[ Upstream commit 6f520ce17920b3cdfbd2479b3ccf27f9706219d0 ]
perf doesn't provide proper symbol information for specially crafted
.debug files.
Sometimes .debug file may not have similar program header as runtime
ELF file. For example if we generate .debug file using objcopy
--only-keep-debug resulting file will not contain .text, .data and
other runtime sections. That means corresponding program headers will
have zero FileSiz and modified Offset.
Example: program header of text section of libxxx.so:
Type Offset VirtAddr PhysAddr
FileSiz MemSiz Flags Align
LOAD 0x00000000003d3000 0x00000000003d3000 0x00000000003d3000
0x000000000055ae80 0x000000000055ae80 R E 0x1000
Same program header after executing:
objcopy --only-keep-debug libxxx.so libxxx.so.debug
LOAD 0x0000000000001000 0x00000000003d3000 0x00000000003d3000
0x0000000000000000 0x000000000055ae80 R E 0x1000
Offset and FileSiz have been changed.
Following formula will not provide correct value, if program header
taken from .debug file (syms_ss):
sym.st_value -= phdr.p_vaddr - phdr.p_offset;
Correct program header information is located inside runtime ELF
file (runtime_ss).
Fixes: 2d86612aacb7805f ("perf symbol: Correct address for bss symbols")
Signed-off-by: Ajay Kaher <akaher@vmware.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Makhalov <amakhalov@vmware.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srivatsa S. Bhat <srivatsab@vmware.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Vasavi Sirnapalli <vsirnapalli@vmware.com>
Link: http://lore.kernel.org/lkml/1669198696-50547-1-git-send-email-akaher@vmware.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5b427df27b94aec1312cace48a746782a0925c53 ]
/proc/kallsyms and /proc/modules are compared before and after the copy
in order to ensure no changes during the copy.
However /proc/modules also might change due to reference counts changing
even though that does not make any difference.
Any modules loaded or unloaded should be visible in changes to kallsyms,
so it is not necessary to check /proc/modules also anyway.
Remove the comparison checking that /proc/modules is unchanged.
Fixes: fc1b691d76 ("perf buildid-cache: Add ability to add kcore to the cache")
Reported-by: Daniel Dao <dqminh@cloudflare.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Daniel Dao <dqminh@cloudflare.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220914122429.8770-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6d518ac7be6223811ab947897273b1bbef846180 ]
The perf jvmti agent doesn't create program headers, in this case
fallback on section headers as happened previously.
Committer notes:
To test this, from a public post by Ian:
1) download a Java workload dacapo-9.12-MR1-bach.jar from
https://sourceforge.net/projects/dacapobench/
2) build perf such as "make -C tools/perf O=/tmp/perf NO_LIBBFD=1" it
should detect Java and create /tmp/perf/libperf-jvmti.so
3) run perf with the jvmti agent:
perf record -k 1 java -agentpath:/tmp/perf/libperf-jvmti.so -jar dacapo-9.12-MR1-bach.jar -n 10 fop
4) run perf inject:
perf inject -i perf.data -o perf-injected.data -j
5) run perf report
perf report -i perf-injected.data | grep org.apache.fop
With this patch reverted I see lots of symbols like:
0.00% java jitted-388040-4656.so [.] org.apache.fop.fo.FObj.bind(org.apache.fop.fo.PropertyList)
With the patch (2d86612aacb7805f ("perf symbol: Correct address for bss
symbols")) I see lots of:
dso__load_sym_internal: failed to find program header for symbol:
Lorg/apache/fop/fo/FObj;bind(Lorg/apache/fop/fo/PropertyList;)V
st_value: 0x40
Fixes: 2d86612aacb7805f ("perf symbol: Correct address for bss symbols")
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20220731164923.691193-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2d86612aacb7805f72873691a2644d7279ed0630 ]
When using 'perf mem' and 'perf c2c', an issue is observed that tool
reports the wrong offset for global data symbols. This is a common
issue on both x86 and Arm64 platforms.
Let's see an example, for a test program, below is the disassembly for
its .bss section which is dumped with objdump:
...
Disassembly of section .bss:
0000000000004040 <completed.0>:
...
0000000000004080 <buf1>:
...
00000000000040c0 <buf2>:
...
0000000000004100 <thread>:
...
First we used 'perf mem record' to run the test program and then used
'perf --debug verbose=4 mem report' to observe what's the symbol info
for 'buf1' and 'buf2' structures.
# ./perf mem record -e ldlat-loads,ldlat-stores -- false_sharing.exe 8
# ./perf --debug verbose=4 mem report
...
dso__load_sym_internal: adjusting symbol: st_value: 0x40c0 sh_addr: 0x4040 sh_offset: 0x3028
symbol__new: buf2 0x30a8-0x30e8
...
dso__load_sym_internal: adjusting symbol: st_value: 0x4080 sh_addr: 0x4040 sh_offset: 0x3028
symbol__new: buf1 0x3068-0x30a8
...
The perf tool relies on libelf to parse symbols, in executable and
shared object files, 'st_value' holds a virtual address; 'sh_addr' is
the address at which section's first byte should reside in memory, and
'sh_offset' is the byte offset from the beginning of the file to the
first byte in the section. The perf tool uses below formula to convert
a symbol's memory address to a file address:
file_address = st_value - sh_addr + sh_offset
^
` Memory address
We can see the final adjusted address ranges for buf1 and buf2 are
[0x30a8-0x30e8) and [0x3068-0x30a8) respectively, apparently this is
incorrect, in the code, the structure for 'buf1' and 'buf2' specifies
compiler attribute with 64-byte alignment.
The problem happens for 'sh_offset', libelf returns it as 0x3028 which
is not 64-byte aligned, combining with disassembly, it's likely libelf
doesn't respect the alignment for .bss section, therefore, it doesn't
return the aligned value for 'sh_offset'.
Suggested by Fangrui Song, ELF file contains program header which
contains PT_LOAD segments, the fields p_vaddr and p_offset in PT_LOAD
segments contain the execution info. A better choice for converting
memory address to file address is using the formula:
file_address = st_value - p_vaddr + p_offset
This patch introduces elf_read_program_header() which returns the
program header based on the passed 'st_value', then it uses the formula
above to calculate the symbol file address; and the debugging log is
updated respectively.
After applying the change:
# ./perf --debug verbose=4 mem report
...
dso__load_sym_internal: adjusting symbol: st_value: 0x40c0 p_vaddr: 0x3d28 p_offset: 0x2d28
symbol__new: buf2 0x30c0-0x3100
...
dso__load_sym_internal: adjusting symbol: st_value: 0x4080 p_vaddr: 0x3d28 p_offset: 0x2d28
symbol__new: buf1 0x3080-0x30c0
...
Fixes: f17e04afaf ("perf report: Fix ELF symbol parsing")
Reported-by: Chang Rui <changruinj@gmail.com>
Suggested-by: Fangrui Song <maskray@google.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220724060013.171050-2-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
The 'dso->kernel' condition is true also for kernel modules now,
and there are several places that were omited by the initial change:
- we need to identify modules separately in dso__process_kernel_symbol
- we need to set 'dso->kernel' for module from buildid table
- there's no need to use 'dso->kernel || kmodule' in one condition
Committer testing:
Before:
# perf test -v object
<SNIP>
Objdump command is: objdump -z -d --start-address=0xffffffff813e682f --stop-address=0xffffffff813e68af /usr/lib/debug/lib/modules/5.7.14-200.fc32.x86_64/vmlinux
Bytes read match those read by objdump
Reading object code for memory address: 0xffffffffc02dc257
File is: /lib/modules/5.7.14-200.fc32.x86_64/kernel/arch/x86/crypto/crc32c-intel.ko.xz
On file address is: 0xffffffffc02dc2e7
dso__data_read_offset failed
test child finished with -1
---- end ----
Object code reading: FAILED!
