)
 	map = __bpf_map_get(f);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
-
-	if (!(f.file->f_mode & FMODE_CAN_READ)) {
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
 		err = -EPERM;
 		goto err_put;
 	}
@@ -1075,8 +1106,7 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr)
 	map = __bpf_map_get(f);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
-
-	if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
 		err = -EPERM;
 		goto err_put;
 	}
@@ -1118,6 +1148,36 @@ err_put:
 	return err;
 }
 
+#define BPF_MAP_FREEZE_LAST_FIELD map_fd
+
+static int map_freeze(const union bpf_attr *attr)
+{
+	int err = 0, ufd = attr->map_fd;
+	struct bpf_map *map;
+	struct fd f;
+
+	if (CHECK_ATTR(BPF_MAP_FREEZE))
+		return -EINVAL;
+
+	f = fdget(ufd);
+	map = __bpf_map_get(f);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+	if (READ_ONCE(map->frozen)) {
+		err = -EBUSY;
+		goto err_put;
+	}
+	if (!capable(CAP_SYS_ADMIN)) {
+		err = -EPERM;
+		goto err_put;
+	}
+
+	WRITE_ONCE(map->frozen, true);
+err_put:
+	fdput(f);
+	return err;
+}
+
 static const struct bpf_prog_ops * const bpf_prog_types[] = {
 #define BPF_PROG_TYPE(_id, _name) \
 	[_id] = & _name ## _prog_ops,
@@ -2072,13 +2132,26 @@ static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
 }
 
 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
-					      unsigned long addr)
+					      unsigned long addr, u32 *off,
+					      u32 *type)
 {
+	const struct bpf_map *map;
 	int i;
 
-	for (i = 0; i < prog->aux->used_map_cnt; i++)
-		if (prog->aux->used_maps[i] == (void *)addr)
-			return prog->aux->used_maps[i];
+	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
+		map = prog->aux->used_maps[i];
+		if (map == (void *)addr) {
+			*type = BPF_PSEUDO_MAP_FD;
+			return map;
+		}
+		if (!map->ops->map_direct_value_meta)
+			continue;
+		if (!map->ops->map_direct_value_meta(map, addr, off)) {
+			*type = BPF_PSEUDO_MAP_VALUE;
+			return map;
+		}
+	}
+
 	return NULL;
 }
 
@@ -2086,6 +2159,7 @@ static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog)
 {
 	const struct bpf_map *map;
 	struct bpf_insn *insns;
+	u32 off, type;
 	u64 imm;
 	int i;
 
@@ -2113,11 +2187,11 @@ static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog)
 			continue;
 
 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
-		map = bpf_map_from_imm(prog, imm);
+		map = bpf_map_from_imm(prog, imm, &off, &type);
 		if (map) {
-			insns[i].src_reg = BPF_PSEUDO_MAP_FD;
+			insns[i].src_reg = type;
 			insns[i].imm = map->id;
-			insns[i + 1].imm = 0;
+			insns[i + 1].imm = off;
 			continue;
 		}
 	}
@@ -2707,6 +2781,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz
 	case BPF_MAP_GET_NEXT_KEY:
 		err = map_get_next_key(&attr);
 		break;
+	case BPF_MAP_FREEZE:
+		err = map_freeze(&attr);
+		break;
 	case BPF_PROG_LOAD:
 		err = bpf_prog_load(&attr, uattr);
 		break;

kernel/bpf/verifier.c

@@ -1439,6 +1439,28 @@ static int check_stack_access(struct bpf_verifier_env *env,
 	return 0;
 }
 
+static int check_map_access_type(struct bpf_verifier_env *env, u32 regno,
+				 int off, int size, enum bpf_access_type type)
+{
+	struct bpf_reg_state *regs = cur_regs(env);
+	struct bpf_map *map = regs[regno].map_ptr;
+	u32 cap = bpf_map_flags_to_cap(map);
+
+	if (type == BPF_WRITE && !(cap & BPF_MAP_CAN_WRITE)) {
+		verbose(env, "write into map forbidden, value_size=%d off=%d size=%d\n",
+			map->value_size, off, size);
+		return -EACCES;
+	}
+
+	if (type == BPF_READ && !(cap & BPF_MAP_CAN_READ)) {
+		verbose(env, "read from map forbidden, value_size=%d off=%d size=%d\n",
+			map->value_size, off, size);
+		return -EACCES;
+	}
+
+	return 0;
+}
+
 /* check read/write into map element returned by bpf_map_lookup_elem() */
 static int __check_map_access(struct bpf_verifier_env *env, u32 regno, int off,
 			      int size, bool zero_size_allowed)
@@ -2024,7 +2046,9 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn
 			verbose(env, "R%d leaks addr into map\n", value_regno);
 			return -EACCES;
 		}
-
+		err = check_map_access_type(env, regno, off, size, t);
+		if (err)
+			return err;
 		err = check_map_access(env, regno, off, size, false);
 		if (!err && t == BPF_READ && value_regno >= 0)
 			mark_reg_unknown(env, regs, value_regno);
@@ -2327,6 +2351,10 @@ static int check_helper_mem_access(struct bpf_verifier_env *env, int regno,
 		return check_packet_access(env, regno, reg->off, access_size,
 					   zero_size_allowed);
 	case PTR_TO_MAP_VALUE:
+		if (check_map_access_type(env, regno, reg->off, access_size,
+					  meta && meta->raw_mode ? BPF_WRITE :
+					  BPF_READ))
+			return -EACCES;
 		return check_map_access(env, regno, reg->off, access_size,
 					zero_size_allowed);
 	default: /* scalar_value|ptr_to_stack or invalid ptr */
@@ -3059,6 +3087,7 @@ record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
 		int func_id, int insn_idx)
 {
 	struct bpf_insn_aux_data *aux = &env->insn_aux_data[insn_idx];
+	struct bpf_map *map = meta->map_ptr;
 
 	if (func_id != BPF_FUNC_tail_call &&
 	    func_id != BPF_FUNC_map_lookup_elem &&
@@ -3069,11 +3098,24 @@ record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
 	    func_id != BPF_FUNC_map_peek_elem)
 		return 0;
 
-	if (meta->map_ptr == NULL) {
+	if (map == NULL) {
 		verbose(env, "kernel subsystem misconfigured verifier\n");
 		return -EINVAL;
 	}
 
+	/* In case of read-only, some additional restrictions
+	 * need to be applied in order to prevent altering the
+	 * state of the map from program side.
+	 */
+	if ((map->map_flags & BPF_F_RDONLY_PROG) &&
+	    (func_id == BPF_FUNC_map_delete_elem ||
+	     func_id == BPF_FUNC_map_update_elem ||
+	     func_id == BPF_FUNC_map_push_elem ||
+	     func_id == BPF_FUNC_map_pop_elem)) {
+		verbose(env, "write into map forbidden\n");
+		return -EACCES;
+	}
+
 	if (!BPF_MAP_PTR(aux->map_state))
 		bpf_map_ptr_store(aux, meta->map_ptr,
 				  meta->map_ptr->unpriv_array);
@@ -5056,18 +5098,12 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
 	return 0;
 }
 
-/* return the map pointer stored inside BPF_LD_IMM64 instruction */
-static struct bpf_map *ld_imm64_to_map_ptr(struct bpf_insn *insn)
-{
-	u64 imm64 = ((u64) (u32) insn[0].imm) | ((u64) (u32) insn[1].imm) << 32;
-
-	return (struct bpf_map *) (unsigned long) imm64;
-}
-
 /* verify BPF_LD_IMM64 instruction */
 static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
 {
+	struct bpf_insn_aux_data *aux = cur_aux(env);
 	struct bpf_reg_state *regs = cur_regs(env);
+	struct bpf_map *map;
 	int err;
 
 	if (BPF_SIZE(insn->code) != BPF_DW) {
@@ -5091,11 +5127,22 @@ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
 		return 0;
 	}
 
-	/* replace_map_fd_with_map_ptr() should have caught bad ld_imm64 */
-	BUG_ON(insn->src_reg != BPF_PSEUDO_MAP_FD);
+	map = env->used_maps[aux->map_index];
+	mark_reg_known_zero(env, regs, insn->dst_reg);
+	regs[insn->dst_reg].map_ptr = map;
+
+	if (insn->src_reg == BPF_PSEUDO_MAP_VALUE) {
+		regs[insn->dst_reg].type = PTR_TO_MAP_VALUE;
+		regs[insn->dst_reg].off = aux->map_off;
+		if (map_value_has_spin_lock(map))
+			regs[insn->dst_reg].id = ++env->id_gen;
+	} else if (insn->src_reg == BPF_PSEUDO_MAP_FD) {
+		regs[insn->dst_reg].type = CONST_PTR_TO_MAP;
+	} else {
+		verbose(env, "bpf verifier is misconfigured\n");
+		return -EINVAL;
+	}
 
-	regs[insn->dst_reg].type = CONST_PTR_TO_MAP;
-	regs[insn->dst_reg].map_ptr = ld_imm64_to_map_ptr(insn);
 	return 0;
 }
 
@@ -6803,8 +6850,10 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
 		}
 
 		if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW)) {
+			struct bpf_insn_aux_data *aux;
 			struct bpf_map *map;
 			struct fd f;
+			u64 addr;
 
 			if (i == insn_cnt - 1 || insn[1].code != 0 ||
 			    insn[1].dst_reg != 0 || insn[1].src_reg != 0 ||
@@ -6813,13 +6862,19 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
 				return -EINVAL;
 			}
 
-			if (insn->src_reg == 0)
+			if (insn[0].src_reg == 0)
 				/* valid generic load 64-bit imm */
 				goto next_insn;
 
-			if (insn[0].src_reg != BPF_PSEUDO_MAP_FD ||
-			    insn[1].imm != 0) {
-				verbose(env, "unrecognized bpf_ld_imm64 insn\n");
+			/* In final convert_pseudo_ld_imm64() step, this is
+			 * converted into regular 64-bit imm load insn.
+			 */
+			if ((insn[0].src_reg != BPF_PSEUDO_MAP_FD &&
+			     insn[0].src_reg != BPF_PSEUDO_MAP_VALUE) ||
+			    (insn[0].src_reg == BPF_PSEUDO_MAP_FD &&
+			     insn[1].imm != 0)) {
+				verbose(env,
+					"unrecognized bpf_ld_imm64 insn\n");
 				return -EINVAL;
 			}
 
@@ -6837,16 +6892,47 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
 				return err;
 			}
 
-			/* store map pointer inside BPF_LD_IMM64 instruction */
-			insn[0].imm = (u32) (unsigned long) map;
-			insn[1].imm = ((u64) (unsigned long) map) >> 32;
+			aux = &env->insn_aux_data[i];
+			if (insn->src_reg == BPF_PSEUDO_MAP_FD) {
+				addr = (unsigned long)map;
+			} else {
+				u32 off = insn[1].imm;
+
+				if (off >= BPF_MAX_VAR_OFF) {
+					verbose(env, "direct value offset of %u is not allowed\n", off);
+					fdput(f);
+					return -EINVAL;
+				}
+
+				if (!map->ops->map_direct_value_addr) {
+					verbose(env, "no direct value access support for this map type\n");
+					fdput(f);
+					return -EINVAL;
+				}
+
+				err = map->ops->map_direct_value_addr(map, &addr, off);
+				if (err) {
+					verbose(env, "invalid access to map value pointer, value_size=%u off=%u\n",
+						map->value_size, off);
+					fdput(f);
+					return err;
+				}
+
+				aux->map_off = off;
+				addr += off;
+			}
+
+			insn[0].imm = (u32)addr;
+			insn[1].imm = addr >> 32;
 
 			/* check whether we recorded this map already */
-			for (j = 0; j < env->used_map_cnt; j++)
+			for (j = 0; j < env->used_map_cnt; j++) {
 				if (env->used_maps[j] == map) {
+					aux->map_index = j;
 					fdput(f);
 					goto next_insn;
 				}
+			}
 
 			if (env->used_map_cnt >= MAX_USED_MAPS) {
 				fdput(f);
@@ -6863,6 +6949,8 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
 				fdput(f);
 				return PTR_ERR(map);
 			}
+
+			aux->map_index = env->used_map_cnt;
 			env->used_maps[env->used_map_cnt++] = map;
 
 			if (bpf_map_is_cgroup_storage(map) &&

tools/bpf/bpftool/btf_dumper.c

@@ -309,6 +309,48 @@ static int btf_dumper_struct(const struct btf_dumper *d, __u32 type_id,
 	return ret;
 }
 
