[ Upstream commit 44382b3ed6b2787710c8ade06c0e97f5970a47c8 ]
err is a 32-bit integer, but elf_update returns an off_t, which is 64-bit
at least on 64-bit platforms. If symbols_patch is called on a binary between
2-4GB in size, the result will be negative when cast to a 32-bit integer,
which the code assumes means an error occurred. This can wrongly trigger
build failures when building very large kernel images.
Fixes: fbbb68de80 ("bpf: Add resolve_btfids tool to resolve BTF IDs in ELF object")
Signed-off-by: Friedrich Vock <friedrich.vock@gmx.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240514070931.199694-1-friedrich.vock@gmx.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f5f30386c78105cba520e443a6a9ee945ec1d066 ]
There exists the following warning when building bpftool:
CC prog.o
prog.c: In function ‘profile_open_perf_events’:
prog.c:2301:24: warning: ‘calloc’ sizes specified with ‘sizeof’ in the earlier argument and not in the later argument [-Wcalloc-transposed-args]
2301 | sizeof(int), obj->rodata->num_cpu * obj->rodata->num_metric);
| ^~~
prog.c:2301:24: note: earlier argument should specify number of elements, later size of each element
Tested with the latest upstream GCC which contains a new warning option
-Wcalloc-transposed-args. The first argument to calloc is documented to
be number of elements in array, while the second argument is size of each
element, just switch the first and second arguments of calloc() to silence
the build warning, compile tested only.
Fixes: 47c09d6a9f ("bpftool: Introduce "prog profile" command")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20240116061920.31172-1-yangtiezhu@loongson.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 658ac06801 ]
Fix the following error when building bpftool:
CLANG profiler.bpf.o
CLANG pid_iter.bpf.o
skeleton/profiler.bpf.c:18:21: error: invalid application of 'sizeof' to an incomplete type 'struct bpf_perf_event_value'
__uint(value_size, sizeof(struct bpf_perf_event_value));
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tools/bpf/bpftool/bootstrap/libbpf/include/bpf/bpf_helpers.h:13:39: note: expanded from macro '__uint'
tools/bpf/bpftool/bootstrap/libbpf/include/bpf/bpf_helper_defs.h:7:8: note: forward declaration of 'struct bpf_perf_event_value'
struct bpf_perf_event_value;
^
struct bpf_perf_event_value is being used in the kernel only when
CONFIG_BPF_EVENTS is enabled, so it misses a BTF entry then.
Define struct bpf_perf_event_value___local with the
`preserve_access_index` attribute inside the pid_iter BPF prog to
allow compiling on any configs. It is a full mirror of a UAPI
structure, so is compatible both with and w/o CO-RE.
bpf_perf_event_read_value() requires a pointer of the original type,
so a cast is needed.
Fixes: 47c09d6a9f ("bpftool: Introduce "prog profile" command")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230707095425.168126-5-quentin@isovalent.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 04cb8453a9 ]
On aarch64, "bpftool feature" reports an incorrect BPF JIT limit:
$ sudo /sbin/bpftool feature
Scanning system configuration...
bpf() syscall restricted to privileged users
JIT compiler is enabled
JIT compiler hardening is disabled
JIT compiler kallsyms exports are enabled for root
skipping kernel config, can't open file: No such file or directory
Global memory limit for JIT compiler for unprivileged users is -201326592 bytes
This is because /proc/sys/net/core/bpf_jit_limit reports
$ sudo cat /proc/sys/net/core/bpf_jit_limit
68169519595520
...and an int is assumed in read_procfs(). Change read_procfs()
to return a long to avoid negative value reporting.
Fixes: 7a4522bbef ("tools: bpftool: add probes for /proc/ eBPF parameters")
Reported-by: Nicky Veitch <nicky.veitch@oracle.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20230512113134.58996-1-alan.maguire@oracle.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 67cf52cdb6 ]
When dumping the control flow graphs for programs using the 16-byte long
load instruction, we need to skip the second part of this instruction
when looking for the next instruction to process. Otherwise, we end up
printing "BUG_ld_00" from the kernel disassembler in the CFG.
Fixes: efcef17a6d ("tools: bpftool: generate .dot graph from CFG information")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/r/20230405132120.59886-3-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c679bbd611 ]
RFC8259 ("The JavaScript Object Notation (JSON) Data Interchange
Format") only specifies \", \\, \/, \b, \f, \n, \r, and \r as valid
two-character escape sequences. This does not include \', which is not
required in JSON because it exclusively uses double quotes as string
separators.
Solidus (/) may be escaped, but does not have to. Only reverse
solidus (\), double quotes ("), and the control characters have to be
escaped. Therefore, with this fix, bpftool correctly supports all valid
two-character escape sequences (but still does not support characters
that require multi-character escape sequences).
