perf map: Add accessor for dso

Later changes will add reference count checking for struct map, with
dso being the most frequently accessed variable. Add an accessor so
that the reference count check

perf map: Add accessor for dso

Later changes will add reference count checking for struct map, with
dso being the most frequently accessed variable. Add an accessor so
that the reference count check is only necessary in one place.

Additional changes:
- add a dso variable to avoid repeated map__dso calls.
- in builtin-mem.c dump_raw_samples, code only partially tested for
dso == NULL. Make the possibility of NULL consistent.
- in thread.c thread__memcpy fix use of spaces and use tabs.

Committer notes:

Did missing conversions on these files:

tools/perf/arch/powerpc/util/skip-callchain-idx.c
tools/perf/arch/powerpc/util/sym-handling.c
tools/perf/ui/browsers/hists.c
tools/perf/ui/gtk/annotate.c
tools/perf/util/cs-etm.c
tools/perf/util/thread.c
tools/perf/util/unwind-libunwind-local.c
tools/perf/util/unwind-libunwind.c

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Miaoqian Lin <linmq006@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Shunsuke Nakamura <nakamura.shun@fujitsu.com>
Cc: Song Liu <song@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Yury Norov <yury.norov@gmail.com>
Link: https://lore.kernel.org/r/20230320212248.1175731-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf maps: Add functions to access maps

Introduce functions to access struct maps. These functions reduce the
number of places reference counting is necessary. While tidying APIs do
some small const

perf maps: Add functions to access maps

Introduce functions to access struct maps. These functions reduce the
number of places reference counting is necessary. While tidying APIs do
some small const-ification, in particlar to unwind_libunwind_ops.

Committer notes:

Fixed up tools/perf/util/unwind-libunwind.c:

- return ops->get_entries(cb, arg, thread, data, max_stack);
+ return ops->get_entries(cb, arg, thread, data, max_stack, best_effort);

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Miaoqian Lin <linmq006@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Shunsuke Nakamura <nakamura.shun@fujitsu.com>
Cc: Song Liu <song@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Yury Norov <yury.norov@gmail.com>
Link: https://lore.kernel.org/r/20230320212248.1175731-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf maps: Remove rb_node from struct map

struct map is reference counted, having it also be a node in an
red-black tree complicates the reference counting. Switch to having a
map_rb_node which is a

perf maps: Remove rb_node from struct map

struct map is reference counted, having it also be a node in an
red-black tree complicates the reference counting. Switch to having a
map_rb_node which is a red-block tree node but points at the reference
counted struct map. This reference is responsible for a single reference
count.

Committer notes:

Fixed up tools/perf/util/unwind-libunwind-local.c to use map_rb_node as
well.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Miaoqian Lin <linmq006@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Shunsuke Nakamura <nakamura.shun@fujitsu.com>
Cc: Song Liu <song@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Yury Norov <yury.norov@gmail.com>
Link: https://lore.kernel.org/r/20230320212248.1175731-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf symbols: Fix unaligned access in get_x86_64_plt_disp()

Use memcpy() to avoid unaligned access.

Discovered using EXTRA_CFLAGS="-fsanitize=undefined -fsanitize=address".

Fixes: ce4c8e7966f317ef

perf symbols: Fix unaligned access in get_x86_64_plt_disp()

Use memcpy() to avoid unaligned access.

Discovered using EXTRA_CFLAGS="-fsanitize=undefined -fsanitize=address".

Fixes: ce4c8e7966f317ef ("perf symbols: Get symbols for .plt.got for x86-64")
Reported-by: kernel test robot <yujie.liu@intel.com>
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: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/oe-lkp/202303061424.6ad43294-yujie.liu@intel.com
Link: https://lore.kernel.org/r/20230316194156.8320-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf symbols: Fix use-after-free in get_plt_got_name()

Fix use-after-free in get_plt_got_name().

Discovered using EXTRA_CFLAGS="-fsanitize=undefined -fsanitize=address".

Fixes: ce4c8e7966f317ef ("

perf symbols: Fix use-after-free in get_plt_got_name()

Fix use-after-free in get_plt_got_name().

Discovered using EXTRA_CFLAGS="-fsanitize=undefined -fsanitize=address".

Fixes: ce4c8e7966f317ef ("perf symbols: Get symbols for .plt.got for x86-64")
Reported-by: kernel test robot <yujie.liu@intel.com>
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: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/oe-lkp/202303061424.6ad43294-yujie.liu@intel.com
Link: https://lore.kernel.org/r/20230316194156.8320-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

Merge drm/drm-next into drm-intel-next

Catch up with 6.3-rc cycle...

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge remote-tracking branch 'drm/drm-next' into msm-next

Merge drm-next into msm-next to pick up external clk and PM dependencies
for improved a6xx GPU reset sequence.

Signed-off-by: Rob Clark <ro

Merge remote-tracking branch 'drm/drm-next' into msm-next

Merge drm-next into msm-next to pick up external clk and PM dependencies
for improved a6xx GPU reset sequence.

Signed-off-by: Rob Clark <robdclark@chromium.org>

show more ...

Merge tag 'v6.3-rc2' into next

Merge with mainline to get of_property_present() and other newer APIs.

perf symbol: Add abi::__cxa_demangle C++ demangling support

Refactor C++ demangling out of symbol-elf into its own files similar
to other languages. Add abi::__cxa_demangle support. As the other
dem

perf symbol: Add abi::__cxa_demangle C++ demangling support

Refactor C++ demangling out of symbol-elf into its own files similar
to other languages. Add abi::__cxa_demangle support. As the other
demanglers are not shippable with distributions, this brings back C++
demangling in a common case. It isn't perfect as the support for
optionally demangling arguments and modifiers isn't present.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andres Freund <andres@anarazel.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin Liška <mliska@suse.cz>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Pavithra Gurushankar <gpavithrasha@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Monnet <quentin@isovalent.com>
Cc: Roberto Sassu <roberto.sassu@huawei.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Tom Rix <trix@redhat.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230311065753.3012826-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

Merge drm/drm-fixes into drm-misc-fixes

Backmerging to get latest upstream.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge drm/drm-next into drm-misc-next

Backmerging to get v6.3-rc1 and sync with the other DRM trees.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge tag 'perf-tools-for-v6.3-1-2023-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull perf tools updates from Arnaldo Carvalho de Melo:
"Miscellaneous:

- Add Ian Rogers

Merge tag 'perf-tools-for-v6.3-1-2023-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull perf tools updates from Arnaldo Carvalho de Melo:
"Miscellaneous:

- Add Ian Rogers to MAINTAINERS as a perf tools reviewer.

- Add support for retire latency feature (pipeline stall of a
instruction compared to the previous one, in cycles) present on
some Intel processors.

- Add 'perf c2c' report option to show false sharing with adjacent
cachelines, to be used in machines with cacheline prefetching,
where accesses to a cacheline brings the next one too.

- Skip 'perf test bpf' when the required kernel-debuginfo package
isn't installed.

- Avoid d3-flame-graph package dependency in 'perf script flamegraph',
making this feature more generally available.

- Add JSON metric events to present CPI stall cycles in Power10.

- Assorted improvements/refactorings on the JSON metrics parsing
code.

perf lock contention:

- Add -o/--lock-owner option:

$ sudo ./perf lock contention -abo -- ./perf bench sched pipe
# Running 'sched/pipe' benchmark:
# Executed 1000000 pipe operations between two processes

Total time: 4.766 [sec]

4.766540 usecs/op
209795 ops/sec
contended total wait max wait avg wait pid owner

403 565.32 us 26.81 us 1.40 us -1 Unknown
4 27.99 us 8.57 us 7.00 us 1583145 sched-pipe
1 8.25 us 8.25 us 8.25 us 1583144 sched-pipe
1 2.03 us 2.03 us 2.03 us 5068 chrome

The owner is unknown in most cases. Filtering only for the
mutex locks, it will more likely get the owners.

- -S/--callstack-filter is to limit display entries having the given
string in the callstack:

$ sudo ./perf lock contention -abv -S net sleep 1
...
contended total wait max wait avg wait type caller

5 70.20 us 16.13 us 14.04 us spinlock __dev_queue_xmit+0xb6d
0xffffffffa5dd1c60 _raw_spin_lock+0x30
0xffffffffa5b8f6ed __dev_queue_xmit+0xb6d
0xffffffffa5cd8267 ip6_finish_output2+0x2c7
0xffffffffa5cdac14 ip6_finish_output+0x1d4
0xffffffffa5cdb477 ip6_xmit+0x457
0xffffffffa5d1fd17 inet6_csk_xmit+0xd7
0xffffffffa5c5f4aa __tcp_transmit_skb+0x54a
0xffffffffa5c6467d tcp_keepalive_timer+0x2fd

Please note that to have the -b option (BPF) working above one has
to build with BUILD_BPF_SKEL=1.

- Add more 'perf test' entries to test these new features.

perf script:

- Add 'cgroup' field for 'perf script' output:

$ perf record --all-cgroups -- true
$ perf script -F comm,pid,cgroup
true 337112 /user.slice/user-657345.slice/user@657345.service/...
true 337112 /user.slice/user-657345.slice/user@657345.service/...
true 337112 /user.slice/user-657345.slice/user@657345.service/...
true 337112 /user.slice/user-657345.slice/user@657345.service/...

- Add support for showing branch speculation information in 'perf
script' and in the 'perf report' raw dump (-D).

perf record:

- Fix 'perf record' segfault with --overwrite and --max-size.

perf test/bench:

- Switch basic BPF filtering test to use syscall tracepoint to avoid
the variable number of probes inserted when using the previous
probe point (do_epoll_wait) that happens on different CPU
architectures.

- Fix DWARF unwind test by adding non-inline to expected function in
a backtrace.

- Use 'grep -c' where the longer form 'grep | wc -l' was being used.

- Add getpid and execve benchmarks to 'perf bench syscall'.

Intel PT:

- Add support for synthesizing "cycle" events from Intel PT traces as
we support "instruction" events when Intel PT CYC packets are
available. This enables much more accurate profiles than when using
the regular 'perf record -e cycles' (the default) when the workload
lasts for very short periods (<10ms).

- .plt symbol handling improvements, better handling IBT (in the past
MPX) done in the context of decoding Intel PT processor traces,
IFUNC symbols on x86_64, static executables, understanding .plt.got
symbols on x86_64.

- Add a 'perf test' to test symbol resolution, part of the .plt
improvements series, this tests things like symbol size in contexts
where only the symbol start is available (kallsyms), etc.

- Better handle auxtrace/Intel PT data when using pipe mode (perf
record sleep 1|perf report).

- Fix symbol lookup with kcore with multiple segments match stext,
getting the symbol resolution to just show DSOs as unknown.

ARM:

- Timestamp improvements for ARM64 systems with ETMv4 (Embedded Trace
Macrocell v4).

- Ensure ARM64 CoreSight timestamps don't go backwards.

- Document that ARM64 SPE (Statistical Profiling Extension) is used
with 'perf c2c/mem'.

- Add raw decoding for ARM64 SPEv1.2 previous branch address.

- Update neoverse-n2-v2 ARM vendor events (JSON tables): topdown L1,
TLB, cache, branch, PE utilization and instruction mix metrics.

- Update decoder code for OpenCSD version 1.4, on ARM64 systems.

- Fix command line auto-complete of CPU events on aarch64.

Build:

- Fix 'perf probe' and 'perf test' when libtraceevent isn't linked,
as several tests use tracepoints, those should be skipped.

- More fallout fixes for the removal of tools/lib/traceevent/.

- Fix build error when linking with libpfm"

* tag 'perf-tools-for-v6.3-1-2023-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (114 commits)
perf tests stat_all_metrics: Change true workload to sleep workload for system wide check
perf vendor events power10: Add JSON metric events to present CPI stall cycles in powerpc
perf intel-pt: Synthesize cycle events
perf c2c: Add report option to show false sharing in adjacent cachelines
perf record: Fix segfault with --overwrite and --max-size
perf stat: Avoid merging/aggregating metric counts twice
perf tools: Fix perf tool build error in util/pfm.c
perf tools: Fix auto-complete on aarch64
perf lock contention: Support old rw_semaphore type
perf lock contention: Add -o/--lock-owner option
perf lock contention: Fix to save callstack for the default modified
perf test bpf: Skip test if kernel-debuginfo is not present
perf probe: Update the exit error codes in function try_to_find_probe_trace_event
perf script: Fix missing Retire Latency fields option documentation
perf event x86: Add retire_lat when synthesizing PERF_SAMPLE_WEIGHT_STRUCT
perf test x86: Support the retire_lat (Retire Latency) sample_type check
perf test bpf: Check for libtraceevent support
perf script: Support Retire Latency
perf report: Support Retire Latency
perf lock contention: Support filters for different aggregation
...

show more ...

Merge branch 'next' into for-linus

Prepare input updates for 6.3 merge window.

perf symbols: Get symbols for .plt.got for x86-64

For x86_64, determine a symbol for .plt.got entries. That requires
computing the target offset and finding that in .rela.dyn, which in
turn means .r

perf symbols: Get symbols for .plt.got for x86-64

For x86_64, determine a symbol for .plt.got entries. That requires
computing the target offset and finding that in .rela.dyn, which in
turn means .rela.dyn needs to be sorted by offset.

Example:

In this example, the GNU C Library is using .plt.got for malloc and
free.

Before:

$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ perf record -e intel_pt//u uname
Linux
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.027 MB perf.data ]
$ perf script --itrace=be --ns -F-event,+addr,-period,-comm,-tid,-cpu > /tmp/cmp1.txt

After:

$ perf script --itrace=be --ns -F-event,+addr,-period,-comm,-tid,-cpu > /tmp/cmp2.txt
$ diff /tmp/cmp1.txt /tmp/cmp2.txt | head -12
15509,15510c15509,15510
< 27046.755390907: 7f0b2943e3ab _nl_normalize_codeset+0x5b (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b29428380 offset_0x28380@plt+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
< 27046.755390907: 7f0b29428384 offset_0x28380@plt+0x4 (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b294a5120 malloc+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
---
> 27046.755390907: 7f0b2943e3ab _nl_normalize_codeset+0x5b (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b29428380 malloc@plt+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
> 27046.755390907: 7f0b29428384 malloc@plt+0x4 (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b294a5120 malloc+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
15821,15822c15821,15822
< 27046.755394865: 7f0b2943850c _nl_load_locale_from_archive+0x5bc (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b29428370 offset_0x28370@plt+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
< 27046.755394865: 7f0b29428374 offset_0x28370@plt+0x4 (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b294a5460 cfree@GLIBC_2.2.5+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
---
> 27046.755394865: 7f0b2943850c _nl_load_locale_from_archive+0x5bc (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b29428370 free@plt+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
> 27046.755394865: 7f0b29428374 free@plt+0x4 (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b294a5460 cfree@GLIBC_2.2.5+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-10-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf symbols: Start adding support for .plt.got for x86

For x86, .plt.got is used, for example, when the address is taken of a
dynamically linked function. Start adding support by synthesizing a
sym

perf symbols: Start adding support for .plt.got for x86

For x86, .plt.got is used, for example, when the address is taken of a
dynamically linked function. Start adding support by synthesizing a
symbol for each entry. A subsequent patch will attempt to get a better
name for the symbol.

Example:

Before:

$ cat tstpltlib.c
void fn1(void) {}
void fn2(void) {}
void fn3(void) {}
void fn4(void) {}
$ cat tstpltgot.c
void fn1(void);
void fn2(void);
void fn3(void);
void fn4(void);

void callfn(void (*fn)(void))
{
fn();
}

int main()
{
fn4();
fn1();
callfn(fn3);
fn2();
fn3();
return 0;
}
$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gcc -Wall -Wextra -shared -o libtstpltlib.so tstpltlib.c
$ gcc -Wall -Wextra -o tstpltgot tstpltgot.c -L . -ltstpltlib -Wl,-rpath="$(pwd)"
$ readelf -SW tstpltgot | grep 'Name\|plt\|dyn'
[Nr] Name Type Address Off Size ES Flg Lk Inf Al
[ 6] .dynsym DYNSYM 00000000000003d8 0003d8 0000f0 18 A 7 1 8
[ 7] .dynstr STRTAB 00000000000004c8 0004c8 0000c6 00 A 0 0 1
[10] .rela.dyn RELA 00000000000005d8 0005d8 0000d8 18 A 6 0 8
[11] .rela.plt RELA 00000000000006b0 0006b0 000048 18 AI 6 24 8
[13] .plt PROGBITS 0000000000001020 001020 000040 10 AX 0 0 16
[14] .plt.got PROGBITS 0000000000001060 001060 000020 10 AX 0 0 16
[15] .plt.sec PROGBITS 0000000000001080 001080 000030 10 AX 0 0 16
[23] .dynamic DYNAMIC 0000000000003d90 002d90 000210 10 WA 7 0 8
$ perf record -e intel_pt//u --filter 'filter main @ ./tstpltgot , filter callfn @ ./tstpltgot' ./tstpltgot
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.011 MB perf.data ]
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
28393.810326915: tr strt 0 [unknown] => 562350baa1b2 main+0x0
28393.810326915: tr end call 562350baa1ba main+0x8 => 562350baa090 fn4@plt+0x0
28393.810326917: tr strt 0 [unknown] => 562350baa1bf main+0xd
28393.810326917: tr end call 562350baa1bf main+0xd => 562350baa080 fn1@plt+0x0
28393.810326917: tr strt 0 [unknown] => 562350baa1c4 main+0x12
28393.810326917: call 562350baa1ce main+0x1c => 562350baa199 callfn+0x0
28393.810326917: tr end call 562350baa1ad callfn+0x14 => 7f607d36110f fn3+0x0
28393.810326922: tr strt 0 [unknown] => 562350baa1af callfn+0x16
28393.810326922: return 562350baa1b1 callfn+0x18 => 562350baa1d3 main+0x21
28393.810326922: tr end call 562350baa1d3 main+0x21 => 562350baa0a0 fn2@plt+0x0
28393.810326924: tr strt 0 [unknown] => 562350baa1d8 main+0x26
28393.810326924: tr end call 562350baa1d8 main+0x26 => 562350baa060 [unknown] <- call to fn3 via .plt.got
28393.810326925: tr strt 0 [unknown] => 562350baa1dd main+0x2b
28393.810326925: tr end return 562350baa1e3 main+0x31 => 7f607d029d90 __libc_start_call_main+0x80