+static int btf_dumper_var(const struct btf_dumper *d, __u32 type_id,
+			  __u8 bit_offset, const void *data)
+{
+	const struct btf_type *t = btf__type_by_id(d->btf, type_id);
+	int ret;
+
+	jsonw_start_object(d->jw);
+	jsonw_name(d->jw, btf__name_by_offset(d->btf, t->name_off));
+	ret = btf_dumper_do_type(d, t->type, bit_offset, data);
+	jsonw_end_object(d->jw);
+
+	return ret;
+}
+
+static int btf_dumper_datasec(const struct btf_dumper *d, __u32 type_id,
+			      const void *data)
+{
+	struct btf_var_secinfo *vsi;
+	const struct btf_type *t;
+	int ret = 0, i, vlen;
+
+	t = btf__type_by_id(d->btf, type_id);
+	if (!t)
+		return -EINVAL;
+
+	vlen = BTF_INFO_VLEN(t->info);
+	vsi = (struct btf_var_secinfo *)(t + 1);
+
+	jsonw_start_object(d->jw);
+	jsonw_name(d->jw, btf__name_by_offset(d->btf, t->name_off));
+	jsonw_start_array(d->jw);
+	for (i = 0; i < vlen; i++) {
+		ret = btf_dumper_do_type(d, vsi[i].type, 0, data + vsi[i].offset);
+		if (ret)
+			break;
+	}
+	jsonw_end_array(d->jw);
+	jsonw_end_object(d->jw);
+
+	return ret;
+}
+
 static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id,
 			      __u8 bit_offset, const void *data)
 {
@@ -341,6 +383,10 @@ static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id,
 	case BTF_KIND_CONST:
 	case BTF_KIND_RESTRICT:
 		return btf_dumper_modifier(d, type_id, bit_offset, data);
+	case BTF_KIND_VAR:
+		return btf_dumper_var(d, type_id, bit_offset, data);
+	case BTF_KIND_DATASEC:
+		return btf_dumper_datasec(d, type_id, data);
 	default:
 		jsonw_printf(d->jw, "(unsupported-kind");
 		return -EINVAL;
@@ -377,6 +423,7 @@ static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id,
 {
 	const struct btf_type *proto_type;
 	const struct btf_array *array;
+	const struct btf_var *var;
 	const struct btf_type *t;
 
 	if (!type_id) {
@@ -440,6 +487,18 @@ static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id,
 		if (pos == -1)
 			return -1;
 		break;
+	case BTF_KIND_VAR:
+		var = (struct btf_var *)(t + 1);
+		if (var->linkage == BTF_VAR_STATIC)
+			BTF_PRINT_ARG("static ");
+		BTF_PRINT_TYPE(t->type);
+		BTF_PRINT_ARG(" %s",
+			      btf__name_by_offset(btf, t->name_off));
+		break;
+	case BTF_KIND_DATASEC:
+		BTF_PRINT_ARG("section (\"%s\") ",
+			      btf__name_by_offset(btf, t->name_off));
+		break;
 	case BTF_KIND_UNKN:
 	default:
 		return -1;

tools/bpf/bpftool/map.c

@@ -153,11 +153,13 @@ static int do_dump_btf(const struct btf_dumper *d,
 	/* start of key-value pair */
 	jsonw_start_object(d->jw);
 
-	jsonw_name(d->jw, "key");
+	if (map_info->btf_key_type_id) {
+		jsonw_name(d->jw, "key");
 
-	ret = btf_dumper_type(d, map_info->btf_key_type_id, key);
-	if (ret)
-		goto err_end_obj;
+		ret = btf_dumper_type(d, map_info->btf_key_type_id, key);
+		if (ret)
+			goto err_end_obj;
+	}
 
 	if (!map_is_per_cpu(map_info->type)) {
 		jsonw_name(d->jw, "value");

tools/bpf/bpftool/xlated_dumper.c

@@ -195,6 +195,9 @@ static const char *print_imm(void *private_data,
 	if (insn->src_reg == BPF_PSEUDO_MAP_FD)
 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
 			 "map[id:%u]", insn->imm);
+	else if (insn->src_reg == BPF_PSEUDO_MAP_VALUE)
+		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
+			 "map[id:%u][0]+%u", insn->imm, (insn + 1)->imm);
 	else
 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
 			 "0x%llx", (unsigned long long)full_imm);

tools/include/linux/filter.h

@@ -278,10 +278,29 @@
 		.off   = 0,					\
 		.imm   = ((__u64) (IMM)) >> 32 })
 
+#define BPF_LD_IMM64_RAW_FULL(DST, SRC, OFF1, OFF2, IMM1, IMM2)	\
+	((struct bpf_insn) {					\
+		.code  = BPF_LD | BPF_DW | BPF_IMM,		\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = OFF1,					\
+		.imm   = IMM1 }),				\
+	((struct bpf_insn) {					\
+		.code  = 0, /* zero is reserved opcode */	\
+		.dst_reg = 0,					\
+		.src_reg = 0,					\
+		.off   = OFF2,					\
+		.imm   = IMM2 })
+
 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
 
 #define BPF_LD_MAP_FD(DST, MAP_FD)				\
-	BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
+	BPF_LD_IMM64_RAW_FULL(DST, BPF_PSEUDO_MAP_FD, 0, 0,	\
+			      MAP_FD, 0)
+
+#define BPF_LD_MAP_VALUE(DST, MAP_FD, VALUE_OFF)		\
+	BPF_LD_IMM64_RAW_FULL(DST, BPF_PSEUDO_MAP_VALUE, 0, 0,	\
+			      MAP_FD, VALUE_OFF)
 
 /* Relative call */
 

tools/include/uapi/linux/bpf.h

@@ -105,6 +105,7 @@ enum bpf_cmd {
 	BPF_BTF_GET_FD_BY_ID,
 	BPF_TASK_FD_QUERY,
 	BPF_MAP_LOOKUP_AND_DELETE_ELEM,
+	BPF_MAP_FREEZE,
 };
 
 enum bpf_map_type {
@@ -255,8 +256,19 @@ enum bpf_attach_type {
  */
 #define BPF_F_ANY_ALIGNMENT	(1U << 1)
 
-/* when bpf_ldimm64->src_reg == BPF_PSEUDO_MAP_FD, bpf_ldimm64->imm == fd */
+/* When BPF ldimm64's insn[0].src_reg != 0 then this can have
+ * two extensions:
+ *
+ * insn[0].src_reg:  BPF_PSEUDO_MAP_FD   BPF_PSEUDO_MAP_VALUE
+ * insn[0].imm:      map fd              map fd
+ * insn[1].imm:      0                   offset into value
+ * insn[0].off:      0                   0
+ * insn[1].off:      0                   0
+ * ldimm64 rewrite:  address of map      address of map[0]+offset
+ * verifier type:    CONST_PTR_TO_MAP    PTR_TO_MAP_VALUE
+ */
 #define BPF_PSEUDO_MAP_FD	1
+#define BPF_PSEUDO_MAP_VALUE	2
 
 /* when bpf_call->src_reg == BPF_PSEUDO_CALL, bpf_call->imm == pc-relative
  * offset to another bpf function
@@ -283,7 +295,7 @@ enum bpf_attach_type {
 
 #define BPF_OBJ_NAME_LEN 16U
 
-/* Flags for accessing BPF object */
+/* Flags for accessing BPF object from syscall side. */
 #define BPF_F_RDONLY		(1U << 3)
 #define BPF_F_WRONLY		(1U << 4)
 
@@ -293,6 +305,10 @@ enum bpf_attach_type {
 /* Zero-initialize hash function seed. This should only be used for testing. */
 #define BPF_F_ZERO_SEED		(1U << 6)
 
+/* Flags for accessing BPF object from program side. */
+#define BPF_F_RDONLY_PROG	(1U << 7)
+#define BPF_F_WRONLY_PROG	(1U << 8)
+
 /* flags for BPF_PROG_QUERY */
 #define BPF_F_QUERY_EFFECTIVE	(1U << 0)
 

tools/include/uapi/linux/btf.h

@@ -39,11 +39,11 @@ struct btf_type {
 	 *             struct, union and fwd
 	 */
 	__u32 info;
-	/* "size" is used by INT, ENUM, STRUCT and UNION.
+	/* "size" is used by INT, ENUM, STRUCT, UNION and DATASEC.
 	 * "size" tells the size of the type it is describing.
 	 *
 	 * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT,
-	 * FUNC and FUNC_PROTO.
+	 * FUNC, FUNC_PROTO and VAR.
 	 * "type" is a type_id referring to another type.
 	 */
 	union {
@@ -70,8 +70,10 @@ struct btf_type {
 #define BTF_KIND_RESTRICT	11	/* Restrict	*/
 #define BTF_KIND_FUNC		12	/* Function	*/
 #define BTF_KIND_FUNC_PROTO	13	/* Function Proto	*/
-#define BTF_KIND_MAX		13
-#define NR_BTF_KINDS		14
+#define BTF_KIND_VAR		14	/* Variable	*/
+#define BTF_KIND_DATASEC	15	/* Section	*/
+#define BTF_KIND_MAX		BTF_KIND_DATASEC
+#define NR_BTF_KINDS		(BTF_KIND_MAX + 1)
 
 /* For some specific BTF_KIND, "struct btf_type" is immediately
  * followed by extra data.
@@ -138,4 +140,26 @@ struct btf_param {
 	__u32	type;
 };
 
+enum {
+	BTF_VAR_STATIC = 0,
+	BTF_VAR_GLOBAL_ALLOCATED,
+};
+
+/* BTF_KIND_VAR is followed by a single "struct btf_var" to describe
+ * additional information related to the variable such as its linkage.
+ */
+struct btf_var {
+	__u32	linkage;
+};
+
+/* BTF_KIND_DATASEC is followed by multiple "struct btf_var_secinfo"
+ * to describe all BTF_KIND_VAR types it contains along with it's
+ * in-section offset as well as size.
+ */
+struct btf_var_secinfo {
+	__u32	type;
+	__u32	offset;
+	__u32	size;
+};
+
 #endif /* _UAPI__LINUX_BTF_H__ */

tools/lib/bpf/Makefile

@@ -3,7 +3,7 @@
 
 BPF_VERSION = 0
 BPF_PATCHLEVEL = 0
-BPF_EXTRAVERSION = 2
+BPF_EXTRAVERSION = 3
 
 MAKEFLAGS += --no-print-directory
 

tools/lib/bpf/bpf.c

@@ -429,6 +429,16 @@ int bpf_map_get_next_key(int fd, const void *key, void *next_key)
 	return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
 }
 
+int bpf_map_freeze(int fd)
+{
+	union bpf_attr attr;
+
+	memset(&attr, 0, sizeof(attr));
+	attr.map_fd = fd;
+
+	return sys_bpf(BPF_MAP_FREEZE, &attr, sizeof(attr));
+}
+
 int bpf_obj_pin(int fd, const char *pathname)
 {
 	union bpf_attr attr;

tools/lib/bpf/bpf.h

@@ -117,6 +117,7 @@ LIBBPF_API int bpf_map_lookup_and_delete_elem(int fd, const void *key,
 					      void *value);
 LIBBPF_API int bpf_map_delete_elem(int fd, const void *key);
 LIBBPF_API int bpf_map_get_next_key(int fd, const void *key, void *next_key);
+LIBBPF_API int bpf_map_freeze(int fd);
 LIBBPF_API int bpf_obj_pin(int fd, const char *pathname);
 LIBBPF_API int bpf_obj_get(const char *pathname);
 LIBBPF_API int bpf_prog_attach(int prog_fd, int attachable_fd,

tools/lib/bpf/btf.c

@@ -24,6 +24,8 @@
 		((k) == BTF_KIND_CONST) || \
 		((k) == BTF_KIND_RESTRICT))
 
+#define IS_VAR(k) ((k) == BTF_KIND_VAR)
+
 static struct btf_type btf_void;
 
 struct btf {
@@ -212,6 +214,10 @@ static int btf_type_size(struct btf_type *t)
 		return base_size + vlen * sizeof(struct btf_member);
 	case BTF_KIND_FUNC_PROTO:
 		return base_size + vlen * sizeof(struct btf_param);
+	case BTF_KIND_VAR:
+		return base_size + sizeof(struct btf_var);
+	case BTF_KIND_DATASEC:
+		return base_size + vlen * sizeof(struct btf_var_secinfo);
 	default:
 		pr_debug("Unsupported BTF_KIND:%u\n", BTF_INFO_KIND(t->info));
 		return -EINVAL;
@@ -283,6 +289,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
 		case BTF_KIND_STRUCT:
 		case BTF_KIND_UNION:
 		case BTF_KIND_ENUM:
+		case BTF_KIND_DATASEC:
 			size = t->size;
 			goto done;
 		case BTF_KIND_PTR:
@@ -292,6 +299,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
 		case BTF_KIND_VOLATILE:
 		case BTF_KIND_CONST:
 		case BTF_KIND_RESTRICT:
+		case BTF_KIND_VAR:
 			type_id = t->type;
 			break;
 		case BTF_KIND_ARRAY:
@@ -326,7 +334,8 @@ int btf__resolve_type(const struct btf *btf, __u32 type_id)
 	t = btf__type_by_id(btf, type_id);
 	while (depth < MAX_RESOLVE_DEPTH &&
 	       !btf_type_is_void_or_null(t) &&
-	       IS_MODIFIER(BTF_INFO_KIND(t->info))) {
+	       (IS_MODIFIER(BTF_INFO_KIND(t->info)) ||
+		IS_VAR(BTF_INFO_KIND(t->info)))) {
 		type_id = t->type;
 		t = btf__type_by_id(btf, type_id);
 		depth++;
@@ -408,6 +417,92 @@ done:
 	return btf;
 }
 
