[ Upstream commit 03e601f48b ]
If libbpf encounters an ELF file that has been stripped of its symbol
table, it will crash in bpf_object__add_programs() when trying to
dereference the obj->efile.symbols pointer.
Fix this by erroring out of bpf_object__elf_collect() if it is not able
able to find the symbol table.
v2:
- Move check into bpf_object__elf_collect() and add nice error message
Fixes: 6245947c1b ("libbpf: Allow gaps in BPF program sections to support overriden weak functions")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210901114812.204720-1-toke@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
The `cpu` argument of perf_evsel__read() must specify the cpu index.
perf_cpu_map__for_each_cpu() is for iterating the cpu number (not index)
and is thus not appropriate for use with perf_evsel__read().
So, if there is an offline CPU, the cpu number specified in the argument
may point out of range because the cpu number and the cpu index are
different.
Fix test_stat_cpu().
Testing it:
# make tests -C tools/lib/perf/
make: Entering directory '/home/nakamura/kernel_src/linux-5.15-rc4_fix/tools/lib/perf'
running static:
- running tests/test-cpumap.c...OK
- running tests/test-threadmap.c...OK
- running tests/test-evlist.c...OK
- running tests/test-evsel.c...OK
running dynamic:
- running tests/test-cpumap.c...OK
- running tests/test-threadmap.c...OK
- running tests/test-evlist.c...OK
- running tests/test-evsel.c...OK
make: Leaving directory '/home/nakamura/kernel_src/linux-5.15-rc4_fix/tools/lib/perf'
Signed-off-by: Shunsuke Nakamura <nakamura.shun@fujitsu.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20211011083704.4108720-1-nakamura.shun@fujitsu.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In test_stat_user_read, following build error occurs except i386 and
x86_64 architectures:
tests/test-evsel.c:129:31: error: variable 'pc' set but not used [-Werror=unused-but-set-variable]
struct perf_event_mmap_page *pc;
Fix build error.
Signed-off-by: Shunsuke Nakamura <nakamura.shun@fujitsu.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20211006095703.477826-1-nakamura.shun@fujitsu.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When fed an empty BPF object, bpftool gen skeleton -L crashes at
btf__set_fd() since it assumes presence of obj->btf, however for
the sequence below clang adds no .BTF section (hence no BTF).
Reproducer:
$ touch a.bpf.c
$ clang -O2 -g -target bpf -c a.bpf.c
$ bpftool gen skeleton -L a.bpf.o
/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/* THIS FILE IS AUTOGENERATED! */
struct a_bpf {
struct bpf_loader_ctx ctx;
Segmentation fault (core dumped)
The same occurs for files compiled without BTF info, i.e. without
clang's -g flag.
Fixes: 6723474373 (libbpf: Generate loader program out of BPF ELF file.)
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210930061634.1840768-1-memxor@gmail.com
Daniel Borkmann says:
====================
pull-request: bpf 2021-09-28
The following pull-request contains BPF updates for your *net* tree.
We've added 10 non-merge commits during the last 14 day(s) which contain
a total of 11 files changed, 139 insertions(+), 53 deletions(-).
The main changes are:
1) Fix MIPS JIT jump code emission for too large offsets, from Piotr Krysiuk.
2) Fix x86 JIT atomic/fetch emission when dst reg maps to rax, from Johan Almbladh.
3) Fix cgroup_sk_alloc corner case when called from interrupt, from Daniel Borkmann.
4) Fix segfault in libbpf's linker for objects without BTF, from Kumar Kartikeya Dwivedi.
5) Fix bpf_jit_charge_modmem for applications with CAP_BPF, from Lorenz Bauer.
6) Fix return value handling for struct_ops BPF programs, from Hou Tao.
7) Various fixes to BPF selftests, from Jiri Benc.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
,
When a BPF object is compiled without BTF info (without -g),
trying to link such objects using bpftool causes a SIGSEGV due to
btf__get_nr_types accessing obj->btf which is NULL. Fix this by
checking for the NULL pointer, and return error.