#
After:
# perf test object
26: Object code reading : Ok
# perf test object
26: Object code reading : Ok
# perf test object
26: Object code reading : Ok
# perf test object
26: Object code reading : Ok
# perf test object
26: Object code reading : Ok
#
Fixes: 02213cec64 ("perf maps: Mark module DSOs with kernel type")
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Rename enum dso_kernel_type to enum dso_space_type, which seems like
better fit.
Committer notes:
This is used with 'struct dso'->kernel, which once was a boolean, so
DSO_SPACE__USER is zero, !zero means some sort of kernel space, be it
the host kernel space or a guest kernel space.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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>
When a map is create to represent the main kernel area (vmlinux) with
map__new2() we allocate an extra area to store a pointer to the 'struct
maps' for the kernel maps, so that we can access that struct when
loading ELF files or kallsyms, as we will need to split it in multiple
maps, one per kernel module or ELF section (such as ".init.text").
So when map->dso->kernel is non-zero, it is expected that
map__kmap(map)->kmaps to be set to the tree of kernel maps (modules,
chunks of the main kernel, bpf progs put in place via
PERF_RECORD_KSYMBOL, the main kernel).
This was not the case when we were splitting the main kernel into chunks
for its ELF sections, which ended up making 'perf report --children'
processing a perf.data file with callchains to trip on
__map__is_kernel(), when we press ENTER to see the popup menu for main
histogram entries that starts at a symbol in the ".init.text" ELF
section, e.g.:
- 8.83% 0.00% swapper [kernel.vmlinux].init.text [k] start_kernel
start_kernel
cpu_startup_entry
do_idle
cpuidle_enter
cpuidle_enter_state
intel_idle
Fix it.
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/20191218190120.GB13282@kernel.org/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
And pick the shortest name: 'struct maps'.
The split existed because we used to have two groups of maps, one for
functions and one for variables, but that only complicated things,
sometimes we needed to figure out what was at some address and then had
to first try it on the functions group and if that failed, fall back to
the variables one.
That split is long gone, so for quite a while we had only one struct
maps per struct map_groups, simplify things by combining those structs.
First patch is the minimum needed to merge both, follow up patches will
rename 'thread->mg' to 'thread->maps', etc.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-hom6639ro7020o708trhxh59@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To test that that function is being called I just added a probe on that
place, enabled it via 'perf trace' asking for at most 16 levels of
backtraces, system wide, and then ran 'perf top' on another xterm,
voilà:
# perf probe -x ~/bin/perf dso__process_kernel_symbol
Added new event:
probe_perf:dso__process_kernel_symbol (on dso__process_kernel_symbol in /home/acme/bin/perf)
You can now use it in all perf tools, such as:
perf record -e probe_perf:dso__process_kernel_symbol -aR sleep 1
# perf trace -e probe_perf:dso__process_kernel_symbol/max-stack=16/ --max-events=2
# perf trace -e probe_perf:dso__process_kernel_symbol/max-stack=16/ --max-events=2
0.000 :17345/17345 probe_perf:dso__process_kernel_symbol(__probe_ip: 5680224)
dso__process_kernel_symbol (/home/acme/bin/perf)
dso__load_vmlinux (/home/acme/bin/perf)
dso__load_vmlinux_path (/home/acme/bin/perf)
dso__load (/home/acme/bin/perf)
map__load (/home/acme/bin/perf)
thread__find_map (/home/acme/bin/perf)
machine__resolve (/home/acme/bin/perf)
deliver_event (/home/acme/bin/perf)
__ordered_events__flush.part.0 (/home/acme/bin/perf)
process_thread (/home/acme/bin/perf)
start_thread (/usr/lib64/libpthread-2.29.so)
0.064 :17345/17345 probe_perf:dso__process_kernel_symbol(__probe_ip: 5680224)
dso__process_kernel_symbol (/home/acme/bin/perf)
dso__load_vmlinux (/home/acme/bin/perf)
dso__load_vmlinux_path (/home/acme/bin/perf)
dso__load (/home/acme/bin/perf)
map__load (/home/acme/bin/perf)
thread__find_map (/home/acme/bin/perf)
machine__resolve (/home/acme/bin/perf)
deliver_event (/home/acme/bin/perf)
__ordered_events__flush.part.0 (/home/acme/bin/perf)
process_thread (/home/acme/bin/perf)
start_thread (/usr/lib64/libpthread-2.29.so)
#
# perf stat -e probe_perf:dso__process_kernel_symbol
^C
Performance counter stats for 'system wide':
107,308 probe_perf:dso__process_kernel_symbol
8.215399813 seconds time elapsed
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-5fy66x5hr5ct9pmw84jkiwvm@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In places where the equivalent was already being done, i.e.:
free(a);
a = NULL;
And in placs where struct members are being freed so that if we have
some erroneous reference to its struct, then accesses to freed members
will result in segfaults, which we can detect faster than use after free
to areas that may still have something seemingly valid.
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-jatyoofo5boc1bsvoig6bb6i@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We got the sane_ctype.h headers from git and kept using it so far, but
since that code originally came from the kernel sources to the git
sources, perhaps its better to just use the one in the kernel, so that
we can leverage tools/perf/check_headers.sh to be notified when our copy
gets out of sync, i.e. when fixes or goodies are added to the code we've
copied.
This will help with things like tools/lib/string.c where we want to have
more things in common with the kernel, such as strim(), skip_spaces(),
etc so as to go on removing the things that we have in tools/perf/util/
and instead using the code in the kernel, indirectly and removing things
like EXPORT_SYMBOL(), etc, getting notified when fixes and improvements
are made to the original code.
Hopefully this also should help with reducing the difference of code
hosted in tools/ to the one in the kernel proper.
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-7k9868l713wqtgo01xxygn12@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
Hardware tracing:
Adrian Hunter:
- Handle calls optimized into jumps to a different symbol
in the thread stack routines used to process hardware traces (Adrian Hunter)
Intel PT:
Adrian Hunter:
- Fix overlap calculation for padding.
- Fix CYC timestamp calculation after OVF.
- Packet splitting can only happen in 32-bit.
- Add timestamp to auxtrace errors.
ARM CoreSight:
Leo Yan:
- Add last instruction information in packet
- Set sample flags for instruction range, exception and
return packets and for a trace discontinuity.
- Add exception number in exception packet
- Change tuple from traceID-CPU# to traceID-metadata
- Add traceID in packet
Mathieu Poirier:
- Add "sinks" group to PMU directory
- Use event attributes to send sink information to kernel
- Remove set_drv_config() API, no longer used.
perf annotate:
Jiri Olsa:
- Delay symbol annotation to the resort phase, speeding up 'perf report'
startup.
perf record:
Alexey Budankov:
- Allow binding userspace buffers to NUMA nodes.
Symbols:
Adrian Hunter:
- Fix calculating of symbol sizes when splitting kallsyms into
maps for kcore processing.
Vendor events:
William Cohen:
- Intel: Fix Load_Miss_Real_Latency on CLX
Misc:
Arnaldo Carvalho de Melo:
- Streamline headers, removing includes when all that is needed are
just forward declarations, fixup the fallout for cases where headers
should have been explicitely included but were instead obtained
indirectly, by sheer luck.
- Add fallback versions for CPU_{OR,EQUAL}(), so that code using it
continue to build on older systems where those were not yet introduced
or in systems using some other libc than the GNU one where those
helpers aren't present.
