x86: xen: insn: Decode Xen and KVM emulate-prefix signature
Decode Xen and KVM's emulate-prefix signature by x86 insn decoder. It is called "prefix" but actually not x86 instruction prefix, so this adds insn.emulate_prefix_size field instead of reusing insn.prefixes. If x86 decoder finds a special sequence of instructions of XEN_EMULATE_PREFIX and 'ud2a; .ascii "kvm"', it just counts the length, set insn.emulate_prefix_size and fold it with the next instruction. In other words, the signature and the next instruction is treated as a single instruction. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: x86@kernel.org Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Borislav Petkov <bp@alien8.de> Cc: xen-devel@lists.xenproject.org Cc: Randy Dunlap <rdunlap@infradead.org> Link: https://lkml.kernel.org/r/156777564986.25081.4964537658500952557.stgit@devnote2
This commit is contained in:
Masami Hiramatsu
Peter Zijlstra
Родитель
b3dc0695fa
Коммит
4d65adfcd1
|
|
@ -45,6 +45,7 @@ struct insn {
|
|||
struct insn_field immediate2; /* for 64bit imm or seg16 */
|
||||
};
|
||||
|
||||
int emulate_prefix_size;
|
||||
insn_attr_t attr;
|
||||
unsigned char opnd_bytes;
|
||||
unsigned char addr_bytes;
|
||||
|
|
@ -128,6 +129,11 @@ static inline int insn_is_evex(struct insn *insn)
|
|||
return (insn->vex_prefix.nbytes == 4);
|
||||
}
|
||||
|
||||
static inline int insn_has_emulate_prefix(struct insn *insn)
|
||||
{
|
||||
return !!insn->emulate_prefix_size;
|
||||
}
|
||||
|
||||
/* Ensure this instruction is decoded completely */
|
||||
static inline int insn_complete(struct insn *insn)
|
||||
{
|
||||
|
|
|
|||
|
|
@ -13,6 +13,8 @@
|
|||
#include <asm/inat.h>
|
||||
#include <asm/insn.h>
|
||||
|
||||
#include <asm/emulate_prefix.h>
|
||||
|
||||
/* Verify next sizeof(t) bytes can be on the same instruction */
|
||||
#define validate_next(t, insn, n) \
|
||||
((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
|
||||
|
|
@ -58,6 +60,36 @@ void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64)
|
|||
insn->addr_bytes = 4;
|
||||
}
|
||||
|
||||
static const insn_byte_t xen_prefix[] = { __XEN_EMULATE_PREFIX };
|
||||
static const insn_byte_t kvm_prefix[] = { __KVM_EMULATE_PREFIX };
|
||||
|
||||
static int __insn_get_emulate_prefix(struct insn *insn,
|
||||
const insn_byte_t *prefix, size_t len)
|
||||
{
|
||||
size_t i;
|
||||
|
||||
for (i = 0; i < len; i++) {
|
||||
if (peek_nbyte_next(insn_byte_t, insn, i) != prefix[i])
|
||||
goto err_out;
|
||||
}
|
||||
|
||||
insn->emulate_prefix_size = len;
|
||||
insn->next_byte += len;
|
||||
|
||||
return 1;
|
||||
|
||||
err_out:
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void insn_get_emulate_prefix(struct insn *insn)
|
||||
{
|
||||
if (__insn_get_emulate_prefix(insn, xen_prefix, sizeof(xen_prefix)))
|
||||
return;
|
||||
|
||||
__insn_get_emulate_prefix(insn, kvm_prefix, sizeof(kvm_prefix));
|
||||
}
|
||||
|
||||
/**
|
||||
* insn_get_prefixes - scan x86 instruction prefix bytes
|
||||
* @insn: &struct insn containing instruction
|
||||
|
|
@ -76,6 +108,8 @@ void insn_get_prefixes(struct insn *insn)
|
|||
if (prefixes->got)
|
||||
return;
|
||||
|
||||
insn_get_emulate_prefix(insn);
|
||||
|
||||
nb = 0;
|
||||
lb = 0;
|
||||
b = peek_next(insn_byte_t, insn);
|
||||
|
|
|
|||
|
|
@ -0,0 +1,14 @@
|
|||
/* SPDX-License-Identifier: GPL-2.0 */
|
||||
#ifndef _ASM_X86_EMULATE_PREFIX_H
|
||||
#define _ASM_X86_EMULATE_PREFIX_H
|
||||
|
||||
/*
|
||||
* Virt escape sequences to trigger instruction emulation;
|
||||
* ideally these would decode to 'whole' instruction and not destroy
|
||||
* the instruction stream; sadly this is not true for the 'kvm' one :/
|
||||
*/
|
||||
|
||||
#define __XEN_EMULATE_PREFIX 0x0f,0x0b,0x78,0x65,0x6e /* ud2 ; .ascii "xen" */
|
||||
#define __KVM_EMULATE_PREFIX 0x0f,0x0b,0x6b,0x76,0x6d /* ud2 ; .ascii "kvm" */
|
||||
|
||||
#endif
|
||||
|
|
@ -45,6 +45,7 @@ struct insn {
|
|||
struct insn_field immediate2; /* for 64bit imm or seg16 */
|
||||
};
|
||||
|
||||
int emulate_prefix_size;
