History log of /linux-master/tools/perf/arch/powerpc/util/sym-handling.c
Revision Date Author Comments
# 78a1f7cd 04-Apr-2023 Ian Rogers <irogers@google.com>

perf map: Add helper for ->map_ip() and ->unmap_ip()

Later changes will add reference count checking for struct map, add a
helper function to invoke the map_ip and unmap_ip function pointers. The
helper allows the reference count check to be in fewer places.

Committer notes:

Add missing conversions to:

tools/perf/util/map.c
tools/perf/util/cs-etm.c
tools/perf/util/annotate.c
tools/perf/arch/powerpc/util/sym-handling.c
tools/perf/arch/s390/annotate/instructions.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/20230404205954.2245628-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 63df0e4b 20-Mar-2023 Ian Rogers <irogers@google.com>

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>


# 7eec00a7 05-Mar-2020 Leo Yan <leo.yan@linaro.org>

perf symbols: Consolidate symbol fixup issue

After copying Arm64's perf archive with object files and perf.data file
to x86 laptop, the x86's perf kernel symbol resolution fails. It
outputs 'unknown' for all symbols parsing.

This issue is root caused by the function elf__needs_adjust_symbols(),
x86 perf tool uses one weak version, Arm64 (and powerpc) has rewritten
their own version. elf__needs_adjust_symbols() decides if need to parse
symbols with the relative offset address; but x86 building uses the weak
function which misses to check for the elf type 'ET_DYN', so that it
cannot parse symbols in Arm DSOs due to the wrong result from
elf__needs_adjust_symbols().

The DSO parsing should not depend on any specific architecture perf
building; e.g. x86 perf tool can parse Arm and Arm64 DSOs, vice versa.
And confirmed by Naveen N. Rao that powerpc64 kernels are not being
built as ET_DYN anymore and change to ET_EXEC.

This patch removes the arch specific functions for Arm64 and powerpc and
changes elf__needs_adjust_symbols() as a common function.

In the common elf__needs_adjust_symbols(), it checks an extra condition
'ET_DYN' for elf header type. With this fixing, the Arm64 DSO can be
parsed properly with x86's perf tool.

Before:

# perf script
main 3258 1 branches: 0 [unknown] ([unknown]) => ffff800010c4665c [unknown] ([kernel.kallsyms])
main 3258 1 branches: ffff800010c46670 [unknown] ([kernel.kallsyms]) => ffff800010c4eaec [unknown] ([kernel.kallsyms])
main 3258 1 branches: ffff800010c4eaec [unknown] ([kernel.kallsyms]) => ffff800010c4eb00 [unknown] ([kernel.kallsyms])
main 3258 1 branches: ffff800010c4eb08 [unknown] ([kernel.kallsyms]) => ffff800010c4e780 [unknown] ([kernel.kallsyms])
main 3258 1 branches: ffff800010c4e7a0 [unknown] ([kernel.kallsyms]) => ffff800010c4eeac [unknown] ([kernel.kallsyms])
main 3258 1 branches: ffff800010c4eebc [unknown] ([kernel.kallsyms]) => ffff800010c4ed80 [unknown] ([kernel.kallsyms])

After:

# perf script
main 3258 1 branches: 0 [unknown] ([unknown]) => ffff800010c4665c coresight_timeout+0x54 ([kernel.kallsyms])
main 3258 1 branches: ffff800010c46670 coresight_timeout+0x68 ([kernel.kallsyms]) => ffff800010c4eaec etm4_enable_hw+0x3cc ([kernel.kallsyms])
main 3258 1 branches: ffff800010c4eaec etm4_enable_hw+0x3cc ([kernel.kallsyms]) => ffff800010c4eb00 etm4_enable_hw+0x3e0 ([kernel.kallsyms])
main 3258 1 branches: ffff800010c4eb08 etm4_enable_hw+0x3e8 ([kernel.kallsyms]) => ffff800010c4e780 etm4_enable_hw+0x60 ([kernel.kallsyms])
main 3258 1 branches: ffff800010c4e7a0 etm4_enable_hw+0x80 ([kernel.kallsyms]) => ffff800010c4eeac etm4_enable+0x2d4 ([kernel.kallsyms])
main 3258 1 branches: ffff800010c4eebc etm4_enable+0x2e4 ([kernel.kallsyms]) => ffff800010c4ed80 etm4_enable+0x1a8 ([kernel.kallsyms])

v3: Changed to check for ET_DYN across all architectures.

v2: Fixed Arm64 and powerpc native building.