Witout this fix, attempting to load a JSON file generated by bpftool
using Python 3.10.6's default json.load() may fail with the error
"Invalid \escape" if the file contains the invalid escaped single
quote (\').
Fixes: b66e907cfe ("tools: bpftool: copy JSON writer from iproute2 repository")
Signed-off-by: Luis Gerhorst <gerhorst@cs.fau.de>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20230227150853.16863-1-gerhorst@cs.fau.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 600b7b26c0 upstream.
binutils changed the signature of init_disassemble_info(), which now causes
compilation to fail for tools/bpf/bpftool/jit_disasm.c, e.g. on debian
unstable.
Relevant binutils commit:
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=60a3da00bd5407f07
Wire up the feature test and switch to init_disassemble_info_compat(),
which were introduced in prior commits, fixing the compilation failure.
I verified that bpftool can still disassemble bpf programs, both with an
old and new dis-asm.h API. There are no output changes for plain and json
formats. When comparing the output from old binutils (2.35)
to new bintuils with the patch (upstream snapshot) there are a few output
differences, but they are unrelated to this patch. An example hunk is:
2f: pop %r14
31: pop %r13
33: pop %rbx
- 34: leaveq
- 35: retq
+ 34: leave
+ 35: ret
Signed-off-by: Andres Freund <andres@anarazel.de>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Ben Hutchings <benh@debian.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Quentin Monnet <quentin@isovalent.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/20220622181918.ykrs5rsnmx3og4sv@alap3.anarazel.de
Link: https://lore.kernel.org/r/20220801013834.156015-8-andres@anarazel.de
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 96ed066054 upstream.
binutils changed the signature of init_disassemble_info(), which now causes
compilation to fail for tools/bpf/bpf_jit_disasm.c, e.g. on debian
unstable.
Relevant binutils commit:
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=60a3da00bd5407f07
Wire up the feature test and switch to init_disassemble_info_compat(),
which were introduced in prior commits, fixing the compilation failure.
I verified that bpf_jit_disasm can still disassemble bpf programs, both
with the old and new dis-asm.h API. With old binutils there's no change in
output before/after this patch. When comparing the output from old
binutils (2.35) to new bintuils with the patch (upstream snapshot) there
are a few output differences, but they are unrelated to this patch. An
example hunk is:
f4: mov %r14,%rsi
f7: mov %r15,%rdx
fa: mov $0x2a,%ecx
- ff: callq 0xffffffffea8c4988
+ ff: call 0xffffffffea8c4988
104: test %rax,%rax
107: jge 0x0000000000000110
109: xor %eax,%eax
- 10b: jmpq 0x0000000000000073
+ 10b: jmp 0x0000000000000073
110: cmp $0x16,%rax
However, I had to use an older kernel to generate the bpf_jit_enabled =
2 output, as that has been broken since 5.18 / 1022a5498f ("bpf,
x86_64: Use bpf_jit_binary_pack_alloc").
https://lore.kernel.org/20220703030210.pmjft7qc2eajzi6c@alap3.anarazel.de
Signed-off-by: Andres Freund <andres@anarazel.de>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Ben Hutchings <benh@debian.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Quentin Monnet <quentin@isovalent.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/20220622181918.ykrs5rsnmx3og4sv@alap3.anarazel.de
Link: https://lore.kernel.org/r/20220801013834.156015-6-andres@anarazel.de
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 377c16fa3f ]
The number of online cpu may be not equal to possible cpu.
"bpftool prog profile" can not create pmu event on possible
but on online cpu.
$ dmidecode -s system-product-name
PowerEdge R620
$ cat /sys/devices/system/cpu/possible
0-47
$ cat /sys/devices/system/cpu/online
0-31
Disable cpu dynamically:
$ echo 0 > /sys/devices/system/cpu/cpuX/online
If one cpu is offline, perf_event_open will return ENODEV.
To fix this issue:
* check value returned and skip offline cpu.
* close pmu_fd immediately on error path, avoid fd leaking.
Fixes: 47c09d6a9f ("bpftool: Introduce "prog profile" command")
Signed-off-by: Tonghao Zhang <tong@infragraf.org>
Cc: Quentin Monnet <quentin@isovalent.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Song Liu <song@kernel.org>
Cc: Yonghong Song <yhs@fb.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20230202131701.29519-1-tong@infragraf.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 34de8e6e0e ]
When using bpftool to pin {PROG, MAP, LINK} without FILE,
segmentation fault will occur. The reson is that the lack
of FILE will cause strlen to trigger NULL pointer dereference.
The corresponding stacktrace is shown below:
do_pin
do_pin_any
do_pin_fd
mount_bpffs_for_pin
strlen(name) <- NULL pointer dereference
Fix it by adding validation to the common process.
Fixes: 75a1e792c3 ("tools: bpftool: Allow all prog/map handles for pinning objects")
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20221102084034.3342995-1-pulehui@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cea558855c ]
When bpftool is linked against libcap, the library runs a "constructor"
function to compute the number of capabilities of the running kernel
[0], at the beginning of the execution of the program. As part of this,
it performs multiple calls to prctl(). Some of these may fail, and set
errno to a non-zero value:
# strace -e prctl ./bpftool version
prctl(PR_CAPBSET_READ, CAP_MAC_OVERRIDE) = 1
prctl(PR_CAPBSET_READ, 0x30 /* CAP_??? */) = -1 EINVAL (Invalid argument)
prctl(PR_CAPBSET_READ, CAP_CHECKPOINT_RESTORE) = 1
prctl(PR_CAPBSET_READ, 0x2c /* CAP_??? */) = -1 EINVAL (Invalid argument)
prctl(PR_CAPBSET_READ, 0x2a /* CAP_??? */) = -1 EINVAL (Invalid argument)
prctl(PR_CAPBSET_READ, 0x29 /* CAP_??? */) = -1 EINVAL (Invalid argument)
** fprintf added at the top of main(): we have errno == 1
./bpftool v7.0.0
using libbpf v1.0
features: libbfd, libbpf_strict, skeletons
+++ exited with 0 +++
This has been addressed in libcap 2.63 [1], but until this version is
available everywhere, we can fix it on bpftool side.
Let's clean errno at the beginning of the main() function, to make sure
that these checks do not interfere with the batch mode, where we error
out if errno is set after a bpftool command.
[0] https://git.kernel.org/pub/scm/libs/libcap/libcap.git/tree/libcap/cap_alloc.c?h=libcap-2.65#n20
[1] https://git.kernel.org/pub/scm/libs/libcap/libcap.git/commit/?id=f25a1b7e69f7b33e6afb58b3e38f3450b7d2d9a0
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220815162205.45043-1-quentin@isovalent.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7184aef9c0 ]
When `data` points to a boolean value, casting it to `int *` is problematic
and could lead to a wrong value being passed to `jsonw_bool`. Change the
cast to `bool *` instead.
Fixes: b12d6ec097 ("bpf: btf: add btf print functionality")
Signed-off-by: Lam Thai <lamthai@arista.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220824225859.9038-1-lamthai@arista.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit edc21dc909 ]
When reworking btf__get_from_id() in commit a19f93cfaf the error
handling when calling bpf_btf_get_fd_by_id() changed. Before the rework
if bpf_btf_get_fd_by_id() failed the error would not be propagated to
callers of btf__get_from_id(), after the rework it is. This lead to a
change in behavior in print_key_value() that now prints an error when
trying to lookup keys in maps with no btf available.
Fix this by following the way used in dumping maps to allow to look up
keys in no-btf maps, by which it decides whether and where to get the
btf info according to the btf value type.
Fixes: a19f93cfaf ("libbpf: Add internal helper to load BTF data by FD")
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/1644249625-22479-1-git-send-email-yinjun.zhang@corigine.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0991f6a38f ]
After `bpftool gen skeleton`, the ${bpf_app}.skel.h will provide that
${bpf_app_name}__open helper to load bpf. If there is some error
like ENOMEM, the ${bpf_app_name}__open will rollback(free) the allocated
object, including `bpf_object_skeleton`.
Since the ${bpf_app_name}__create_skeleton set the obj->skeleton first
and not rollback it when error, it will cause double-free in
${bpf_app_name}__destory at ${bpf_app_name}__open. Therefore, we should
set the obj->skeleton before return 0;
Fixes: 5dc7a8b211 ("bpftool, selftests/bpf: Embed object file inside skeleton")
Signed-off-by: Wei Fu <fuweid89@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220108084008.1053111-1-fuweid89@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 7f3bdbc3f1 upstream.
When building with 'make -s', there is some output from resolve_btfids:
$ make -sj"$(nproc)" oldconfig prepare
MKDIR .../tools/bpf/resolve_btfids/libbpf/
MKDIR .../tools/bpf/resolve_btfids//libsubcmd
LINK resolve_btfids
Silent mode means that no information should be emitted about what is
currently being done. Use the $(silent) variable from Makefile.include
to avoid defining the msg macro so that there is no information printed.
Fixes: fbbb68de80 ("bpf: Add resolve_btfids tool to resolve BTF IDs in ELF object")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220201212503.731732-1-nathan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 986dec18bb upstream.
Mixed indentation levels in the lists of options in bpftool's
documentation produces some unexpected results. For the "bpftool" man
page, it prints a warning:
$ make -C bpftool.8
GEN bpftool.8
<stdin>:26: (ERROR/3) Unexpected indentation.
For other pages, there is no warning, but it results in a line break
appearing in the option lists in the generated man pages.
RST paragraphs should have a uniform indentation level. Let's fix it.
Fixes: c07ba629df ("tools: bpftool: Update and synchronise option list in doc and help msg")
Fixes: 8cc8c6357c ("tools: bpftool: Document and add bash completion for -L, -B options")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211110114632.24537-5-quentin@isovalent.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 48f5aef4c4 upstream.
Bpftool's Makefile, and the Makefile for its documentation, both include
scripts/utilities.mak, but they use none of the items defined in this
file. Remove the includes.
Fixes: 71bb428fe2 ("tools: bpf: add bpftool")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211110114632.24537-3-quentin@isovalent.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1a1a0b0364 ]
The output of bpftool prog tracelog is currently buffered, which is
inconvenient when piping the output into other commands. A simple
tracelog | grep will typically not display anything. This patch fixes it
by enabling line buffering on stdout for the whole bpftool binary.
Fixes: 30da46b5dc ("tools: bpftool: add a command to dump the trace pipe")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Paul Chaignon <paul@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211220214528.GA11706@Mem
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ebbd7f64a3 ]
Following the extraction of prog_dump() from do_dump(), the struct btf
allocated in prog_dump() is no longer freed on error; the struct
bpf_prog_linfo is not freed at all. Make sure we release them before
exiting the function.
Fixes: ec2025095c ("bpftool: Match several programs with same tag")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211110114632.24537-2-quentin@isovalent.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e89ef634f8 ]
Bpftool creates a new JSON object for writing program metadata in plain
text mode, regardless of metadata being present or not. Then this writer
is freed if any metadata has been found and printed, but it leaks
otherwise. We cannot destroy the object unconditionally, because the
destructor prints an undesirable line break. Instead, make sure the
writer is created only after we have found program metadata to print.
Found with valgrind.
Fixes: aff52e685e ("bpftool: Support dumping metadata")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211022094743.11052-1-quentin@isovalent.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Andrii Nakryiko says:
====================
bpf-next 2021-07-30
We've added 64 non-merge commits during the last 15 day(s) which contain
a total of 83 files changed, 5027 insertions(+), 1808 deletions(-).
The main changes are:
1) BTF-guided binary data dumping libbpf API, from Alan.
2) Internal factoring out of libbpf CO-RE relocation logic, from Alexei.
3) Ambient BPF run context and cgroup storage cleanup, from Andrii.
4) Few small API additions for libbpf 1.0 effort, from Evgeniy and Hengqi.
5) bpf_program__attach_kprobe_opts() fixes in libbpf, from Jiri.
6) bpf_{get,set}sockopt() support in BPF iterators, from Martin.
7) BPF map pinning improvements in libbpf, from Martynas.
8) Improved module BTF support in libbpf and bpftool, from Quentin.
9) Bpftool cleanups and documentation improvements, from Quentin.
10) Libbpf improvements for supporting CO-RE on old kernels, from Shuyi.
11) Increased maximum cgroup storage size, from Stanislav.
12) Small fixes and improvements to BPF tests and samples, from various folks.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (64 commits)
tools: bpftool: Complete metrics list in "bpftool prog profile" doc
tools: bpftool: Document and add bash completion for -L, -B options
selftests/bpf: Update bpftool's consistency script for checking options
tools: bpftool: Update and synchronise option list in doc and help msg
tools: bpftool: Complete and synchronise attach or map types
selftests/bpf: Check consistency between bpftool source, doc, completion
tools: bpftool: Slightly ease bash completion updates
unix_bpf: Fix a potential deadlock in unix_dgram_bpf_recvmsg()
libbpf: Add btf__load_vmlinux_btf/btf__load_module_btf
tools: bpftool: Support dumping split BTF by id
libbpf: Add split BTF support for btf__load_from_kernel_by_id()
tools: Replace btf__get_from_id() with btf__load_from_kernel_by_id()
tools: Free BTF objects at various locations
libbpf: Rename btf__get_from_id() as btf__load_from_kernel_by_id()
libbpf: Rename btf__load() as btf__load_into_kernel()
libbpf: Return non-null error on failures in libbpf_find_prog_btf_id()
bpf: Emit better log message if bpf_iter ctx arg btf_id == 0
tools/resolve_btfids: Emit warnings and patch zero id for missing symbols
bpf: Increase supported cgroup storage value size
libbpf: Fix race when pinning maps in parallel
...
====================
Link: https://lore.kernel.org/r/20210730225606.1897330-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Profiling programs with bpftool was extended some time ago to support
two new metrics, namely itlb_misses and dtlb_misses (misses for the
instruction/data translation lookaside buffer). Update the manual page
and bash completion accordingly.
Fixes: 450d060e8f ("bpftool: Add {i,d}tlb_misses support for bpftool profile")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210730215435.7095-8-quentin@isovalent.com
The -L|--use-loader option for using loader programs when loading, or
when generating a skeleton, did not have any documentation or bash
completion. Same thing goes for -B|--base-btf, used to pass a path to a
base BTF object for split BTF such as BTF for kernel modules.
This patch documents and adds bash completion for those options.