|
||||
insn_attr_t attr;
|
||||
unsigned char opnd_bytes;
|
||||
unsigned char addr_bytes;
|
||||
|
|
@ -128,6 +129,11 @@ static inline int insn_is_evex(struct insn *insn)
|
|||
return (insn->vex_prefix.nbytes == 4);
|
||||
}
|
||||
|
||||
static inline int insn_has_emulate_prefix(struct insn *insn)
|
||||
{
|
||||
return !!insn->emulate_prefix_size;
|
||||
}
|
||||
|
||||
/* Ensure this instruction is decoded completely */
|
||||
static inline int insn_complete(struct insn *insn)
|
||||
{
|
||||
|
|
|
|||
|
|
@ -13,6 +13,8 @@
|
|||
#include "../include/asm/inat.h"
|
||||
#include "../include/asm/insn.h"
|
||||
|
||||
#include "../include/asm/emulate_prefix.h"
|
||||
|
||||
/* Verify next sizeof(t) bytes can be on the same instruction */
|
||||
#define validate_next(t, insn, n) \
|
||||
((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
|
||||
|
|
@ -58,6 +60,36 @@ void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64)
|
|||
insn->addr_bytes = 4;
|
||||
}
|
||||
|
||||
static const insn_byte_t xen_prefix[] = { __XEN_EMULATE_PREFIX };
|
||||
static const insn_byte_t kvm_prefix[] = { __KVM_EMULATE_PREFIX };
|
||||
|
||||
static int __insn_get_emulate_prefix(struct insn *insn,
|
||||
const insn_byte_t *prefix, size_t len)
|
||||
{
|
||||
size_t i;
|
||||
|
||||
for (i = 0; i < len; i++) {
|
||||
if (peek_nbyte_next(insn_byte_t, insn, i) != prefix[i])
|
||||
goto err_out;
|
||||
}
|
||||
|
||||
insn->emulate_prefix_size = len;
|
||||
insn->next_byte += len;
|
||||
|
||||
return 1;
|
||||
|
||||
err_out:
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void insn_get_emulate_prefix(struct insn *insn)
|
||||
{
|
||||
if (__insn_get_emulate_prefix(insn, xen_prefix, sizeof(xen_prefix)))
|
||||
return;
|
||||
|
||||
__insn_get_emulate_prefix(insn, kvm_prefix, sizeof(kvm_prefix));
|
||||
}
|
||||
|
||||
/**
|
||||
* insn_get_prefixes - scan x86 instruction prefix bytes
|
||||
* @insn: &struct insn containing instruction
|
||||
|
|
@ -76,6 +108,8 @@ void insn_get_prefixes(struct insn *insn)
|
|||
if (prefixes->got)
|
||||
return;
|
||||
|
||||
insn_get_emulate_prefix(insn);
|
||||
|
||||
nb = 0;
|
||||
lb = 0;
|
||||
b = peek_next(insn_byte_t, insn);
|
||||
|
|
|
|||
|
|
@ -4,6 +4,7 @@
|
|||
FILES='
|
||||
arch/x86/include/asm/inat_types.h
|
||||
arch/x86/include/asm/orc_types.h
|
||||
arch/x86/include/asm/emulate_prefix.h
|
||||
arch/x86/lib/x86-opcode-map.txt
|
||||
arch/x86/tools/gen-insn-attr-x86.awk
|
||||
'
|
||||
|
|
@ -46,6 +47,6 @@ done
|
|||
check arch/x86/include/asm/inat.h '-I "^#include [\"<]\(asm/\)*inat_types.h[\">]"'
|
||||
check arch/x86/include/asm/insn.h '-I "^#include [\"<]\(asm/\)*inat.h[\">]"'
|
||||
check arch/x86/lib/inat.c '-I "^#include [\"<]\(../include/\)*asm/insn.h[\">]"'
|
||||
check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]"'
|
||||
check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]" -I "^#include [\"<]\(../include/\)*asm/emulate_prefix.h[\">]"'
|
||||
|
||||
cd -
|
||||
|
|
|
|||
|
|
@ -28,6 +28,7 @@ arch/x86/include/asm/disabled-features.h
|
|||
arch/x86/include/asm/required-features.h
|
||||
arch/x86/include/asm/cpufeatures.h
|
||||
arch/x86/include/asm/inat_types.h
|
||||
arch/x86/include/asm/emulate_prefix.h
|
||||
arch/x86/include/uapi/asm/prctl.h
|
||||
arch/x86/lib/x86-opcode-map.txt
|
||||
arch/x86/tools/gen-insn-attr-x86.awk
|
||||
|
|
@ -116,7 +117,7 @@ check lib/ctype.c '-I "^EXPORT_SYMBOL" -I "^#include <linux/export.h>" -B
|
|||
check arch/x86/include/asm/inat.h '-I "^#include [\"<]\(asm/\)*inat_types.h[\">]"'
|
||||
check arch/x86/include/asm/insn.h '-I "^#include [\"<]\(asm/\)*inat.h[\">]"'
|
||||
check arch/x86/lib/inat.c '-I "^#include [\"<]\(../include/\)*asm/insn.h[\">]"'
|
||||
check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]"'
|
||||
check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]" -I "^#include [\"<]\(../include/\)*asm/emulate_prefix.h[\">]"'
|
||||
|
||||
# diff non-symmetric files
|
||||
check_2 tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче