The live mode works similar to simple `perf stat` command, by profiling
the target and printing results on the terminal as soon as the target
finishes.
Example usage:
# perf sched stats -- true
Description
----------------------------------------------------------------------------------------------------
DESC -> Description of the field
COUNT -> Value of the field
PCT_CHANGE -> Percent change with corresponding base value
AVG_JIFFIES -> Avg time in jiffies between two consecutive occurrence of event
----------------------------------------------------------------------------------------------------
Time elapsed (in jiffies) : 1
----------------------------------------------------------------------------------------------------
CPU: <ALL CPUS SUMMARY>
----------------------------------------------------------------------------------------------------
DESC COUNT PCT_CHANGE
----------------------------------------------------------------------------------------------------
yld_count : 0
array_exp : 0
sched_count : 0
sched_goidle : 0 ( 0.00% )
ttwu_count : 0
ttwu_local : 0 ( 0.00% )
rq_cpu_time : 27875
run_delay : 0 ( 0.00% )
pcount : 0
----------------------------------------------------------------------------------------------------
CPU: <ALL CPUS SUMMARY> | DOMAIN: SMT
----------------------------------------------------------------------------------------------------
DESC COUNT AVG_JIFFIES
----------------------------------------- <Category busy> ------------------------------------------
busy_lb_count : 0 $ 0.00 $
busy_lb_balanced : 0 $ 0.00 $
busy_lb_failed : 0 $ 0.00 $
busy_lb_imbalance_load : 0
busy_lb_imbalance_util : 0
busy_lb_imbalance_task : 0
busy_lb_imbalance_misfit : 0
busy_lb_gained : 0
busy_lb_hot_gained : 0
busy_lb_nobusyq : 0 $ 0.00 $
busy_lb_nobusyg : 0 $ 0.00 $
*busy_lb_success_count : 0
*busy_lb_avg_pulled : 0.00
... and so on. Output will show similar data for all the cpus in the
system.
Co-developed-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Swapnil Sapkal <swapnil.sapkal@amd.com>
Tested-by: Chen Yu <yu.c.chen@intel.com>
Tested-by: James Clark <james.clark@linaro.org>
Acked-by: Ian Rogers <irogers@google.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anubhav Shelat <ashelat@redhat.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Chun-Tse Shao <ctshao@google.com>
Cc: David Vernet <void@manifault.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Dr. David Alan Gilbert <linux@treblig.org>
Cc: Gautham Shenoy <gautham.shenoy@amd.com>
Cc: Graham Woodward <graham.woodward@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Madadi Vineeth Reddy <vineethr@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Santosh Shukla <santosh.shukla@amd.com>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Falcon <thomas.falcon@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Yang Jihong <yangjihong@bytedance.com>
Cc: Yujie Liu <yujie.liu@intel.com>
Cc: Zhongqiu Han <quic_zhonhan@quicinc.com>
[ Avoid potentially using 'sv' uninitialized by calling free_cpu_domain_info() only when build_cpu_domain_map() is called ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf tools updates from Namhyung Kim:
"Perf event/metric description:
Unify all event and metric descriptions in JSON format. Now event
parsing and handling is greatly simplified by that.
From users point of view, perf list will provide richer information
about hardware events like the following.
