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| author | Aaron Tomlin <atomlin@atomlin.com> | 2026-06-13 01:56:10 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2026-06-15 20:33:49 +0300 |
| commit | cd355f6dc70503191249c5147e2f2e8f3c8838bd (patch) | |
| tree | b5df194cb4ce3e8ae3ef0dd0d1175432b03cb9b0 /scripts/Makefile.thinlto | |
| parent | 190c4546384461f3dee70a649b438aa41c24d01e (diff) | |
| download | linux-cd355f6dc70503191249c5147e2f2e8f3c8838bd.tar.xz | |
perf trace: Fix noise and signed formatting of __probe_ip in bare dynamic probes
When a dynamic probe is created without explicitly requested arguments
via perf probe --add, the Ftrace subsystem automatically appends
"__probe_ip" to the tracepoint format to record the instruction pointer.
Currently, perf trace prints this implicit field by default.
Furthermore, because the formatting logic defaults to a standard signed
integer representation, the kernel space memory address is erroneously
displayed as a meaningless negative integer.
❯ sudo ./perf trace --event probe:proc_sys_open --max-events 1
0.000 ps/1316543 probe:proc_sys_open(__probe_ip: -1406056956)
This patch addresses the user experience by combining two refinements:
1. "__probe_ip" is now hidden from the standard output, as its
presence adds no contextual value for a bare probe.
2. If the user explicitly requests verbose output (--verbose),
"__probe_ip" is intercepted and properly formatted as a hexadecimal
kernel address, restoring its utility for debugging inline
function hits.
❯ sudo ./perf trace --event probe:proc_sys_open --max-events 1
0.000 ps/1314074 probe:proc_sys_open()
❯ sudo ./perf trace --verbose --event probe:proc_sys_open --max-events 1
Using CPUID GenuineIntel-6-8E-C
mmap size 528384B
0.000 ps/1314366 probe:proc_sys_open(__probe_ip: 0xffffffffac314604)
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Daniel Vacek <neelx@suse.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Ashe <sean@ashe.io>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'scripts/Makefile.thinlto')
0 files changed, 0 insertions, 0 deletions