Fixes: 75fa177769 ("tools/bpftool: Add bpftool support for split BTF")
Fixes: d510296d33 ("bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210730215435.7095-7-quentin@isovalent.com
All bpftool commands support the options for JSON output and debug from
libbpf. In addition, some commands support additional options
corresponding to specific use cases.
The list of options described in the man pages for the different
commands are not always accurate. The messages for interactive help are
mostly limited to HELP_SPEC_OPTIONS, and are even less representative of
the actual set of options supported for the commands.
Let's update the lists:
- HELP_SPEC_OPTIONS is modified to contain the "default" options (JSON
and debug), and to be extensible (no ending curly bracket).
- All commands use HELP_SPEC_OPTIONS in their help message, and then
complete the list with their specific options.
- The lists of options in the man pages are updated.
- The formatting of the list for bpftool.rst is adjusted to match
formatting for the other man pages. This is for consistency, and also
because it will be helpful in a future patch to automatically check
that the files are synchronised.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210730215435.7095-5-quentin@isovalent.com
Update bpftool's list of attach type names to tell it about the latest
attach types, or the "ringbuf" map. Also update the documentation, help
messages, and bash completion when relevant.
These missing items were reported by the newly added Python script used
to help maintain consistency in bpftool.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210730215435.7095-4-quentin@isovalent.com
Bash completion for bpftool gets two minor improvements in this patch.
Move the detection of attach types for "bpftool cgroup attach" outside
of the "case/esac" bloc, where we cannot reuse our variable holding the
list of supported attach types as a pattern list. After the change, we
have only one list of cgroup attach types to update when new types are
added, instead of the former two lists.
Also rename the variables holding lists of names for program types, map
types, and attach types, to make them more unique. This can make it
slightly easier to point people to the relevant variables to update, but
the main objective here is to help run a script to check that bash
completion is up-to-date with bpftool's source code.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210730215435.7095-2-quentin@isovalent.com
Split BTF objects are typically BTF objects for kernel modules, which
are incrementally built on top of kernel BTF instead of redefining all
kernel symbols they need. We can use bpftool with its -B command-line
option to dump split BTF objects. It works well when the handle provided
for the BTF object to dump is a "path" to the BTF object, typically
under /sys/kernel/btf, because bpftool internally calls
btf__parse_split() which can take a "base_btf" pointer and resolve the
BTF reconstruction (although in that case, the "-B" option is
unnecessary because bpftool performs autodetection).
However, it did not work so far when passing the BTF object through its
id, because bpftool would call btf__get_from_id() which did not provide
a way to pass a "base_btf" pointer.
In other words, the following works:
# bpftool btf dump file /sys/kernel/btf/i2c_smbus -B /sys/kernel/btf/vmlinux
But this was not possible:
# bpftool btf dump id 6 -B /sys/kernel/btf/vmlinux
The libbpf API has recently changed, and btf__get_from_id() has been
deprecated in favour of btf__load_from_kernel_by_id() and its version
with support for split BTF, btf__load_from_kernel_by_id_split(). Let's
update bpftool to make it able to dump the BTF object in the second case
as well.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210729162028.29512-9-quentin@isovalent.com
Replace the calls to function btf__get_from_id(), which we plan to
deprecate before the library reaches v1.0, with calls to
btf__load_from_kernel_by_id() in tools/ (bpftool, perf, selftests).
Update the surrounding code accordingly (instead of passing a pointer to
the btf struct, get it as a return value from the function).
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210729162028.29512-6-quentin@isovalent.com
Make sure to call btf__free() (and not simply free(), which does not
free all pointers stored in the struct) on pointers to struct btf
objects retrieved at various locations.
These were found while updating the calls to btf__get_from_id().
Fixes: 999d82cbc0 ("tools/bpf: enhance test_btf file testing to test func info")
Fixes: 254471e57a ("tools/bpf: bpftool: add support for func types")
Fixes: 7b612e291a ("perf tools: Synthesize PERF_RECORD_* for loaded BPF programs")
Fixes: d56354dc49 ("perf tools: Save bpf_prog_info and BTF of new BPF programs")
Fixes: 47c09d6a9f ("bpftool: Introduce "prog profile" command")
Fixes: fa853c4b83 ("perf stat: Enable counting events for BPF programs")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210729162028.29512-5-quentin@isovalent.com
Kernel functions referenced by .BTF_ids may be changed from global to static
and get inlined or get renamed/removed, and thus disappears from BTF.
This causes kernel build failure when resolve_btfids do id patch for symbols
in .BTF_ids in vmlinux. Update resolve_btfids to emit warning messages and
patch zero id for missing symbols instead of aborting kernel build process.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210727132532.2473636-2-hengqi.chen@gmail.com
make[2]: *** No rule to make target 'install'. Stop.
make[1]: *** [Makefile:122: runqslower_install] Error 2
make: *** [Makefile:116: bpf_install] Error 2
There is no rule for target 'install' in tools/bpf/runqslower/Makefile,
and there is no need to install it, so just remove 'runqslower_install'.