After:

$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
28393.810326915: tr strt 0 [unknown] => 562350baa1b2 main+0x0
28393.810326915: tr end call 562350baa1ba main+0x8 => 562350baa090 fn4@plt+0x0
28393.810326917: tr strt 0 [unknown] => 562350baa1bf main+0xd
28393.810326917: tr end call 562350baa1bf main+0xd => 562350baa080 fn1@plt+0x0
28393.810326917: tr strt 0 [unknown] => 562350baa1c4 main+0x12
28393.810326917: call 562350baa1ce main+0x1c => 562350baa199 callfn+0x0
28393.810326917: tr end call 562350baa1ad callfn+0x14 => 7f607d36110f fn3+0x0
28393.810326922: tr strt 0 [unknown] => 562350baa1af callfn+0x16
28393.810326922: return 562350baa1b1 callfn+0x18 => 562350baa1d3 main+0x21
28393.810326922: tr end call 562350baa1d3 main+0x21 => 562350baa0a0 fn2@plt+0x0
28393.810326924: tr strt 0 [unknown] => 562350baa1d8 main+0x26
28393.810326924: tr end call 562350baa1d8 main+0x26 => 562350baa060 offset_0x1060@plt+0x0
28393.810326925: tr strt 0 [unknown] => 562350baa1dd main+0x2b
28393.810326925: tr end return 562350baa1e3 main+0x31 => 7f607d029d90 __libc_start_call_main+0x80

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-9-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf symbols: Allow for static executables with .plt

A statically linked executable can have a .plt due to IFUNCs, in which
case .symtab is used not .dynsym. Check the section header link to see
if

perf symbols: Allow for static executables with .plt

A statically linked executable can have a .plt due to IFUNCs, in which
case .symtab is used not .dynsym. Check the section header link to see
if that is the case, and then use symtab instead.

Example:

Before:

$ cat tstifunc.c
#include <stdio.h>

void thing1(void)
{
printf("thing1\n");
}

void thing2(void)
{
printf("thing2\n");
}

typedef void (*thing_fn_t)(void);

thing_fn_t thing_ifunc(void)
{
int x;

if (x & 1)
return thing2;
return thing1;
}

void thing(void) __attribute__ ((ifunc ("thing_ifunc")));

int main()
{
thing();
return 0;
}
$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gcc -static -Wall -Wextra -Wno-uninitialized -o tstifuncstatic tstifunc.c
$ readelf -SW tstifuncstatic | grep 'Name\|plt\|dyn'
[Nr] Name Type Address Off Size ES Flg Lk Inf Al
[ 4] .rela.plt RELA 00000000004002e8 0002e8 000258 18 AI 29 20 8
[ 6] .plt PROGBITS 0000000000401020 001020 000190 00 AX 0 0 16
[20] .got.plt PROGBITS 00000000004c5000 0c4000 0000e0 08 WA 0 0 8
$ perf record -e intel_pt//u --filter 'filter main @ ./tstifuncstatic' ./tstifuncstatic
thing1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.008 MB perf.data ]
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
15786.690189535: tr strt 0 [unknown] => 4017cd main+0x0
15786.690189535: tr end call 4017d5 main+0x8 => 401170 [unknown]
15786.690197660: tr strt 0 [unknown] => 4017da main+0xd
15786.690197660: tr end return 4017e0 main+0x13 => 401c1a __libc_start_call_main+0x6a

After:

$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
15786.690189535: tr strt 0 [unknown] => 4017cd main+0x0
15786.690189535: tr end call 4017d5 main+0x8 => 401170 thing_ifunc@plt+0x0
15786.690197660: tr strt 0 [unknown] => 4017da main+0xd
15786.690197660: tr end return 4017e0 main+0x13 => 401c1a __libc_start_call_main+0x6a

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-8-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf symbols: Allow for .plt without header

A static executable can have a .plt due to the presence of IFUNCs. In
that case the .plt does not have a header. Check for whether there is a
header by c

perf symbols: Allow for .plt without header

A static executable can have a .plt due to the presence of IFUNCs. In
that case the .plt does not have a header. Check for whether there is a
header by comparing the number of entries to the number of relocation
entries.

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-7-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf symbols: Add support for IFUNC symbols for x86_64

For x86_64, the GNU linker is putting IFUNC information in the relocation
addend, so use it to try to find a symbol for plt entries that refer

perf symbols: Add support for IFUNC symbols for x86_64

For x86_64, the GNU linker is putting IFUNC information in the relocation
addend, so use it to try to find a symbol for plt entries that refer to
IFUNCs.

Example:

Before:

$ cat tstpltlib.c
void fn1(void) {}
void fn2(void) {}
void fn3(void) {}
void fn4(void) {}
$ cat tstpltifunc.c
#include <stdio.h>

void thing1(void)
{
printf("thing1\n");
}

void thing2(void)
{
printf("thing2\n");
}

typedef void (*thing_fn_t)(void);

thing_fn_t thing_ifunc(void)
{
int x;

if (x & 1)
return thing2;
return thing1;
}

void thing(void) __attribute__ ((ifunc ("thing_ifunc")));

void fn1(void);
void fn2(void);
void fn3(void);
void fn4(void);

int main()
{
fn4();
fn1();
thing();
fn2();
fn3();
return 0;
}
$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gcc -Wall -Wextra -shared -o libtstpltlib.so tstpltlib.c
$ gcc -Wall -Wextra -Wno-uninitialized -o tstpltifunc tstpltifunc.c -L . -ltstpltlib -Wl,-rpath="$(pwd)"
$ readelf -rW tstpltifunc | grep -A99 plt
Relocation section '.rela.plt' at offset 0x738 contains 8 entries:
Offset Info Type Symbol's Value Symbol's Name + Addend
0000000000003f98 0000000300000007 R_X86_64_JUMP_SLOT 0000000000000000 puts@GLIBC_2.2.5 + 0
0000000000003fa8 0000000400000007 R_X86_64_JUMP_SLOT 0000000000000000 __stack_chk_fail@GLIBC_2.4 + 0
0000000000003fb0 0000000500000007 R_X86_64_JUMP_SLOT 0000000000000000 fn1 + 0
0000000000003fb8 0000000600000007 R_X86_64_JUMP_SLOT 0000000000000000 fn3 + 0
0000000000003fc0 0000000800000007 R_X86_64_JUMP_SLOT 0000000000000000 fn4 + 0
0000000000003fc8 0000000900000007 R_X86_64_JUMP_SLOT 0000000000000000 fn2 + 0
0000000000003fd0 0000000b00000007 R_X86_64_JUMP_SLOT 0000000000000000 getrandom@GLIBC_2.25 + 0
0000000000003fa0 0000000000000025 R_X86_64_IRELATIVE 125d
$ perf record -e intel_pt//u --filter 'filter main @ ./tstpltifunc' ./tstpltifunc
thing2
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.016 MB perf.data ]
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
21860.073683659: tr strt 0 [unknown] => 561e212c42be main+0x0
21860.073683659: tr end call 561e212c42c6 main+0x8 => 561e212c4110 fn4@plt+0x0
21860.073683661: tr strt 0 [unknown] => 561e212c42cb main+0xd
21860.073683661: tr end call 561e212c42cb main+0xd => 561e212c40f0 fn1@plt+0x0
21860.073683661: tr strt 0 [unknown] => 561e212c42d0 main+0x12
21860.073683661: tr end call 561e212c42d0 main+0x12 => 561e212c40d0 offset_0x10d0@plt+0x0
21860.073698451: tr strt 0 [unknown] => 561e212c42d5 main+0x17
21860.073698451: tr end call 561e212c42d5 main+0x17 => 561e212c4120 fn2@plt+0x0
21860.073698451: tr strt 0 [unknown] => 561e212c42da main+0x1c
21860.073698451: tr end call 561e212c42da main+0x1c => 561e212c4100 fn3@plt+0x0
21860.073698452: tr strt 0 [unknown] => 561e212c42df main+0x21
21860.073698452: tr end return 561e212c42e5 main+0x27 => 7fb51cc29d90 __libc_start_call_main+0x80

After:

$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
21860.073683659: tr strt 0 [unknown] => 561e212c42be main+0x0
21860.073683659: tr end call 561e212c42c6 main+0x8 => 561e212c4110 fn4@plt+0x0
21860.073683661: tr strt 0 [unknown] => 561e212c42cb main+0xd
21860.073683661: tr end call 561e212c42cb main+0xd => 561e212c40f0 fn1@plt+0x0
21860.073683661: tr strt 0 [unknown] => 561e212c42d0 main+0x12
21860.073683661: tr end call 561e212c42d0 main+0x12 => 561e212c40d0 thing_ifunc@plt+0x0
21860.073698451: tr strt 0 [unknown] => 561e212c42d5 main+0x17
21860.073698451: tr end call 561e212c42d5 main+0x17 => 561e212c4120 fn2@plt+0x0
21860.073698451: tr strt 0 [unknown] => 561e212c42da main+0x1c
21860.073698451: tr end call 561e212c42da main+0x1c => 561e212c4100 fn3@plt+0x0
21860.073698452: tr strt 0 [unknown] => 561e212c42df main+0x21
21860.073698452: tr end return 561e212c42e5 main+0x27 => 7fb51cc29d90 __libc_start_call_main+0x80

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-6-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf symbols: Sort plt relocations for x86

For x86, with the addition of IFUNCs, relocation information becomes
disordered with respect to plt. Correct that by sorting the relocations by
offset.

Ex

perf symbols: Sort plt relocations for x86

For x86, with the addition of IFUNCs, relocation information becomes
disordered with respect to plt. Correct that by sorting the relocations by
offset.

Example:

Before:

$ cat tstpltlib.c
void fn1(void) {}
void fn2(void) {}
void fn3(void) {}
void fn4(void) {}
$ cat tstpltifunc.c
#include <stdio.h>

void thing1(void)
{
printf("thing1\n");
}

void thing2(void)
{
printf("thing2\n");
}

typedef void (*thing_fn_t)(void);

thing_fn_t thing_ifunc(void)
{
int x;

if (x & 1)
return thing2;
return thing1;
}

void thing(void) __attribute__ ((ifunc ("thing_ifunc")));

void fn1(void);
void fn2(void);
void fn3(void);
void fn4(void);

int main()
{
fn4();
fn1();
thing();
fn2();
fn3();
return 0;
}
$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gcc -Wall -Wextra -shared -o libtstpltlib.so tstpltlib.c
$ gcc -Wall -Wextra -Wno-uninitialized -o tstpltifunc tstpltifunc.c -L . -ltstpltlib -Wl,-rpath="$(pwd)"
$ readelf -rW tstpltifunc | grep -A99 plt
Relocation section '.rela.plt' at offset 0x738 contains 8 entries:
Offset Info Type Symbol's Value Symbol's Name + Addend
0000000000003f98 0000000300000007 R_X86_64_JUMP_SLOT 0000000000000000 puts@GLIBC_2.2.5 + 0
0000000000003fa8 0000000400000007 R_X86_64_JUMP_SLOT 0000000000000000 __stack_chk_fail@GLIBC_2.4 + 0
0000000000003fb0 0000000500000007 R_X86_64_JUMP_SLOT 0000000000000000 fn1 + 0
0000000000003fb8 0000000600000007 R_X86_64_JUMP_SLOT 0000000000000000 fn3 + 0
0000000000003fc0 0000000800000007 R_X86_64_JUMP_SLOT 0000000000000000 fn4 + 0
0000000000003fc8 0000000900000007 R_X86_64_JUMP_SLOT 0000000000000000 fn2 + 0
0000000000003fd0 0000000b00000007 R_X86_64_JUMP_SLOT 0000000000000000 getrandom@GLIBC_2.25 + 0
0000000000003fa0 0000000000000025 R_X86_64_IRELATIVE 125d
$ perf record -e intel_pt//u --filter 'filter main @ ./tstpltifunc' ./tstpltifunc
thing2
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.029 MB perf.data ]
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
20417.302513948: tr strt 0 [unknown] => 5629a74892be main+0x0
20417.302513948: tr end call 5629a74892c6 main+0x8 => 5629a7489110 fn2@plt+0x0
20417.302513949: tr strt 0 [unknown] => 5629a74892cb main+0xd
20417.302513949: tr end call 5629a74892cb main+0xd => 5629a74890f0 fn3@plt+0x0
20417.302513950: tr strt 0 [unknown] => 5629a74892d0 main+0x12
20417.302513950: tr end call 5629a74892d0 main+0x12 => 5629a74890d0 __stack_chk_fail@plt+0x0
20417.302528114: tr strt 0 [unknown] => 5629a74892d5 main+0x17
20417.302528114: tr end call 5629a74892d5 main+0x17 => 5629a7489120 getrandom@plt+0x0
20417.302528115: tr strt 0 [unknown] => 5629a74892da main+0x1c
20417.302528115: tr end call 5629a74892da main+0x1c => 5629a7489100 fn4@plt+0x0
20417.302528115: tr strt 0 [unknown] => 5629a74892df main+0x21
20417.302528115: tr end return 5629a74892e5 main+0x27 => 7ff14da29d90 __libc_start_call_main+0x80

After:

$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
20417.302513948: tr strt 0 [unknown] => 5629a74892be main+0x0
20417.302513948: tr end call 5629a74892c6 main+0x8 => 5629a7489110 fn4@plt+0x0
20417.302513949: tr strt 0 [unknown] => 5629a74892cb main+0xd
20417.302513949: tr end call 5629a74892cb main+0xd => 5629a74890f0 fn1@plt+0x0
20417.302513950: tr strt 0 [unknown] => 5629a74892d0 main+0x12
20417.302513950: tr end call 5629a74892d0 main+0x12 => 5629a74890d0 offset_0x10d0@plt+0x0
20417.302528114: tr strt 0 [unknown] => 5629a74892d5 main+0x17
20417.302528114: tr end call 5629a74892d5 main+0x17 => 5629a7489120 fn2@plt+0x0
20417.302528115: tr strt 0 [unknown] => 5629a74892da main+0x1c
20417.302528115: tr end call 5629a74892da main+0x1c => 5629a7489100 fn3@plt+0x0
20417.302528115: tr strt 0 [unknown] => 5629a74892df main+0x21
20417.302528115: tr end return 5629a74892e5 main+0x27 => 7ff14da29d90 __libc_start_call_main+0x80

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf symbols: Add support for x86 .plt.sec

The section .plt.sec was originally added for MPX and was first called
.plt.bnd. While MPX has been deprecated, .plt.sec is now also used for
IBT. On x86_

perf symbols: Add support for x86 .plt.sec

The section .plt.sec was originally added for MPX and was first called
.plt.bnd. While MPX has been deprecated, .plt.sec is now also used for
IBT. On x86_64, IBT may be enabled by default, but can be switched off
using gcc option -fcf-protection=none, or switched on by -z ibt or -z
ibtplt. On 32-bit, option -z ibt or -z ibtplt will enable IBT.

With .plt.sec, calls are made into .plt.sec instead of .plt, so it makes
more sense to put the symbols there instead of .plt. A notable
difference is that .plt.sec does not have a header entry.

For x86, when synthesizing symbols for plt, use offset and entry size of
.plt.sec instead of .plt when there is a .plt.sec section.

Example on Ubuntu 22.04 gcc 11.3:

Before:

$ cat tstpltlib.c
void fn1(void) {}
void fn2(void) {}
void fn3(void) {}
void fn4(void) {}
$ cat tstplt.c
void fn1(void);
void fn2(void);
void fn3(void);
void fn4(void);

int main()
{
fn4();
fn1();
fn2();
fn3();
return 0;
}
$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gcc -Wall -Wextra -shared -o libtstpltlib.so tstpltlib.c
$ gcc -Wall -Wextra -z ibt -o tstplt tstplt.c -L . -ltstpltlib -Wl,-rpath=$(pwd)
$ readelf -SW tstplt | grep 'plt\|Name'
[Nr] Name Type Address Off Size ES Flg Lk Inf Al
[11] .rela.plt RELA 0000000000000698 000698 000060 18 AI 6 24 8
[13] .plt PROGBITS 0000000000001020 001020 000050 10 AX 0 0 16
[14] .plt.got PROGBITS 0000000000001070 001070 000010 10 AX 0 0 16
[15] .plt.sec PROGBITS 0000000000001080 001080 000040 10 AX 0 0 16
$ perf record -e intel_pt//u --filter 'filter main @ ./tstplt' ./tstplt
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.015 MB perf.data ]
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
38970.522546686: tr strt 0 [unknown] => 55fc222a81a9 main+0x0
38970.522546686: tr end call 55fc222a81b1 main+0x8 => 55fc222a80a0 [unknown]
38970.522546687: tr strt 0 [unknown] => 55fc222a81b6 main+0xd
38970.522546687: tr end call 55fc222a81b6 main+0xd => 55fc222a8080 [unknown]
38970.522546688: tr strt 0 [unknown] => 55fc222a81bb main+0x12
38970.522546688: tr end call 55fc222a81bb main+0x12 => 55fc222a80b0 [unknown]
38970.522546688: tr strt 0 [unknown] => 55fc222a81c0 main+0x17
38970.522546688: tr end call 55fc222a81c0 main+0x17 => 55fc222a8090 [unknown]
38970.522546689: tr strt 0 [unknown] => 55fc222a81c5 main+0x1c
38970.522546894: tr end return 55fc222a81cb main+0x22 => 7f3a4dc29d90 __libc_start_call_main+0x80

