lwn.git/tools/perf/util/bpf-event.c, branch v6.9-rc4

perf maps: Get map before returning in maps__find

2024-02-12T20:35:26+00:00

Finding a map is done under a lock, returning the map without a reference count means it can be removed without notice and causing uses after free. Grab a reference count to the map within the lock region and return this. Fix up locations that need a map__put following this. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: K Prateek Nayak Cc: James Clark Cc: Vincent Whitchurch Cc: Alexey Dobriyan Cc: Colin Ian King Cc: Changbin Du Cc: Masami Hiramatsu Cc: Song Liu Cc: Leo Yan Cc: Athira Rajeev Cc: Liam Howlett Cc: Artem Savkov Cc: bpf@vger.kernel.org Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240210031746.4057262-3-irogers@google.com

perf env: Avoid recursively taking env->bpf_progs.lock

2024-01-03T20:54:54+00:00

Add variants of perf_env__insert_bpf_prog_info(), perf_env__insert_btf() and perf_env__find_btf prefixed with __ to indicate the env->bpf_progs.lock is assumed held. Call these variants when the lock is held to avoid recursively taking it and potentially having a thread deadlock with itself. Fixes: f8dfeae009effc0b ("perf bpf: Show more BPF program info in print_bpf_prog_info()") Signed-off-by: Ian Rogers Acked-by: Jiri Olsa Acked-by: Song Liu Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Huacai Chen Cc: Ingo Molnar Cc: K Prateek Nayak Cc: Kan Liang Cc: Mark Rutland Cc: Ming Wang Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Ravi Bangoria Link: https://lore.kernel.org/r/20231207014655.1252484-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf bpf: Don't synthesize BPF events when disabled

2023-11-09T16:49:33+00:00

If BPF sideband events are disabled on the command line, don't synthesize BPF events too. Signed-off-by: Ian Rogers Acked-by: Song Liu Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Athira Jajeev Cc: Changbin Du Cc: Colin Ian King Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: German Gomez Cc: Huacai Chen Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: K Prateek Nayak Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Li Dong Cc: Liam Howlett Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Miguel Ojeda Cc: Ming Wang Cc: Namhyung Kim Cc: Nick Terrell Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sandipan Das Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Vincent Whitchurch Cc: Wenyu Liu Cc: Yang Jihong Link: https://lore.kernel.org/r/20231102175735.2272696-13-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf map: Add accessor for dso

2023-04-04T19:41:57+00:00

Later changes will add reference count checking for struct map, with dso being the most frequently accessed variable. Add an accessor so that the reference count check is only necessary in one place. Additional changes: - add a dso variable to avoid repeated map__dso calls. - in builtin-mem.c dump_raw_samples, code only partially tested for dso == NULL. Make the possibility of NULL consistent. - in thread.c thread__memcpy fix use of spaces and use tabs. Committer notes: Did missing conversions on these files: tools/perf/arch/powerpc/util/skip-callchain-idx.c tools/perf/arch/powerpc/util/sym-handling.c tools/perf/ui/browsers/hists.c tools/perf/ui/gtk/annotate.c tools/perf/util/cs-etm.c tools/perf/util/thread.c tools/perf/util/unwind-libunwind-local.c tools/perf/util/unwind-libunwind.c Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexey Bayduraev Cc: Andi Kleen Cc: Andrew Morton Cc: Andy Shevchenko Cc: Darren Hart Cc: Davidlohr Bueso Cc: Dmitriy Vyukov Cc: Eric Dumazet Cc: German Gomez Cc: Hao Luo Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Madhavan Srinivasan Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Miaoqian Lin Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Riccardo Mancini Cc: Shunsuke Nakamura Cc: Song Liu Cc: Stephane Eranian Cc: Stephen Brennan Cc: Steven Rostedt (VMware) Cc: Thomas Gleixner Cc: Thomas Richter Cc: Yury Norov Link: https://lore.kernel.org/r/20230320212248.1175731-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf bpf: Remove pre libbpf 1.0 conditional logic

