kernel/linux.git/tools/perf/util/annotate.c, branch v5.10.257

perf annotate bpf: Don't enclose non-debug code with an assert()

2023-09-19T10:20:25+00:00

[ Upstream commit 979e9c9fc9c2a761303585e07fe2699bdd88182f ] In 616b14b47a86d880 ("perf build: Conditionally define NDEBUG") we started using NDEBUG=1 when DEBUG=1 isn't present, so code that is enclosed with assert() is not called. In dd317df072071903 ("perf build: Make binutil libraries opt in") we stopped linking against binutils-devel, for licensing reasons. Recently people asked me why annotation of BPF programs wasn't working, i.e. this: $ perf annotate bpf_prog_5280546344e3f45c_kfree_skb was returning: case SYMBOL_ANNOTATE_ERRNO__NO_LIBOPCODES_FOR_BPF: scnprintf(buf, buflen, "Please link with binutils's libopcode to enable BPF annotation"); This was on a fedora rpm, so its new enough that I had to try to test by rebuilding using BUILD_NONDISTRO=1, only to get it segfaulting on me. This combination made this libopcode function not to be called: assert(bfd_check_format(bfdf, bfd_object)); Changing it to: if (!bfd_check_format(bfdf, bfd_object)) abort(); Made it work, looking at this "check" function made me realize it changes the 'bfdf' internal state, i.e. we better call it. So stop using assert() on it, just call it and abort if it fails. Probably it is better to propagate the error, etc, but it seems it is unlikely to fail from the usage done so far and we really need to stop using libopcodes, so do the quick fix above and move on. With it we have BPF annotation back working when built with BUILD_NONDISTRO=1: ⬢[acme@toolbox perf-tools-next]$ perf annotate --stdio2 bpf_prog_5280546344e3f45c_kfree_skb | head No kallsyms or vmlinux with build-id 939bc71a1a51cdc434e60af93c7e734f7d5c0e7e was found Samples: 12 of event 'cpu-clock:ppp', 4000 Hz, Event count (approx.): 3000000, [percent: local period] bpf_prog_5280546344e3f45c_kfree_skb() bpf_prog_5280546344e3f45c_kfree_skb Percent int kfree_skb(struct trace_event_raw_kfree_skb *args) { nop 33.33 xchg %ax,%ax push %rbp mov %rsp,%rbp sub $0x180,%rsp push %rbx push %r13 ⬢[acme@toolbox perf-tools-next]$ Fixes: 6987561c9e86eace ("perf annotate: Enable annotation of BPF programs") Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Mohamed Mahmoud Cc: Namhyung Kim Cc: Dave Tucker Cc: Derek Barbosa Cc: Song Liu Link: https://lore.kernel.org/lkml/ZMrMzoQBe0yqMek1@kernel.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf annotate: Fix jump parsing for C++ code.