$ perf list hw
List of pre-defined events (to be used in -e or -M):
legacy hardware:
branch-instructions
[Retired branch instructions [This event is an alias of branches]. Unit: cpu]
branch-misses
[Mispredicted branch instructions. Unit: cpu]
branches
[Retired branch instructions [This event is an alias of branch-instructions]. Unit: cpu]
bus-cycles
[Bus cycles,which can be different from total cycles. Unit: cpu]
cache-misses
[Cache misses. Usually this indicates Last Level Cache misses; this is intended to be used in conjunction with the
PERF_COUNT_HW_CACHE_REFERENCES event to calculate cache miss rates. Unit: cpu]
cache-references
[Cache accesses. Usually this indicates Last Level Cache accesses but this may vary depending on your CPU. This may include
prefetches and coherency messages; again this depends on the design of your CPU. Unit: cpu]
cpu-cycles
[Total cycles. Be wary of what happens during CPU frequency scaling [This event is an alias of cycles]. Unit: cpu]
cycles
[Total cycles. Be wary of what happens during CPU frequency scaling [This event is an alias of cpu-cycles]. Unit: cpu]
instructions
[Retired instructions. Be careful,these can be affected by various issues,most notably hardware interrupt counts. Unit: cpu]
ref-cycles
[Total cycles; not affected by CPU frequency scaling. Unit: cpu]
But most notable changes would be in the perf stat. On the right side,
the default metrics are better named and aligned. :)
$ perf stat -- perf test -w noploop
Performance counter stats for 'perf test -w noploop':
11 context-switches # 10.8 cs/sec cs_per_second
0 cpu-migrations # 0.0 migrations/sec migrations_per_second
3,612 page-faults # 3532.5 faults/sec page_faults_per_second
1,022.51 msec task-clock # 1.0 CPUs CPUs_utilized
110,466 branch-misses # 0.0 % branch_miss_rate (88.66%)
6,934,452,104 branches # 6781.8 M/sec branch_frequency (88.66%)
4,657,032,590 cpu-cycles # 4.6 GHz cycles_frequency (88.65%)
27,755,874,218 instructions # 6.0 instructions insn_per_cycle (89.03%)
TopdownL1 # 0.3 % tma_backend_bound
# 9.3 % tma_bad_speculation (89.05%)
# 9.7 % tma_frontend_bound (77.86%)
# 80.7 % tma_retiring (88.81%)
1.025318171 seconds time elapsed
1.013248000 seconds user
0.012014000 seconds sys
Deferred unwinding support:
With the kernel support (commit c69993ecdd: "perf: Support deferred
user unwind"), perf can use deferred callchains for userspace stack
trace with frame pointers like below:
$ perf record --call-graph fp,defer ...
This will be transparent to users when it comes to other commands like
perf report and perf script. They will merge the deferred callchains
to the previous samples as if they were collected together.
ARM SPE updates
- Extensive enhancements to support various kinds of memory
operations including GCS, MTE allocation tags, memcpy/memset,
register access, and SIMD operations.
- Add inverted data source filter (inv_data_src_filter) support to
exclude certain data sources.
- Improve documentation.
Vendor event updates:
- Intel: Updated event files for Sierra Forest, Panther Lake, Meteor
Lake, Lunar Lake, Granite Rapids, and others.
- Arm64: Added metrics for i.MX94 DDR PMU and Cortex-A720AE
definitions.
- RISC-V: Added JSON support for T-HEAD C920V2.
Misc:
- Improve pointer tracking in data type profiling. It'd give better
output when the variable is using container_of() to convert type.
- Annotation support for perf c2c report in TUI. Press 'a' key to
enter annotation view from cacheline browser window. This will show
which instruction is causing the cacheline contention.
- Lots of fixes and test coverage improvements!"
* tag 'perf-tools-for-v6.19-2025-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (214 commits)
libperf: Use 'extern' in LIBPERF_API visibility macro
perf stat: Improve handling of termination by signal
perf tests stat: Add test for error for an offline CPU
perf stat: When no events, don't report an error if there is none
perf tests stat: Add "--null" coverage
perf cpumap: Add "any" CPU handling to cpu_map__snprint_mask
libperf cpumap: Fix perf_cpu_map__max for an empty/NULL map
perf stat: Allow no events to open if this is a "--null" run
perf test kvm: Add some basic perf kvm test coverage
perf tests evlist: Add basic evlist test
perf tests script dlfilter: Add a dlfilter test
perf tests kallsyms: Add basic kallsyms test
perf tests timechart: Add a perf timechart test
perf tests top: Add basic perf top coverage test
perf tests buildid: Add purge and remove testing
perf tests c2c: Add a basic c2c
perf c2c: Clean up some defensive gets and make asan clean
perf jitdump: Fix missed dso__put
perf mem-events: Don't leak online CPU map
perf hist: In init, ensure mem_info is put on error paths
...
Writing currently fails on non-x86 and hybrid CPUs. Switch to the more
regular find_core_pmu that is normally used in this case. Tested on
hybrid alderlake system.
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
With commit f0d0f978f3 ("perf header: Don't write empty BPF/BTF
info"), the write_bpf_( prog_info() | btf() ) functions exit without
writing anything if env->bpf_prog.(infos| btfs)_cnt is zero.
process_bpf_( prog_info() | btf() ), however, still expect a "count"
value to exist in the data file. If btf information is empty, for
example, process_bpf_btf will read garbage or some other data as the
number of btf nodes in the data file. As a result, the data file will
not be processed correctly.
Instead, write the count to the data file and exit if it is zero.
