When peeking an event, it has a short path and a long path. The short
path uses the session pointer "one_mmap_addr" to directly fetch the
event; and the long path needs to read out the event header and the
following event data from file and fill into the buffer pointer passed
through the argument "buf".
The issue is in the long path that it copies the event header and event
data into the same destination address which pointer "buf", this means
the event header is overwritten. We are just lucky to run into the
short path in most cases, so we don't hit the issue in the long path.
This patch adds the offset "hdr_sz" to the pointer "buf" when copying
the event data, so that it can reserve the event header which can be
used properly by its caller.
Fixes: 5a52f33adf ("perf session: Add perf_session__peek_event()")
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210605052957.1070720-1-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Report permission error for the tracefs open and rewrite whole the error
message code around it.
You'll see a hint according to what you want to do with perf probe as
below.
$ perf probe -l
No permission to read tracefs.
Please try 'sudo mount -o remount,mode=755 /sys/kernel/tracing/'
Error: Failed to show event list.
$ perf probe -d \*
No permission to write tracefs.
Please run this command again with sudo.
Error: Failed to delete events.
This also fixes -ENOTSUP checking for mounting tracefs/debugfs.
Actually open returns -ENOENT in that case and we have to check it with
current mount point list. If we unmount debugfs and tracefs perf probe
shows correct message as below.
$ perf probe -l
Debugfs or tracefs is not mounted
Please try 'sudo mount -t tracefs nodev /sys/kernel/tracing/'
Error: Failed to show event list.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Link: http://lore.kernel.org/lkml/162299456839.503471.13863002017089255222.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Report possible permission error including kptr_restrict setting
for map__load() failure. This can happen when non-superuser runs
perf probe.
With this patch, perf probe shows the following message.
$ perf probe vfs_read
Failed to load symbols from /proc/kallsyms
Please ensure you can read the /proc/kallsyms symbol addresses.
If the /proc/sys/kernel/kptr_restrict is '2', you can not read
kernel symbol address even if you are a superuser. Please change
it to '1'. If kptr_restrict is '1', the superuser can read the
symbol addresses.
In that case, please run this command again with sudo.
Error: Failed to add events.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Link: http://lore.kernel.org/lkml/162282065877.448336.10047912688119745151.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
ASan reported a memory leak caused by info_linear not being deallocated.
The info_linear was allocated during in perf_event__synthesize_one_bpf_prog().
This patch adds the corresponding free() when bpf_prog_info_node
is freed in perf_env__purge_bpf().
$ sudo ./perf record -- sleep 5
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.025 MB perf.data (8 samples) ]
=================================================================
==297735==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 7688 byte(s) in 19 object(s) allocated from:
#0 0x4f420f in malloc (/home/user/linux/tools/perf/perf+0x4f420f)
#1 0xc06a74 in bpf_program__get_prog_info_linear /home/user/linux/tools/lib/bpf/libbpf.c:11113:16
#2 0xb426fe in perf_event__synthesize_one_bpf_prog /home/user/linux/tools/perf/util/bpf-event.c:191:16
#3 0xb42008 in perf_event__synthesize_bpf_events /home/user/linux/tools/perf/util/bpf-event.c:410:9
#4 0x594596 in record__synthesize /home/user/linux/tools/perf/builtin-record.c:1490:8
#5 0x58c9ac in __cmd_record /home/user/linux/tools/perf/builtin-record.c:1798:8
#6 0x58990b in cmd_record /home/user/linux/tools/perf/builtin-record.c:2901:8
#7 0x7b2a20 in run_builtin /home/user/linux/tools/perf/perf.c:313:11
#8 0x7b12ff in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8
#9 0x7b2583 in run_argv /home/user/linux/tools/perf/perf.c:409:2
#10 0x7b0d79 in main /home/user/linux/tools/perf/perf.c:539:3
#11 0x7fa357ef6b74 in __libc_start_main /usr/src/debug/glibc-2.33-8.fc34.x86_64/csu/../csu/libc-start.c:332:16
Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Link: http://lore.kernel.org/lkml/20210602224024.300485-1-rickyman7@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The perf_mem_events__name() can generate the mem-load event name.