2023-03-14T11:29:46+00:00

Tests are no longer applicable as libbpf 1.0 can be assumed. Signed-off-by: Ian Rogers Acked/Tested-by: Jiri Olsa Acked/Tested-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andres Freund Cc: Andrii Nakryiko Cc: Christy Lee Cc: Ingo Molnar Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Roberto Sassu Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230116010115.490713-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf bpf: Fix build with libbpf 0.7.0 by adding prototype for bpf_load_program()

2022-10-25T20:40:48+00:00

The bpf_load_program() prototype appeared in tools/lib/bpf/bpf.h as deprecated, but nowadays its completely removed, so add it back for building with the system libbpf when using 'make LIBBPF_DYNAMIC=1'. This is a stop gap hack till we do like tools/bpf does with bpftool, i.e. bootstrap the libbpf build and install it in the perf build directory when not using 'make LIBBPF_DYNAMIC=1'. That has to be done to all libraries in tools/lib/, so tha we can remove -Itools/lib/ from the tools/perf CFLAGS. Noticed when building with LIBBPF_DYNAMIC=1 and libbpf 0.7.0 on RHEL9. Signed-off-by: Arnaldo Carvalho de Melo

perf build: Stop using weak btfraw_data() to handle older libbpf versions

2022-05-26T14:02:02+00:00

By adding a feature test for btf__raw_data() and providing a fallback if it isn't present in older versions of libbpf. Committer testing: $ rpm -q libbpf-devel libbpf-devel-0.4.0-2.fc35.x86_64 $ make -C tools/perf LIBBPF_DYNAMIC=1 O=/tmp/build/perf install-bin $ cat /tmp/build/perf/feature/test-libbpf-btf__raw_data.make.output test-libbpf-btf__raw_data.c: In function ‘main’: test-libbpf-btf__raw_data.c:6:9: error: implicit declaration of function ‘btf__raw_data’; did you mean ‘btf__get_raw_data’? [-Werror=implicit-function-declaration] 6 | btf__raw_data(NULL /* btf_ro */, NULL /* size */); | ^~~~~~~~~~~~~ | btf__get_raw_data cc1: all warnings being treated as errors $ objdump -dS /tmp/build/perf/perf | grep ':' -A20 00000000005b3050 : { 5b3050: 55 push %rbp 5b3051: 48 89 e5 mov %rsp,%rbp 5b3054: 48 83 ec 10 sub $0x10,%rsp 5b3058: 64 48 8b 04 25 28 00 mov %fs:0x28,%rax 5b305f: 00 00 5b3061: 48 89 45 f8 mov %rax,-0x8(%rbp) 5b3065: 31 c0 xor %eax,%eax return btf__get_raw_data(btf_ro, size); 5b3067: 48 8b 45 f8 mov -0x8(%rbp),%rax 5b306b: 64 48 2b 04 25 28 00 sub %fs:0x28,%rax 5b3072: 00 00 5b3074: 75 06 jne 5b307c } 5b3076: c9 leave return btf__get_raw_data(btf_ro, size); 5b3077: e9 14 99 e5 ff jmp 40c990 5b307c: e8 af a7 e5 ff call 40d830 <__stack_chk_fail@plt> 5b3081: 66 66 2e 0f 1f 84 00 data16 cs nopw 0x0(%rax,%rax,1) 5b3088: 00 00 00 00 $ Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Heiko Carstens Cc: Ian Rogers Cc: Ilya Leoshkevich Cc: Sumanth Korikkar Cc: Sven Schnelle Cc: Thomas Richter Cc: Vasily Gorbik Link: http://lore.kernel.org/linux-perf-users/YozLKby7ITEtchC9@krava Signed-off-by: Arnaldo Carvalho de Melo

perf build: Stop using __weak bpf_object__next_map() to handle older libbpf versions