+static int compare_vsi_off(const void *_a, const void *_b)
+{
+	const struct btf_var_secinfo *a = _a;
+	const struct btf_var_secinfo *b = _b;
+
+	return a->offset - b->offset;
+}
+
+static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf,
+			     struct btf_type *t)
+{
+	__u32 size = 0, off = 0, i, vars = BTF_INFO_VLEN(t->info);
+	const char *name = btf__name_by_offset(btf, t->name_off);
+	const struct btf_type *t_var;
+	struct btf_var_secinfo *vsi;
+	struct btf_var *var;
+	int ret;
+
+	if (!name) {
+		pr_debug("No name found in string section for DATASEC kind.\n");
+		return -ENOENT;
+	}
+
+	ret = bpf_object__section_size(obj, name, &size);
+	if (ret || !size || (t->size && t->size != size)) {
+		pr_debug("Invalid size for section %s: %u bytes\n", name, size);
+		return -ENOENT;
+	}
+
+	t->size = size;
+
+	for (i = 0, vsi = (struct btf_var_secinfo *)(t + 1);
+	     i < vars; i++, vsi++) {
+		t_var = btf__type_by_id(btf, vsi->type);
+		var = (struct btf_var *)(t_var + 1);
+
+		if (BTF_INFO_KIND(t_var->info) != BTF_KIND_VAR) {
+			pr_debug("Non-VAR type seen in section %s\n", name);
+			return -EINVAL;
+		}
+
+		if (var->linkage == BTF_VAR_STATIC)
+			continue;
+
+		name = btf__name_by_offset(btf, t_var->name_off);
+		if (!name) {
+			pr_debug("No name found in string section for VAR kind\n");
+			return -ENOENT;
+		}
+
+		ret = bpf_object__variable_offset(obj, name, &off);
+		if (ret) {
+			pr_debug("No offset found in symbol table for VAR %s\n", name);
+			return -ENOENT;
+		}
+
+		vsi->offset = off;
+	}
+
+	qsort(t + 1, vars, sizeof(*vsi), compare_vsi_off);
+	return 0;
+}
+
+int btf__finalize_data(struct bpf_object *obj, struct btf *btf)
+{
+	int err = 0;
+	__u32 i;
+
+	for (i = 1; i <= btf->nr_types; i++) {
+		struct btf_type *t = btf->types[i];
+
+		/* Loader needs to fix up some of the things compiler
+		 * couldn't get its hands on while emitting BTF. This
+		 * is section size and global variable offset. We use
+		 * the info from the ELF itself for this purpose.
+		 */
+		if (BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC) {
+			err = btf_fixup_datasec(obj, btf, t);
+			if (err)
+				break;
+		}
+	}
+
+	return err;
+}
+
 int btf__load(struct btf *btf)
 {
 	__u32 log_buf_size = BPF_LOG_BUF_SIZE;

tools/lib/bpf/btf.h

@@ -21,6 +21,8 @@ struct btf;
 struct btf_ext;
 struct btf_type;
 
+struct bpf_object;
+
 /*
  * The .BTF.ext ELF section layout defined as
  *   struct btf_ext_header
@@ -57,6 +59,7 @@ struct btf_ext_header {
 
 LIBBPF_API void btf__free(struct btf *btf);
 LIBBPF_API struct btf *btf__new(__u8 *data, __u32 size);
+LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
 LIBBPF_API int btf__load(struct btf *btf);
 LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
 				   const char *type_name);

tools/lib/bpf/libbpf.c

@@ -7,6 +7,7 @@
  * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
  * Copyright (C) 2015 Huawei Inc.
  * Copyright (C) 2017 Nicira, Inc.
+ * Copyright (C) 2019 Isovalent, Inc.
  */
 
 #ifndef _GNU_SOURCE
@@ -149,6 +150,7 @@ struct bpf_program {
 		enum {
 			RELO_LD64,
 			RELO_CALL,
+			RELO_DATA,
 		} type;
 		int insn_idx;
 		union {
@@ -182,6 +184,19 @@ struct bpf_program {
 	__u32 line_info_cnt;
 };
 
+enum libbpf_map_type {
+	LIBBPF_MAP_UNSPEC,
+	LIBBPF_MAP_DATA,
+	LIBBPF_MAP_BSS,
+	LIBBPF_MAP_RODATA,
+};
+
+static const char * const libbpf_type_to_btf_name[] = {
+	[LIBBPF_MAP_DATA]	= ".data",
+	[LIBBPF_MAP_BSS]	= ".bss",
+	[LIBBPF_MAP_RODATA]	= ".rodata",
+};
+
 struct bpf_map {
 	int fd;
 	char *name;
@@ -193,11 +208,18 @@ struct bpf_map {
 	__u32 btf_value_type_id;
 	void *priv;
 	bpf_map_clear_priv_t clear_priv;
+	enum libbpf_map_type libbpf_type;
+};
+
+struct bpf_secdata {
+	void *rodata;
+	void *data;
 };
 
 static LIST_HEAD(bpf_objects_list);
 
 struct bpf_object {
+	char name[BPF_OBJ_NAME_LEN];
 	char license[64];
 	__u32 kern_version;
 
@@ -205,6 +227,7 @@ struct bpf_object {
 	size_t nr_programs;
 	struct bpf_map *maps;
 	size_t nr_maps;
+	struct bpf_secdata sections;
 
 	bool loaded;
 	bool has_pseudo_calls;
@@ -220,6 +243,9 @@ struct bpf_object {
 		Elf *elf;
 		GElf_Ehdr ehdr;
 		Elf_Data *symbols;
+		Elf_Data *data;
+		Elf_Data *rodata;
+		Elf_Data *bss;
 		size_t strtabidx;
 		struct {
 			GElf_Shdr shdr;
@@ -228,6 +254,9 @@ struct bpf_object {
 		int nr_reloc;
 		int maps_shndx;
 		int text_shndx;
+		int data_shndx;
+		int rodata_shndx;
+		int bss_shndx;
 	} efile;
 	/*
 	 * All loaded bpf_object is linked in a list, which is
@@ -449,6 +478,7 @@ static struct bpf_object *bpf_object__new(const char *path,
 					  size_t obj_buf_sz)
 {
 	struct bpf_object *obj;
+	char *end;
 
 	obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1);
 	if (!obj) {
@@ -457,8 +487,14 @@ static struct bpf_object *bpf_object__new(const char *path,
 	}
 
 	strcpy(obj->path, path);
-	obj->efile.fd = -1;
+	/* Using basename() GNU version which doesn't modify arg. */
+	strncpy(obj->name, basename((void *)path),
+		sizeof(obj->name) - 1);
+	end = strchr(obj->name, '.');
+	if (end)
+		*end = 0;
 
+	obj->efile.fd = -1;
 	/*
 	 * Caller of this function should also calls
 	 * bpf_object__elf_finish() after data collection to return
@@ -468,6 +504,9 @@ static struct bpf_object *bpf_object__new(const char *path,
 	obj->efile.obj_buf = obj_buf;
 	obj->efile.obj_buf_sz = obj_buf_sz;
 	obj->efile.maps_shndx = -1;
+	obj->efile.data_shndx = -1;
+	obj->efile.rodata_shndx = -1;
+	obj->efile.bss_shndx = -1;
 
 	obj->loaded = false;
 
@@ -486,6 +525,9 @@ static void bpf_object__elf_finish(struct bpf_object *obj)
 		obj->efile.elf = NULL;
 	}
 	obj->efile.symbols = NULL;
+	obj->efile.data = NULL;
+	obj->efile.rodata = NULL;
+	obj->efile.bss = NULL;
 
 	zfree(&obj->efile.reloc);
 	obj->efile.nr_reloc = 0;
@@ -627,27 +669,182 @@ static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)
 	return false;
 }
 
+static int bpf_object_search_section_size(const struct bpf_object *obj,
+					  const char *name, size_t *d_size)
+{
+	const GElf_Ehdr *ep = &obj->efile.ehdr;
+	Elf *elf = obj->efile.elf;
+	Elf_Scn *scn = NULL;
+	int idx = 0;
+
+	while ((scn = elf_nextscn(elf, scn)) != NULL) {
+		const char *sec_name;
+		Elf_Data *data;
+		GElf_Shdr sh;
+
+		idx++;
+		if (gelf_getshdr(scn, &sh) != &sh) {
+			pr_warning("failed to get section(%d) header from %s\n",
+				   idx, obj->path);
+			return -EIO;
+		}
+
+		sec_name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
+		if (!sec_name) {
+			pr_warning("failed to get section(%d) name from %s\n",
+				   idx, obj->path);
+			return -EIO;
+		}
+
+		if (strcmp(name, sec_name))
+			continue;
+
+		data = elf_getdata(scn, 0);
+		if (!data) {
+			pr_warning("failed to get section(%d) data from %s(%s)\n",
+				   idx, name, obj->path);
+			return -EIO;
+		}
+
+		*d_size = data->d_size;
+		return 0;
+	}
+
+	return -ENOENT;
+}
+
+int bpf_object__section_size(const struct bpf_object *obj, const char *name,
+			     __u32 *size)
+{
+	int ret = -ENOENT;
+	size_t d_size;
+
+	*size = 0;
+	if (!name) {
+		return -EINVAL;
+	} else if (!strcmp(name, ".data")) {
+		if (obj->efile.data)
+			*size = obj->efile.data->d_size;
+	} else if (!strcmp(name, ".bss")) {
+		if (obj->efile.bss)
+			*size = obj->efile.bss->d_size;
+	} else if (!strcmp(name, ".rodata")) {
+		if (obj->efile.rodata)
+			*size = obj->efile.rodata->d_size;
+	} else {
+		ret = bpf_object_search_section_size(obj, name, &d_size);
+		if (!ret)
+			*size = d_size;
+	}
+
+	return *size ? 0 : ret;
+}
+
+int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
+				__u32 *off)
+{
+	Elf_Data *symbols = obj->efile.symbols;
+	const char *sname;
+	size_t si;
+
+	if (!name || !off)
+		return -EINVAL;
+
+	for (si = 0; si < symbols->d_size / sizeof(GElf_Sym); si++) {
+		GElf_Sym sym;
+
+		if (!gelf_getsym(symbols, si, &sym))
+			continue;
+		if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL ||
+		    GELF_ST_TYPE(sym.st_info) != STT_OBJECT)
+			continue;
+
+		sname = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
+				   sym.st_name);
+		if (!sname) {
+			pr_warning("failed to get sym name string for var %s\n",
+				   name);
+			return -EIO;
+		}
+		if (strcmp(name, sname) == 0) {
+			*off = sym.st_value;
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+static bool bpf_object__has_maps(const struct bpf_object *obj)
+{
+	return obj->efile.maps_shndx >= 0 ||
+	       obj->efile.data_shndx >= 0 ||
+	       obj->efile.rodata_shndx >= 0 ||
+	       obj->efile.bss_shndx >= 0;
+}
+
+static int
+bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map,
+			      enum libbpf_map_type type, Elf_Data *data,
+			      void **data_buff)
+{
+	struct bpf_map_def *def = &map->def;
+	char map_name[BPF_OBJ_NAME_LEN];
+
+	map->libbpf_type = type;
+	map->offset = ~(typeof(map->offset))0;
+	snprintf(map_name, sizeof(map_name), "%.8s%.7s", obj->name,
+		 libbpf_type_to_btf_name[type]);
+	map->name = strdup(map_name);
+	if (!map->name) {
+		pr_warning("failed to alloc map name\n");
+		return -ENOMEM;
+	}
+
+	def->type = BPF_MAP_TYPE_ARRAY;
+	def->key_size = sizeof(int);
+	def->value_size = data->d_size;
+	def->max_entries = 1;
+	def->map_flags = type == LIBBPF_MAP_RODATA ?
+			 BPF_F_RDONLY_PROG : 0;
+	if (data_buff) {
+		*data_buff = malloc(data->d_size);
+		if (!*data_buff) {
+			zfree(&map->name);
+			pr_warning("failed to alloc map content buffer\n");
+			return -ENOMEM;
+		}
+		memcpy(*data_buff, data->d_buf, data->d_size);
+	}
+
+	pr_debug("map %ld is \"%s\"\n", map - obj->maps, map->name);
+	return 0;
+}
+
 static int
 bpf_object__init_maps(struct bpf_object *obj, int flags)
 {
+	int i, map_idx, map_def_sz, nr_syms, nr_maps = 0, nr_maps_glob = 0;
 	bool strict = !(flags & MAPS_RELAX_COMPAT);
-	int i, map_idx, map_def_sz, nr_maps = 0;
-	Elf_Scn *scn;
-	Elf_Data *data = NULL;
 	Elf_Data *symbols = obj->efile.symbols;
+	Elf_Data *data = NULL;
+	int ret = 0;
 