It uses a variable 'mem_loads_name__init' to avoid generating the
event name every time (because perf_pmu__scan takes some time).
The perf_mem_events__name() assumes the pmu is "cpu" but it's not
correct for hybrid platform. For Alderlake, the pmu is "cpu_core" or
"cpu_atom"
Introduce a new parameter 'pmu_name' in perf_mem_events__name
to let the caller specify a pmu name.
Considering such event name is x86 specific, so move
perf_mem_events[] to arch/x86/util/mem-events.c.
We still keep the variable 'mem_loads_name__init' but it's only
used when pmu_name is NULL (compatible for original behavior). When
pmu_name is not NULL (e.g. "cpu_core"), this patch doesn't have
optimization. That can be implemented in follow up patch.
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210527001610.10553-3-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix to return a negative error code from the error handling case instead
of 0, as done elsewhere in this function.
Committer notes:
Added the missing {} for the now multiline 'if' block, fixing this error:
CC /tmp/build/perf/util/bpf_counter.o
util/bpf_counter.c: In function ‘bperf__load’:
util/bpf_counter.c:523:9: error: this ‘if’ clause does not guard... [-Werror=misleading-indentation]
523 | if (evsel->bperf_leader_link_fd < 0 &&
| ^~
util/bpf_counter.c:526:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘if’
526 | goto out;
| ^~~~
cc1: all warnings being treated as errors
Fixes: 7fac83aaf2 ("perf stat: Introduce 'bperf' to share hardware PMCs with BPF")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Link: http://lore.kernel.org/lkml/20210517081254.1561564-1-yukuai3@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
I found that checking cgroup sampling support using the missing features
doesn't work on old kernels. Because it added both attr.cgroup bit and
PERF_SAMPLE_CGROUP bit, it needs to check whichever comes first (usually
the actual event, not dummy).
But it only checks the attr.cgroup bit which is set only in the dummy
event so cannot detect failtures due the sample bits. Also we don't
ignore the missing feature and retry, it'd be better checking it with
the API probing logic.
Committer notes:
Extracted the minimal part to check using the new cgroup API probe
routine, the part that removes the cgroup member can be left for further
discussion.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210527182835.1634339-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If we just check whether the variable can be converted, 'tvar' should be
a null pointer. However, the null pointer check is missing in the
'Constant value' execution path.
The following cases can trigger this problem:
$ cat test.c
#include <stdio.h>
void main(void)
{
int a;
const int b = 1;
asm volatile("mov %1, %0" : "=r"(a): "i"(b));
printf("a: %d\n", a);
}
$ gcc test.c -o test -O -g
$ sudo ./perf probe -x ./test -L "main"
<main@/home/lhf/test.c:0>
0 void main(void)
{
2 int a;
const int b = 1;
asm volatile("mov %1, %0" : "=r"(a): "i"(b));
6 printf("a: %d\n", a);
}
$ sudo ./perf probe -x ./test -V "main:6"
Segmentation fault
The check on 'tvar' is added. If 'tavr' is a null pointer, we return 0
to indicate that the variable can be converted. Now, we can successfully
show the variables that can be accessed.
$ sudo ./perf probe -x ./test -V "main:6"
Available variables at main:6
@<main+13>
char* __fmt
int a
int b
However, the variable 'b' cannot be tracked.
$ sudo ./perf probe -x ./test -D "main:6 b"
Failed to find the location of the 'b' variable at this address.
Perhaps it has been optimized out.
Use -V with the --range option to show 'b' location range.
Error: Failed to add events.
This is because __die_find_variable_cb() did not successfully match
variable 'b', which has the DW_AT_const_value attribute instead of
DW_AT_location. We added support for DW_AT_const_value in
__die_find_variable_cb(). With this modification, we can successfully
track the variable 'b'.
$ sudo ./perf probe -x ./test -D "main:6 b"
p:probe_test/main_L6 /home/lhf/test:0x1156 b=\1:s32
Fixes: 66f69b2197 ("perf probe: Support DW_AT_const_value constant value")
Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Jianlin Lv <jianlin.lv@arm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Zhang Jinhao <zhangjinhao2@huawei.com>
http://lore.kernel.org/lkml/20210601092750.169601-1-lihuafei1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When run as normal user with default sysctl kernel.kptr_restrict=0
and kernel.perf_event_paranoid=2, perf probe fails with:
$ ./perf probe move_page_tables
Relocated base symbol is not found!
The warning message is not much informative. The reason perf fails
is because /proc/kallsyms is restricted by perf_event_paranoid=2
for normal user and thus perf fails to read relocated address of
the base symbol.
Tweaking kptr_restrict and perf_event_paranoid can change the
behavior of perf probe. Also, running as root or privileged user
works too. Add these details in the warning message.
Plus, kmap->ref_reloc_sym might not be always set even if
host_machine is initialized. Above is the example of the same.
Remove that comment.
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20210525043744.193297-1-ravi.bangoria@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As we'll use it in the upcoming python interfaces and when built with:
make_minimal_O: make NO_LIBPERL=1 NO_LIBPYTHON=1 NO_NEWT=1 NO_GTK2=1 NO_DEMANGLE=1 NO_LIBELF=1 NO_LIBUNWIND=1 NO_BACKTRACE=1 NO_LIBNUMA=1 NO_LIBAUDIT=1 NO_LIBBIONIC=1 NO_LIBDW_DWARF_UNWIND=1 NO_AUXTRACE=1 NO_LIBBPF=1 NO_LIBCRYPTO=1 NO_SDT=1 NO_JVMTI=1
+NO_LIBZSTD=1 NO_LIBCAP=1 NO_SYSCALL_TABLE=1
make NO_LIBPERL=1 NO_LIBPYTHON=1 NO_NEWT=1 NO_GTK2=1 NO_DEMANGLE=1 NO_LIBELF=1 NO_LIBUNWIND=1 NO_BACKTRACE=1 NO_LIBNUMA=1 NO_LIBAUDIT=1 NO_LIBBIONIC=1 NO_LIBDW_DWARF_UNWIND=1 NO_AUXTRACE=1 NO_LIBBPF=1 NO_LIBCRYPTO=1 NO_SDT=1 NO_JVMTI=1 NO_LIBZSTD=1 NO_LIBCAP=1
+NO_SYSCALL_TABLE=1
BUILD: Doing 'make -j24' parallel build
<SNIP>
CC /tmp/tmp.rGrdpQlTCr/builtin-daemon.o
In file included from util/events_stats.h:8,
from util/evlist.h:12,
from builtin-script.c:18:
builtin-script.c: In function ‘process_auxtrace_error’:
util/auxtrace.h:708:57: error: called object is not a function or function pointer
708 | #define perf_event__process_auxtrace_error 0
| ^
builtin-script.c:2443:16: note: in expansion of macro ‘perf_event__process_auxtrace_error’
2443 | return perf_event__process_auxtrace_error(session, event);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
MKDIR /tmp/tmp.rGrdpQlTCr/tests/
MKDIR /tmp/tmp.rGrdpQlTCr/bench/
CC /tmp/tmp.rGrdpQlTCr/tests/builtin-test.o
CC /tmp/tmp.rGrdpQlTCr/bench/sched-messaging.o
builtin-script.c:2444:1: error: control reaches end of non-void function [-Werror=return-type]
2444 | }
| ^
To: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When all events of a perf-stat session use BPF, it is not necessary to
call evlist__enable() and evlist__disable(). Skip them when
all_counters_use_bpf is true.
Signed-off-by: Song Liu <song@kernel.org>
Reported-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It counts how often cgroups are changed actually during the context
switches.
# perf stat -a -e context-switches,cgroup-switches -a sleep 1
Performance counter stats for 'system wide':
11,267 context-switches
10,950 cgroup-switches
1.015634369 seconds time elapsed
Committer notes:
The kernel patches landed in v5.13, but this entry wasn't filled in
perf's parse-events tables, which was leading to a segfault when running
'perf list' on a kernel with that feature, as reported by Thomas
Richter.
Also removed the part touching tools/include/uapi/linux/perf_event.h as
it was updated in the usual sync with the kernel UAPI headers, in a
previous, already upstream, patch.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20210210083327.22726-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The decoder reports the current instruction if it was decoded. In some
cases the current instruction is not decoded, in which case the instruction
bytes length must be set to zero. Ensure that is always done.
Note perf script can anyway get the instruction bytes for any samples where
they are not present.
Also note, that there is a redundant "ptq->insn_len = 0" statement which is
not removed until a subsequent patch in order to make this patch apply
cleanly to stable branches.
Example:
A machne that supports TSX is required. It will have flag "rtm". Kernel
parameter tsx=on may be required.
# for w in `cat /proc/cpuinfo | grep -m1 flags `;do echo $w | grep rtm ; done
rtm
Test program:
#include <stdio.h>
#include <immintrin.h>
int main()
{
int x = 0;
if (_xbegin() == _XBEGIN_STARTED) {
x = 1;
_xabort(1);
} else {
printf("x = %d\n", x);
}
return 0;
}
Compile with -mrtm i.e.
gcc -Wall -Wextra -mrtm xabort.c -o xabort
Record:
perf record -e intel_pt/cyc/u --filter 'filter main @ ./xabort' ./xabort
Before:
# perf script --itrace=xe -F+flags,+insn,-period --xed --ns
xabort 1478 [007] 92161.431348581: transactions: x 400b81 main+0x14 (/root/xabort) mov $0xffffffff, %eax
xabort 1478 [007] 92161.431348624: transactions: tx abrt 400b93 main+0x26 (/root/xabort) mov $0xffffffff, %eax
After:
# perf script --itrace=xe -F+flags,+insn,-period --xed --ns
xabort 1478 [007] 92161.431348581: transactions: x 400b81 main+0x14 (/root/xabort) xbegin 0x6
xabort 1478 [007] 92161.431348624: transactions: tx abrt 400b93 main+0x26 (/root/xabort) xabort $0x1
Fixes: faaa87680b ("perf intel-pt/bts: Report instruction bytes and length in sample")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20210519074515.9262-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Compiling perf with make LIBPFM4=1 includes libpfm support and
enables test case 63 'Test libpfm4 support'. This test reports an error
on all platforms for subtest 63.2 'test groups of --pfm-events'.
The reported error message is 'nested event groups not supported'
# ./perf test -F 63
63: Test libpfm4 support :
63.1: test of individual --pfm-events :
Error:
failed to parse event stereolab : event not found
Error:
failed to parse event stereolab,instructions : event not found
Error:
failed to parse event instructions,stereolab : event not found
Ok
63.2: test groups of --pfm-events :
Error:
nested event groups not supported <------ Error message here
Error:
failed to parse event {stereolab} : event not found
Error:
failed to parse event {instructions,cycles},{instructions,stereolab} :\
event not found
Ok
#
This patch addresses the error message 'nested event groups not supported'.
The root cause is function parse_libpfm_events_option() which parses the
event string '{},{instructions}' and can not handle a leading empty
group notation '{},...'.
The code detects the first (empty) group indicator '{' but does not
terminate group processing on the following group closing character '}'.
So when the second group indicator '{' is detected, the code assumes
a nested group and returns an error.
With the error message fixed, also change the expected event number to
one for the test case to succeed.
While at it also fix a memory leak. In good case the function does not
free the duplicated string given as first parameter.
Output after:
# ./perf test -F 63
63: Test libpfm4 support :
63.1: test of individual --pfm-events :
Error:
failed to parse event stereolab : event not found
Error:
failed to parse event stereolab,instructions : event not found
Error:
failed to parse event instructions,stereolab : event not found
Ok
63.2: test groups of --pfm-events :
Error:
failed to parse event {stereolab} : event not found
Error:
failed to parse event {instructions,cycles},{instructions,stereolab} : \
event not found
Ok
#
Error message 'nested event groups not supported' is gone.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-By: Ian Rogers <irogers@google.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20210517140931.2559364-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