Documentation:
Changbin Du:
- Add documentation for BPF event selection.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When perf is built with the annobin plugin (RHEL8 build) extra symbols
are added to its binary:
# nm perf | grep annobin | head -10
0000000000241100 t .annobin_annotate.c
0000000000326490 t .annobin_annotate.c
0000000000249255 t .annobin_annotate.c_end
00000000003283a8 t .annobin_annotate.c_end
00000000001bce18 t .annobin_annotate.c_end.hot
00000000001bce18 t .annobin_annotate.c_end.hot
00000000001bc3e2 t .annobin_annotate.c_end.unlikely
00000000001bc400 t .annobin_annotate.c_end.unlikely
00000000001bce18 t .annobin_annotate.c.hot
00000000001bce18 t .annobin_annotate.c.hot
...
Those symbols have no use for report or annotation and should be
skipped. Moreover they interfere with the DWARF unwind test on the PPC
arch, where they are mixed with checked symbols and then the test fails:
# perf test dwarf -v
59: Test dwarf unwind :
--- start ---
test child forked, pid 8515
unwind: .annobin_dwarf_unwind.c:ip = 0x10dba40dc (0x2740dc)
...
got: .annobin_dwarf_unwind.c 0x10dba40dc, expecting test__arch_unwind_sample
unwind: failed with 'no error'
The annobin symbols are defined as NOTYPE/LOCAL/HIDDEN:
# readelf -s ./perf | grep annobin | head -1
40: 00000000001bce4f 0 NOTYPE LOCAL HIDDEN 13 .annobin_init.c
They can still pass the check for the label symbol. Adding check for
HIDDEN and INTERNAL (as suggested by Nick below) visibility and filter
out such symbols.
> Just to be awkward, if you are going to ignore STV_HIDDEN
> symbols then you should probably also ignore STV_INTERNAL ones
> as well... Annobin does not generate them, but you never know,
> one day some other tool might create some.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Clifton <nickc@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190128133526.GD15461@krava
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf updates and fixes from Ingo Molnar:
"These are almost all tooling updates: 'perf top', 'perf trace' and
'perf script' fixes and updates, an UAPI header sync with the merge
window versions, license marker updates, much improved Sparc support
from David Miller, and a number of fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (66 commits)
perf intel-pt/bts: Calculate cpumode for synthesized samples
perf intel-pt: Insert callchain context into synthesized callchains
perf tools: Don't clone maps from parent when synthesizing forks
perf top: Start display thread earlier
tools headers uapi: Update linux/if_link.h header copy
tools headers uapi: Update linux/netlink.h header copy
tools headers: Sync the various kvm.h header copies
tools include uapi: Update linux/mmap.h copy
perf trace beauty: Use the mmap flags table generated from headers
perf beauty: Wire up the mmap flags table generator to the Makefile
perf beauty: Add a generator for MAP_ mmap's flag constants
tools include uapi: Update asound.h copy
tools arch uapi: Update asm-generic/unistd.h and arm64 unistd.h copies
tools include uapi: Update linux/fs.h copy
perf callchain: Honour the ordering of PERF_CONTEXT_{USER,KERNEL,etc}
perf cs-etm: Correct CPU mode for samples
perf unwind: Take pgoff into account when reporting elf to libdwfl
perf top: Do not use overwrite mode by default
perf top: Allow disabling the overwrite mode
perf trace: Beautify mount's first pathname arg
...
Remove the split of symbol tables for data (MAP__VARIABLE) and for
functions (MAP__FUNCTION), its unneeded and there were various places
doing two lookups to find a symbol, so simplify this.
We still will consider only the symbols that matched the filters in
place, i.e. see the (elf_(sec,sym)|symbol_type)__filter() routines in
the patch, just so that we consider only the same symbols as before,
to reduce the possibility of regressions.
All the tests on 50-something build environments, in varios versions
of lots of distros and cross build environments were performed without
build regressions, as usual with all pull requests the other tests were
also performed: 'perf test' and 'make -C tools/perf build-test'.
Also this was done at a great granularity so that regressions can be
bisected more easily.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-hiq0fy2rsleupnqqwuojo1ne@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