Reported-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Allison Randal <allison@lohutok.net>
Cc: Enrico Weigelt <info@metux.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Link: http://lore.kernel.org/lkml/20200306015759.10084-1-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 4a903c2e 03-Sep-2019 Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Remove debug.h from places where it is not needed

Pruning a bit more the includes dependency tree. Building this thing on
lots of containers takes time, we better reduce the time per build, each
container is doing 6 builds when clang and clang-devel are available,
and the plan is to do a 'make -C tools/perf build-test' that have many
more.

Also helps when doing normal development, as touching some random file
will have a much reduced chance of triggering lots of rebuilds.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-r889ur2cxe16m91m2a4pl15p@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# b1d1b094 30-Aug-2019 Arnaldo Carvalho de Melo <acme@redhat.com>

perf symbols: Move symsrc prototypes to a separate header

So that we can remove dso.h from symbol.h and reduce the header
dependency tree.

Fixup cases where struct dso guts are needed but were obtained via
symbol.h, indirectly.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-ip683cegt306ncu3gsz7ii21@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# d2912cb1 04-Jun-2019 Thomas Gleixner <tglx@linutronix.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# fa694160 28-Aug-2018 Sandipan Das <sandipan@linux.ibm.com>

perf probe powerpc: Ignore SyS symbols irrespective of endianness

This makes sure that the SyS symbols are ignored for any powerpc system,
not just the big endian ones.

Reported-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Fixes: fb6d59423115 ("perf probe ppc: Use the right prefix when ignoring SyS symbols on ppc")
Link: http://lkml.kernel.org/r/20180828090848.1914-1-sandipan@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 354b064b 09-Aug-2018 Sandipan Das <sandipan@linux.ibm.com>

perf probe powerpc: Fix trace event post-processing

In some cases, a symbol may have multiple aliases. Attempting to add an
entry probe for such symbols results in a probe being added at an
incorrect location while it fails altogether for return probes. This is
only applicable for binaries with debug information.

During the arch-dependent post-processing, the offset from the start of
the symbol at which the probe is to be attached is determined and added
to the start address of the symbol to get the probe's location. In case
there are multiple aliases, this offset gets added multiple times for
each alias of the symbol and we end up with an incorrect probe location.

This can be verified on a powerpc64le system as shown below.

$ nm /lib/modules/$(uname -r)/build/vmlinux | grep "sys_open$"
...
c000000000414290 T __se_sys_open
c000000000414290 T sys_open

$ objdump -d /lib/modules/$(uname -r)/build/vmlinux | grep -A 10 "<__se_sys_open>:"

c000000000414290 <__se_sys_open>:
c000000000414290: 19 01 4c 3c addis r2,r12,281
c000000000414294: 70 c4 42 38 addi r2,r2,-15248
c000000000414298: a6 02 08 7c mflr r0
c00000000041429c: e8 ff a1 fb std r29,-24(r1)
c0000000004142a0: f0 ff c1 fb std r30,-16(r1)
c0000000004142a4: f8 ff e1 fb std r31,-8(r1)
c0000000004142a8: 10 00 01 f8 std r0,16(r1)
c0000000004142ac: c1 ff 21 f8 stdu r1,-64(r1)
c0000000004142b0: 78 23 9f 7c mr r31,r4
c0000000004142b4: 78 1b 7e 7c mr r30,r3

For both the entry probe and the return probe, the probe location
should be _text+4276888 (0xc000000000414298). Since another alias
exists for 'sys_open', the post-processing code will end up adding
the offset (8 for powerpc64le) twice and perf will attempt to add
the probe at _text+4276896 (0xc0000000004142a0) instead.

Before:

# perf probe -v -a sys_open

probe-definition(0): sys_open
symbol:sys_open file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
Looking at the vmlinux_path (8 entries long)
Using /lib/modules/4.18.0-rc8+/build/vmlinux for symbols
Open Debuginfo file: /lib/modules/4.18.0-rc8+/build/vmlinux
Try to find probe point from debuginfo.
Symbol sys_open address found : c000000000414290
Matched function: __se_sys_open [2ad03a0]
Probe point found: __se_sys_open+0
Found 1 probe_trace_events.
Opening /sys/kernel/debug/tracing/kprobe_events write=1
Writing event: p:probe/sys_open _text+4276896
Added new event:
probe:sys_open (on sys_open)
...