Reproducer:
$ cat a.bpf.c
extern int foo(void);
int bar(void) { return foo(); }
$ cat b.bpf.c
int foo(void) { return 0; }
$ clang -O2 -target bpf -c a.bpf.c
$ clang -O2 -target bpf -c b.bpf.c
$ bpftool gen obj out a.bpf.o b.bpf.o
Segmentation fault (core dumped)
After fix:
$ bpftool gen obj out a.bpf.o b.bpf.o
libbpf: failed to find BTF info for object 'a.bpf.o'
Error: failed to link 'a.bpf.o': Unknown error -22 (-22)
Fixes: a46349227c (libbpf: Add linker extern resolution support for functions and global variables)
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210924023725.70228-1-memxor@gmail.com
FD uses xyarray__entry that may return NULL if an index is out of
bounds. If NULL is returned then a segv happens as FD unconditionally
dereferences the pointer. This was happening in a case of with perf
iostat as shown below. The fix is to make FD an "int*" rather than an
int and handle the NULL case as either invalid input or a closed fd.
$ sudo gdb --args perf stat --iostat list
...
Breakpoint 1, perf_evsel__alloc_fd (evsel=0x5555560951a0, ncpus=1, nthreads=1) at evsel.c:50
50 {
(gdb) bt
#0 perf_evsel__alloc_fd (evsel=0x5555560951a0, ncpus=1, nthreads=1) at evsel.c:50
#1 0x000055555585c188 in evsel__open_cpu (evsel=0x5555560951a0, cpus=0x555556093410,
threads=0x555556086fb0, start_cpu=0, end_cpu=1) at util/evsel.c:1792
#2 0x000055555585cfb2 in evsel__open (evsel=0x5555560951a0, cpus=0x0, threads=0x555556086fb0)
at util/evsel.c:2045
#3 0x000055555585d0db in evsel__open_per_thread (evsel=0x5555560951a0, threads=0x555556086fb0)
at util/evsel.c:2065
#4 0x00005555558ece64 in create_perf_stat_counter (evsel=0x5555560951a0,
config=0x555555c34700 <stat_config>, target=0x555555c2f1c0 <target>, cpu=0) at util/stat.c:590
#5 0x000055555578e927 in __run_perf_stat (argc=1, argv=0x7fffffffe4a0, run_idx=0)
at builtin-stat.c:833
#6 0x000055555578f3c6 in run_perf_stat (argc=1, argv=0x7fffffffe4a0, run_idx=0)
at builtin-stat.c:1048
#7 0x0000555555792ee5 in cmd_stat (argc=1, argv=0x7fffffffe4a0) at builtin-stat.c:2534
#8 0x0000555555835ed3 in run_builtin (p=0x555555c3f540 <commands+288>, argc=3,
argv=0x7fffffffe4a0) at perf.c:313
#9 0x0000555555836154 in handle_internal_command (argc=3, argv=0x7fffffffe4a0) at perf.c:365
#10 0x000055555583629f in run_argv (argcp=0x7fffffffe2ec, argv=0x7fffffffe2e0) at perf.c:409
#11 0x0000555555836692 in main (argc=3, argv=0x7fffffffe4a0) at perf.c:539
...
(gdb) c
Continuing.
Error:
The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (uncore_iio_0/event=0x83,umask=0x04,ch_mask=0xF,fc_mask=0x07/).
/bin/dmesg | grep -i perf may provide additional information.
Program received signal SIGSEGV, Segmentation fault.
0x00005555559b03ea in perf_evsel__close_fd_cpu (evsel=0x5555560951a0, cpu=1) at evsel.c:166
166 if (FD(evsel, cpu, thread) >= 0)
v3. fixes a bug in perf_evsel__run_ioctl where the sense of a branch was
backward.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210918054440.2350466-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
New features:
- Improvements for the flamegraph python script, including:
- Display perf.data header
- Display PIDs of user stacks
- Added option to change color scheme
- Default to blue/green color scheme to improve accessibility
- Correctly identify kernel stacks when debuginfo is available
- Improvements for 'perf bench futex':
- Add --mlockall parameter
- Add --broadcast and --pi to the 'requeue' sub benchmark
- Add support for PMU aliases.
- Introduce an ARM Coresight ETE decoder.
- Add a 'perf bench' entry for evlist open/close operations, to help quantify
improvements with multithreading 'perf record'.
- Allow reporting the [un]throttle PERF_RECORD_ meta event in 'perf script's
python scripting.
- Add a 'perf test' entry for PMU aliases.
- Add a 'perf test' entry for 'perf record/perf report/perf script' pipe mode.