Fixes: 9c01546d26 ("tools/bpf: Add runqslower tool to tools/bpf")
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210628030409.3459095-1-liwei391@huawei.com
Commit 2f064a59a1 ("sched: Change task_struct::state") renamed task->state
to task->__state in task_struct. Fix runqslower to use the new name of the
field.
Fixes: 2f064a59a1 ("sched: Change task_struct::state")
Signed-off-by: SanjayKumar Jeyakumar <vjsanjay@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210707052914.21473-1-vjsanjay@gmail.com
va_list 'ap' was opened but not closed by va_end() in error case. It should
be closed by va_end() before the return.
Fixes: aa52bcbe0e ("tools: bpftool: Fix json dump crash on powerpc")
Signed-off-by: Gu Shengxian <gushengxian@yulong.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/bpf/20210706013543.671114-1-gushengxian507419@gmail.com
Trivial conflict in net/netfilter/nf_tables_api.c.
Duplicate fix in tools/testing/selftests/net/devlink_port_split.py
- take the net-next version.
skmsg, and L4 bpf - keep the bpf code but remove the flags
and err params.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The vmlinux ".BTF_ids" ELF section is declared in btf_ids.h to hold a list
of zero-filled BTF IDs, which is then patched at link-time with correct
values by resolv_btfids. The section is flagged as "allocable" to preclude
compression, but notably the section contents (BTF IDs) are untyped.
When patching the BTF IDs, resolve_btfids writes in host-native endianness
and relies on libelf for any required translation on reading and updating
vmlinux. However, since the type of the .BTF_ids section content defaults
to ELF_T_BYTE (i.e. unsigned char), no translation occurs. This results in
incorrect patched values when cross-compiling to non-native endianness,
and can manifest as kernel Oops and test failures which are difficult to
troubleshoot [1].
Explicitly set the type of patched data to ELF_T_WORD, the architecture-
neutral ELF type corresponding to the u32 BTF IDs. This enables libelf to
transparently perform any needed endian conversions.
Fixes: fbbb68de80 ("bpf: Add resolve_btfids tool to resolve BTF IDs in ELF object")
Signed-off-by: Tony Ambardar <Tony.Ambardar@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Frank Eigler <fche@redhat.com>
Cc: Mark Wielaard <mark@klomp.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/CAPGftE_eY-Zdi3wBcgDfkz_iOr1KF10n=9mJHm1_a_PykcsoeA@mail.gmail.com [1]
Link: https://lore.kernel.org/bpf/20210618061404.818569-1-Tony.Ambardar@gmail.com
Daniel Borkmann says:
====================
pull-request: bpf-next 2021-06-17
The following pull-request contains BPF updates for your *net-next* tree.
We've added 50 non-merge commits during the last 25 day(s) which contain
a total of 148 files changed, 4779 insertions(+), 1248 deletions(-).
The main changes are:
1) BPF infrastructure to migrate TCP child sockets from a listener to another
in the same reuseport group/map, from Kuniyuki Iwashima.
2) Add a provably sound, faster and more precise algorithm for tnum_mul() as
noted in https://arxiv.org/abs/2105.05398, from Harishankar Vishwanathan.
3) Streamline error reporting changes in libbpf as planned out in the
'libbpf: the road to v1.0' effort, from Andrii Nakryiko.
4) Add broadcast support to xdp_redirect_map(), from Hangbin Liu.
5) Extends bpf_map_lookup_and_delete_elem() functionality to 4 more map
types, that is, {LRU_,PERCPU_,LRU_PERCPU_,}HASH, from Denis Salopek.
6) Support new LLVM relocations in libbpf to make them more linker friendly,
also add a doc to describe the BPF backend relocations, from Yonghong Song.
7) Silence long standing KUBSAN complaints on register-based shifts in
interpreter, from Daniel Borkmann and Eric Biggers.
8) Add dummy PT_REGS macros in libbpf to fail BPF program compilation when
target arch cannot be determined, from Lorenz Bauer.
9) Extend AF_XDP to support large umems with 1M+ pages, from Magnus Karlsson.
10) Fix two minor libbpf tc BPF API issues, from Kumar Kartikeya Dwivedi.
11) Move libbpf BPF_SEQ_PRINTF/BPF_SNPRINTF macros that can be used by BPF
programs to bpf_helpers.h header, from Florent Revest.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.
Fixes: 668da745af ("tools: bpftool: add support for quotations ...")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20210609115916.2186872-1-chengzhihao1@huawei.com
When the bootstrap and final bpftool have different architectures, we
need to build two distinct disasm.o objects. Add a recipe for the
bootstrap disasm.o.