2021-09-03T08:09:29+00:00

commit 1f0e6edcd968ff19211245f7da6039e983aa51e5 upstream. Considering the following testcase: int foo(int a, int b) { for (unsigned i = 0; i < 1000000000; i++) a += b; return a; } int main() { foo (3, 4); return 0; } 'perf annotate' displays: 86.52 │40055e: → ja 40056c 13.37 │400560: mov -0x18(%rbp),%eax │400563: add %eax,-0x14(%rbp) │400566: addl $0x1,-0x4(%rbp) 0.11 │40056a: → jmp 400557 │40056c: mov -0x14(%rbp),%eax │40056f: pop %rbp and the 'ja 40056c' does not link to the location in the function. It's caused by fact that comma is wrongly parsed, it's part of function signature. With my patch I see: 86.52 │ ┌──ja 26 13.37 │ │ mov -0x18(%rbp),%eax │ │ add %eax,-0x14(%rbp) │ │ addl $0x1,-0x4(%rbp) 0.11 │ │↑ jmp 11 │26:└─→mov -0x14(%rbp),%eax and 'o' output prints: 86.52 │4005┌── ↓ ja 40056c 13.37 │4005│0: mov -0x18(%rbp),%eax │4005│3: add %eax,-0x14(%rbp) │4005│6: addl $0x1,-0x4(%rbp) 0.11 │4005│a: ↑ jmp 400557 │4005└─→ mov -0x14(%rbp),%eax On the contrary, compiling the very same file with gcc -x c, the parsing is fine because function arguments are not displayed: jmp 400543 Committer testing: Before: $ cat cpp_args_annotate.c int foo(int a, int b) { for (unsigned i = 0; i < 1000000000; i++) a += b; return a; } int main() { foo (3, 4); return 0; } $ gcc --version |& head -1 gcc (GCC) 10.2.1 20201125 (Red Hat 10.2.1-9) $ gcc -g cpp_args_annotate.c -o cpp_args_annotate $ perf record ./cpp_args_annotate [ perf record: Woken up 2 times to write data ] [ perf record: Captured and wrote 0.275 MB perf.data (7188 samples) ] $ perf annotate --stdio2 foo Samples: 7K of event 'cycles:u', 4000 Hz, Event count (approx.): 7468429289, [percent: local period] foo() /home/acme/c/cpp_args_annotate Percent 0000000000401106 : foo(): int foo(int a, int b) { push %rbp mov %rsp,%rbp mov %edi,-0x14(%rbp) mov %esi,-0x18(%rbp) for (unsigned i = 0; i < 1000000000; i++) movl $0x0,-0x4(%rbp) ↓ jmp 1d a += b; 13.45 13: mov -0x18(%rbp),%eax add %eax,-0x14(%rbp) for (unsigned i = 0; i < 1000000000; i++) addl $0x1,-0x4(%rbp) 0.09 1d: cmpl $0x3b9ac9ff,-0x4(%rbp) 86.46 ↑ jbe 13 return a; mov -0x14(%rbp),%eax } pop %rbp ← retq $ I.e. works for C, now lets switch to C++: $ g++ -g cpp_args_annotate.c -o cpp_args_annotate $ perf record ./cpp_args_annotate [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.268 MB perf.data (6976 samples) ] $ perf annotate --stdio2 foo Samples: 6K of event 'cycles:u', 4000 Hz, Event count (approx.): 7380681761, [percent: local period] foo() /home/acme/c/cpp_args_annotate Percent 0000000000401106 : foo(int, int): int foo(int a, int b) { push %rbp mov %rsp,%rbp mov %edi,-0x14(%rbp) mov %esi,-0x18(%rbp) for (unsigned i = 0; i < 1000000000; i++) movl $0x0,-0x4(%rbp) cmpl $0x3b9ac9ff,-0x4(%rbp) 86.53 → ja 40112c a += b; 13.32 mov -0x18(%rbp),%eax 0.00 add %eax,-0x14(%rbp) for (unsigned i = 0; i < 1000000000; i++) addl $0x1,-0x4(%rbp) 0.15 → jmp 401117 return a; mov -0x14(%rbp),%eax } pop %rbp ← retq $ Reproduced. Now with this patch: Reusing the C++ built binary, as we can see here: $ readelf -wi cpp_args_annotate | grep producer DW_AT_producer : (indirect string, offset: 0x2e): GNU C++14 10.2.1 20201125 (Red Hat 10.2.1-9) -mtune=generic -march=x86-64 -g $ And furthermore: $ file cpp_args_annotate cpp_args_annotate: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=4fe3cab260204765605ec630d0dc7a7e93c361a9, for GNU/Linux 3.2.0, with debug_info, not stripped $ perf buildid-list -i cpp_args_annotate 4fe3cab260204765605ec630d0dc7a7e93c361a9 $ perf buildid-list | grep cpp_args_annotate 4fe3cab260204765605ec630d0dc7a7e93c361a9 /home/acme/c/cpp_args_annotate $ It now works: $ perf annotate --stdio2 foo Samples: 6K of event 'cycles:u', 4000 Hz, Event count (approx.): 7380681761, [percent: local period] foo() /home/acme/c/cpp_args_annotate Percent 0000000000401106 : foo(int, int): int foo(int a, int b) { push %rbp mov %rsp,%rbp mov %edi,-0x14(%rbp) mov %esi,-0x18(%rbp) for (unsigned i = 0; i < 1000000000; i++) movl $0x0,-0x4(%rbp) 11: cmpl $0x3b9ac9ff,-0x4(%rbp) 86.53 ↓ ja 26 a += b; 13.32 mov -0x18(%rbp),%eax 0.00 add %eax,-0x14(%rbp) for (unsigned i = 0; i < 1000000000; i++) addl $0x1,-0x4(%rbp) 0.15 ↑ jmp 11 return a; 26: mov -0x14(%rbp),%eax } pop %rbp ← retq $ Signed-off-by: Martin Liška Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Slaby Link: http://lore.kernel.org/lkml/13e1a405-edf9-e4c2-4327-a9b454353730@suse.cz Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Hanjun Guo Signed-off-by: Greg Kroah-Hartman

perf tools: Pass build_id object to build_id__sprintf()

2020-10-14T11:46:22+00:00

Passing build_id object to build_id__sprintf function, so it can operate with the proper size of build id. This will create proper md5 build id readable names, like following: a50e350e97c43b4708d09bcd85ebfff7 instead of: a50e350e97c43b4708d09bcd85ebfff700000000 Signed-off-by: Jiri Olsa Acked-by: Ian Rogers Link: https://lore.kernel.org/r/20201013192441.1299447-5-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use build_id object in dso

2020-10-14T11:44:47+00:00

Replace build_id byte array with struct build_id object and all the code that references it. The objective is to carry size together with build id array, so it's better to keep both together. This is preparatory change for following patches, and there's no functional change. Signed-off-by: Jiri Olsa Acked-by: Ian Rogers Link: https://lore.kernel.org/r/20201013192441.1299447-2-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Allow configuring the 'disassembler_style' knob via 'perf config'