Fixes:
- perf script dlfilter (API for filtering via dynamically loaded shared object
introduced in v5.14) fixes and a 'perf test' entry for it.
- Fix get_current_dir_name() compilation on Android.
- Fix issues with asciidoc and double dashes uses.
- Fix memory leaks in the BTF handling code.
- Fix leftover problems in the Documentation from the infrastructure originally
lifted from the git codebase.
- Fix *probe_vfs_getname.sh 'perf test' failures.
- Handle fd gaps in 'perf test's test__dso_data_reopen().
- Make sure to show disasembly warnings for 'perf annotate --stdio'.
- Fix output from pipe to file and vice-versa in 'perf record/report/script'.
- Correct 'perf data -h' output.
- Fix wrong comm in system-wide mode with 'perf record --delay'.
- Do not allow --for-each-cgroup without cpu in 'perf stat'
- Make 'perf test --skip' work on shell tests.
- Fix libperf's verbose printing.
Misc improvements:
- Preparatory patches for multithreading varios 'perf record' phases
(synthesizing, opening, recording, etc).
- Add sparse context/locking annotations in compiler-types.h, also to help with
the multithreading effort.
- Optimize the generation of the arch specific erno tables used in 'perf trace'.
- Optimize libperf's perf_cpu_map__max().
- Improve ARM's CoreSight warnings.
- Report collisions in AUX records.
- Improve warnings for the LLVM 'perf test' entry.
- Improve the PMU events 'perf test' codebase.
- perf test: Do not compare overheads in the zstd comp test
- Better support annotation on ARM.
- Update 'perf trace's cmd string table to decode sys_bpf() first arg.
Vendor events:
- Add JSON events and metrics for Intel's Ice Lake, Tiger Lake and Elhart Lake.
- Update JSON eventsand metrics for Intel's Cascade Lake and Sky Lake servers.
Hardware tracing:
- Improvements for the ARM hardware tracing auxtrace support.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-tools-for-v5.15-2021-09-04' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux
Pull perf tool updates from Arnaldo Carvalho de Melo:
"New features:
- Improvements for the flamegraph python script, including:
- Display perf.data header
- Display PIDs of user stacks
- Added option to change color scheme
- Default to blue/green color scheme to improve accessibility
- Correctly identify kernel stacks when debuginfo is available
- Improvements for 'perf bench futex':
- Add --mlockall parameter
- Add --broadcast and --pi to the 'requeue' sub benchmark
- Add support for PMU aliases.
- Introduce an ARM Coresight ETE decoder.
- Add a 'perf bench' entry for evlist open/close operations, to help
quantify improvements with multithreading 'perf record'.
- Allow reporting the [un]throttle PERF_RECORD_ meta event in 'perf
script's python scripting.
- Add a 'perf test' entry for PMU aliases.
- Add a 'perf test' entry for 'perf record/perf report/perf script'
pipe mode.
Fixes:
- perf script dlfilter (API for filtering via dynamically loaded
shared object introduced in v5.14) fixes and a 'perf test' entry
for it.
- Fix get_current_dir_name() compilation on Android.
- Fix issues with asciidoc and double dashes uses.
- Fix memory leaks in the BTF handling code.
- Fix leftover problems in the Documentation from the infrastructure
originally lifted from the git codebase.
- Fix *probe_vfs_getname.sh 'perf test' failures.
- Handle fd gaps in 'perf test's test__dso_data_reopen().
- Make sure to show disasembly warnings for 'perf annotate --stdio'.
- Fix output from pipe to file and vice-versa in 'perf
record/report/script'.
- Correct 'perf data -h' output.
- Fix wrong comm in system-wide mode with 'perf record --delay'.
- Do not allow --for-each-cgroup without cpu in 'perf stat'
- Make 'perf test --skip' work on shell tests.
- Fix libperf's verbose printing.
Misc improvements:
- Preparatory patches for multithreading various 'perf record' phases
(synthesizing, opening, recording, etc).
- Add sparse context/locking annotations in compiler-types.h, also to
help with the multithreading effort.
- Optimize the generation of the arch specific erno tables used in
'perf trace'.
- Optimize libperf's perf_cpu_map__max().
- Improve ARM's CoreSight warnings.
- Report collisions in AUX records.
- Improve warnings for the LLVM 'perf test' entry.
- Improve the PMU events 'perf test' codebase.