After commit d510296d33 ("bpftool: Use syscall/loader program in
"prog load" and "gen skeleton" command.") cross-building bpftool didn't
work anymore, because the bootstrap bpftool was linked using objects
from different architectures:
$ make O=/tmp/bpftool ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/bpf/bpftool/ V=1
[...]
aarch64-linux-gnu-gcc ... -c -MMD -o /tmp/bpftool/disasm.o /home/z/src/linux/kernel/bpf/disasm.c
gcc ... -c -MMD -o /tmp/bpftool//bootstrap/main.o main.c
gcc ... -o /tmp/bpftool//bootstrap/bpftool /tmp/bpftool//bootstrap/main.o ... /tmp/bpftool/disasm.o
/usr/bin/ld: /tmp/bpftool/disasm.o: Relocations in generic ELF (EM: 183)
/usr/bin/ld: /tmp/bpftool/disasm.o: Relocations in generic ELF (EM: 183)
/usr/bin/ld: /tmp/bpftool/disasm.o: Relocations in generic ELF (EM: 183)
/usr/bin/ld: /tmp/bpftool/disasm.o: error adding symbols: file in wrong format
collect2: error: ld returned 1 exit status
[...]
The final bpftool was built for e.g. arm64, while the bootstrap bpftool,
executed on the host, was built for x86. The problem here was that disasm.o
linked into the bootstrap bpftool was arm64 rather than x86. With the fix
we build two disasm.o, one for the target bpftool in arm64, and one for
the bootstrap bpftool in x86.
Fixes: d510296d33 ("bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210603170515.1854642-1-jean-philippe@linaro.org
Follow libbpf's error handling conventions and pass through errors and errno
properly. Skeleton code always returned NULL on errors (not ERR_PTR(err)), so
there are no backwards compatibility concerns. But now we also set errno
properly, so it's possible to distinguish different reasons for failure, if
necessary.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210525035935.1461796-6-andrii@kernel.org
The help information was not added at the time when the function got added.
Fix this and add the missing information to its cli, documentation and bash
completion.
Fixes: db94cc0b48 ("bpftool: Add support for BPF_CGROUP_INET_SOCK_RELEASE")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20210525014139.323859-1-liujian56@huawei.com
Add -L flag to bpftool to use libbpf gen_trace facility and syscall/loader program
for skeleton generation and program loading.
"bpftool gen skeleton -L" command will generate a "light skeleton" or "loader skeleton"
that is similar to existing skeleton, but has one major difference:
$ bpftool gen skeleton lsm.o > lsm.skel.h
$ bpftool gen skeleton -L lsm.o > lsm.lskel.h
$ diff lsm.skel.h lsm.lskel.h
@@ -5,34 +4,34 @@
#define __LSM_SKEL_H__
#include <stdlib.h>
-#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
The light skeleton does not use majority of libbpf infrastructure.
It doesn't need libelf. It doesn't parse .o file.
It only needs few sys_bpf wrappers. All of them are in bpf/bpf.h file.
In future libbpf/bpf.c can be inlined into bpf.h, so not even libbpf.a would be
needed to work with light skeleton.
"bpftool prog load -L file.o" command is introduced for debugging of syscall/loader
program generation. Just like the same command without -L it will try to load
the programs from file.o into the kernel. It won't even try to pin them.
"bpftool prog load -L -d file.o" command will provide additional debug messages
on how syscall/loader program was generated.
Also the execution of syscall/loader program will use bpf_trace_printk() for
each step of loading BTF, creating maps, and loading programs.
The user can do "cat /.../trace_pipe" for further debug.
An example of fexit_sleep.lskel.h generated from progs/fexit_sleep.c:
struct fexit_sleep {
struct bpf_loader_ctx ctx;
struct {
struct bpf_map_desc bss;
} maps;
struct {
struct bpf_prog_desc nanosleep_fentry;
struct bpf_prog_desc nanosleep_fexit;
} progs;
struct {
int nanosleep_fentry_fd;
int nanosleep_fexit_fd;
} links;
struct fexit_sleep__bss {
int pid;
int fentry_cnt;
int fexit_cnt;
} *bss;
};
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210514003623.28033-18-alexei.starovoitov@gmail.com
As discussed in [0], stop emitting static variables in BPF skeletons to avoid
issues with name-conflicting static variables across multiple
statically-linked BPF object files.
Users using static variables to pass data between BPF programs and user-space
should do a trivial one-time switch according to the following simple rules:
- read-only `static volatile const` variables should be converted to
`volatile const`;
- read/write `static volatile` variables should just drop `static volatile`
modifiers to become global variables/symbols. To better handle older Clang
versions, such newly converted global variables should be explicitly
initialized with a specific value or `= 0`/`= {}`, whichever is
appropriate.
