kernel/linux.git/tools/perf/builtin-probe.c, branch linux-7.1.y

perf tools: Add layout support for --symfs option

2026-03-11T06:13:30+00:00

Add support for parsing an optional layout parameter in the --symfs command line option. The format is: --symfs Where layout can be: - 'hierarchy': matches full path (default) - 'flat': only matches base name When debugging symbol files from a copy of the filesystem (e.g., from a container or remote machine), the debug files are often stored in a flat directory structure with only filenames, not the full original paths. In this case, using 'flat' layout allows perf to find debug symbols by matching only the filename rather than the full path. For example, given a binary path like: /build/output/lib/foo.so With 'perf report --symfs /debug/files,flat', perf will look for: /debug/files/foo.so Instead of: /debug/files/build/output/lib/foo.so This is particularly useful when: - Extracting debug files from containers with different directory layouts - Working with build systems that flatten directory structures Signed-off-by: Changbin Du Signed-off-by: Namhyung Kim

perf tools: Switch printf("...%s", strerror(errno)) to printf("...%m")

2026-01-14T20:22:50+00:00

strerror() has thread safety issues, strerror_r() requires stack allocated buffers. Code in perf has already been using the "%m" formatting flag that is a widely support glibc extension to print the current errno's description. Expand the usage of this formatting flag and remove usage of strerror()/strerror_r(). Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexandre Ghiti Cc: Blake Jones Cc: Chun-Tse Shao Cc: Dmitriy Vyukov Cc: Dr. David Alan Gilbert Cc: Haibo Xu Cc: Howard Chu Cc: Ingo Molnar Cc: Jiri Olsa Cc: Leo Yan Cc: Peter Zijlstra Cc: Stephen Brennan Cc: Thomas Falcon Cc: Yunseong Kim Cc: Zhongqiu Han Signed-off-by: Arnaldo Carvalho de Melo

perf build: Rename HAVE_DWARF_SUPPORT to HAVE_LIBDW_SUPPORT

2024-10-18T17:17:40+00:00

In Makefile.config for unwinding the name dwarf implies either libunwind or libdw. Make it clearer that HAVE_DWARF_SUPPORT is really just defined when libdw is present by renaming to HAVE_LIBDW_SUPPORT. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Tested-by: Leo Yan Cc: Anup Patel Cc: Yang Jihong Cc: Palmer Dabbelt Cc: David S. Miller Cc: Albert Ou Cc: Shenlin Liang Cc: Nick Terrell Cc: Guilherme Amadio Cc: Steinar H. Gunderson Cc: Changbin Du Cc: Alexander Lobakin Cc: Przemek Kitszel Cc: Huacai Chen Cc: Guo Ren Cc: Masahiro Yamada Cc: Masami Hiramatsu (Google) Cc: Will Deacon Cc: James Clark Cc: Mike Leach Cc: Chen Pei Cc: Leo Yan Cc: Oliver Upton Cc: Aditya Gupta Cc: Kajol Jain Cc: Athira Rajeev Cc: linux-arm-kernel@lists.infradead.org Cc: linux-riscv@lists.infradead.org Cc: Bibo Mao Cc: John Garry Cc: Atish Patra Cc: Dima Kogan Cc: Paul Walmsley Cc: Dr. David Alan Gilbert Cc: linux-csky@vger.kernel.org Link: https://lore.kernel.org/r/20241017001354.56973-11-irogers@google.com Signed-off-by: Namhyung Kim

perf build: Rename NO_DWARF to NO_LIBDW

2024-10-18T17:17:40+00:00

NO_DWARF could mean more than NO_LIBDW support, in particular no libunwind support. Rename to be more intention revealing. Signed-off-by: Ian Rogers Reviewed-by: Masami Hiramatsu (Google) Acked-by: Namhyung Kim Tested-by: Leo Yan Cc: Anup Patel Cc: Yang Jihong Cc: Palmer Dabbelt Cc: David S. Miller Cc: Albert Ou Cc: Shenlin Liang Cc: Nick Terrell Cc: Guilherme Amadio Cc: Steinar H. Gunderson Cc: Changbin Du Cc: Alexander Lobakin Cc: Przemek Kitszel Cc: Huacai Chen Cc: Guo Ren Cc: Masahiro Yamada Cc: Will Deacon Cc: James Clark Cc: Mike Leach Cc: Chen Pei Cc: Leo Yan Cc: Oliver Upton Cc: Aditya Gupta Cc: Kajol Jain Cc: Athira Rajeev Cc: linux-arm-kernel@lists.infradead.org Cc: linux-riscv@lists.infradead.org Cc: Bibo Mao Cc: John Garry Cc: Atish Patra Cc: Dima Kogan Cc: Paul Walmsley Cc: Dr. David Alan Gilbert Cc: linux-csky@vger.kernel.org Link: https://lore.kernel.org/r/20241017001354.56973-3-irogers@google.com Signed-off-by: Namhyung Kim

perf probe: Use zfree() to avoid possibly accessing dangling pointers

2024-05-07T15:44:02+00:00

When freeing a->b it is good practice to set a->b to NULL using zfree(&a->b) so that when we have a bug where a reference to a freed 'a' pointer is kept somewhere, we can more quickly cause a segfault if some code tries to use a->b. Convert one such case in the 'perf probe' codebase. Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Kan Liang Cc: Namhyung Kim Link: https://lore.kernel.org/lkml/ZjpBnkL2wO3QJa5W@x1 Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Dynamically allocate params memory