-	if (obj->efile.maps_shndx < 0)
-		return -EINVAL;
 	if (!symbols)
 		return -EINVAL;
+	nr_syms = symbols->d_size / sizeof(GElf_Sym);
 
-	scn = elf_getscn(obj->efile.elf, obj->efile.maps_shndx);
-	if (scn)
-		data = elf_getdata(scn, NULL);
-	if (!scn || !data) {
-		pr_warning("failed to get Elf_Data from map section %d\n",
-			   obj->efile.maps_shndx);
-		return -EINVAL;
+	if (obj->efile.maps_shndx >= 0) {
+		Elf_Scn *scn = elf_getscn(obj->efile.elf,
+					  obj->efile.maps_shndx);
+
+		if (scn)
+			data = elf_getdata(scn, NULL);
+		if (!scn || !data) {
+			pr_warning("failed to get Elf_Data from map section %d\n",
+				   obj->efile.maps_shndx);
+			return -EINVAL;
+		}
 	}
 
 	/*
@@ -657,7 +854,13 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
 	 *
 	 * TODO: Detect array of map and report error.
 	 */
-	for (i = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) {
+	if (obj->efile.data_shndx >= 0)
+		nr_maps_glob++;
+	if (obj->efile.rodata_shndx >= 0)
+		nr_maps_glob++;
+	if (obj->efile.bss_shndx >= 0)
+		nr_maps_glob++;
+	for (i = 0; data && i < nr_syms; i++) {
 		GElf_Sym sym;
 
 		if (!gelf_getsym(symbols, i, &sym))
@@ -670,19 +873,21 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
 	/* Alloc obj->maps and fill nr_maps. */
 	pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path,
 		 nr_maps, data->d_size);
-
-	if (!nr_maps)
+	if (!nr_maps && !nr_maps_glob)
 		return 0;
 
 	/* Assume equally sized map definitions */
-	map_def_sz = data->d_size / nr_maps;
-	if (!data->d_size || (data->d_size % nr_maps) != 0) {
-		pr_warning("unable to determine map definition size "
-			   "section %s, %d maps in %zd bytes\n",
-			   obj->path, nr_maps, data->d_size);
-		return -EINVAL;
+	if (data) {
+		map_def_sz = data->d_size / nr_maps;
+		if (!data->d_size || (data->d_size % nr_maps) != 0) {
+			pr_warning("unable to determine map definition size "
+				   "section %s, %d maps in %zd bytes\n",
+				   obj->path, nr_maps, data->d_size);
+			return -EINVAL;
+		}
 	}
 
+	nr_maps += nr_maps_glob;
 	obj->maps = calloc(nr_maps, sizeof(obj->maps[0]));
 	if (!obj->maps) {
 		pr_warning("alloc maps for object failed\n");
@@ -703,7 +908,7 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
 	/*
 	 * Fill obj->maps using data in "maps" section.
 	 */
-	for (i = 0, map_idx = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) {
+	for (i = 0, map_idx = 0; data && i < nr_syms; i++) {
 		GElf_Sym sym;
 		const char *map_name;
 		struct bpf_map_def *def;
@@ -716,6 +921,8 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
 		map_name = elf_strptr(obj->efile.elf,
 				      obj->efile.strtabidx,
 				      sym.st_name);
+
+		obj->maps[map_idx].libbpf_type = LIBBPF_MAP_UNSPEC;
 		obj->maps[map_idx].offset = sym.st_value;
 		if (sym.st_value + map_def_sz > data->d_size) {
 			pr_warning("corrupted maps section in %s: last map \"%s\" too small\n",
@@ -764,8 +971,27 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
 		map_idx++;
 	}
 
-	qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]), compare_bpf_map);
-	return 0;
+	/*
+	 * Populate rest of obj->maps with libbpf internal maps.
+	 */
+	if (obj->efile.data_shndx >= 0)
+		ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
+						    LIBBPF_MAP_DATA,
+						    obj->efile.data,
+						    &obj->sections.data);
+	if (!ret && obj->efile.rodata_shndx >= 0)
+		ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
+						    LIBBPF_MAP_RODATA,
+						    obj->efile.rodata,
+						    &obj->sections.rodata);
+	if (!ret && obj->efile.bss_shndx >= 0)
+		ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
+						    LIBBPF_MAP_BSS,
+						    obj->efile.bss, NULL);
+	if (!ret)
+		qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]),
+		      compare_bpf_map);
+	return ret;
 }
 
 static bool section_have_execinstr(struct bpf_object *obj, int idx)
@@ -791,6 +1017,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 	Elf *elf = obj->efile.elf;
 	GElf_Ehdr *ep = &obj->efile.ehdr;
 	Elf_Data *btf_ext_data = NULL;
+	Elf_Data *btf_data = NULL;
 	Elf_Scn *scn = NULL;
 	int idx = 0, err = 0;
 
@@ -834,32 +1061,18 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 			 (int)sh.sh_link, (unsigned long)sh.sh_flags,
 			 (int)sh.sh_type);
 
-		if (strcmp(name, "license") == 0)
+		if (strcmp(name, "license") == 0) {
 			err = bpf_object__init_license(obj,
 						       data->d_buf,
 						       data->d_size);
-		else if (strcmp(name, "version") == 0)
+		} else if (strcmp(name, "version") == 0) {
 			err = bpf_object__init_kversion(obj,
 							data->d_buf,
 							data->d_size);
-		else if (strcmp(name, "maps") == 0)
+		} else if (strcmp(name, "maps") == 0) {
 			obj->efile.maps_shndx = idx;
-		else if (strcmp(name, BTF_ELF_SEC) == 0) {
-			obj->btf = btf__new(data->d_buf, data->d_size);
-			if (IS_ERR(obj->btf)) {
-				pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
-					   BTF_ELF_SEC, PTR_ERR(obj->btf));
-				obj->btf = NULL;
-				continue;
-			}
-			err = btf__load(obj->btf);
-			if (err) {
-				pr_warning("Error loading %s into kernel: %d. Ignored and continue.\n",
-					   BTF_ELF_SEC, err);
-				btf__free(obj->btf);
-				obj->btf = NULL;
-				err = 0;
-			}
+		} else if (strcmp(name, BTF_ELF_SEC) == 0) {
+			btf_data = data;
 		} else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) {
 			btf_ext_data = data;
 		} else if (sh.sh_type == SHT_SYMTAB) {
@@ -871,20 +1084,28 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 				obj->efile.symbols = data;
 				obj->efile.strtabidx = sh.sh_link;
 			}
-		} else if ((sh.sh_type == SHT_PROGBITS) &&
-			   (sh.sh_flags & SHF_EXECINSTR) &&
-			   (data->d_size > 0)) {
-			if (strcmp(name, ".text") == 0)
-				obj->efile.text_shndx = idx;
-			err = bpf_object__add_program(obj, data->d_buf,
-						      data->d_size, name, idx);
-			if (err) {
-				char errmsg[STRERR_BUFSIZE];
-				char *cp = libbpf_strerror_r(-err, errmsg,
-							     sizeof(errmsg));
+		} else if (sh.sh_type == SHT_PROGBITS && data->d_size > 0) {
+			if (sh.sh_flags & SHF_EXECINSTR) {
+				if (strcmp(name, ".text") == 0)
+					obj->efile.text_shndx = idx;
+				err = bpf_object__add_program(obj, data->d_buf,
+							      data->d_size, name, idx);
+				if (err) {
+					char errmsg[STRERR_BUFSIZE];
+					char *cp = libbpf_strerror_r(-err, errmsg,
+								     sizeof(errmsg));
 
-				pr_warning("failed to alloc program %s (%s): %s",
-					   name, obj->path, cp);
+					pr_warning("failed to alloc program %s (%s): %s",
+						   name, obj->path, cp);
+				}
+			} else if (strcmp(name, ".data") == 0) {
+				obj->efile.data = data;
+				obj->efile.data_shndx = idx;
+			} else if (strcmp(name, ".rodata") == 0) {
+				obj->efile.rodata = data;
+				obj->efile.rodata_shndx = idx;
+			} else {
+				pr_debug("skip section(%d) %s\n", idx, name);
 			}
 		} else if (sh.sh_type == SHT_REL) {
 			void *reloc = obj->efile.reloc;
@@ -912,6 +1133,9 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 				obj->efile.reloc[n].shdr = sh;
 				obj->efile.reloc[n].data = data;
 			}
+		} else if (sh.sh_type == SHT_NOBITS && strcmp(name, ".bss") == 0) {
+			obj->efile.bss = data;
+			obj->efile.bss_shndx = idx;
 		} else {
 			pr_debug("skip section(%d) %s\n", idx, name);
 		}
@@ -923,6 +1147,25 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 		pr_warning("Corrupted ELF file: index of strtab invalid\n");
 		return LIBBPF_ERRNO__FORMAT;
 	}
+	if (btf_data) {
+		obj->btf = btf__new(btf_data->d_buf, btf_data->d_size);
+		if (IS_ERR(obj->btf)) {
+			pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
+				   BTF_ELF_SEC, PTR_ERR(obj->btf));
+			obj->btf = NULL;
+		} else {
+			err = btf__finalize_data(obj, obj->btf);
+			if (!err)
+				err = btf__load(obj->btf);
+			if (err) {
+				pr_warning("Error finalizing and loading %s into kernel: %d. Ignored and continue.\n",
+					   BTF_ELF_SEC, err);
+				btf__free(obj->btf);
+				obj->btf = NULL;
+				err = 0;
+			}
+		}
+	}
 	if (btf_ext_data) {
 		if (!obj->btf) {
 			pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",
@@ -938,7 +1181,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 			}
 		}
 	}
-	if (obj->efile.maps_shndx >= 0) {
+	if (bpf_object__has_maps(obj)) {
 		err = bpf_object__init_maps(obj, flags);
 		if (err)
 			goto out;
@@ -974,13 +1217,46 @@ bpf_object__find_program_by_title(struct bpf_object *obj, const char *title)
 	return NULL;
 }
 
+static bool bpf_object__shndx_is_data(const struct bpf_object *obj,
+				      int shndx)
+{
+	return shndx == obj->efile.data_shndx ||
+	       shndx == obj->efile.bss_shndx ||
+	       shndx == obj->efile.rodata_shndx;
+}
+
+static bool bpf_object__shndx_is_maps(const struct bpf_object *obj,
+				      int shndx)
+{
+	return shndx == obj->efile.maps_shndx;
+}
+
+static bool bpf_object__relo_in_known_section(const struct bpf_object *obj,
+					      int shndx)
+{
+	return shndx == obj->efile.text_shndx ||
+	       bpf_object__shndx_is_maps(obj, shndx) ||
+	       bpf_object__shndx_is_data(obj, shndx);
+}
+
+static enum libbpf_map_type
+bpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx)
+{
+	if (shndx == obj->efile.data_shndx)
+		return LIBBPF_MAP_DATA;
+	else if (shndx == obj->efile.bss_shndx)
+		return LIBBPF_MAP_BSS;
+	else if (shndx == obj->efile.rodata_shndx)
+		return LIBBPF_MAP_RODATA;
+	else
+		return LIBBPF_MAP_UNSPEC;
+}
+
 static int
 bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
 			   Elf_Data *data, struct bpf_object *obj)
 {
 	Elf_Data *symbols = obj->efile.symbols;
-	int text_shndx = obj->efile.text_shndx;
-	int maps_shndx = obj->efile.maps_shndx;
 	struct bpf_map *maps = obj->maps;
 	size_t nr_maps = obj->nr_maps;
 	int i, nrels;
@@ -1000,7 +1276,10 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
 		GElf_Sym sym;
 		GElf_Rel rel;
 		unsigned int insn_idx;
+		unsigned int shdr_idx;
 		struct bpf_insn *insns = prog->insns;
+		enum libbpf_map_type type;
+		const char *name;
 		size_t map_idx;
 
 		if (!gelf_getrel(data, i, &rel)) {
@@ -1015,13 +1294,18 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
 				   GELF_R_SYM(rel.r_info));
 			return -LIBBPF_ERRNO__FORMAT;
 		}
-		pr_debug("relo for %lld value %lld name %d\n",
-			 (long long) (rel.r_info >> 32),
-			 (long long) sym.st_value, sym.st_name);
 