Fixes: f0d0f978f3 ("perf header: Don't write empty BPF/BTF info")
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Thomas Falcon <thomas.falcon@intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Getting context for what a tool is doing, such as the perf_inject
instance, using container_of the tool is a common pattern in the
code. This isn't possible event_op2, event_op3 and event_op4 callbacks
as the tool isn't passed. Add the argument and then fix function
signatures to match. As tools maybe reading a tool from somewhere
else, change that code to use the passed in tool.
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Recent change on enabling --buildid-mmap by default brought an issue
with build-id handling. With build-ID in MMAP2 records, we don't need
to save the build-ID table in the header of a perf data file.
But the actual file contents still need to be cached in the debug
directory for annotation etc. Split the build-ID header processing and
caching and make sure perf record to save hit DSOs in the build-ID cache
by moving perf_session__cache_build_ids() to the end of the record__
finish_output().
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
The session holds a perf_env pointer env. In UI code container_of is
used to turn the env to a session, but this assumes the session
header's env is in use. Rather than a dubious container_of, hold the
session in the evlist and derive the env from the session with
evsel__env, perf_session__env, etc.
Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250724163302.596743-11-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
The env.pmu_mapping can be leaked when it reads data from a pipe on AMD.
For a pipe data, it reads the header data including pmu_mapping from
PERF_RECORD_HEADER_FEATURE runtime. But it's already set in:
perf_session__new()
__perf_session__new()
evlist__init_trace_event_sample_raw()
evlist__has_amd_ibs()
perf_env__nr_pmu_mappings()
Then it'll overwrite that when it processes the HEADER_FEATURE record.
Here's a report from address sanitizer.
Direct leak of 2689 byte(s) in 1 object(s) allocated from:
#0 0x7fed8f814596 in realloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:98
#1 0x5595a7d416b1 in strbuf_grow util/strbuf.c:64
#2 0x5595a7d414ef in strbuf_init util/strbuf.c:25
#3 0x5595a7d0f4b7 in perf_env__read_pmu_mappings util/env.c:362
#4 0x5595a7d12ab7 in perf_env__nr_pmu_mappings util/env.c:517
#5 0x5595a7d89d2f in evlist__has_amd_ibs util/amd-sample-raw.c:315
#6 0x5595a7d87fb2 in evlist__init_trace_event_sample_raw util/sample-raw.c:23
#7 0x5595a7d7f893 in __perf_session__new util/session.c:179
#8 0x5595a7b79572 in perf_session__new util/session.h:115
#9 0x5595a7b7e9dc in cmd_report builtin-report.c:1603
#10 0x5595a7c019eb in run_builtin perf.c:351
#11 0x5595a7c01c92 in handle_internal_command perf.c:404
#12 0x5595a7c01deb in run_argv perf.c:448
#13 0x5595a7c02134 in main perf.c:556
#14 0x7fed85833d67 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
Let's free the existing pmu_mapping data if any.
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20250311000416.817631-1-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Previously inject->is_pipe was set if the input or output were a
pipe. Determining the input was a pipe had to be done prior to
starting the session and opening the file. This was done by comparing
the input file name with '-' but it fails if the pipe file is written
to disk.
Opening a pipe file from disk will correctly set perf_data.is_pipe, but
this is too late for 'perf inject' and results in a broken file. A
workaround is 'cat pipe_perf|perf inject -i - ...'.
This change removes inject->is_pipe and changes the dependent
conditions to use the is_pipe flag on the input
(inject->session->data) and output files (inject->output). This
ensures the is_pipe condition reflects things like the header being
read.
The change removes the use of perf file header repiping, that is
writing the file header out while reading it in. The case of input
pipe and output file cannot repipe as the attributes for the file are
unknown. To resolve this, write the file header when writing to disk
and as the attributes may be unknown, write them after the data.
Update sessions repipe variable to be trace_event_repipe as those are
the only events now impacted by it. Update __perf_session__new as the
repipe_fd no longer needs passing. Fully removing repipe from session
header reading will be done in a later change.