After:

$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
38970.522546686: tr strt 0 [unknown] => 55fc222a81a9 main+0x0
38970.522546686: tr end call 55fc222a81b1 main+0x8 => 55fc222a80a0 fn4@plt+0x0
38970.522546687: tr strt 0 [unknown] => 55fc222a81b6 main+0xd
38970.522546687: tr end call 55fc222a81b6 main+0xd => 55fc222a8080 fn1@plt+0x0
38970.522546688: tr strt 0 [unknown] => 55fc222a81bb main+0x12
38970.522546688: tr end call 55fc222a81bb main+0x12 => 55fc222a80b0 fn2@plt+0x0
38970.522546688: tr strt 0 [unknown] => 55fc222a81c0 main+0x17
38970.522546688: tr end call 55fc222a81c0 main+0x17 => 55fc222a8090 fn3@plt+0x0
38970.522546689: tr strt 0 [unknown] => 55fc222a81c5 main+0x1c
38970.522546894: tr end return 55fc222a81cb main+0x22 => 7f3a4dc29d90 __libc_start_call_main+0x80

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf symbols: Correct plt entry sizes for x86

In 32-bit executables the .plt entry size can be set to 4 when it is really
16. In fact the only sizes used for x86 (32 or 64 bit) are 8 or 16, so
check

perf symbols: Correct plt entry sizes for x86

In 32-bit executables the .plt entry size can be set to 4 when it is really
16. In fact the only sizes used for x86 (32 or 64 bit) are 8 or 16, so
check for those and, if not, use the alignment to choose which it is.

Example on Ubuntu 22.04 gcc 11.3:

Before:

$ cat tstpltlib.c
void fn1(void) {}
void fn2(void) {}
void fn3(void) {}
void fn4(void) {}
$ cat tstplt.c
void fn1(void);
void fn2(void);
void fn3(void);
void fn4(void);

int main()
{
fn4();
fn1();
fn2();
fn3();
return 0;
}
$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gcc -m32 -Wall -Wextra -shared -o libtstpltlib32.so tstpltlib.c
$ gcc -m32 -Wall -Wextra -o tstplt32 tstplt.c -L . -ltstpltlib32 -Wl,-rpath=$(pwd)
$ perf record -e intel_pt//u --filter 'filter main @ ./tstplt32' ./tstplt32
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.011 MB perf.data ]
$ readelf -SW tstplt32 | grep 'plt\|Name'
[Nr] Name Type Addr Off Size ES Flg Lk Inf Al
[10] .rel.plt REL 0000041c 00041c 000028 08 AI 5 22 4
[12] .plt PROGBITS 00001030 001030 000060 04 AX 0 0 16 <- ES is 0x04, should be 0x10
[13] .plt.got PROGBITS 00001090 001090 000008 08 AX 0 0 8
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
17894.383903029: tr strt 0 [unknown] => 565b81cd main+0x0
17894.383903029: tr end call 565b81d4 main+0x7 => 565b80d0 __x86.get_pc_thunk.bx+0x0
17894.383903031: tr strt 0 [unknown] => 565b81d9 main+0xc
17894.383903031: tr end call 565b81df main+0x12 => 565b8070 [unknown]
17894.383903032: tr strt 0 [unknown] => 565b81e4 main+0x17
17894.383903032: tr end call 565b81e4 main+0x17 => 565b8050 [unknown]
17894.383903033: tr strt 0 [unknown] => 565b81e9 main+0x1c
17894.383903033: tr end call 565b81e9 main+0x1c => 565b8080 [unknown]
17894.383903033: tr strt 0 [unknown] => 565b81ee main+0x21
17894.383903033: tr end call 565b81ee main+0x21 => 565b8060 [unknown]
17894.383903237: tr strt 0 [unknown] => 565b81f3 main+0x26
17894.383903237: tr end return 565b81fc main+0x2f => f7c21519 [unknown]

After:

$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
17894.383903029: tr strt 0 [unknown] => 565b81cd main+0x0
17894.383903029: tr end call 565b81d4 main+0x7 => 565b80d0 __x86.get_pc_thunk.bx+0x0
17894.383903031: tr strt 0 [unknown] => 565b81d9 main+0xc
17894.383903031: tr end call 565b81df main+0x12 => 565b8070 fn4@plt+0x0
17894.383903032: tr strt 0 [unknown] => 565b81e4 main+0x17
17894.383903032: tr end call 565b81e4 main+0x17 => 565b8050 fn1@plt+0x0
17894.383903033: tr strt 0 [unknown] => 565b81e9 main+0x1c
17894.383903033: tr end call 565b81e9 main+0x1c => 565b8080 fn2@plt+0x0
17894.383903033: tr strt 0 [unknown] => 565b81ee main+0x21
17894.383903033: tr end call 565b81ee main+0x21 => 565b8060 fn3@plt+0x0
17894.383903237: tr strt 0 [unknown] => 565b81f3 main+0x26
17894.383903237: tr end return 565b81fc main+0x2f => f7c21519 [unknown]

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf symbols: Check SHT_RELA and SHT_REL type earlier

Make the code more readable by checking for SHT_RELA and SHT_REL type
earlier.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by:

perf symbols: Check SHT_RELA and SHT_REL type earlier

Make the code more readable by checking for SHT_RELA and SHT_REL type
earlier.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-11-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf symbols: Combine handling for SHT_RELA and SHT_REL

SHT_REL and SHT_RELA are handled the same way. Simplify by combining the
handling.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Ack

perf symbols: Combine handling for SHT_RELA and SHT_REL

SHT_REL and SHT_RELA are handled the same way. Simplify by combining the
handling.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-10-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf symbols: Allow for .plt entries with no symbol

Create a sensible name for .plt entries with no symbol.