# perf probe -v -a sys_open%return $retval

probe-definition(0): sys_open%return
symbol:sys_open file:(null) line:0 offset:0 return:1 lazy:(null)
0 arguments
Looking at the vmlinux_path (8 entries long)
Using /lib/modules/4.18.0-rc8+/build/vmlinux for symbols
Open Debuginfo file: /lib/modules/4.18.0-rc8+/build/vmlinux
Try to find probe point from debuginfo.
Symbol sys_open address found : c000000000414290
Matched function: __se_sys_open [2ad03a0]
Probe point found: __se_sys_open+0
Found 1 probe_trace_events.
Opening /sys/kernel/debug/tracing/README write=0
Opening /sys/kernel/debug/tracing/kprobe_events write=1
Parsing probe_events: p:probe/sys_open _text+4276896
Group:probe Event:sys_open probe:p
Writing event: r:probe/sys_open__return _text+4276896
Failed to write event: Invalid argument
Error: Failed to add events. Reason: Invalid argument (Code: -22)

After:

# perf probe -v -a sys_open

probe-definition(0): sys_open
symbol:sys_open file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
Looking at the vmlinux_path (8 entries long)
Using /lib/modules/4.18.0-rc8+/build/vmlinux for symbols
Open Debuginfo file: /lib/modules/4.18.0-rc8+/build/vmlinux
Try to find probe point from debuginfo.
Symbol sys_open address found : c000000000414290
Matched function: __se_sys_open [2ad03a0]
Probe point found: __se_sys_open+0
Found 1 probe_trace_events.
Opening /sys/kernel/debug/tracing/kprobe_events write=1
Writing event: p:probe/sys_open _text+4276888
Added new event:
probe:sys_open (on sys_open)
...

# perf probe -v -a sys_open%return $retval

probe-definition(0): sys_open%return
symbol:sys_open file:(null) line:0 offset:0 return:1 lazy:(null)
0 arguments
Looking at the vmlinux_path (8 entries long)
Using /lib/modules/4.18.0-rc8+/build/vmlinux for symbols
Open Debuginfo file: /lib/modules/4.18.0-rc8+/build/vmlinux
Try to find probe point from debuginfo.
Symbol sys_open address found : c000000000414290
Matched function: __se_sys_open [2ad03a0]
Probe point found: __se_sys_open+0
Found 1 probe_trace_events.
Opening /sys/kernel/debug/tracing/README write=0
Opening /sys/kernel/debug/tracing/kprobe_events write=1
Parsing probe_events: p:probe/sys_open _text+4276888
Group:probe Event:sys_open probe:p
Writing event: r:probe/sys_open__return _text+4276888
Added new event:
probe:sys_open__return (on sys_open%return)
...

Reported-by: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Fixes: 99e608b5954c ("perf probe ppc64le: Fix probe location when using DWARF")
Link: http://lkml.kernel.org/r/20180809161929.35058-1-sandipan@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 4b3a2716 08-Dec-2017 Masami Hiramatsu <mhiramat@kernel.org>

perf probe: Find versioned symbols from map

Commit d80406453ad4 ("perf symbols: Allow user probes on versioned
symbols") allows user to find default versioned symbols (with "@@") in
map. However, it did not enable normal versioned symbol (with "@") for
perf-probe. E.g.

=====
# ./perf probe -x /lib64/libc-2.25.so malloc_get_state
Failed to find symbol malloc_get_state in /usr/lib64/libc-2.25.so
Error: Failed to add events.
=====

This solves above issue by improving perf-probe symbol search function,
as below.

