Got following build fail on powerpc:
CC arch/powerpc/util/skip-callchain-idx.o
In function ‘check_return_reg’,
inlined from ‘check_return_addr’ at arch/powerpc/util/skip-callchain-idx.c:213:7,
inlined from ‘arch_skip_callchain_idx’ at arch/powerpc/util/skip-callchain-idx.c:265:7:
arch/powerpc/util/skip-callchain-idx.c:54:18: error: ‘dwarf_frame_register’ accessing 96 bytes \
in a region of size 64 [-Werror=stringop-overflow=]
54 | result = dwarf_frame_register(frame, ra_regno, ops_mem, &ops, &nops);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/powerpc/util/skip-callchain-idx.c: In function ‘arch_skip_callchain_idx’:
arch/powerpc/util/skip-callchain-idx.c:54:18: note: referencing argument 3 of type ‘Dwarf_Op *’
In file included from /usr/include/elfutils/libdwfl.h:32,
from arch/powerpc/util/skip-callchain-idx.c:10:
/usr/include/elfutils/libdw.h:1069:12: note: in a call to function ‘dwarf_frame_register’
1069 | extern int dwarf_frame_register (Dwarf_Frame *frame, int regno,
| ^~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
The dwarf_frame_register args changed with [1],
Updating ops_mem accordingly.
[1] https://sourceware.org/git/?p=elfutils.git;a=commit;h=5621fe5443da23112170235dd5cac161e5c75e65
Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Mark Wieelard <mjw@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: https://lore.kernel.org/r/20210928195253.1267023-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
All we need is a bunch of struct forward declarations and then add
event.h to the only place that was getting it indirectly via
callchain.h.
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-qq2xhyuxcvx5vmxha9otjd8d@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Based on 1 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 as published by
the free software foundation either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It uses several structs but don't explicitely includes the headers where
they are defined, getting them by sheer luck from one of the headers it
includes, since those are being streamlined to avoid unnecessary
rebuilds when changes are made to a random header, they will break, fix
them now so that they continue to build.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Maynard Johnson <maynard@us.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: https://lkml.kernel.org/n/tip-j1nyksegpnz36wi3qx2p46i1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For powerpc64, perf will filter out the second entry in the callchain,
i.e. the LR value, if the return address of the function corresponding
to the probed location has already been saved on its caller's stack.
The state of the return address is determined using debug information.
At any point within a function, if the return address is already saved
somewhere, a DWARF expression can tell us about its location. If the
return address in still in LR only, no DWARF expression would exist.
Typically, the instructions in a function's prologue first copy the LR
value to R0 and then pushes R0 on to the stack. If LR has already been
copied to R0 but R0 is yet to be pushed to the stack, we can still get a
DWARF expression that says that the return address is in R0. This is
indicating that getting a DWARF expression for the return address does
not guarantee the fact that it has already been saved on the stack.
This can be observed on a powerpc64le system running Fedora 27 as shown
below.
# objdump -d /usr/lib64/libc-2.26.so | less
...
000000000015af20 <inet_pton>:
15af20: 0b 00 4c 3c addis r2,r12,11
15af24: e0 c1 42 38 addi r2,r2,-15904
15af28: a6 02 08 7c mflr r0
15af2c: f0 ff c1 fb std r30,-16(r1)
15af30: f8 ff e1 fb std r31,-8(r1)
15af34: 78 1b 7f 7c mr r31,r3
15af38: 78 23 83 7c mr r3,r4
15af3c: 78 2b be 7c mr r30,r5
15af40: 10 00 01 f8 std r0,16(r1)
15af44: c1 ff 21 f8 stdu r1,-64(r1)
15af48: 28 00 81 f8 std r4,40(r1)
...
# readelf --debug-dump=frames-interp /usr/lib64/libc-2.26.so | less
...
00027024 0000000000000024 00027028 FDE cie=00000000 pc=000000000015af20..000000000015af88
LOC CFA r30 r31 ra
000000000015af20 r1+0 u u u
000000000015af34 r1+0 c-16 c-8 r0
000000000015af48 r1+64 c-16 c-8 c+16
000000000015af5c r1+0 c-16 c-8 c+16
000000000015af78 r1+0 u u
...
# perf probe -x /usr/lib64/libc-2.26.so -a inet_pton+0x18
# perf record -e probe_libc:inet_pton -g ping -6 -c 1 ::1
# perf script
Before:
ping 2829 [005] 512917.460174: probe_libc:inet_pton: (7fff7e2baf38)
7fff7e2baf38 __GI___inet_pton+0x18 (/usr/lib64/libc-2.26.so)
7fff7e2705b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
12f152d70 _init+0xbfc (/usr/bin/ping)
7fff7e1836a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
7fff7e183898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
0 [unknown] ([unknown])
After:
ping 2829 [005] 512917.460174: probe_libc:inet_pton: (7fff7e2baf38)
7fff7e2baf38 __GI___inet_pton+0x18 (/usr/lib64/libc-2.26.so)
7fff7e26fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)
7fff7e2705b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
12f152d70 _init+0xbfc (/usr/bin/ping)
7fff7e1836a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
7fff7e183898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
0 [unknown] ([unknown])
Reported-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Maynard Johnson <maynard@us.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/66e848a7bdf2d43b39210a705ff6d828a0865661.1530724939.git.sandipan@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For some cases, the callchain provided by the kernel may be empty. So,
the callchain ip filtering code will cause a crash if we do not check
whether the struct ip_callchain pointer is NULL before accessing any
members.