-		if (sym.st_shndx != maps_shndx && sym.st_shndx != text_shndx) {
-			pr_warning("Program '%s' contains non-map related relo data pointing to section %u\n",
-				   prog->section_name, sym.st_shndx);
+		name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
+				  sym.st_name) ? : "<?>";
+
+		pr_debug("relo for %lld value %lld name %d (\'%s\')\n",
+			 (long long) (rel.r_info >> 32),
+			 (long long) sym.st_value, sym.st_name, name);
+
+		shdr_idx = sym.st_shndx;
+		if (!bpf_object__relo_in_known_section(obj, shdr_idx)) {
+			pr_warning("Program '%s' contains unrecognized relo data pointing to section %u\n",
+				   prog->section_name, shdr_idx);
 			return -LIBBPF_ERRNO__RELOC;
 		}
 
@@ -1046,24 +1330,39 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
 			return -LIBBPF_ERRNO__RELOC;
 		}
 
-		/* TODO: 'maps' is sorted. We can use bsearch to make it faster. */
-		for (map_idx = 0; map_idx < nr_maps; map_idx++) {
-			if (maps[map_idx].offset == sym.st_value) {
-				pr_debug("relocation: find map %zd (%s) for insn %u\n",
-					 map_idx, maps[map_idx].name, insn_idx);
-				break;
+		if (bpf_object__shndx_is_maps(obj, shdr_idx) ||
+		    bpf_object__shndx_is_data(obj, shdr_idx)) {
+			type = bpf_object__section_to_libbpf_map_type(obj, shdr_idx);
+			if (type != LIBBPF_MAP_UNSPEC &&
+			    GELF_ST_BIND(sym.st_info) == STB_GLOBAL) {
+				pr_warning("bpf: relocation: not yet supported relo for non-static global \'%s\' variable found in insns[%d].code 0x%x\n",
+					   name, insn_idx, insns[insn_idx].code);
+				return -LIBBPF_ERRNO__RELOC;
 			}
-		}
 
-		if (map_idx >= nr_maps) {
-			pr_warning("bpf relocation: map_idx %d large than %d\n",
-				   (int)map_idx, (int)nr_maps - 1);
-			return -LIBBPF_ERRNO__RELOC;
-		}
+			for (map_idx = 0; map_idx < nr_maps; map_idx++) {
+				if (maps[map_idx].libbpf_type != type)
+					continue;
+				if (type != LIBBPF_MAP_UNSPEC ||
+				    (type == LIBBPF_MAP_UNSPEC &&
+				     maps[map_idx].offset == sym.st_value)) {
+					pr_debug("relocation: find map %zd (%s) for insn %u\n",
+						 map_idx, maps[map_idx].name, insn_idx);
+					break;
+				}
+			}
 
-		prog->reloc_desc[i].type = RELO_LD64;
-		prog->reloc_desc[i].insn_idx = insn_idx;
-		prog->reloc_desc[i].map_idx = map_idx;
+			if (map_idx >= nr_maps) {
+				pr_warning("bpf relocation: map_idx %d large than %d\n",
+					   (int)map_idx, (int)nr_maps - 1);
+				return -LIBBPF_ERRNO__RELOC;
+			}
+
+			prog->reloc_desc[i].type = type != LIBBPF_MAP_UNSPEC ?
+						   RELO_DATA : RELO_LD64;
+			prog->reloc_desc[i].insn_idx = insn_idx;
+			prog->reloc_desc[i].map_idx = map_idx;
+		}
 	}
 	return 0;
 }
@@ -1071,18 +1370,27 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
 static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf)
 {
 	struct bpf_map_def *def = &map->def;
-	__u32 key_type_id, value_type_id;
+	__u32 key_type_id = 0, value_type_id = 0;
 	int ret;
 
-	ret = btf__get_map_kv_tids(btf, map->name, def->key_size,
-				   def->value_size, &key_type_id,
-				   &value_type_id);
-	if (ret)
+	if (!bpf_map__is_internal(map)) {
+		ret = btf__get_map_kv_tids(btf, map->name, def->key_size,
+					   def->value_size, &key_type_id,
+					   &value_type_id);
+	} else {
+		/*
+		 * LLVM annotates global data differently in BTF, that is,
+		 * only as '.data', '.bss' or '.rodata'.
+		 */
+		ret = btf__find_by_name(btf,
+				libbpf_type_to_btf_name[map->libbpf_type]);
+	}
+	if (ret < 0)
 		return ret;
 
 	map->btf_key_type_id = key_type_id;
-	map->btf_value_type_id = value_type_id;
-
+	map->btf_value_type_id = bpf_map__is_internal(map) ?
+				 ret : value_type_id;
 	return 0;
 }
 
@@ -1193,6 +1501,34 @@ bpf_object__probe_caps(struct bpf_object *obj)
 	return bpf_object__probe_name(obj);
 }
 
+static int
+bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
+{
+	char *cp, errmsg[STRERR_BUFSIZE];
+	int err, zero = 0;
+	__u8 *data;
+
+	/* Nothing to do here since kernel already zero-initializes .bss map. */
+	if (map->libbpf_type == LIBBPF_MAP_BSS)
+		return 0;
+
+	data = map->libbpf_type == LIBBPF_MAP_DATA ?
+	       obj->sections.data : obj->sections.rodata;
+
+	err = bpf_map_update_elem(map->fd, &zero, data, 0);
+	/* Freeze .rodata map as read-only from syscall side. */
+	if (!err && map->libbpf_type == LIBBPF_MAP_RODATA) {
+		err = bpf_map_freeze(map->fd);
+		if (err) {
+			cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
+			pr_warning("Error freezing map(%s) as read-only: %s\n",
+				   map->name, cp);
+			err = 0;
+		}
+	}
+	return err;
+}
+
 static int
 bpf_object__create_maps(struct bpf_object *obj)
 {
@@ -1250,6 +1586,7 @@ bpf_object__create_maps(struct bpf_object *obj)
 			size_t j;
 
 			err = *pfd;
+err_out:
 			cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
 			pr_warning("failed to create map (name: '%s'): %s\n",
 				   map->name, cp);
@@ -1257,6 +1594,15 @@ bpf_object__create_maps(struct bpf_object *obj)
 				zclose(obj->maps[j].fd);
 			return err;
 		}
+
+		if (bpf_map__is_internal(map)) {
+			err = bpf_object__populate_internal_map(obj, map);
+			if (err < 0) {
+				zclose(*pfd);
+				goto err_out;
+			}
+		}
+
 		pr_debug("create map %s: fd=%d\n", map->name, *pfd);
 	}
 
@@ -1411,21 +1757,29 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
 		return 0;
 
 	for (i = 0; i < prog->nr_reloc; i++) {
-		if (prog->reloc_desc[i].type == RELO_LD64) {
+		if (prog->reloc_desc[i].type == RELO_LD64 ||
+		    prog->reloc_desc[i].type == RELO_DATA) {
+			bool relo_data = prog->reloc_desc[i].type == RELO_DATA;
 			struct bpf_insn *insns = prog->insns;
 			int insn_idx, map_idx;
 
 			insn_idx = prog->reloc_desc[i].insn_idx;
 			map_idx = prog->reloc_desc[i].map_idx;
 
-			if (insn_idx >= (int)prog->insns_cnt) {
+			if (insn_idx + 1 >= (int)prog->insns_cnt) {
 				pr_warning("relocation out of range: '%s'\n",
 					   prog->section_name);
 				return -LIBBPF_ERRNO__RELOC;
 			}
-			insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
+
+			if (!relo_data) {
+				insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
+			} else {
+				insns[insn_idx].src_reg = BPF_PSEUDO_MAP_VALUE;
+				insns[insn_idx + 1].imm = insns[insn_idx].imm;
+			}
 			insns[insn_idx].imm = obj->maps[map_idx].fd;
-		} else {
+		} else if (prog->reloc_desc[i].type == RELO_CALL) {
 			err = bpf_program__reloc_text(prog, obj,
 						      &prog->reloc_desc[i]);
 			if (err)
@@ -2319,6 +2673,9 @@ void bpf_object__close(struct bpf_object *obj)
 		obj->maps[i].priv = NULL;
 		obj->maps[i].clear_priv = NULL;
 	}
+
+	zfree(&obj->sections.rodata);
+	zfree(&obj->sections.data);
 	zfree(&obj->maps);
 	obj->nr_maps = 0;
 
@@ -2796,6 +3153,11 @@ bool bpf_map__is_offload_neutral(struct bpf_map *map)
 	return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY;
 }
 
+bool bpf_map__is_internal(struct bpf_map *map)
+{
+	return map->libbpf_type != LIBBPF_MAP_UNSPEC;
+}
+
 void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex)
 {
 	map->map_ifindex = ifindex;

tools/lib/bpf/libbpf.h

@@ -75,6 +75,10 @@ struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr,
 LIBBPF_API struct bpf_object *bpf_object__open_buffer(void *obj_buf,
 						      size_t obj_buf_sz,
 						      const char *name);
+int bpf_object__section_size(const struct bpf_object *obj, const char *name,
+			     __u32 *size);
+int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
+				__u32 *off);
 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj,
 				      const char *path);
@@ -301,6 +305,7 @@ LIBBPF_API void *bpf_map__priv(struct bpf_map *map);
 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
 LIBBPF_API int bpf_map__resize(struct bpf_map *map, __u32 max_entries);
 LIBBPF_API bool bpf_map__is_offload_neutral(struct bpf_map *map);
+LIBBPF_API bool bpf_map__is_internal(struct bpf_map *map);
 LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);

tools/lib/bpf/libbpf.map

@@ -157,3 +157,10 @@ LIBBPF_0.0.2 {
 		bpf_program__bpil_addr_to_offs;
 		bpf_program__bpil_offs_to_addr;
 } LIBBPF_0.0.1;
+
+LIBBPF_0.0.3 {
+	global:
+		bpf_map__is_internal;
+		bpf_map_freeze;
+		btf__finalize_data;
+} LIBBPF_0.0.2;

tools/testing/selftests/bpf/bpf_helpers.h

@@ -9,14 +9,14 @@
 #define SEC(NAME) __attribute__((section(NAME), used))
 
 /* helper functions called from eBPF programs written in C */
-static void *(*bpf_map_lookup_elem)(void *map, void *key) =
+static void *(*bpf_map_lookup_elem)(void *map, const void *key) =
 	(void *) BPF_FUNC_map_lookup_elem;
-static int (*bpf_map_update_elem)(void *map, void *key, void *value,
+static int (*bpf_map_update_elem)(void *map, const void *key, const void *value,
 				  unsigned long long flags) =
 	(void *) BPF_FUNC_map_update_elem;
-static int (*bpf_map_delete_elem)(void *map, void *key) =
+static int (*bpf_map_delete_elem)(void *map, const void *key) =
 	(void *) BPF_FUNC_map_delete_elem;
-static int (*bpf_map_push_elem)(void *map, void *value,
+static int (*bpf_map_push_elem)(void *map, const void *value,
 				unsigned long long flags) =
 	(void *) BPF_FUNC_map_push_elem;
 static int (*bpf_map_pop_elem)(void *map, void *value) =