- perf test: Do not compare overheads in the zstd comp test
- Better support annotation on ARM.
- Update 'perf trace's cmd string table to decode sys_bpf() first
arg.
Vendor events:
- Add JSON events and metrics for Intel's Ice Lake, Tiger Lake and
Elhart Lake.
- Update JSON eventsand metrics for Intel's Cascade Lake and Sky Lake
servers.
Hardware tracing:
- Improvements for the ARM hardware tracing auxtrace support"
* tag 'perf-tools-for-v5.15-2021-09-04' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (130 commits)
perf tests: Add test for PMU aliases
perf pmu: Add PMU alias support
perf session: Report collisions in AUX records
perf script python: Allow reporting the [un]throttle PERF_RECORD_ meta event
perf build: Report failure for testing feature libopencsd
perf cs-etm: Show a warning for an unknown magic number
perf cs-etm: Print the decoder name
perf cs-etm: Create ETE decoder
perf cs-etm: Update OpenCSD decoder for ETE
perf cs-etm: Fix typo
perf cs-etm: Save TRCDEVARCH register
perf cs-etm: Refactor out ETMv4 header saving
perf cs-etm: Initialise architecture based on TRCIDR1
perf cs-etm: Refactor initialisation of decoder params.
tools build: Fix feature detect clean for out of source builds
perf evlist: Add evlist__for_each_entry_from() macro
perf evsel: Handle precise_ip fallback in evsel__open_cpu()
perf evsel: Move bpf_counter__install_pe() to success path in evsel__open_cpu()
perf evsel: Move test_attr__open() to success path in evsel__open_cpu()
perf evsel: Move ignore_missing_thread() to fallback code
...
From commit 7074674e73 ("perf cpumap: Maintain cpumaps ordered and
without dups"), perf_cpu_map elements are sorted in ascending order.
This patch improves the perf_cpu_map__max function by returning the last
element.
Committer notes:
Do it as a ternary to keep it in just one return line, add a comment
explaining it is sorted and what functions does it.
Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/fb79f02e7b86ea8044d563adb1e9890c906f982f.1629490974.git.rickyman7@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch adds OPT_UINTEGER_OPTARG, which is the same as OPT_UINTEGER,
but also makes it possible to use the option without any value, setting
the variable to a default value, d.
Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/c46749b3dff796729078352ff164d363457a3587.1629490974.git.rickyman7@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
libperf's verbose printing checks the -v option every time the macro _T_ START
is called.
Since there are currently four libperf tests registered, the macro _T_ START is
called four times, but verbose printing after the second time is not output.
Resets the index of the element processed by getopt() and fix verbose printing
so that it prints in all tests.
Signed-off-by: Shunsuke Nakamura <nakamura.shun@fujitsu.com>
Acked-by: Rob Herring <robh@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210820093908.734503-3-nakamura.shun@fujitsu.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When attaching to uprobes through perf subsystem, it's possible to specify
offset of a so-called USDT semaphore, which is just a reference counted u16,
used by kernel to keep track of how many tracers are attached to a given
location. Support for this feature was added in [0], so just wire this through
uprobe_opts. This is important to enable implementing USDT attachment and
tracing through libbpf's bpf_program__attach_uprobe_opts() API.
[0] a6ca88b241 ("trace_uprobe: support reference counter in fd-based uprobe")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-16-andrii@kernel.org
Wire through bpf_cookie for all attach APIs that use perf_event_open under the
hood:
- for kprobes, extend existing bpf_kprobe_opts with bpf_cookie field;
- for perf_event, uprobe, and tracepoint APIs, add their _opts variants and
pass bpf_cookie through opts.
For kernel that don't support BPF_LINK_CREATE for perf_events, and thus
bpf_cookie is not supported either, return error and log warning for user.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-12-andrii@kernel.org
Add ability to specify bpf_cookie value when creating BPF perf link with
bpf_link_create() low-level API.
Given BPF_LINK_CREATE command is growing and keeps getting new fields that are
specific to the type of BPF_LINK, extend libbpf side of bpf_link_create() API
and corresponding OPTS struct to accomodate such changes. Add extra checks to
prevent using incompatible/unexpected combinations of fields.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-11-andrii@kernel.org
Detect kernel support for BPF perf link and prefer it when attaching to
perf_event, tracepoint, kprobe/uprobe. Underlying perf_event FD will be kept
open until BPF link is destroyed, at which point both perf_event FD and BPF
link FD will be closed.