[0] https://lore.kernel.org/bpf/CAEf4BzZo7_r-hsNvJt3w3kyrmmBJj7ghGY8+k4nvKF0KLjma=w@mail.gmail.com/T/#m664d4b0d6b31ac8b2669360e0fc2d6962e9f5ec1
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210507054119.270888-5-andrii@kernel.org
For better future extensibility add per-file linker options. Currently
the set of available options is empty. This changes bpf_linker__add_file()
API, but it's not a breaking change as bpf_linker APIs hasn't been released
yet.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210507054119.270888-3-andrii@kernel.org
Similarly to .rodata, strip any const/volatile/restrict modifiers when
generating BPF skeleton. They are not helpful and actually just get in the way.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210507054119.270888-2-andrii@kernel.org
Dump succinct information for each member of DATASEC: its kinds and name. This
is extremely helpful to see at a quick glance what is inside each DATASEC of
a given BTF. Without this, one has to jump around BTF data to just find out
the name of a VAR or FUNC. DATASEC's var_secinfo member is special in that
regard because it doesn't itself contain the name of the member, delegating
that to the referenced VAR and FUNC kinds. Other kinds, like
STRUCT/UNION/FUNC/ENUM, encode member names directly and thus are clearly
identifiable in BTF dump.
The new output looks like this:
[35] DATASEC '.bss' size=0 vlen=6
type_id=8 offset=0 size=4 (VAR 'input_bss1')
type_id=13 offset=0 size=4 (VAR 'input_bss_weak')
type_id=16 offset=0 size=4 (VAR 'output_bss1')
type_id=17 offset=0 size=4 (VAR 'output_data1')
type_id=18 offset=0 size=4 (VAR 'output_rodata1')
type_id=20 offset=0 size=8 (VAR 'output_sink1')
[36] DATASEC '.data' size=0 vlen=2
type_id=9 offset=0 size=4 (VAR 'input_data1')
type_id=14 offset=0 size=4 (VAR 'input_data_weak')
[37] DATASEC '.kconfig' size=0 vlen=2
type_id=25 offset=0 size=4 (VAR 'LINUX_KERNEL_VERSION')
type_id=28 offset=0 size=1 (VAR 'CONFIG_BPF_SYSCALL')
[38] DATASEC '.ksyms' size=0 vlen=1
type_id=30 offset=0 size=1 (VAR 'bpf_link_fops')
[39] DATASEC '.rodata' size=0 vlen=2
type_id=12 offset=0 size=4 (VAR 'input_rodata1')
type_id=15 offset=0 size=4 (VAR 'input_rodata_weak')
[40] DATASEC 'license' size=0 vlen=1
type_id=24 offset=0 size=4 (VAR 'LICENSE')
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210423181348.1801389-3-andrii@kernel.org
Add dumping of "extern" linkage for BTF VAR kind. Also shorten
"global-allocated" to "global" to be in line with FUNC's "global".
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210423181348.1801389-2-andrii@kernel.org
With clang compiler:
make -j60 LLVM=1 LLVM_IAS=1 <=== compile kernel
# build selftests/bpf or bpftool
make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1
make -j60 -C tools/bpf/bpftool LLVM=1 LLVM_IAS=1
the following compilation warning showed up,
net.c:160:37: warning: comparison of integers of different signs: '__u32' (aka 'unsigned int') and 'int' [-Wsign-compare]
for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);
^~~~~~~~~~~~~~~~~
.../tools/include/uapi/linux/netlink.h:99:24: note: expanded from macro 'NLMSG_OK'
(nlh)->nlmsg_len <= (len))
~~~~~~~~~~~~~~~~ ^ ~~~
In this particular case, "len" is defined as "int" and (nlh)->nlmsg_len is "unsigned int".
The macro NLMSG_OK is defined as below in uapi/linux/netlink.h.
#define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
(nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
(nlh)->nlmsg_len <= (len))
The clang compiler complains the comparision "(nlh)->nlmsg_len <= (len))",
but in bpftool/net.c, it is already ensured that "len > 0" must be true.
So theoretically the compiler could deduce that comparison of
"(nlh)->nlmsg_len" and "len" is okay, but this really depends on compiler
internals. Let us add an explicit type conversion (from "int" to "unsigned int")
for "len" in NLMSG_OK to silence this warning right now.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210413153435.3029635-1-yhs@fb.com
Friedrich Vock
Tiezhu Yang
Alexander Lobakin
Alan Maguire
Quentin Monnet
Luis Gerhorst
Andres Freund
Tonghao Zhang
Pu Lehui
Lam Thai
Yinjun Zhang
Wei Fu
Andrii Nakryiko
Nathan Chancellor
Paul Chaignon
Jakub Kicinski
Hengqi Chen
Tobias Klauser
Wei Li
SanjayKumar Jeyakumar
Gu Shengxian
Tony Ambardar
David S. Miller
Zhihao Cheng
Jean-Philippe Brucker
Liu Jian
Alexei Starovoitov
Yonghong Song