tools/testing/selftests/bpf/prog_tests/global_data.c

@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+
+static void test_global_data_number(struct bpf_object *obj, __u32 duration)
+{
+	int i, err, map_fd;
+	uint64_t num;
+
+	map_fd = bpf_find_map(__func__, obj, "result_number");
+	if (map_fd < 0) {
+		error_cnt++;
+		return;
+	}
+
+	struct {
+		char *name;
+		uint32_t key;
+		uint64_t num;
+	} tests[] = {
+		{ "relocate .bss reference",     0, 0 },
+		{ "relocate .data reference",    1, 42 },
+		{ "relocate .rodata reference",  2, 24 },
+		{ "relocate .bss reference",     3, 0 },
+		{ "relocate .data reference",    4, 0xffeeff },
+		{ "relocate .rodata reference",  5, 0xabab },
+		{ "relocate .bss reference",     6, 1234 },
+		{ "relocate .bss reference",     7, 0 },
+		{ "relocate .rodata reference",  8, 0xab },
+		{ "relocate .rodata reference",  9, 0x1111111111111111 },
+		{ "relocate .rodata reference", 10, ~0 },
+	};
+
+	for (i = 0; i < sizeof(tests) / sizeof(tests[0]); i++) {
+		err = bpf_map_lookup_elem(map_fd, &tests[i].key, &num);
+		CHECK(err || num != tests[i].num, tests[i].name,
+		      "err %d result %lx expected %lx\n",
+		      err, num, tests[i].num);
+	}
+}
+
+static void test_global_data_string(struct bpf_object *obj, __u32 duration)
+{
+	int i, err, map_fd;
+	char str[32];
+
+	map_fd = bpf_find_map(__func__, obj, "result_string");
+	if (map_fd < 0) {
+		error_cnt++;
+		return;
+	}
+
+	struct {
+		char *name;
+		uint32_t key;
+		char str[32];
+	} tests[] = {
+		{ "relocate .rodata reference", 0, "abcdefghijklmnopqrstuvwxyz" },
+		{ "relocate .data reference",   1, "abcdefghijklmnopqrstuvwxyz" },
+		{ "relocate .bss reference",    2, "" },
+		{ "relocate .data reference",   3, "abcdexghijklmnopqrstuvwxyz" },
+		{ "relocate .bss reference",    4, "\0\0hello" },
+	};
+
+	for (i = 0; i < sizeof(tests) / sizeof(tests[0]); i++) {
+		err = bpf_map_lookup_elem(map_fd, &tests[i].key, str);
+		CHECK(err || memcmp(str, tests[i].str, sizeof(str)),
+		      tests[i].name, "err %d result \'%s\' expected \'%s\'\n",
+		      err, str, tests[i].str);
+	}
+}
+
+struct foo {
+	__u8  a;
+	__u32 b;
+	__u64 c;
+};
+
+static void test_global_data_struct(struct bpf_object *obj, __u32 duration)
+{
+	int i, err, map_fd;
+	struct foo val;
+
+	map_fd = bpf_find_map(__func__, obj, "result_struct");
+	if (map_fd < 0) {
+		error_cnt++;
+		return;
+	}
+
+	struct {
+		char *name;
+		uint32_t key;
+		struct foo val;
+	} tests[] = {
+		{ "relocate .rodata reference", 0, { 42, 0xfefeefef, 0x1111111111111111ULL, } },
+		{ "relocate .bss reference",    1, { } },
+		{ "relocate .rodata reference", 2, { } },
+		{ "relocate .data reference",   3, { 41, 0xeeeeefef, 0x2111111111111111ULL, } },
+	};
+
+	for (i = 0; i < sizeof(tests) / sizeof(tests[0]); i++) {
+		err = bpf_map_lookup_elem(map_fd, &tests[i].key, &val);
+		CHECK(err || memcmp(&val, &tests[i].val, sizeof(val)),
+		      tests[i].name, "err %d result { %u, %u, %llu } expected { %u, %u, %llu }\n",
+		      err, val.a, val.b, val.c, tests[i].val.a, tests[i].val.b, tests[i].val.c);
+	}
+}
+
+static void test_global_data_rdonly(struct bpf_object *obj, __u32 duration)
+{
+	int err = -ENOMEM, map_fd, zero = 0;
+	struct bpf_map *map;
+	__u8 *buff;
+
+	map = bpf_object__find_map_by_name(obj, "test_glo.rodata");
+	if (!map || !bpf_map__is_internal(map)) {
+		error_cnt++;
+		return;
+	}
+
+	map_fd = bpf_map__fd(map);
+	if (map_fd < 0) {
+		error_cnt++;
+		return;
+	}
+
+	buff = malloc(bpf_map__def(map)->value_size);
+	if (buff)
+		err = bpf_map_update_elem(map_fd, &zero, buff, 0);
+	free(buff);
+	CHECK(!err || errno != EPERM, "test .rodata read-only map",
+	      "err %d errno %d\n", err, errno);
+}
+
+void test_global_data(void)
+{
+	const char *file = "./test_global_data.o";
+	__u32 duration = 0, retval;
+	struct bpf_object *obj;
+	int err, prog_fd;
+
+	err = bpf_prog_load(file, BPF_PROG_TYPE_SCHED_CLS, &obj, &prog_fd);
+	if (CHECK(err, "load program", "error %d loading %s\n", err, file))
+		return;
+
+	err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4),
+				NULL, NULL, &retval, &duration);
+	CHECK(err || retval, "pass global data run",
+	      "err %d errno %d retval %d duration %d\n",
+	      err, errno, retval, duration);
+
+	test_global_data_number(obj, duration);
+	test_global_data_string(obj, duration);
+	test_global_data_struct(obj, duration);
+	test_global_data_rdonly(obj, duration);
+
+	bpf_object__close(obj);
+}

tools/testing/selftests/bpf/progs/test_global_data.c

@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019 Isovalent, Inc.
+
+#include <linux/bpf.h>
+#include <linux/pkt_cls.h>
+#include <string.h>
+
+#include "bpf_helpers.h"
+
+struct bpf_map_def SEC("maps") result_number = {
+	.type		= BPF_MAP_TYPE_ARRAY,
+	.key_size	= sizeof(__u32),
+	.value_size	= sizeof(__u64),
+	.max_entries	= 11,
+};
+
+struct bpf_map_def SEC("maps") result_string = {
+	.type		= BPF_MAP_TYPE_ARRAY,
+	.key_size	= sizeof(__u32),
+	.value_size	= 32,
+	.max_entries	= 5,
+};
+
+struct foo {
+	__u8  a;
+	__u32 b;
+	__u64 c;
+};
+
+struct bpf_map_def SEC("maps") result_struct = {
+	.type		= BPF_MAP_TYPE_ARRAY,
+	.key_size	= sizeof(__u32),
+	.value_size	= sizeof(struct foo),
+	.max_entries	= 5,
+};
+
+/* Relocation tests for __u64s. */
+static       __u64 num0;
+static       __u64 num1 = 42;
+static const __u64 num2 = 24;
+static       __u64 num3 = 0;
+static       __u64 num4 = 0xffeeff;
+static const __u64 num5 = 0xabab;
+static const __u64 num6 = 0xab;
+
+/* Relocation tests for strings. */
+static const char str0[32] = "abcdefghijklmnopqrstuvwxyz";
+static       char str1[32] = "abcdefghijklmnopqrstuvwxyz";
+static       char str2[32];
+
+/* Relocation tests for structs. */
+static const struct foo struct0 = {
+	.a = 42,
+	.b = 0xfefeefef,
+	.c = 0x1111111111111111ULL,
+};
+static struct foo struct1;
+static const struct foo struct2;
+static struct foo struct3 = {
+	.a = 41,
+	.b = 0xeeeeefef,
+	.c = 0x2111111111111111ULL,
+};
+
+#define test_reloc(map, num, var)					\
+	do {								\
+		__u32 key = num;					\
+		bpf_map_update_elem(&result_##map, &key, var, 0);	\
+	} while (0)
+
+SEC("static_data_load")
+int load_static_data(struct __sk_buff *skb)
+{
+	static const __u64 bar = ~0;
+
+	test_reloc(number, 0, &num0);
+	test_reloc(number, 1, &num1);
+	test_reloc(number, 2, &num2);
+	test_reloc(number, 3, &num3);
+	test_reloc(number, 4, &num4);
+	test_reloc(number, 5, &num5);
+	num4 = 1234;
+	test_reloc(number, 6, &num4);
+	test_reloc(number, 7, &num0);
+	test_reloc(number, 8, &num6);
+
+	test_reloc(string, 0, str0);
+	test_reloc(string, 1, str1);
+	test_reloc(string, 2, str2);
+	str1[5] = 'x';
+	test_reloc(string, 3, str1);
+	__builtin_memcpy(&str2[2], "hello", sizeof("hello"));
+	test_reloc(string, 4, str2);
+
+	test_reloc(struct, 0, &struct0);
+	test_reloc(struct, 1, &struct1);
+	test_reloc(struct, 2, &struct2);
+	test_reloc(struct, 3, &struct3);
+
+	test_reloc(number,  9, &struct0.c);
+	test_reloc(number, 10, &bar);
+
+	return TC_ACT_OK;
+}
+
+char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/test_btf.c

@@ -85,6 +85,11 @@ static int __base_pr(enum libbpf_print_level level __attribute__((unused)),
 #define BTF_UNION_ENC(name, nr_elems, sz)	\
 	BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_UNION, 0, nr_elems), sz)
 