This preserves current behavior in which perf_event FD is open for the
duration of bpf_link's lifetime and user is able to "disconnect" bpf_link from
underlying FD (with bpf_link__disconnect()), so that bpf_link__destroy()
doesn't close underlying perf_event FD.When BPF perf link is used, disconnect
will keep both perf_event and bpf_link FDs open, so it will be up to
(advanced) user to close them. This approach is demonstrated in bpf_cookie.c
selftests, added in this patch set.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-10-andrii@kernel.org
bpf_link->destroy() isn't used by any code, so remove it. Instead, add ability
to override deallocation procedure, with default doing plain free(link). This
is necessary for cases when we want to "subclass" struct bpf_link to keep
extra information, as is the case in the next patch adding struct
bpf_link_perf.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-9-andrii@kernel.org
Ensure libbpf.so is re-built whenever libbpf.map is modified. Without this,
changes to libbpf.map are not detected and versioned symbols mismatch error
will be reported until `make clean && make` is used, which is a suboptimal
developer experience.
Fixes: 306b267cb3 ("libbpf: Verify versioned symbols")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210815070609.987780-8-andrii@kernel.org
Currently weak typeless ksyms have default value zero, when they don't
exist in the kernel. However, weak typed ksyms are rejected by libbpf
if they can not be resolved. This means that if a bpf object contains
the declaration of a nonexistent weak typed ksym, it will be rejected
even if there is no program that references the symbol.
Nonexistent weak typed ksyms can also default to zero just like
typeless ones. This allows programs that access weak typed ksyms to be
accepted by verifier, if the accesses are guarded. For example,
extern const int bpf_link_fops3 __ksym __weak;
/* then in BPF program */
if (&bpf_link_fops3) {
/* use bpf_link_fops3 */
}
If actual use of nonexistent typed ksym is not guarded properly,
verifier would see that register is not PTR_TO_BTF_ID and wouldn't
allow to use it for direct memory reads or passing it to BPF helpers.
Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210812003819.2439037-1-haoluo@google.com
libperf already has a static function called 'cpu_map__default_new()'.
Add a new API perf_cpu_map__default_new() to export the function.
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https //lore.kernel.org/r/20210723063433.7318-2-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Before this patch, btf_new() was liable to close an arbitrary FD 0 if
BTF parsing failed. This was because:
* btf->fd was initialized to 0 through the calloc()
* btf__free() (in the `done` label) closed any FDs >= 0
* btf->fd is left at 0 if parsing fails
This issue was discovered on a system using libbpf v0.3 (without
BTF_KIND_FLOAT support) but with a kernel that had BTF_KIND_FLOAT types
in BTF. Thus, parsing fails.
While this patch technically doesn't fix any issues b/c upstream libbpf
has BTF_KIND_FLOAT support, it'll help prevent issues in the future if
more BTF types are added. It also allow the fix to be backported to
older libbpf's.
Fixes: 3289959b97 ("libbpf: Support BTF loading and raw data output in both endianness")
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/5969bb991adedb03c6ae93e051fd2a00d293cf25.1627513670.git.dxu@dxuuu.xyz
This patch fixes the probe for BPF_PROG_TYPE_CGROUP_SOCKOPT,
so the probe reports accurate results when used by e.g.
bpftool.
Fixes: 4cdbfb59c4 ("libbpf: support sockopt hooks")
Signed-off-by: Robin Gögge <r.goegge@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20210728225825.2357586-1-r.goegge@gmail.com
Add two new APIs: btf__load_vmlinux_btf and btf__load_module_btf.
btf__load_vmlinux_btf is just an alias to the existing API named
libbpf_find_kernel_btf, rename to be more precisely and consistent
with existing BTF APIs. btf__load_module_btf can be used to load
module BTF, add it for completeness. These two APIs are useful for
implementing tracing tools and introspection tools. This is part
of the effort towards libbpf 1.0 ([0]).
[0] Closes: https://github.com/libbpf/libbpf/issues/280
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210730114012.494408-1-hengqi.chen@gmail.com
Add a new API function btf__load_from_kernel_by_id_split(), which takes
a pointer to a base BTF object in order to support split BTF objects
when retrieving BTF information from the kernel.