This can be observed on a powerpc64le system running Fedora 27 as shown
below.
# perf record -b -e cycles:u ls
Before:
# perf report --branch-history
perf: Segmentation fault
-------- backtrace --------
perf[0x1027615c]
linux-vdso64.so.1(__kernel_sigtramp_rt64+0x0)[0x7fff856304d8]
perf(arch_skip_callchain_idx+0x44)[0x10257c58]
perf[0x1017f2e4]
perf(thread__resolve_callchain+0x124)[0x1017ff5c]
perf(sample__resolve_callchain+0xf0)[0x10172788]
...
After:
# perf report --branch-history
Samples: 25 of event 'cycles:u', Event count (approx.): 2306870
Overhead Source:Line Symbol Shared Object
+ 11.60% _init+35736 [.] _init ls
+ 9.84% strcoll_l.c:137 [.] __strcoll_l libc-2.26.so
+ 9.16% memcpy.S:175 [.] __memcpy_power7 libc-2.26.so
+ 9.01% gconv_charset.h:54 [.] _nl_find_locale libc-2.26.so
+ 8.87% dl-addr.c:52 [.] _dl_addr libc-2.26.so
+ 8.83% _init+236 [.] _init ls
...
Reported-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Acked-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20180611104049.11048-1-sandipan@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Out of thread__find_addr_location(..., MAP__FUNCTION, ...), idea here is to
continue removing references to MAP__{FUNCTION,VARIABLE} ahead of
getting both types of symbols in the same rbtree, as various places do
two lookups, looking first at MAP__FUNCTION, then at MAP__VARIABLE.
So thread__find_symbol() will eventually do just that, and 'struct
symbol' will have the symbol type, for code that cares about that.
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-n7528en9e08yd3flzmb26tth@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
dwfl_report_offline() works only when libraries are prelinked.
Replace dwfl_report_offline() with dwfl_report_elf() so we correctly
extract debug info even from libraries that are not prelinked.
Reported-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Link: http://lkml.kernel.org/r/20150114221045.GA17703@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
So stop passing both machine and thread to several thread methods,
reducing function signature length.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ckcy19dcp1jfkmdihdjcqdn1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cache the DWARF debug info for DSO so we don't have to rebuild it for each
address in the DSO.
Note that dso__new() uses calloc() so don't need to set dso->dwfl to NULL.
$ /tmp/perf.orig --version
perf version 3.18.rc1.gc2661b8
$ /tmp/perf.new --version
perf version 3.18.rc1.g402d62
$ perf stat -e cycles,instructions /tmp/perf.orig report -g > orig
Performance counter stats for '/tmp/perf.orig report -g':
6,428,177,183 cycles # 0.000 GHz
4,176,288,391 instructions # 0.65 insns per cycle
1.840666132 seconds time elapsed
$ perf stat -e cycles,instructions /tmp/perf.new report -g > new
Performance counter stats for '/tmp/perf.new report -g':
305,773,142 cycles # 0.000 GHz
276,048,272 instructions # 0.90 insns per cycle
0.087693543 seconds time elapsed
$ diff orig new
$
Changelog[v2]:
[Arnaldo Carvalho] Cache in existing global objects rather than create
new static/globals in functions.
Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Anton Blanchard <anton@au1.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20141022000958.GB2228@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Looks like util/debug.h was indirectly included before and is no longer
included now. pr_debug is left undefined and the build of perf tool
fails on Powerpc.
Explicitly include util/debug.h.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Link: http://lkml.kernel.org/r/20140807072700.GA17623@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When saving the callchain on Power, the kernel conservatively saves excess
entries in the callchain. A few of these entries are needed in some cases
but not others. We should use the DWARF debug information to determine
when the entries are needed.
Eg: the value in the link register (LR) is needed only when it holds the
return address of a function. At other times it must be ignored.
If the unnecessary entries are not ignored, we end up with duplicate arcs
in the call-graphs.
Use the DWARF debug information to determine if any callchain entries
should be ignored when building call-graphs.
Callgraph before the patch:
14.67% 2234 sprintft libc-2.18.so [.] __random
|
--- __random
|
|--61.12%-- __random
| |
| |--97.15%-- rand
| | do_my_sprintf
| | main
| | generic_start_main.isra.0
| | __libc_start_main
| | 0x0
| |
| --2.85%-- do_my_sprintf
| main
| generic_start_main.isra.0
| __libc_start_main
| 0x0
|
--38.88%-- rand
|
|--94.01%-- rand
| do_my_sprintf
| main
| generic_start_main.isra.0
| __libc_start_main
| 0x0
|
--5.99%-- do_my_sprintf
main
generic_start_main.isra.0
__libc_start_main
0x0
Callgraph after the patch:
14.67% 2234 sprintft libc-2.18.so [.] __random
|
--- __random
|
|--95.93%-- rand
| do_my_sprintf
| main
| generic_start_main.isra.0
| __libc_start_main
| 0x0
|
--4.07%-- do_my_sprintf
main
generic_start_main.isra.0
__libc_start_main
0x0
TODO: For split-debug info objects like glibc, we can only determine
the call-frame-address only when both .eh_frame and .debug_info
sections are available. We should be able to determin the CFA
even without the .eh_frame section.
Fix suggested by Anton Blanchard.
Thanks to valuable input on DWARF debug information from Ulrich Weigand.
Reported-by: Maynard Johnson <maynard@us.ibm.com>
Tested-by: Maynard Johnson <maynard@us.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20140625154903.GA29607@us.ibm.com
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