+#define BTF_VAR_ENC(name, type, linkage)	\
+	BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), type), (linkage)
+#define BTF_VAR_SECINFO_ENC(type, offset, size)	\
+	(type), (offset), (size)
+
 #define BTF_MEMBER_ENC(name, type, bits_offset)	\
 	(name), (type), (bits_offset)
 #define BTF_ENUM_ENC(name, val) (name), (val)
@@ -291,7 +296,6 @@ static struct btf_raw_test raw_tests[] = {
 	.value_type_id = 3,
 	.max_entries = 4,
 },
-
 {
 	.descr = "struct test #3 Invalid member offset",
 	.raw_types = {
@@ -319,7 +323,664 @@ static struct btf_raw_test raw_tests[] = {
 	.btf_load_err = true,
 	.err_str = "Invalid member bits_offset",
 },
-
+/*
+ * struct A {
+ *	unsigned long long m;
+ *	int n;
+ *	char o;
+ *	[3 bytes hole]
+ *	int p[8];
+ * };
+ */
+{
+	.descr = "global data test #1",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		/* unsigned long long */
+		BTF_TYPE_INT_ENC(0, 0, 0, 64, 8),		/* [2] */
+		/* char */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 8, 1),	/* [3] */
+		/* int[8] */
+		BTF_TYPE_ARRAY_ENC(1, 1, 8),			/* [4] */
+		/* struct A { */				/* [5] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 4), 48),
+		BTF_MEMBER_ENC(NAME_TBD, 2, 0),	/* unsigned long long m;*/
+		BTF_MEMBER_ENC(NAME_TBD, 1, 64),/* int n;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 3, 96),/* char o;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 4, 128),/* int p[8]		*/
+		/* } */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0m\0n\0o\0p",
+	.str_sec_size = sizeof("\0A\0m\0n\0o\0p"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "struct_test1_map",
+	.key_size = sizeof(int),
+	.value_size = 48,
+	.key_type_id = 1,
+	.value_type_id = 5,
+	.max_entries = 4,
+},
+/*
+ * struct A {
+ *	unsigned long long m;
+ *	int n;
+ *	char o;
+ *	[3 bytes hole]
+ *	int p[8];
+ * };
+ * static struct A t; <- in .bss
+ */
+{
+	.descr = "global data test #2",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		/* unsigned long long */
+		BTF_TYPE_INT_ENC(0, 0, 0, 64, 8),		/* [2] */
+		/* char */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 8, 1),	/* [3] */
+		/* int[8] */
+		BTF_TYPE_ARRAY_ENC(1, 1, 8),			/* [4] */
+		/* struct A { */				/* [5] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 4), 48),
+		BTF_MEMBER_ENC(NAME_TBD, 2, 0),	/* unsigned long long m;*/
+		BTF_MEMBER_ENC(NAME_TBD, 1, 64),/* int n;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 3, 96),/* char o;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 4, 128),/* int p[8]		*/
+		/* } */
+		/* static struct A t */
+		BTF_VAR_ENC(NAME_TBD, 5, 0),			/* [6] */
+		/* .bss section */				/* [7] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 48),
+		BTF_VAR_SECINFO_ENC(6, 0, 48),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0m\0n\0o\0p\0t\0.bss",
+	.str_sec_size = sizeof("\0A\0m\0n\0o\0p\0t\0.bss"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 48,
+	.key_type_id = 0,
+	.value_type_id = 7,
+	.max_entries = 1,
+},
+{
+	.descr = "global data test #3",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		/* static int t */
+		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [2] */
+		/* .bss section */				/* [3] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+		BTF_VAR_SECINFO_ENC(2, 0, 4),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0t\0.bss",
+	.str_sec_size = sizeof("\0t\0.bss"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 0,
+	.value_type_id = 3,
+	.max_entries = 1,
+},
+{
+	.descr = "global data test #4, unsupported linkage",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		/* static int t */
+		BTF_VAR_ENC(NAME_TBD, 1, 2),			/* [2] */
+		/* .bss section */				/* [3] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+		BTF_VAR_SECINFO_ENC(2, 0, 4),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0t\0.bss",
+	.str_sec_size = sizeof("\0t\0.bss"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 0,
+	.value_type_id = 3,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Linkage not supported",
+},
+{
+	.descr = "global data test #5, invalid var type",
+	.raw_types = {
+		/* static void t */
+		BTF_VAR_ENC(NAME_TBD, 0, 0),			/* [1] */
+		/* .bss section */				/* [2] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+		BTF_VAR_SECINFO_ENC(1, 0, 4),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0t\0.bss",
+	.str_sec_size = sizeof("\0t\0.bss"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 0,
+	.value_type_id = 2,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid type_id",
+},
+{
+	.descr = "global data test #6, invalid var type (fwd type)",
+	.raw_types = {
+		/* union A */
+		BTF_TYPE_ENC(NAME_TBD,
+			     BTF_INFO_ENC(BTF_KIND_FWD, 1, 0), 0), /* [1] */
+		/* static union A t */
+		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [2] */
+		/* .bss section */				/* [3] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+		BTF_VAR_SECINFO_ENC(2, 0, 4),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0t\0.bss",
+	.str_sec_size = sizeof("\0A\0t\0.bss"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 0,
+	.value_type_id = 2,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid type",
+},
+{
+	.descr = "global data test #7, invalid var type (fwd type)",
+	.raw_types = {
+		/* union A */
+		BTF_TYPE_ENC(NAME_TBD,
+			     BTF_INFO_ENC(BTF_KIND_FWD, 1, 0), 0), /* [1] */
+		/* static union A t */
+		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [2] */
+		/* .bss section */				/* [3] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+		BTF_VAR_SECINFO_ENC(1, 0, 4),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0t\0.bss",
+	.str_sec_size = sizeof("\0A\0t\0.bss"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 0,
+	.value_type_id = 2,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid type",
+},
+{
+	.descr = "global data test #8, invalid var size",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		/* unsigned long long */
+		BTF_TYPE_INT_ENC(0, 0, 0, 64, 8),		/* [2] */
+		/* char */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 8, 1),	/* [3] */
+		/* int[8] */
+		BTF_TYPE_ARRAY_ENC(1, 1, 8),			/* [4] */
+		/* struct A { */				/* [5] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 4), 48),
+		BTF_MEMBER_ENC(NAME_TBD, 2, 0),	/* unsigned long long m;*/
+		BTF_MEMBER_ENC(NAME_TBD, 1, 64),/* int n;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 3, 96),/* char o;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 4, 128),/* int p[8]		*/
+		/* } */
+		/* static struct A t */
+		BTF_VAR_ENC(NAME_TBD, 5, 0),			/* [6] */
+		/* .bss section */				/* [7] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 48),
+		BTF_VAR_SECINFO_ENC(6, 0, 47),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0m\0n\0o\0p\0t\0.bss",
+	.str_sec_size = sizeof("\0A\0m\0n\0o\0p\0t\0.bss"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 48,
+	.key_type_id = 0,
+	.value_type_id = 7,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid size",
+},
+{
+	.descr = "global data test #9, invalid var size",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		/* unsigned long long */
+		BTF_TYPE_INT_ENC(0, 0, 0, 64, 8),		/* [2] */
+		/* char */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 8, 1),	/* [3] */
+		/* int[8] */
+		BTF_TYPE_ARRAY_ENC(1, 1, 8),			/* [4] */
+		/* struct A { */				/* [5] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 4), 48),
+		BTF_MEMBER_ENC(NAME_TBD, 2, 0),	/* unsigned long long m;*/
+		BTF_MEMBER_ENC(NAME_TBD, 1, 64),/* int n;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 3, 96),/* char o;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 4, 128),/* int p[8]		*/
+		/* } */
+		/* static struct A t */
+		BTF_VAR_ENC(NAME_TBD, 5, 0),			/* [6] */
+		/* .bss section */				/* [7] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 46),
+		BTF_VAR_SECINFO_ENC(6, 0, 48),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0m\0n\0o\0p\0t\0.bss",
+	.str_sec_size = sizeof("\0A\0m\0n\0o\0p\0t\0.bss"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 48,
+	.key_type_id = 0,
+	.value_type_id = 7,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid size",
+},
+{
+	.descr = "global data test #10, invalid var size",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		/* unsigned long long */
+		BTF_TYPE_INT_ENC(0, 0, 0, 64, 8),		/* [2] */
+		/* char */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 8, 1),	/* [3] */
+		/* int[8] */
+		BTF_TYPE_ARRAY_ENC(1, 1, 8),			/* [4] */
+		/* struct A { */				/* [5] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 4), 48),
+		BTF_MEMBER_ENC(NAME_TBD, 2, 0),	/* unsigned long long m;*/
+		BTF_MEMBER_ENC(NAME_TBD, 1, 64),/* int n;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 3, 96),/* char o;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 4, 128),/* int p[8]		*/
+		/* } */
+		/* static struct A t */
+		BTF_VAR_ENC(NAME_TBD, 5, 0),			/* [6] */
+		/* .bss section */				/* [7] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 46),
+		BTF_VAR_SECINFO_ENC(6, 0, 46),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0m\0n\0o\0p\0t\0.bss",
+	.str_sec_size = sizeof("\0A\0m\0n\0o\0p\0t\0.bss"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 48,
+	.key_type_id = 0,
+	.value_type_id = 7,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid size",
+},
+{
+	.descr = "global data test #11, multiple section members",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		/* unsigned long long */
+		BTF_TYPE_INT_ENC(0, 0, 0, 64, 8),		/* [2] */
+		/* char */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 8, 1),	/* [3] */
+		/* int[8] */
+		BTF_TYPE_ARRAY_ENC(1, 1, 8),			/* [4] */
+		/* struct A { */				/* [5] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 4), 48),
+		BTF_MEMBER_ENC(NAME_TBD, 2, 0),	/* unsigned long long m;*/
+		BTF_MEMBER_ENC(NAME_TBD, 1, 64),/* int n;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 3, 96),/* char o;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 4, 128),/* int p[8]		*/
+		/* } */
+		/* static struct A t */
+		BTF_VAR_ENC(NAME_TBD, 5, 0),			/* [6] */
+		/* static int u */
+		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [7] */
+		/* .bss section */				/* [8] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 2), 62),
+		BTF_VAR_SECINFO_ENC(6, 10, 48),
+		BTF_VAR_SECINFO_ENC(7, 58, 4),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0m\0n\0o\0p\0t\0u\0.bss",
+	.str_sec_size = sizeof("\0A\0m\0n\0o\0p\0t\0u\0.bss"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 62,
+	.key_type_id = 0,
+	.value_type_id = 8,
+	.max_entries = 1,
+},
+{
+	.descr = "global data test #12, invalid offset",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		/* unsigned long long */
+		BTF_TYPE_INT_ENC(0, 0, 0, 64, 8),		/* [2] */
+		/* char */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 8, 1),	/* [3] */
+		/* int[8] */
+		BTF_TYPE_ARRAY_ENC(1, 1, 8),			/* [4] */
+		/* struct A { */				/* [5] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 4), 48),
+		BTF_MEMBER_ENC(NAME_TBD, 2, 0),	/* unsigned long long m;*/
+		BTF_MEMBER_ENC(NAME_TBD, 1, 64),/* int n;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 3, 96),/* char o;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 4, 128),/* int p[8]		*/
+		/* } */
+		/* static struct A t */
+		BTF_VAR_ENC(NAME_TBD, 5, 0),			/* [6] */
+		/* static int u */
+		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [7] */
+		/* .bss section */				/* [8] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 2), 62),
+		BTF_VAR_SECINFO_ENC(6, 10, 48),
+		BTF_VAR_SECINFO_ENC(7, 60, 4),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0m\0n\0o\0p\0t\0u\0.bss",
+	.str_sec_size = sizeof("\0A\0m\0n\0o\0p\0t\0u\0.bss"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 62,
+	.key_type_id = 0,
+	.value_type_id = 8,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid offset+size",
+},
+{
+	.descr = "global data test #13, invalid offset",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		/* unsigned long long */
+		BTF_TYPE_INT_ENC(0, 0, 0, 64, 8),		/* [2] */
+		/* char */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 8, 1),	/* [3] */
+		/* int[8] */
+		BTF_TYPE_ARRAY_ENC(1, 1, 8),			/* [4] */
+		/* struct A { */				/* [5] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 4), 48),
+		BTF_MEMBER_ENC(NAME_TBD, 2, 0),	/* unsigned long long m;*/
+		BTF_MEMBER_ENC(NAME_TBD, 1, 64),/* int n;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 3, 96),/* char o;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 4, 128),/* int p[8]		*/
+		/* } */
+		/* static struct A t */
+		BTF_VAR_ENC(NAME_TBD, 5, 0),			/* [6] */
+		/* static int u */
+		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [7] */
+		/* .bss section */				/* [8] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 2), 62),
+		BTF_VAR_SECINFO_ENC(6, 10, 48),
+		BTF_VAR_SECINFO_ENC(7, 12, 4),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0m\0n\0o\0p\0t\0u\0.bss",
+	.str_sec_size = sizeof("\0A\0m\0n\0o\0p\0t\0u\0.bss"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 62,
+	.key_type_id = 0,
+	.value_type_id = 8,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid offset",
+},
+{
+	.descr = "global data test #14, invalid offset",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		/* unsigned long long */
+		BTF_TYPE_INT_ENC(0, 0, 0, 64, 8),		/* [2] */
+		/* char */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 8, 1),	/* [3] */
+		/* int[8] */
+		BTF_TYPE_ARRAY_ENC(1, 1, 8),			/* [4] */
+		/* struct A { */				/* [5] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 4), 48),
+		BTF_MEMBER_ENC(NAME_TBD, 2, 0),	/* unsigned long long m;*/
+		BTF_MEMBER_ENC(NAME_TBD, 1, 64),/* int n;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 3, 96),/* char o;		*/
+		BTF_MEMBER_ENC(NAME_TBD, 4, 128),/* int p[8]		*/
+		/* } */
+		/* static struct A t */
+		BTF_VAR_ENC(NAME_TBD, 5, 0),			/* [6] */
+		/* static int u */
+		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [7] */
+		/* .bss section */				/* [8] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 2), 62),
+		BTF_VAR_SECINFO_ENC(7, 58, 4),
+		BTF_VAR_SECINFO_ENC(6, 10, 48),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0m\0n\0o\0p\0t\0u\0.bss",
+	.str_sec_size = sizeof("\0A\0m\0n\0o\0p\0t\0u\0.bss"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 62,
+	.key_type_id = 0,
+	.value_type_id = 8,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid offset",
+},
+{
+	.descr = "global data test #15, not var kind",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [2] */
+		/* .bss section */				/* [3] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+		BTF_VAR_SECINFO_ENC(1, 0, 4),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0t\0.bss",
+	.str_sec_size = sizeof("\0A\0t\0.bss"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 0,
+	.value_type_id = 3,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Not a VAR kind member",
+},
+{
+	.descr = "global data test #16, invalid var referencing sec",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		BTF_VAR_ENC(NAME_TBD, 5, 0),			/* [2] */
+		BTF_VAR_ENC(NAME_TBD, 2, 0),			/* [3] */
+		/* a section */					/* [4] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+		BTF_VAR_SECINFO_ENC(3, 0, 4),
+		/* a section */					/* [5] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+		BTF_VAR_SECINFO_ENC(6, 0, 4),
+		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [6] */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0t\0s\0a\0a",
+	.str_sec_size = sizeof("\0A\0t\0s\0a\0a"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 0,
+	.value_type_id = 4,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid type_id",
+},
+{
+	.descr = "global data test #17, invalid var referencing var",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [2] */
+		BTF_VAR_ENC(NAME_TBD, 2, 0),			/* [3] */
+		/* a section */					/* [4] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+		BTF_VAR_SECINFO_ENC(3, 0, 4),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0t\0s\0a\0a",
+	.str_sec_size = sizeof("\0A\0t\0s\0a\0a"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 0,
+	.value_type_id = 4,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid type_id",
+},
+{
+	.descr = "global data test #18, invalid var loop",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		BTF_VAR_ENC(NAME_TBD, 2, 0),			/* [2] */
+		/* .bss section */				/* [3] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+		BTF_VAR_SECINFO_ENC(2, 0, 4),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0t\0aaa",
+	.str_sec_size = sizeof("\0A\0t\0aaa"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 0,
+	.value_type_id = 4,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid type_id",
+},
+{
+	.descr = "global data test #19, invalid var referencing var",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		BTF_VAR_ENC(NAME_TBD, 3, 0),			/* [2] */
+		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [3] */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0t\0s\0a\0a",
+	.str_sec_size = sizeof("\0A\0t\0s\0a\0a"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 0,
+	.value_type_id = 4,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid type_id",
+},
+{
+	.descr = "global data test #20, invalid ptr referencing var",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		/* PTR type_id=3	*/			/* [2] */
+		BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), 3),
+		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [3] */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0t\0s\0a\0a",
+	.str_sec_size = sizeof("\0A\0t\0s\0a\0a"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 0,
+	.value_type_id = 4,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid type_id",
+},
+{
+	.descr = "global data test #21, var included in struct",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		/* struct A { */				/* [2] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 2), sizeof(int) * 2),
+		BTF_MEMBER_ENC(NAME_TBD, 1, 0),	/* int m; */
+		BTF_MEMBER_ENC(NAME_TBD, 3, 32),/* VAR type_id=3; */
+		/* } */
+		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [3] */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0t\0s\0a\0a",
+	.str_sec_size = sizeof("\0A\0t\0s\0a\0a"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 0,
+	.value_type_id = 4,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid member",
+},
+{
+	.descr = "global data test #22, array of var",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		BTF_TYPE_ARRAY_ENC(3, 1, 4),			/* [2] */
+		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [3] */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0t\0s\0a\0a",
+	.str_sec_size = sizeof("\0A\0t\0s\0a\0a"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 0,
+	.value_type_id = 4,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Invalid elem",
+},
 /* Test member exceeds the size of struct.
  *
  * struct A {

tools/testing/selftests/bpf/test_verifier.c

@@ -52,7 +52,7 @@
 #define MAX_INSNS	BPF_MAXINSNS
 #define MAX_TEST_INSNS	1000000
 #define MAX_FIXUPS	8
-#define MAX_NR_MAPS	14
+#define MAX_NR_MAPS	16
 #define MAX_TEST_RUNS	8
 #define POINTER_VALUE	0xcafe4all
 #define TEST_DATA_LEN	64
@@ -82,6 +82,9 @@ struct bpf_test {
 	int fixup_cgroup_storage[MAX_FIXUPS];
 	int fixup_percpu_cgroup_storage[MAX_FIXUPS];
 	int fixup_map_spin_lock[MAX_FIXUPS];
+	int fixup_map_array_ro[MAX_FIXUPS];
+	int fixup_map_array_wo[MAX_FIXUPS];
+	int fixup_map_array_small[MAX_FIXUPS];
 	const char *errstr;
 	const char *errstr_unpriv;
 	uint32_t retval, retval_unpriv, insn_processed;
@@ -285,13 +288,15 @@ static bool skip_unsupported_map(enum bpf_map_type map_type)
 	return false;
 }
 