Reference: https://github.com/libbpf/libbpf/issues/314
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/20210729162028.29512-8-quentin@isovalent.com
Rename function btf__get_from_id() as btf__load_from_kernel_by_id() to
better indicate what the function does. Change the new function so that,
instead of requiring a pointer to the pointer to update and returning
with an error code, it takes a single argument (the id of the BTF
object) and returns the corresponding pointer. This is more in line with
the existing constructors.
The other tools calling the (soon-to-be) deprecated btf__get_from_id()
function will be updated in a future commit.
References:
- https://github.com/libbpf/libbpf/issues/278
- https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#btfh-apis
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/20210729162028.29512-4-quentin@isovalent.com
Variable "err" is initialised to -EINVAL so that this error code is
returned when something goes wrong in libbpf_find_prog_btf_id().
However, a recent change in the function made use of the variable in
such a way that it is set to 0 if retrieving linear information on the
program is successful, and this 0 value remains if we error out on
failures at later stages.
Let's fix this by setting err to -EINVAL later in the function.
Fixes: e9fc3ce99b ("libbpf: Streamline error reporting for high-level APIs")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210729162028.29512-2-quentin@isovalent.com
When loading in parallel multiple programs which use the same to-be
pinned map, it is possible that two instances of the loader will call
bpf_object__create_maps() at the same time. If the map doesn't exist
when both instances call bpf_object__reuse_map(), then one of the
instances will fail with EEXIST when calling bpf_map__pin().
Fix the race by retrying reusing a map if bpf_map__pin() returns
EEXIST. The fix is similar to the one in iproute2: e4c4685fd6e4 ("bpf:
Fix race condition with map pinning").
Before retrying the pinning, we don't do any special cleaning of an
internal map state. The closer code inspection revealed that it's not
required:
- bpf_object__create_map(): map->inner_map is destroyed after a
successful call, map->fd is closed if pinning fails.
- bpf_object__populate_internal_map(): created map elements is
destroyed upon close(map->fd).
- init_map_slots(): slots are freed after their initialization.
Signed-off-by: Martynas Pumputis <m@lambda.lt>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210726152001.34845-1-m@lambda.lt
Move CO-RE logic into separate file.
The internal interface between libbpf and CO-RE is through
bpf_core_apply_relo_insn() function and few structs defined in relo_core.h.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210721000822.40958-5-alexei.starovoitov@gmail.com
CO-RE processing functions don't need to know 'struct bpf_program' details.
Cleanup the layering to eventually be able to move CO-RE logic into a separate file.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210721000822.40958-2-alexei.starovoitov@gmail.com
Export bpf_program__attach_kprobe_opts as a public API.
Rename bpf_program_attach_kprobe_opts to bpf_kprobe_opts and turn it into OPTS
struct.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20210721215810.889975-4-jolsa@kernel.org
When retrieving the enum value associated with typed data during
"is data zero?" checking in btf_dump_type_data_check_zero(), the
return value of btf_dump_get_enum_value() is not passed to the caller
if the function returns a non-zero (error) value. Currently, 0
is returned if the function returns an error. We should instead
propagate the error to the caller.
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1626770993-11073-4-git-send-email-alan.maguire@oracle.com
__int128 is not supported for some 32-bit platforms (arm and i386).
__int128 was used in carrying out computations on bitfields which
aid display, but the same calculations could be done with __u64
with the small effect of not supporting 128-bit bitfields.
With these changes, a big-endian issue with casting 128-bit integers
to 64-bit for enum bitfields is solved also, as we now use 64-bit
integers for bitfield calculations.
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1626770993-11073-2-git-send-email-alan.maguire@oracle.com
If creating an outer map of a BTF-defined map-in-map fails (via
bpf_object__create_map()), then the previously created its inner map
won't be destroyed.
Fix this by ensuring that the destroy routines are not bypassed in the
case of a failure.