=====
# ./perf probe -x /lib64/libc-2.25.so malloc_get_state
Added new event:
probe_libc:malloc_get_state (on malloc_get_state in /usr/lib64/libc-2.25.so)

You can now use it in all perf tools, such as:

perf record -e probe_libc:malloc_get_state -aR sleep 1

# ./perf probe -l
probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so)
=====

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Acked-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: bhargavb <bhargavaramudu@gmail.com>
Cc: linux-rt-users@vger.kernel.org
Link: http://lkml.kernel.org/r/151275049269.24652.1639103455496216255.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 544abd44 05-Jul-2017 Krister Johansen <kjlx@templeofstupid.com>

perf probe: Allow placing uprobes in alternate namespaces.

Teaches perf how to place a uprobe on a file that's in a different mount
namespace. The user must add the probe using the --target-ns argument
to perf probe. Once it has been placed, it may be recorded against
without further namespace-specific commands.

Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
[ PPC build fixed by Ravi: ]
Link: http://lkml.kernel.org/r/1500287542-6219-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
[ Fix !HAVE_DWARF_SUPPORT build ]
Link: http://lkml.kernel.org/r/1499305693-1599-4-git-send-email-kjlx@templeofstupid.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# d8040645 25-Apr-2017 Paul Clarke <pc@us.ibm.com>

perf symbols: Allow user probes on versioned symbols

Symbol versioning, as in glibc, results in symbols being defined as:

<real symbol>@[@]<version>

(Note that "@@" identifies a default symbol, if the symbol name is
repeated.)

perf is currently unable to deal with this, and is unable to create user
probes at such symbols:

--
$ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create
0000000000008d30 t __pthread_create_2_1
0000000000008d30 T pthread_create@@GLIBC_2.17
$ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create
probe-definition(0): pthread_create
symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
Open Debuginfo file: /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so
Try to find probe point from debuginfo.
Probe point 'pthread_create' not found.
Error: Failed to add events. Reason: No such file or directory (Code: -2)
--

One is not able to specify the fully versioned symbol, either, due to
syntactic conflicts with other uses of "@" by perf:

--
$ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create@@GLIBC_2.17
probe-definition(0): pthread_create@@GLIBC_2.17
Semantic error :SRC@SRC is not allowed.
0 arguments
Error: Command Parse Error. Reason: Invalid argument (Code: -22)
--

This patch ignores versioning for default symbols, thus allowing probes to be
created for these symbols:

--
$ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create
Added new event:
probe_libpthread:pthread_create (on pthread_create in /lib/powerpc64le-linux-gnu/libpthread-2.19.so)

You can now use it in all perf tools, such as:

perf record -e probe_libpthread:pthread_create -aR sleep 1

$ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ]
$ /usr/bin/sudo ./perf script
test 2915 [000] 19124.260729: probe_libpthread:pthread_create: (3fff99248d38)
test 2916 [000] 19124.260962: probe_libpthread:pthread_create: (3fff99248d38)
$ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create
Removed event: probe_libpthread:pthread_create
--

Committer note:

Change the variable storing the result of strlen() to 'int', to fix the build
on debian:experimental-x-mipsel, fedora:24-x-ARC-uClibc, ubuntu:16.04-x-arm,
etc:

util/symbol.c: In function 'symbol__match_symbol_name':
util/symbol.c:422:11: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
if (len < versioning - name)
^

Signed-off-by: Paul A. Clarke <pc@us.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/r/c2b18d9c-17f8-9285-4868-f58b6359ccac@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 44ca9341 08-Mar-2017 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

perf powerpc: Choose local entry point with kretprobes

perf now uses an offset from _text/_stext for kretprobes if the kernel
supports it, rather than the actual function name. As such, let's choose
the LEP for powerpc ABIv2 so as to ensure the probe gets hit. Do it only
if the kernel supports specifying offsets with kretprobes.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/7445b5334673ef5404ac1d12609bad4d73d2b567.1488961018.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# a1d9972e 04-Oct-2016 Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>

perf uretprobe ppc64le: Fix probe location

Perf uretprobe probes on GEP(Global Entry Point) which fails to record
all function calls via LEP(Local Entry Point). Fix that by probing on LEP.