2020-09-04T19:07:23+00:00

# perf annotate --stdio2 acpi_processor_ffh_cstate_enter > default # perf config annotate.disassembler_style=intel # perf config annotate.disassembler_style annotate.disassembler_style=intel # perf annotate --stdio2 acpi_processor_ffh_cstate_enter > intel # diff -u default intel --- default 2020-09-04 13:09:26.019205732 -0300 +++ intel 2020-09-04 13:09:52.823795081 -0300 @@ -1,42 +1,42 @@ Samples: 1K of event 'cycles', 4000 Hz, Event count (approx.): 990065316, [percent: local period] acpi_processor_ffh_cstate_enter() /lib/modules/5.9.0-rc3/build/vmlinux -Percent → callq __fentry__ - mov cpu_number,%edx - mov %edx,%edx - mov cpu_cstate_entry,%rax - add -0x7dbe9700(,%rdx,8),%rax - movzbl 0x9(%rdi),%edx - mov 0x4(%rax,%rdx,8),%edi - mov (%rax,%rdx,8),%esi - → jmpq 137ccc6 - 2d: → jmpq 137ccd8 +Percent → call __fentry__ + mov edx,DWORD PTR gs:[rip+0x7e541d74] + mov edx,edx + mov rax,QWORD PTR [rip+0x152b8fb] + add rax,QWORD PTR [rdx*8-0x7dbe9700] + movzx edx,BYTE PTR [rdi+0x9] + mov edi,DWORD PTR [rax+rdx*8+0x4] + mov esi,DWORD PTR [rax+rdx*8] + → jmp 137ccc6 + 2d: → jmp 137ccd8 mfence - mov %gs:0x17bc0,%rax - clflush (%rax) + mov rax,QWORD PTR gs:0x17bc0 + clflush BYTE PTR [rax] mfence - xor %edx,%edx - mov %rdx,%rcx - mov %gs:0x17bc0,%rax - 0.00 monitor %rax,%ecx,%edx - mov (%rax),%rax - test $0x8,%al + xor edx,edx + mov rcx,rdx + mov rax,QWORD PTR gs:0x17bc0 + 0.00 monitor + mov rax,QWORD PTR [rax] + test al,0x8 ↓ jne 71 - ↓ jmpq 68 - verw 0x538b08(%rip) # ffffffff82008150 - 68: mov %rsi,%rax - mov %rdi,%rcx -100.00 mwait %eax,%ecx - 71: mov %gs:0x17bc0,%rax - lock andb $0xdf,0x2(%rax) - lock addl $0x0,-0x4(%rsp) - mov (%rax),%rax - test $0x8,%al + ↓ jmp 68 + verw WORD PTR [rip+0x538b08] # ffffffff82008150 + 68: mov rax,rsi + mov rcx,rdi +100.00 mwait + 71: mov rax,QWORD PTR gs:0x17bc0 + lock and BYTE PTR [rax+0x2],0xdf + lock add DWORD PTR [rsp-0x4],0x0 + mov rax,QWORD PTR [rax] + test al,0x8 ↓ je 97 - andl $0x7fffffff,__preempt_count - 97: ← retq - mov %gs:0x17bc0,%rax - lock orb $0x20,0x2(%rax) - mov (%rax),%rax - test $0x8,%al + and DWORD PTR gs:[rip+0x7e548509],0x7fffffff + 97: ret + mov rax,QWORD PTR gs:0x17bc0 + lock or BYTE PTR [rax+0x2],0x20 + mov rax,QWORD PTR [rax] + test al,0x8 ↑ jne 71 - ↑ jmpq 2d + ↑ jmp 2d # Requested-by: Matt P. Dziubinski Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Fix non-null terminated buffer returned by readlink()

2020-07-09T15:36:50+00:00

Our local MSAN (Memory Sanitizer) build of perf throws a warning that comes from the "dso__disassemble_filename" function in "tools/perf/util/annotate.c" when running perf record. The warning stems from the call to readlink, in which "build_id_path" was being read into "linkname". Since readlink does not null terminate, an uninitialized memory access would later occur when "linkname" is passed into the strstr function. This is simply fixed by null-terminating "linkname" after the call to readlink. To reproduce this warning, build perf by running: $ make -C tools/perf CLANG=1 CC=clang EXTRA_CFLAGS="-fsanitize=memory -fsanitize-memory-track-origins" (Additionally, llvm might have to be installed and clang might have to be specified as the compiler - export CC=/usr/bin/clang) Then running: tools/perf/perf record -o - ls / | tools/perf/perf --no-pager annotate -i - --stdio Please see the cover letter for why false positive warnings may be generated. Signed-off-by: Numfor Mbiziwo-Tiapo Acked-by: Ian Rogers Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Ian Rogers Cc: Mark Drayton Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Song Liu Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20190729205750.193289-1-nums@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Remove some duplicated includes

2020-06-02T14:09:41+00:00

There exists some duplicated includes in tools/perf, remove them. Signed-off-by: Tiezhu Yang Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: xuefeng li Link: http://lore.kernel.org/lkml/1591071304-19338-2-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Rename perf_evselenv() to evselenv()

2020-05-05T19:35:31+00:00

As it is a 'struct evsel' method, not part of tools/lib/perf/, aka libperf, to whom the perf_ prefix belongs. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Rename perf_evsel__is_() to evsel__is()