Fixes: 646f02ffdd ("libbpf: Add BTF-defined map-in-map support")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Martynas Pumputis <m@lambda.lt>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210719173838.423148-2-m@lambda.lt
By using the stack for this small structure, we avoid the need
for freeing memory in error paths.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1626475617-25984-4-git-send-email-alan.maguire@oracle.com
__s64 can be defined as either long or long long, depending on the
architecture. On ppc64le it's defined as long, giving this error:
In file included from btf_dump.c:22:
btf_dump.c: In function 'btf_dump_type_data_check_overflow':
libbpf_internal.h:111:22: error: format '%lld' expects argument of
type 'long long int', but argument 3 has type '__s64' {aka 'long int'}
[-Werror=format=]
111 | libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__); \
| ^~~~~~~~~~
libbpf_internal.h:114:27: note: in expansion of macro '__pr'
114 | #define pr_warn(fmt, ...) __pr(LIBBPF_WARN, fmt, ##__VA_ARGS__)
| ^~~~
btf_dump.c:1992:3: note: in expansion of macro 'pr_warn'
1992 | pr_warn("unexpected size [%lld] for id [%u]\n",
| ^~~~~~~
btf_dump.c:1992:32: note: format string is defined here
1992 | pr_warn("unexpected size [%lld] for id [%u]\n",
| ~~~^
| |
| long long int
| %ld
Cast to size_t and use %zu instead.
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1626475617-25984-3-git-send-email-alan.maguire@oracle.com
If data is packed, data structures can store it outside of usual
boundaries. For example a 4-byte int can be stored on a unaligned
boundary in a case like this:
struct s {
char f1;
int f2;
} __attribute((packed));
...the int is stored at an offset of one byte. Some platforms have
problems dereferencing data that is not aligned with its size, and
code exists to handle most cases of this for BTF typed data display.
However pointer display was missed, and a simple function to test if
"ptr_is_aligned(data, data_sz)" would help clarify this code.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1626475617-25984-2-git-send-email-alan.maguire@oracle.com
Add a BTF dumper for typed data, so that the user can dump a typed
version of the data provided.
The API is
int btf_dump__dump_type_data(struct btf_dump *d, __u32 id,
void *data, size_t data_sz,
const struct btf_dump_type_data_opts *opts);
...where the id is the BTF id of the data pointed to by the "void *"
argument; for example the BTF id of "struct sk_buff" for a
"struct skb *" data pointer. Options supported are
- a starting indent level (indent_lvl)
- a user-specified indent string which will be printed once per
indent level; if NULL, tab is chosen but any string <= 32 chars
can be provided.
- a set of boolean options to control dump display, similar to those
used for BPF helper bpf_snprintf_btf(). Options are
- compact : omit newlines and other indentation
- skip_names: omit member names
- emit_zeroes: show zero-value members
Default output format is identical to that dumped by bpf_snprintf_btf(),
for example a "struct sk_buff" representation would look like this:
struct sk_buff){
(union){
(struct){
.next = (struct sk_buff *)0xffffffffffffffff,
.prev = (struct sk_buff *)0xffffffffffffffff,
(union){
.dev = (struct net_device *)0xffffffffffffffff,
.dev_scratch = (long unsigned int)18446744073709551615,
},
},
...
If the data structure is larger than the *data_sz*
number of bytes that are available in *data*, as much
of the data as possible will be dumped and -E2BIG will
be returned. This is useful as tracers will sometimes
not be able to capture all of the data associated with
a type; for example a "struct task_struct" is ~16k.
Being able to specify that only a subset is available is
important for such cases. On success, the amount of data
dumped is returned.
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1626362126-27775-2-git-send-email-alan.maguire@oracle.com
Alexei Starovoitov says:
====================
pull-request: bpf-next 2021-07-15
The following pull-request contains BPF updates for your *net-next* tree.
We've added 45 non-merge commits during the last 15 day(s) which contain
a total of 52 files changed, 3122 insertions(+), 384 deletions(-).
The main changes are:
1) Introduce bpf timers, from Alexei.
2) Add sockmap support for unix datagram socket, from Cong.
3) Fix potential memleak and UAF in the verifier, from He.
4) Add bpf_get_func_ip helper, from Jiri.
5) Improvements to generic XDP mode, from Kumar.
6) Support for passing xdp_md to XDP programs in bpf_prog_run, from Zvi.
===================
Signed-off-by: David S. Miller <davem@davemloft.net>
kprobes can be placed on most instructions in a function, not
just entry, and ftrace and bpftrace support the function+offset
notification for probe placement. Adding parsing of func_name
into func+offset to bpf_program__attach_kprobe() allows the
user to specify
SEC("kprobe/bpf_fentry_test5+0x6")
...for example, and the offset can be passed to perf_event_open_probe()
to support kprobe attachment.
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210714094400.396467-8-jolsa@kernel.org