-static int create_map(uint32_t type, uint32_t size_key,
-		      uint32_t size_value, uint32_t max_elem)
+static int __create_map(uint32_t type, uint32_t size_key,
+			uint32_t size_value, uint32_t max_elem,
+			uint32_t extra_flags)
 {
 	int fd;
 
 	fd = bpf_create_map(type, size_key, size_value, max_elem,
-			    type == BPF_MAP_TYPE_HASH ? BPF_F_NO_PREALLOC : 0);
+			    (type == BPF_MAP_TYPE_HASH ?
+			     BPF_F_NO_PREALLOC : 0) | extra_flags);
 	if (fd < 0) {
 		if (skip_unsupported_map(type))
 			return -1;
@@ -301,6 +306,12 @@ static int create_map(uint32_t type, uint32_t size_key,
 	return fd;
 }
 
+static int create_map(uint32_t type, uint32_t size_key,
+		      uint32_t size_value, uint32_t max_elem)
+{
+	return __create_map(type, size_key, size_value, max_elem, 0);
+}
+
 static void update_map(int fd, int index)
 {
 	struct test_val value = {
@@ -527,6 +538,9 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type,
 	int *fixup_cgroup_storage = test->fixup_cgroup_storage;
 	int *fixup_percpu_cgroup_storage = test->fixup_percpu_cgroup_storage;
 	int *fixup_map_spin_lock = test->fixup_map_spin_lock;
+	int *fixup_map_array_ro = test->fixup_map_array_ro;
+	int *fixup_map_array_wo = test->fixup_map_array_wo;
+	int *fixup_map_array_small = test->fixup_map_array_small;
 
 	if (test->fill_helper) {
 		test->fill_insns = calloc(MAX_TEST_INSNS, sizeof(struct bpf_insn));
@@ -652,6 +666,35 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type,
 			fixup_map_spin_lock++;
 		} while (*fixup_map_spin_lock);
 	}
+	if (*fixup_map_array_ro) {
+		map_fds[14] = __create_map(BPF_MAP_TYPE_ARRAY, sizeof(int),
+					   sizeof(struct test_val), 1,
+					   BPF_F_RDONLY_PROG);
+		update_map(map_fds[14], 0);
+		do {
+			prog[*fixup_map_array_ro].imm = map_fds[14];
+			fixup_map_array_ro++;
+		} while (*fixup_map_array_ro);
+	}
+	if (*fixup_map_array_wo) {
+		map_fds[15] = __create_map(BPF_MAP_TYPE_ARRAY, sizeof(int),
+					   sizeof(struct test_val), 1,
+					   BPF_F_WRONLY_PROG);
+		update_map(map_fds[15], 0);
+		do {
+			prog[*fixup_map_array_wo].imm = map_fds[15];
+			fixup_map_array_wo++;
+		} while (*fixup_map_array_wo);
+	}
+	if (*fixup_map_array_small) {
+		map_fds[16] = __create_map(BPF_MAP_TYPE_ARRAY, sizeof(int),
+					   1, 1, 0);
+		update_map(map_fds[16], 0);
+		do {
+			prog[*fixup_map_array_small].imm = map_fds[16];
+			fixup_map_array_small++;
+		} while (*fixup_map_array_small);
+	}
 }
 
 static int set_admin(bool admin)

tools/testing/selftests/bpf/verifier/array_access.c

@@ -217,3 +217,162 @@
 	.result = REJECT,
 	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
 },
+{
+	"valid read map access into a read-only array 1",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_ro = { 3 },
+	.result = ACCEPT,
+	.retval = 28,
+},
+{
+	"valid read map access into a read-only array 2",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
+
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+	BPF_MOV64_IMM(BPF_REG_2, 4),
+	BPF_MOV64_IMM(BPF_REG_3, 0),
+	BPF_MOV64_IMM(BPF_REG_4, 0),
+	BPF_MOV64_IMM(BPF_REG_5, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+		     BPF_FUNC_csum_diff),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.fixup_map_array_ro = { 3 },
+	.result = ACCEPT,
+	.retval = -29,
+},
+{
+	"invalid write map access into a read-only array 1",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
+	BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 42),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_ro = { 3 },
+	.result = REJECT,
+	.errstr = "write into map forbidden",
+},
+{
+	"invalid write map access into a read-only array 2",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+	BPF_MOV64_IMM(BPF_REG_2, 0),
+	BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
+	BPF_MOV64_IMM(BPF_REG_4, 8),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+		     BPF_FUNC_skb_load_bytes),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.fixup_map_array_ro = { 4 },
+	.result = REJECT,
+	.errstr = "write into map forbidden",
+},
+{
+	"valid write map access into a write-only array 1",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
+	BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 42),
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_wo = { 3 },
+	.result = ACCEPT,
+	.retval = 1,
+},
+{
+	"valid write map access into a write-only array 2",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+	BPF_MOV64_IMM(BPF_REG_2, 0),
+	BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
+	BPF_MOV64_IMM(BPF_REG_4, 8),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+		     BPF_FUNC_skb_load_bytes),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.fixup_map_array_wo = { 4 },
+	.result = ACCEPT,
+	.retval = 0,
+},
+{
+	"invalid read map access into a write-only array 1",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_wo = { 3 },
+	.result = REJECT,
+	.errstr = "read from map forbidden",
+},
+{
+	"invalid read map access into a write-only array 2",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
+
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+	BPF_MOV64_IMM(BPF_REG_2, 4),
+	BPF_MOV64_IMM(BPF_REG_3, 0),
+	BPF_MOV64_IMM(BPF_REG_4, 0),
+	BPF_MOV64_IMM(BPF_REG_5, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+		     BPF_FUNC_csum_diff),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.fixup_map_array_wo = { 3 },
+	.result = REJECT,
+	.errstr = "read from map forbidden",
+},

tools/testing/selftests/bpf/verifier/direct_value_access.c

@@ -0,0 +1,347 @@
+{
+	"direct map access, write test 1",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 0),
+	BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 4242),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = ACCEPT,
+	.retval = 1,
+},
+{
+	"direct map access, write test 2",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 8),
+	BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 4242),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = ACCEPT,
+	.retval = 1,
+},
+{
+	"direct map access, write test 3",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 8),
+	BPF_ST_MEM(BPF_DW, BPF_REG_1, 8, 4242),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = ACCEPT,
+	.retval = 1,
+},
+{
+	"direct map access, write test 4",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 40),
+	BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 4242),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = ACCEPT,
+	.retval = 1,
+},
+{
+	"direct map access, write test 5",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 32),
+	BPF_ST_MEM(BPF_DW, BPF_REG_1, 8, 4242),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = ACCEPT,
+	.retval = 1,
+},
+{
+	"direct map access, write test 6",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 40),
+	BPF_ST_MEM(BPF_DW, BPF_REG_1, 4, 4242),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "R1 min value is outside of the array range",
+},
+{
+	"direct map access, write test 7",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, -1),
+	BPF_ST_MEM(BPF_DW, BPF_REG_1, 4, 4242),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "direct value offset of 4294967295 is not allowed",
+},
+{
+	"direct map access, write test 8",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 1),
+	BPF_ST_MEM(BPF_DW, BPF_REG_1, -1, 4242),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = ACCEPT,
+	.retval = 1,
+},
+{
+	"direct map access, write test 9",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 48),
+	BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 4242),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "invalid access to map value pointer",
+},
+{
+	"direct map access, write test 10",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 47),
+	BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 4),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = ACCEPT,
+	.retval = 1,
+},
+{
+	"direct map access, write test 11",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 48),
+	BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 4),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "invalid access to map value pointer",
+},
+{
+	"direct map access, write test 12",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, (1<<29)),
+	BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 4),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "direct value offset of 536870912 is not allowed",
+},
+{
+	"direct map access, write test 13",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, (1<<29)-1),
+	BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 4),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "invalid access to map value pointer, value_size=48 off=536870911",
+},
+{
+	"direct map access, write test 14",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 47),
+	BPF_LD_MAP_VALUE(BPF_REG_2, 0, 46),
+	BPF_ST_MEM(BPF_H, BPF_REG_2, 0, 0xffff),
+	BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1, 3 },
+	.result = ACCEPT,
+	.retval = 0xff,
+},
+{
+	"direct map access, write test 15",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 46),
+	BPF_LD_MAP_VALUE(BPF_REG_2, 0, 46),
+	BPF_ST_MEM(BPF_H, BPF_REG_2, 0, 0xffff),
+	BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1, 3 },
+	.result = ACCEPT,
+	.retval = 0xffff,
+},
+{
+	"direct map access, write test 16",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 46),
+	BPF_LD_MAP_VALUE(BPF_REG_2, 0, 47),
+	BPF_ST_MEM(BPF_H, BPF_REG_2, 0, 0xffff),
+	BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1, 3 },
+	.result = REJECT,
+	.errstr = "invalid access to map value, value_size=48 off=47 size=2",
+},
+{
+	"direct map access, write test 17",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 46),
+	BPF_LD_MAP_VALUE(BPF_REG_2, 0, 46),
+	BPF_ST_MEM(BPF_H, BPF_REG_2, 1, 0xffff),
+	BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1, 3 },
+	.result = REJECT,
+	.errstr = "invalid access to map value, value_size=48 off=47 size=2",
+},
+{
+	"direct map access, write test 18",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 0),
+	BPF_ST_MEM(BPF_H, BPF_REG_1, 0, 42),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_small = { 1 },
+	.result = REJECT,
+	.errstr = "R1 min value is outside of the array range",
+},
+{
+	"direct map access, write test 19",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 0),
+	BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_small = { 1 },
+	.result = ACCEPT,
+	.retval = 1,
+},
+{
+	"direct map access, write test 20",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_MAP_VALUE(BPF_REG_1, 0, 1),
+	BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_small = { 1 },
+	.result = REJECT,
+	.errstr = "invalid access to map value pointer",
+},
+{
+	"direct map access, invalid insn test 1",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_VALUE, 0, 1, 0, 47),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "invalid bpf_ld_imm64 insn",
+},
+{
+	"direct map access, invalid insn test 2",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_VALUE, 1, 0, 0, 47),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "BPF_LD_IMM64 uses reserved fields",
+},
+{
+	"direct map access, invalid insn test 3",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_VALUE, ~0, 0, 0, 47),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "BPF_LD_IMM64 uses reserved fields",
+},
+{
+	"direct map access, invalid insn test 4",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_VALUE, 0, ~0, 0, 47),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "invalid bpf_ld_imm64 insn",
+},
+{
+	"direct map access, invalid insn test 5",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_VALUE, ~0, ~0, 0, 47),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "invalid bpf_ld_imm64 insn",
+},
+{
+	"direct map access, invalid insn test 6",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_FD, ~0, 0, 0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "BPF_LD_IMM64 uses reserved fields",
+},
+{
+	"direct map access, invalid insn test 7",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_FD, 0, ~0, 0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "invalid bpf_ld_imm64 insn",
+},
+{
+	"direct map access, invalid insn test 8",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_FD, ~0, ~0, 0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "invalid bpf_ld_imm64 insn",
+},
+{
+	"direct map access, invalid insn test 9",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_FD, 0, 0, 0, 47),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 1 },
+	.result = REJECT,
+	.errstr = "unrecognized bpf_ld_imm64 insn",
+},