Objdump:

00000000100005f0 <doit>:
100005f0: 02 10 40 3c lis r2,4098
100005f4: 00 7f 42 38 addi r2,r2,32512
100005f8: a6 02 08 7c mflr r0
100005fc: 10 00 01 f8 std r0,16(r1)
10000600: f8 ff e1 fb std r31,-8(r1)

Before applying patch:

$ cat /sys/kernel/debug/tracing/uprobe_events
r:probe_uprobe_test/doit /home/ravi/uprobe_test:0x00000000000005f0

After applying patch:

$ cat /sys/kernel/debug/tracing/uprobe_events
r:probe_uprobe_test/doit /home/ravi/uprobe_test:0x00000000000005f8

This is not the case with kretprobes because the kernel itself finds LEP
and probes on it.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1475576865-6562-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# be39db9f 01-Sep-2016 Arnaldo Carvalho de Melo <acme@redhat.com>

perf symbols: Remove symbol_filter_t machinery

We're not using it anymore, few users were, but we really could do
without it, simplify lots of functions by removing it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-1zng8wdznn00iiz08bb7q3vn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# f046f3df 11-Aug-2016 Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>

perf ppc64le: Fix build failure when libelf is not present

arch__post_process_probe_trace_events() calls get_target_map() to
prepare symbol table. get_target_map() is defined inside
util/probe-event.c.

probe-event.c will only get included in perf binary if CONFIG_LIBELF is
set. Hence arch__post_process_probe_trace_events() needs to be defined
inside #ifdef HAVE_LIBELF_SUPPORT to solve compilation error.

Reported-and-Tested-by: Anton Blanchard <anton@samba.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/57ABFF88.8030905@linux.vnet.ibm.com
[ Thunderbird MUA mangled it, fix that ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 99e608b5 09-Aug-2016 Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>

perf probe ppc64le: Fix probe location when using DWARF

Powerpc has Global Entry Point and Local Entry Point for functions. LEP
catches call from both the GEP and the LEP. Symbol table of ELF contains
GEP and Offset from which we can calculate LEP, but debuginfo does not
have LEP info.

Currently, perf prioritize symbol table over dwarf to probe on LEP for
ppc64le. But when user tries to probe with function parameter, we fall
back to using dwarf(i.e. GEP) and when function called via LEP, probe
will never hit.

For example:

$ objdump -d vmlinux
...
do_sys_open():
c0000000002eb4a0: e8 00 4c 3c addis r2,r12,232
c0000000002eb4a4: 60 00 42 38 addi r2,r2,96
c0000000002eb4a8: a6 02 08 7c mflr r0
c0000000002eb4ac: d0 ff 41 fb std r26,-48(r1)

$ sudo ./perf probe do_sys_open
$ sudo cat /sys/kernel/debug/tracing/kprobe_events
p:probe/do_sys_open _text+3060904

$ sudo ./perf probe 'do_sys_open filename:string'
$ sudo cat /sys/kernel/debug/tracing/kprobe_events
p:probe/do_sys_open _text+3060896 filename_string=+0(%gpr4):string

For second case, perf probed on GEP. So when function will be called via
LEP, probe won't hit.

$ sudo ./perf record -a -e probe:do_sys_open ls
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.195 MB perf.data ]

To resolve this issue, let's not prioritize symbol table, let perf
decide what it wants to use. Perf is already converting GEP to LEP when
it uses symbol table. When perf uses debuginfo, let it find LEP offset
form symbol table. This way we fall back to probe on LEP for all cases.

After patch:

$ sudo ./perf probe 'do_sys_open filename:string'
$ sudo cat /sys/kernel/debug/tracing/kprobe_events
p:probe/do_sys_open _text+3060904 filename_string=+0(%gpr4):string

$ sudo ./perf record -a -e probe:do_sys_open ls
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.197 MB perf.data (11 samples) ]

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1470723805-5081-2-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 0b3c2264 12-Apr-2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

perf symbols: Fix kallsyms perf test on ppc64le

ppc64le functions have a Global Entry Point (GEP) and a Local Entry
Point (LEP). While placing a probe, we always prefer the LEP since it
catches function calls through both the GEP and the LEP. In order to do
this, we fixup the function entry points during elf symbol table lookup
to point to the LEPs. This works, but breaks 'perf test kallsyms' since
the symbols loaded from the symbol table (pointing to the LEP) do not
match the symbols in kallsyms.

To fix this, we do not adjust all the symbols during symbol table load.
Instead, we note down st_other in a newly introduced arch-specific
member of perf symbol structure, and later use this to adjust the probe
trace point.

Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Cc: Mark Wielaard <mjw@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/6be7c2b17e370100c2f79dd444509df7929bdd3e.1460451721.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 239aeba7 12-Apr-2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

perf powerpc: Fix kprobe and kretprobe handling with kallsyms on ppc64le

So far, we used to treat probe point offsets as being offset from the
LEP. However, userspace applications (objdump/readelf) always show
disassembly and offsets from the function GEP. This is confusing to the
user as we will end up probing at an address different from what the
user expects when looking at the function disassembly with
readelf/objdump. Fix this by changing how we modify probe address with
perf.

If only the function name is provided, we assume the user needs the LEP.
Otherwise, if an offset is specified, we assume that the user knows the
exact address to probe based on function disassembly, and so we just
place the probe from the GEP offset.

Finally, kretprobe was also broken with kallsyms as we were trying to
specify an offset. This patch also fixes that issue.

Reported-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Cc: Mark Wielaard <mjw@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/75df860aad8216bf4b9bcd10c6351ecc0e3dee54.1460451721.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 7b6ff0bd 28-Apr-2015 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

perf probe ppc64le: Fixup function entry if using kallsyms lookup

On powerpc ABIv2, if no debug-info is found and we use kallsyms, we need
to fixup the function entry to point to the local entry point. Use
offset of 8 since current toolchains always generate 2 instructions (8
bytes).

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/92253021e77a104b23b615c8c23bf9501dfe60bf.1430217967.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# d5c2e2c1 28-Apr-2015 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

perf probe ppc64le: Prefer symbol table lookup over DWARF

Use symbol table lookups by default if DWARF is not necessary, since
powerpc ABIv2 encodes local entry points in the symbol table and the
function entry address in DWARF may not be appropriate for kprobes, as
described here:

https://sourceware.org/bugzilla/show_bug.cgi?id=17638

"The DWARF address ranges deliberately include the *whole* function,
both global and local entry points."
...
"If you want to set probes on a local entry point, you should look up
the symbol in the main symbol table (not DWARF), and check the st_other
bits; they will indicate whether the function has a local entry point,
and what its offset from the global entry point is. Note that GDB does
the same when setting a breakpoint on a function entry."

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/88a10e22f4aaba2aef812824ca4b10d7beeea012.1430217967.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# c50fc0a4 28-Apr-2015 Ananth N Mavinakayanahalli <ananth@in.ibm.com>

perf probe ppc64le: Fix ppc64 ABIv2 symbol decoding

ppc64 ELF ABIv2 has a Global Entry Point (GEP) and a Local Entry Point
(LEP). For purposes of probing, we need the LEP - the offset to which is
encoded in st_other.

Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/ab9cc5e2b9de4cbaaf50f6ef2346a6a81100bad1.1430217967.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 031b84c4 28-Apr-2015 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

perf probe ppc: Enable matching against dot symbols automatically

Allow perf probe to work on ppc ABIv1 without the need to specify the
leading dot '.' for functions. 'perf probe do_fork' works with this
patch.

We do this by changing how symbol name comparison works on ppc ABIv1 -
we simply ignore and skip over the initial dot, if one exists, during
symbol name comparison.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/652a8f3bfa919bd02a1836a128370eaed59b4a34.1430217967.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# fb6d5942 28-Apr-2015 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

perf probe ppc: Use the right prefix when ignoring SyS symbols on ppc

Use the proper prefix when ignoring SyS symbols on ppc ABIv1. While at
it, generalize symbol selection so architectures can implement their own
logic.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/adf1f98b121ecaf292777fe5cc69fe1038feabce.1430217967.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# d2332098 28-Apr-2015 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

perf probe ppc: Fix symbol fixup issues due to ELF type

If using the symbol table, symbol addresses are not being fixed up
properly, resulting in probes being placed at wrong addresses:

# perf probe do_fork
Added new event:
probe:do_fork (on do_fork)

You can now use it in all perf tools, such as:

perf record -e probe:do_fork -aR sleep 1

# cat /sys/kernel/debug/tracing/kprobe_events
p:probe/do_fork _text+635952
# printf "%x" 635952
9b430
# grep do_fork /boot/System.map
c0000000000ab430 T .do_fork

Fix by checking for ELF type ET_DYN used by ppc64 kernels.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/41392bb856ef62d929995e0b61967689b7915207.1430217967.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>