2022-05-26T14:02:02+00:00

By adding a feature test for bpf_object__next_map() and providing a fallback if it isn't present in older versions of libbpf. Committer testing: $ rpm -q libbpf-devel libbpf-devel-0.4.0-2.fc35.x86_64 $ make -C tools/perf LIBBPF_DYNAMIC=1 O=/tmp/build/perf install-bin $ cat /tmp/build/perf/feature/test-libbpf-bpf_object__next_map.make.output test-libbpf-bpf_object__next_map.c: In function ‘main’: test-libbpf-bpf_object__next_map.c:6:9: error: implicit declaration of function ‘bpf_object__next_map’; did you mean ‘bpf_object__next’? [-Werror=implicit-function-declaration] 6 | bpf_object__next_map(NULL /* obj */, NULL /* prev */); | ^~~~~~~~~~~~~~~~~~~~ | bpf_object__next cc1: all warnings being treated as errors $ $ objdump -dS /tmp/build/perf/perf | grep ':' -A20 00000000005b2e00 : { 5b2e00: 55 push %rbp 5b2e01: 48 89 e5 mov %rsp,%rbp 5b2e04: 48 83 ec 10 sub $0x10,%rsp 5b2e08: 64 48 8b 04 25 28 00 mov %fs:0x28,%rax 5b2e0f: 00 00 5b2e11: 48 89 45 f8 mov %rax,-0x8(%rbp) 5b2e15: 31 c0 xor %eax,%eax return bpf_map__next(prev, obj); 5b2e17: 48 8b 45 f8 mov -0x8(%rbp),%rax 5b2e1b: 64 48 2b 04 25 28 00 sub %fs:0x28,%rax 5b2e22: 00 00 5b2e24: 75 0f jne 5b2e35 } 5b2e26: c9 leave 5b2e27: 49 89 f8 mov %rdi,%r8 5b2e2a: 48 89 f7 mov %rsi,%rdi return bpf_map__next(prev, obj); 5b2e2d: 4c 89 c6 mov %r8,%rsi 5b2e30: e9 cb b1 e5 ff jmp 40e000 $ Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Heiko Carstens Cc: Ian Rogers Cc: Ilya Leoshkevich Cc: Sumanth Korikkar Cc: Sven Schnelle Cc: Thomas Richter Cc: Vasily Gorbik Link: http://lore.kernel.org/linux-perf-users/YozLKby7ITEtchC9@krava Signed-off-by: Arnaldo Carvalho de Melo

perf build: Stop using __weak bpf_object__next_program() to handle older libbpf versions

2022-05-26T14:02:02+00:00

By adding a feature test for bpf_object__next_program() and providing a fallback if it isn't present in older versions of libbpf. Committer testing: $ rpm -q libbpf-devel libbpf-devel-0.4.0-2.fc35.x86_64 $ make -C tools/perf LIBBPF_DYNAMIC=1 O=/tmp/build/perf install-bin $ cat /tmp/build/perf/feature/test-libbpf-bpf_object__next_program.make.output test-libbpf-bpf_object__next_program.c: In function ‘main’: test-libbpf-bpf_object__next_program.c:6:9: error: implicit declaration of function ‘bpf_object__next_program’; did you mean ‘bpf_object__unpin_programs’? [-Werror=implicit-function-declaration] 6 | bpf_object__next_program(NULL /* obj */, NULL /* prev */); | ^~~~~~~~~~~~~~~~~~~~~~~~ | bpf_object__unpin_programs cc1: all warnings being treated as errors $ $ objdump -dS /tmp/build/perf/perf | grep ':' -A20 00000000005b2dc0 : { 5b2dc0: 55 push %rbp 5b2dc1: 48 89 e5 mov %rsp,%rbp 5b2dc4: 48 83 ec 10 sub $0x10,%rsp 5b2dc8: 64 48 8b 04 25 28 00 mov %fs:0x28,%rax 5b2dcf: 00 00 5b2dd1: 48 89 45 f8 mov %rax,-0x8(%rbp) 5b2dd5: 31 c0 xor %eax,%eax return bpf_program__next(prev, obj); 5b2dd7: 48 8b 45 f8 mov -0x8(%rbp),%rax 5b2ddb: 64 48 2b 04 25 28 00 sub %fs:0x28,%rax 5b2de2: 00 00 5b2de4: 75 0f jne 5b2df5 } 5b2de6: c9 leave 5b2de7: 49 89 f8 mov %rdi,%r8 5b2dea: 48 89 f7 mov %rsi,%rdi return bpf_program__next(prev, obj); 5b2ded: 4c 89 c6 mov %r8,%rsi 5b2df0: e9 3b b4 e5 ff jmp 40e230 $ Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Heiko Carstens Cc: Ian Rogers Cc: Ilya Leoshkevich Cc: Sumanth Korikkar Cc: Sven Schnelle Cc: Thomas Richter Cc: Vasily Gorbik Link: http://lore.kernel.org/linux-perf-users/YozLKby7ITEtchC9@krava Signed-off-by: Arnaldo Carvalho de Melo