Committer testing:
root@number:~# perf record -e syscalls:sys_enter_*sleep/max-stack=4/ -o - sleep 0.01 | perf report -i -
# To display the perf.data header info, please use --header/--header-only options.
#
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.050 MB - ]
#
# Total Lost Samples: 0
#
# Samples: 1 of event 'syscalls:sys_enter_clock_nanosleep'
# Event count (approx.): 1
#
# Overhead Command Shared Object Symbol
# ........ ....... ............. ...............................
#
100.00% sleep libc.so.6 [.] clock_nanosleep@GLIBC_2.2.5
|
---__libc_start_main@@GLIBC_2.34
__libc_start_call_main
0x562fc2560a9f
clock_nanosleep@GLIBC_2.2.5
#
# (Tip: Create an archive with symtabs to analyse on other machine: perf archive)
#
root@number:~# perf record -e syscalls:sys_enter_*sleep/max-stack=4/ -o - sleep 0.01 > pipe.data
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.050 MB - ]
root@number:~# perf report --stdio -i pipe.data
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 1 of event 'syscalls:sys_enter_clock_nanosleep'
# Event count (approx.): 1
#
# Overhead Command Shared Object Symbol
# ........ ....... ............. ...............................
#
100.00% sleep libc.so.6 [.] clock_nanosleep@GLIBC_2.2.5
|
---__libc_start_main@@GLIBC_2.34
__libc_start_call_main
0x55f775975a9f
clock_nanosleep@GLIBC_2.2.5
#
# (Tip: To set sampling period of individual events use perf record -e cpu/cpu-cycles,period=100001/,cpu/branches,period=10001/ ...)
#
root@number:~#
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yanteng Si <siyanteng@loongson.cn>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20240829150154.37929-7-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Buggy perf.data files can have the attributes and data
overlapping.
For example, when processing pipe data the attributes aren't known and
so file offset header calculations can consider them not present.
Later this can cause the attributes to overwrite the data. This can be
seen in:
$ perf record -o - true > a.data
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.059 MB - ]
$ perf inject -i a.data -o b.data
$ perf report --stats -i b.data
0x68 [0]: failed to process type: 510379 [Invalid argument]
Error:
failed to process sample
$
This change makes reading the corrupt file fail:
$ perf report --stats -i b.data
Perf file header corrupt: Attributes and data overlap
incompatible file format (rerun with -v to learn more)
$
Which is more informative.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yanteng Si <siyanteng@loongson.cn>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20240829150154.37929-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Do not increase the node count unless a node has been successfully read,
because it can lead to a segfault if an error occurs.
For example, if perf exceeds the open file limit in memory_node__read(),
which, on a test system, could be made to happen by setting the file limit
to exactly 32:
Before:
$ ulimit -n 32
$ perf mem record --all-user -- sleep 1
[ perf record: Woken up 1 times to write data ]
failed: can't open memory sysfs data
perf: Segmentation fault
Obtained 14 stack frames.
perf(sighandler_dump_stack+0x48) [0x55f4b1f59558]
/lib/x86_64-linux-gnu/libc.so.6(+0x42520) [0x7f4ba1c42520]
/lib/x86_64-linux-gnu/libc.so.6(free+0x1e) [0x7f4ba1ca53fe]
perf(+0x178ff4) [0x55f4b1f48ff4]
perf(+0x179a70) [0x55f4b1f49a70]
perf(+0x17ef5d) [0x55f4b1f4ef5d]
perf(+0x85c0b) [0x55f4b1e55c0b]
perf(cmd_record+0xe1d) [0x55f4b1e5920d]
perf(cmd_mem+0xc96) [0x55f4b1e80e56]
perf(+0x130460) [0x55f4b1f00460]
perf(main+0x689) [0x55f4b1e427d9]
/lib/x86_64-linux-gnu/libc.so.6(+0x29d90) [0x7f4ba1c29d90]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x80) [0x7f4ba1c29e40]
perf(_start+0x25) [0x55f4b1e42a25]
Segmentation fault (core dumped)
$
After:
$ ulimit -n 32
$ perf mem record --all-user -- sleep 1
[ perf record: Woken up 1 times to write data ]
failed: can't open memory sysfs data
[ perf record: Captured and wrote 0.005 MB perf.data (11 samples) ]
$
Fixes: f8e502b9d1 ("perf header: Ensure bitmaps are freed")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20231123075848.9652-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The PERF_RECORD_ATTR is used for a pipe mode to describe an event with
attribute and IDs. The ID table comes after the attr and it calculate
size of the table using the total record size and the attr size.
n_ids = (total_record_size - end_of_the_attr_field) / sizeof(u64)
This is fine for most use cases, but sometimes it saves the pipe output
in a file and then process it later. And it becomes a problem if there
is a change in attr size between the record and report.