2023-05-28T13:24:02+00:00

Avoid 14,432 bytes in .bss by dynamically allocating params. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20230526183401.2326121-12-irogers@google.com Cc: K Prateek Nayak Cc: Ravi Bangoria Cc: Mark Rutland Cc: Ross Zwisler Cc: Steven Rostedt (Google) Cc: Sean Christopherson Cc: Yang Jihong Cc: Peter Zijlstra Cc: Adrian Hunter Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Masami Hiramatsu (Google) Cc: Namhyung Kim Cc: Leo Yan Cc: Andi Kleen Cc: Alexander Shishkin Cc: Kan Liang Cc: Tiezhu Yang Cc: Ingo Molnar Cc: Paolo Bonzini Cc: linux-kernel@vger.kernel.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

tools: Rename __fallthrough to fallthrough

2023-04-07T00:41:00+00:00

Rename the fallthrough attribute to better align with the kernel version. Copy the definition from include/linux/compiler_attributes.h including the #else clause. Adding the #else clause allows the tools compiler.h header to drop the check for a definition entirely and keeps both definitions together. Change any __fallthrough statements to fallthrough anywhere it was used within perf. This allows other tools to use the same key word as the kernel. Committer notes: Did some missing conversions to: builtin-list.c Also included gtk.h before the 'fallthrough' definition in: tools/perf/ui/gtk/hists.c tools/perf/ui/gtk/helpline.c tools/perf/ui/gtk/browser.c As it is the arg name for a macro in glib.h: /var/home/acme/git/perf-tools-next/tools/include/linux/compiler-gcc.h:16:55: error: missing binary operator before token "(" 16 | # define fallthrough __attribute__((__fallthrough__)) | ^ /usr/include/glib-2.0/glib/gmacros.h:637:28: note: in expansion of macro ‘fallthrough’ 637 | #if g_macro__has_attribute(fallthrough) Reviewed-by: Miguel Ojeda Signed-off-by: Liam Howlett Cc: Ingo Molnar Cc: Mark Rutland Cc: Miguel Ojeda Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Peter Zijlstra Cc: Rasmus Villemoes Cc: Tom Rix Cc: linux-sparse@vger.kernel.org Cc: llvm@lists.linux.dev Link: https://lore.kernel.org/r/20221125154947.2163498-1-Liam.Howlett@oracle.com Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Fix usage when libtraceevent is missing

2023-02-02T19:32:19+00:00

While parsing the tracepoint events in parse_events_add_tracepoint() function, code checks for HAVE_LIBTRACEEVENT support. This is needed since libtraceevent is necessary for tracepoint. But while adding probe points, check for LIBTRACEEVENT is not done in case of perf probe. Hence, in environment with missing libtraceevent-devel, it is observed that adding a probe point shows below message though it can't be used via perf record. Example: Adding probe point: ./perf probe 'vfs_getname=getname_flags:72 pathname=result->name:string' Added new event: probe:vfs_getname (on getname_flags:72 with pathname=result->name:string) You can now use it in all perf tools, such as: perf record -e probe:vfs_getname -aR sleep 1 But trying perf record: ./perf record -e probe:vfs_getname -aR sleep 1 event syntax error: 'probe:vfs_getname' \___ unsupported tracepoint libtraceevent is necessary for tracepoint support Run 'perf list' for a list of valid events The builtin tool like perf record needs libtraceevent to parse tracefs. But still the probe can be used by enabling via tracefs. Patch fixes the probe usage message to the user based on presence of libtraceevent. With the fix, # ./perf probe 'pmu:myprobe=schedule' Added new event: pmu:myprobe (on schedule) perf is not linked with libtraceevent, to use the new probe you can use tracefs: cd /sys/kernel/tracing/ echo 1 > events/pmu/myprobe/enable echo 1 > tracing_on cat trace_pipe Before removing the probe, echo 0 > events/pmu/myprobe/enable Signed-off-by: Athira Rajeev Cc: Andi Kleen Cc: Disha Goel Cc: Ian Rogers Cc: James Clark Cc: Jiri Olsa Cc: Kajol Jain Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Nageswara R Sastry Cc: Namhyung Kim Cc: linuxppc-dev@lists.ozlabs.org Link: https://lore.kernel.org/r/20230131134748.54567-1-atrajeev@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Check -v and -q options in the right place

2022-12-20T18:16:33+00:00

Check the -q and -v options first to return earlier on error. Before: # perf probe -q -v test probe-definition(0): test symbol:test file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments Error: -v and -q are exclusive. After: # perf probe -q -v test Error: -v and -q are exclusive. Fixes: 5e17b28f1e246b98 ("perf probe: Add --quiet option to suppress output result message") Reviewed-by: Adrian Hunter Signed-off-by: Yang Jihong Cc: Alexander Shishkin Cc: Andi Kleen Cc: Carsten Haitzler Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Leo Yan Cc: Mark Rutland Cc: Martin KaFai Lau Cc: Masami Hiramatsu Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Ravi Bangoria Link: https://lore.kernel.org/r/20221220035702.188413-4-yangjihong1@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Make quiet mode consistent between tools

2022-10-27T19:37:26+00:00

Use the global quiet variable everywhere so that all tools hide warnings in quiet mode and update the documentation to reflect this. 'perf probe' claimed that errors are not printed in quiet mode but I don't see this so remove it from the docs. Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20221018094137.783081-3-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo