perf_evsel::sample_id is an xyarray which can cause a segfault when
accessed beyond its size. e.g.
# perf record -e intel_pt// -C 1 sleep 1
Segmentation fault (core dumped)
#
That is happening because a dummy event is opened to capture text poke
events accross all CPUs, however the mmap logic is allocating according
to the number of user_requested_cpus.
In general, perf sometimes uses the evsel cpus to open events, and
sometimes the evlist user_requested_cpus. However, it is not necessary
to determine which case is which because the opened event file
descriptors are also in an xyarray, the size of whch can be used
to correctly allocate the size of the sample_id xyarray, because there
is one ID per file descriptor.
Note, in the affected code path, perf_evsel fd array is subsequently
used to get the file descriptor for the mmap, so it makes sense for the
xyarrays to be the same size there.
Fixes: d1a177595b ("libperf: Adopt perf_evlist__mmap()/munmap() from tools/perf")
Fixes: 246eba8e90 ("perf tools: Add support for PERF_RECORD_TEXT_POKE")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: stable@vger.kernel.org # 5.5+
Link: https://lore.kernel.org/r/20220413114232.26914-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull Kbuild updates from Masahiro Yamada:
- Add new environment variables, USERCFLAGS and USERLDFLAGS to allow
additional flags to be passed to user-space programs.
- Fix missing fflush() bugs in Kconfig and fixdep
- Fix a minor bug in the comment format of the .config file
- Make kallsyms ignore llvm's local labels, .L*
- Fix UAPI compile-test for cross-compiling with Clang
- Extend the LLVM= syntax to support LLVM=<suffix> form for using a
particular version of LLVm, and LLVM=<prefix> form for using custom
LLVM in a particular directory path.
- Clean up Makefiles
* tag 'kbuild-v5.18-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: Make $(LLVM) more flexible
kbuild: add --target to correctly cross-compile UAPI headers with Clang
fixdep: use fflush() and ferror() to ensure successful write to files
arch: syscalls: simplify uapi/kapi directory creation
usr/include: replace extra-y with always-y
certs: simplify empty certs creation in certs/Makefile
certs: include certs/signing_key.x509 unconditionally
kallsyms: ignore all local labels prefixed by '.L'
kconfig: fix missing '# end of' for empty menu
kconfig: add fflush() before ferror() check
kbuild: replace $(if A,A,B) with $(or A,B)
kbuild: Add environment variables for userprogs flags
kbuild: unify cmd_copy and cmd_shipped
Pull perf tools updates from Arnaldo Carvalho de Melo:
"New features:
perf ftrace:
- Add -n/--use-nsec option to the 'latency' subcommand.
Default: usecs:
$ sudo perf ftrace latency -T dput -a sleep 1
# DURATION | COUNT | GRAPH |
0 - 1 us | 2098375 | ############################# |
1 - 2 us | 61 | |
2 - 4 us | 33 | |
4 - 8 us | 13 | |
8 - 16 us | 124 | |
16 - 32 us | 123 | |
32 - 64 us | 1 | |
64 - 128 us | 0 | |
128 - 256 us | 1 | |
256 - 512 us | 0 | |
Better granularity with nsec:
$ sudo perf ftrace latency -T dput -a -n sleep 1
# DURATION | COUNT | GRAPH |
0 - 1 us | 0 | |
1 - 2 ns | 0 | |
2 - 4 ns | 0 | |
4 - 8 ns | 0 | |
8 - 16 ns | 0 | |
16 - 32 ns | 0 | |
32 - 64 ns | 0 | |
64 - 128 ns | 1163434 | ############## |
128 - 256 ns | 914102 | ############# |
256 - 512 ns | 884 | |
512 - 1024 ns | 613 | |
1 - 2 us | 31 | |
2 - 4 us | 17 | |
4 - 8 us | 7 | |
8 - 16 us | 123 | |
16 - 32 us | 83 | |
perf lock:
- Add -c/--combine-locks option to merge lock instances in the same
class into a single entry.
# perf lock report -c
Name acquired contended avg wait(ns) total wait(ns) max wait(ns) min wait(ns)
rcu_read_lock 251225 0 0 0 0 0
hrtimer_bases.lock 39450 0 0 0 0 0
&sb->s_type->i_l... 10301 1 662 662 662 662
ptlock_ptr(page) 10173 2 701 1402 760 642
&(ei->i_block_re... 8732 0 0 0 0 0
&xa->xa_lock 8088 0 0 0 0 0
&base->lock 6705 0 0 0 0 0
&p->pi_lock 5549 0 0 0 0 0
&dentry->d_lockr... 5010 4 1274 5097 1844 789
&ep->lock 3958 0 0 0 0 0
- Add -F/--field option to customize the list of fields to output:
$ perf lock report -F contended,wait_max -k avg_wait
Name contended max wait(ns) avg wait(ns)
slock-AF_INET6 1 23543 23543
&lruvec->lru_lock 5 18317 11254
slock-AF_INET6 1 10379 10379
rcu_node_1 1 2104 2104
&dentry->d_lockr... 1 1844 1844
&dentry->d_lockr... 1 1672 1672
&newf->file_lock 15 2279 1025
&dentry->d_lockr... 1 792 792
- Add --synth=no option for record, as there is no need to symbolize,
lock names comes from the tracepoints.
perf record:
- Threaded recording, opt-in, via the new --threads command line
option.