Example:

Before:

$ perf test --dso /usr/lib/x86_64-linux-gnu/libc.so.6 -vv Symbols

perf symbols: Allow for .plt entries with no symbol

Create a sensible name for .plt entries with no symbol.

Example:

Before:

$ perf test --dso /usr/lib/x86_64-linux-gnu/libc.so.6 -vv Symbols 2>/tmp/cmp1.txt

After:

$ perf test --dso /usr/lib/x86_64-linux-gnu/libc.so.6 -vv Symbols 2>/tmp/cmp2.txt
$ diff /tmp/cmp1.txt /tmp/cmp2.txt
4c4
< test child forked, pid 53043
---
> test child forked, pid 54372
23,62c23,62
< 280f0-28100 g @plt
< 28100-28110 g @plt
< 28110-28120 g @plt
< 28120-28130 g @plt
< 28130-28140 g @plt
< 28140-28150 g @plt
< 28150-28160 g @plt
< 28160-28170 g @plt
< 28170-28180 g @plt
< 28180-28190 g @plt
< 28190-281a0 g @plt
< 281a0-281b0 g @plt
< 281b0-281c0 g @plt
< 281c0-281d0 g @plt
< 281d0-281e0 g @plt
< 281e0-281f0 g @plt
< 281f0-28200 g @plt
< 28200-28210 g @plt
< 28210-28220 g @plt
< 28220-28230 g @plt
< 28230-28240 g @plt
< 28240-28250 g @plt
< 28250-28260 g @plt
< 28260-28270 g @plt
< 28270-28280 g @plt
< 28280-28290 g @plt
< 28290-282a0 g @plt
< 282a0-282b0 g @plt
< 282b0-282c0 g @plt
< 282c0-282d0 g @plt
< 282d0-282e0 g @plt
< 282e0-282f0 g @plt
< 282f0-28300 g @plt
< 28300-28310 g @plt
< 28310-28320 g @plt
< 28320-28330 g @plt
< 28330-28340 g @plt
< 28340-28350 g @plt
< 28350-28360 g @plt
< 28360-28370 g @plt
---
> 280f0-28100 g offset_0x280f0@plt
> 28100-28110 g offset_0x28100@plt
> 28110-28120 g offset_0x28110@plt
> 28120-28130 g offset_0x28120@plt
> 28130-28140 g offset_0x28130@plt
> 28140-28150 g offset_0x28140@plt
> 28150-28160 g offset_0x28150@plt
> 28160-28170 g offset_0x28160@plt
> 28170-28180 g offset_0x28170@plt
> 28180-28190 g offset_0x28180@plt
> 28190-281a0 g offset_0x28190@plt
> 281a0-281b0 g offset_0x281a0@plt
> 281b0-281c0 g offset_0x281b0@plt
> 281c0-281d0 g offset_0x281c0@plt
> 281d0-281e0 g offset_0x281d0@plt
> 281e0-281f0 g offset_0x281e0@plt
> 281f0-28200 g offset_0x281f0@plt
> 28200-28210 g offset_0x28200@plt
> 28210-28220 g offset_0x28210@plt
> 28220-28230 g offset_0x28220@plt
> 28230-28240 g offset_0x28230@plt
> 28240-28250 g offset_0x28240@plt
> 28250-28260 g offset_0x28250@plt
> 28260-28270 g offset_0x28260@plt
> 28270-28280 g offset_0x28270@plt
> 28280-28290 g offset_0x28280@plt
> 28290-282a0 g offset_0x28290@plt
> 282a0-282b0 g offset_0x282a0@plt
> 282b0-282c0 g offset_0x282b0@plt
> 282c0-282d0 g offset_0x282c0@plt
> 282d0-282e0 g offset_0x282d0@plt
> 282e0-282f0 g offset_0x282e0@plt
> 282f0-28300 g offset_0x282f0@plt
> 28300-28310 g offset_0x28300@plt
> 28310-28320 g offset_0x28310@plt
> 28320-28330 g offset_0x28320@plt
> 28330-28340 g offset_0x28330@plt
> 28340-28350 g offset_0x28340@plt
> 28350-28360 g offset_0x28350@plt
> 28360-28370 g offset_0x28360@plt

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-9-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf symbols: Add symbol for .plt header

perf expands the _init symbol over .plt because there are no PLT symbols
at that point, but then dso__synthesize_plt_symbols() creates them.

Fix by truncati

perf symbols: Add symbol for .plt header

perf expands the _init symbol over .plt because there are no PLT symbols
at that point, but then dso__synthesize_plt_symbols() creates them.

Fix by truncating the previous symbol and inserting a symbol for .plt
header.

Example:

Before:

$ perf test --dso `which uname` -v Symbols
74: Symbols :
--- start ---
test child forked, pid 191028
Problems creating module maps, continuing anyway...
Testing /usr/bin/uname
Overlapping symbols:
2000-25f0 g _init
2040-2050 g free@plt
test child finished with -1
---- end ----
Symbols: FAILED!
$ perf test --dso `which uname` -vv Symbols 2>/tmp/cmp1.txt

After:

$ perf test --dso `which uname` -v Symbols
74: Symbols :
--- start ---
test child forked, pid 194291
Testing /usr/bin/uname
test child finished with 0
---- end ----
Symbols: Ok
$ perf test --dso `which uname` -vv Symbols 2>/tmp/cmp2.txt
$ diff /tmp/cmp1.txt /tmp/cmp2.txt
4,5c4
< test child forked, pid 191031
< Problems creating module maps, continuing anyway...
---
> test child forked, pid 194296
9c8,9
< 2000-25f0 g _init
---
> 2000-2030 g _init
> 2030-2040 g .plt
100,103c100
< Overlapping symbols:
< 2000-25f0 g _init
< 2040-2050 g free@plt
< test child finished with -1
---
> test child finished with 0
105c102
< Symbols: FAILED!
---
> Symbols: Ok
$

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-8-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...