perf build: Stop using __weak bpf_prog_load() to handle older libbpf versions

2022-05-26T14:02:02+00:00

By adding a feature test for bpf_prog_load() and providing a fallback if it isn't present in older versions of libbpf. Committer testing: $ rpm -q libbpf-devel libbpf-devel-0.4.0-2.fc35.x86_64 $ make -C tools/perf LIBBPF_DYNAMIC=1 O=/tmp/build/perf install-bin $ cat /tmp/build/perf/feature/test-libbpf-bpf_prog_load.make.output test-libbpf-bpf_prog_load.c: In function ‘main’: test-libbpf-bpf_prog_load.c:6:16: error: implicit declaration of function ‘bpf_prog_load’ [-Werror=implicit-function-declaration] 6 | return bpf_prog_load(0 /* prog_type */, NULL /* prog_name */, | ^~~~~~~~~~~~~ cc1: all warnings being treated as errors $ $ objdump -dS /tmp/build/perf/perf | grep ':' -A20 00000000005b2d70 : { 5b2d70: 55 push %rbp 5b2d71: 48 89 ce mov %rcx,%rsi 5b2d74: 4c 89 c8 mov %r9,%rax 5b2d77: 49 89 d2 mov %rdx,%r10 5b2d7a: 4c 89 c2 mov %r8,%rdx 5b2d7d: 48 89 e5 mov %rsp,%rbp 5b2d80: 48 83 ec 18 sub $0x18,%rsp 5b2d84: 64 48 8b 0c 25 28 00 mov %fs:0x28,%rcx 5b2d8b: 00 00 5b2d8d: 48 89 4d f8 mov %rcx,-0x8(%rbp) 5b2d91: 31 c9 xor %ecx,%ecx return bpf_load_program(prog_type, insns, insn_cnt, license, 5b2d93: 41 8b 49 5c mov 0x5c(%r9),%ecx 5b2d97: 51 push %rcx 5b2d98: 4d 8b 49 60 mov 0x60(%r9),%r9 5b2d9c: 4c 89 d1 mov %r10,%rcx 5b2d9f: 44 8b 40 1c mov 0x1c(%rax),%r8d 5b2da3: e8 f8 aa e5 ff call 40d8a0 } $ Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Heiko Carstens Cc: Ian Rogers Cc: Ilya Leoshkevich Cc: Sumanth Korikkar Cc: Sven Schnelle Cc: Thomas Richter Cc: Vasily Gorbik Link: http://lore.kernel.org/linux-perf-users/YozLKby7ITEtchC9@krava Signed-off-by: Arnaldo Carvalho de Melo

lwn.git/tools/perf/util/bpf-event.c, branch v6.9-rc4

perf maps: Get map before returning in maps__find

perf env: Avoid recursively taking env->bpf_progs.lock

perf bpf: Don't synthesize BPF events when disabled

perf map: Add accessor for dso

perf bpf: Remove pre libbpf 1.0 conditional logic

perf bpf: Fix build with libbpf 0.7.0 by adding prototype for bpf_load_program()

perf build: Stop using __weak btf__raw_data() to handle older libbpf versions

perf build: Stop using __weak bpf_object__next_map() to handle older libbpf versions

perf build: Stop using __weak bpf_object__next_program() to handle older libbpf versions

perf build: Stop using __weak bpf_prog_load() to handle older libbpf versions

perf build: Stop using weak btfraw_data() to handle older libbpf versions