- Improve AMD IBS (Instruction-Based Sampling) error handling
messages.
perf script:
- Add 'brstackinsnlen' field (use it with -F) for branch stacks.
- Output branch sample type in 'perf script'.
perf report:
- Add "addr_from" and "addr_to" sort dimensions.
- Print branch stack entry type in 'perf report --dump-raw-trace'
- Fix symbolization for chrooted workloads.
Hardware tracing:
Intel PT:
- Add CFE (Control Flow Event) and EVD (Event Data) packets support.
- Add MODE.Exec IFLAG bit support.
Explanation about these features from the "Intel® 64 and IA-32
architectures software developer’s manual combined volumes: 1, 2A,
2B, 2C, 2D, 3A, 3B, 3C, 3D, and 4" PDF at:
https://cdrdv2.intel.com/v1/dl/getContent/671200
At page 3951:
"32.2.4
Event Trace is a capability that exposes details about the
asynchronous events, when they are generated, and when their
corresponding software event handler completes execution. These
include:
o Interrupts, including NMI and SMI, including the interrupt
vector when defined.
o Faults, exceptions including the fault vector.
- Page faults additionally include the page fault address,
when in context.
o Event handler returns, including IRET and RSM.
o VM exits and VM entries.¹
- VM exits include the values written to the “exit reason”
and “exit qualification” VMCS fields. INIT and SIPI events.
o TSX aborts, including the abort status returned for the RTM
instructions.
o Shutdown.
Additionally, it provides indication of the status of the
Interrupt Flag (IF), to indicate when interrupts are masked"
ARM CoreSight:
- Use advertised caps/min_interval as default sample_period on ARM
spe.
- Update deduction of TRCCONFIGR register for branch broadcast on
ARM's CoreSight ETM.
Vendor Events (JSON):
Intel:
- Update events and metrics for: Alderlake, Broadwell, Broadwell DE,
BroadwellX, CascadelakeX, Elkhartlake, Bonnell, Goldmont,
GoldmontPlus, Westmere EP-DP, Haswell, HaswellX, Icelake, IcelakeX,
Ivybridge, Ivytown, Jaketown, Knights Landing, Nehalem EP,
Sandybridge, Silvermont, Skylake, Skylake Server, SkylakeX,
Tigerlake, TremontX, Westmere EP-SP, and Westmere EX.
ARM:
- Add support for HiSilicon CPA PMU aliasing.
perf stat:
- Fix forked applications enablement of counters.
- The 'slots' should only be printed on a different order than the
one specified on the command line when 'topdown' events are
present, fix it.
Miscellaneous:
- Sync msr-index, cpufeatures header files with the kernel sources.
- Stop using some deprecated libbpf APIs in 'perf trace'.
- Fix some spelling mistakes.
- Refactor the maps pointers usage to pave the way for using refcount
debugging.
- Only offer the --tui option on perf top, report and annotate when
perf was built with libslang.
- Don't mention --to-ctf in 'perf data --help' when not linking with
the required library, libbabeltrace.
- Use ARRAY_SIZE() instead of ad hoc equivalent, spotted by
array_size.cocci.
- Enhance the matching of sub-commands abbreviations:
'perf c2c rec' -> 'perf c2c record'
'perf c2c recport -> error
- Set build-id using build-id header on new mmap records.
- Fix generation of 'perf --version' string.
perf test:
- Add test for the arm_spe event.
- Add test to check unwinding using fame-pointer (fp) mode on arm64.
- Make metric testing more robust in 'perf test'.
- Add error message for unsupported branch stack cases.
libperf:
- Add API for allocating new thread map array.
- Fix typo in perf_evlist__open() failure error messages in libperf
tests.
perf c2c:
- Replace bitmap_weight() with bitmap_empty() where appropriate"
* tag 'perf-tools-for-v5.18-2022-03-26' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (143 commits)
perf evsel: Improve AMD IBS (Instruction-Based Sampling) error handling messages
perf python: Add perf_env stubs that will be needed in evsel__open_strerror()
perf tools: Enhance the matching of sub-commands abbreviations
libperf tests: Fix typo in perf_evlist__open() failure error messages
tools arm64: Import cputype.h
perf lock: Add -F/--field option to control output
perf lock: Extend struct lock_key to have print function
perf lock: Add --synth=no option for record
tools headers cpufeatures: Sync with the kernel sources
tools headers cpufeatures: Sync with the kernel sources
perf stat: Fix forked applications enablement of counters
tools arch x86: Sync the msr-index.h copy with the kernel sources
perf evsel: Make evsel__env() always return a valid env
perf build-id: Fix spelling mistake "Cant" -> "Can't"
perf header: Fix spelling mistake "could't" -> "couldn't"
perf script: Add 'brstackinsnlen' for branch stacks
perf parse-events: Move slots only with topdown
perf ftrace latency: Update documentation
perf ftrace latency: Add -n/--use-nsec option
perf tools: Fix version kernel tag
...
Pull flexible-array transformations from Gustavo Silva:
"Treewide patch that replaces zero-length arrays with flexible-array
members.
This has been baking in linux-next for a whole development cycle"
* tag 'flexible-array-transformations-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
treewide: Replace zero-length arrays with flexible-array members