$ perf record -o- > perf-pipe.data # old version
$ perf report -i- < perf-pipe.data # new version
For example, if the attr size is 128 and it has 4 IDs, then it would
save them in 168 byte like below:
8 byte: perf event header { .type = PERF_RECORD_ATTR, .size = 168 },
128 byte: perf event attr { .size = 128, ... },
32 byte: event IDs [] = { 1234, 1235, 1236, 1237 },
But when report later, it thinks the attr size is 136 then it only read
the last 3 entries as ID.
8 byte: perf event header { .type = PERF_RECORD_ATTR, .size = 168 },
136 byte: perf event attr { .size = 136, ... },
24 byte: event IDs [] = { 1235, 1236, 1237 }, // 1234 is missing
So it should use the recorded version of the attr. The attr has the
size field already then it should honor the size when reading data.
Fixes: 2c46dbb517 ("perf: Convert perf header attrs into attr events")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230825152552.112913-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
intel-pt tests were failing:
-- Test virtual LBR ---
Linux
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.126 MB /tmp/perf-test-intel-pt-sh.FW57CXnCqQ/test-perf.data ]
Failed with virtual lbr
...
```
The root cause is an out-of-bounds read in header (where maxbrstack.py
is from test_intel_pt.sh):
```
$ perf --no-pager script --itrace=L -s maxbrstack.py
=================================================================
==3907930==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6020000095a8 at pc 0x563c26c840bb bp 0x7fff43582710 sp 0x7fff43582708
READ of size 4 at 0x6020000095a8 thread T0
#0 0x563c26c840ba in process_group_desc util/header.c:2847
#1 0x563c26c8bc78 in perf_file_section__process util/header.c:4037
#2 0x563c26c8aa9b in perf_header__process_sections util/header.c:3813
#3 0x563c26c8d028 in perf_session__read_header util/header.c:4286
#4 0x563c26cbab29 in perf_session__open util/session.c:113
#5 0x563c26cbb3d0 in __perf_session__new util/session.c:221
#6 0x563c26aacb14 in perf_session__new util/session.h:73
#7 0x563c26acf7f1 in cmd_script tools/perf/builtin-script.c:4212
#8 0x563c26bb58ff in run_builtin tools/perf/perf.c:323
#9 0x563c26bb5e70 in handle_internal_command tools/perf/perf.c:377
#10 0x563c26bb6238 in run_argv tools/perf/perf.c:421
#11 0x563c26bb67a0 in main tools/perf/perf.c:537
#12 0x7f34bde46189 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
#13 0x7f34bde46244 in __libc_start_main_impl ../csu/libc-start.c:381
#14 0x563c26a33390 in _start (/tmp/perf/perf+0x1eb390)
0x6020000095a8 is located 8 bytes to the right of 16-byte region [0x602000009590,0x6020000095a0)
allocated by thread T0 here:
#0 0x7f34beeb83b7 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:77
#1 0x563c26c83df8 in process_group_desc util/header.c:2824
#2 0x563c26c8bc78 in perf_file_section__process util/header.c:4037
#3 0x563c26c8aa9b in perf_header__process_sections util/header.c:3813
#4 0x563c26c8d028 in perf_session__read_header util/header.c:4286
#5 0x563c26cbab29 in perf_session__open util/session.c:113
#6 0x563c26cbb3d0 in __perf_session__new util/session.c:221
#7 0x563c26aacb14 in perf_session__new util/session.h:73
#8 0x563c26acf7f1 in cmd_script tools/perf/builtin-script.c:4212
#9 0x563c26bb58ff in run_builtin tools/perf/perf.c:323
#10 0x563c26bb5e70 in handle_internal_command tools/perf/perf.c:377
#11 0x563c26bb6238 in run_argv tools/perf/perf.c:421
#12 0x563c26bb67a0 in main tools/perf/perf.c:537
#13 0x7f34bde46189 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
```
Avoid the out-of-bounds read checking for the leader. Leave the 'nr'
check intact as nr will be 0 or the counting down and evsel be a group
member.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ali Saidi <alisaidi@amazon.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Brian Robbins <brianrob@linux.microsoft.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Dmitrii Dolgov <9erthalion6@gmail.com>
Cc: Fangrui Song <maskray@google.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Babrou <ivan@cloudflare.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Steinar H. Gunderson <sesse@google.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Wenyu Liu <liuwenyu7@huawei.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Ye Xingchen <ye.xingchen@zte.com.cn>
Cc: Yuan Can <yuancan@huawei.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/lkml/20230608232823.4027869-24-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
