commit 12a6d2940b5f02b4b9f71ce098e3bb02bc24a9ea upstream.
On s390 the modules loaded in memory have the text segment located after
the GOT and Relocation table. This can be seen with this output:
[root@m35lp76 perf]# fgrep qeth /proc/modules
qeth 151552 1 qeth_l2, Live 0x000003ff800b2000
...
[root@m35lp76 perf]# cat /sys/module/qeth/sections/.text
0x000003ff800b3990
[root@m35lp76 perf]#
There is an offset of 0x1990 bytes. The size of the qeth module is
151552 bytes (0x25000 in hex).
The location of the GOT/relocation table at the beginning of a module is
unique to s390.
commit 203d8a4aa6ed ("perf s390: Fix 'start' address of module's map")
adjusts the start address of a module in the map structures, but does
not adjust the size of the modules. This leads to overlapping of module
maps as this example shows:
[root@m35lp76 perf] # ./perf report -D
0 0 0xfb0 [0xa0]: PERF_RECORD_MMAP -1/0: [0x3ff800b3990(0x25000)
@ 0]: x /lib/modules/.../qeth.ko.xz
0 0 0x1050 [0xb0]: PERF_RECORD_MMAP -1/0: [0x3ff800d85a0(0x8000)
@ 0]: x /lib/modules/.../ip6_tables.ko.xz
The module qeth.ko has an adjusted start address modified to b3990, but
its size is unchanged and the module ends at 0x3ff800d8990. This end
address overlaps with the next modules start address of 0x3ff800d85a0.
When the size of the leading GOT/Relocation table stored in the
beginning of the text segment (0x1990 bytes) is subtracted from module
qeth end address, there are no overlaps anymore:
0x3ff800d8990 - 0x1990 = 0x0x3ff800d7000
which is the same as
0x3ff800b2000 + 0x25000 = 0x0x3ff800d7000.
To fix this issue, also adjust the modules size in function
arch__fix_module_text_start(). Add another function parameter named size
and reduce the size of the module when the text segment start address is
changed.
Output after:
0 0 0xfb0 [0xa0]: PERF_RECORD_MMAP -1/0: [0x3ff800b3990(0x23670)
@ 0]: x /lib/modules/.../qeth.ko.xz
0 0 0x1050 [0xb0]: PERF_RECORD_MMAP -1/0: [0x3ff800d85a0(0x7a60)
@ 0]: x /lib/modules/.../ip6_tables.ko.xz
Reported-by: Stefan Liebler <stli@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: stable@vger.kernel.org
Fixes: 203d8a4aa6ed ("perf s390: Fix 'start' address of module's map")
Link: http://lkml.kernel.org/r/20190724122703.3996-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e45c48a9a4d20ebc7b639a62c3ef8f4b08007027 ] This patch adds the necessary intelligence to properly compute the value of 'old' and 'head' when operating in snapshot mode. That way we can get the latest information in the AUX buffer and be compatible with the generic AUX ring buffer mechanic. Tester notes: > Leo, have you had the chance to test/review this one? Suzuki? Sure. I applied this patch on the perf/core branch (with latest commit 3e4fbf36c1e3 'perf augmented_raw_syscalls: Move reading filename to the loop') and passed testing with below steps: # perf record -e cs_etm/@tmc_etr0/ -S -m,64 --per-thread ./sort & [1] 19097 Bubble sorting array of 30000 elements # kill -USR2 19097 # kill -USR2 19097 # kill -USR2 19097 [ perf record: Woken up 4 times to write data ] [ perf record: Captured and wrote 0.753 MB perf.data ] Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Tested-by: Leo Yan <leo.yan@linaro.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20190605161633.12245-1-mathieu.poirier@linaro.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6738028dd57df064b969d8392c943ef3b3ae705d ]
Command 'perf record' and 'perf report' on a system without kernel
debuginfo packages uses /proc/kallsyms and /proc/modules to find
addresses for kernel and module symbols. On x86 this works for root and
non-root users.
On s390, when invoked as non-root user, many of the following warnings
are shown and module symbols are missing:
proc/{kallsyms,modules} inconsistency while looking for
"[sha1_s390]" module!
Command 'perf record' creates a list of module start addresses by
parsing the output of /proc/modules and creates a PERF_RECORD_MMAP
record for the kernel and each module. The following function call
sequence is executed:
machine__create_kernel_maps
machine__create_module
modules__parse
machine__create_module --> for each line in /proc/modules
arch__fix_module_text_start
Function arch__fix_module_text_start() is s390 specific. It opens
file /sys/module/<name>/sections/.text to extract the module's .text
section start address. On s390 the module loader prepends a header
before the first section, whereas on x86 the module's text section
address is identical the the module's load address.
However module section files are root readable only. For non-root the
read operation fails and machine__create_module() returns an error.
Command perf record does not generate any PERF_RECORD_MMAP record
for loaded modules. Later command perf report complains about missing
module maps.
To fix this function arch__fix_module_text_start() always returns
success. For root users there is no change, for non-root users
the module's load address is used as module's text start address
(the prepended header then counts as part of the text section).
This enable non-root users to use module symbols and avoid the
warning when perf report is executed.
Output before:
[tmricht@m83lp54 perf]$ ./perf report -D | fgrep MMAP
0 0x168 [0x50]: PERF_RECORD_MMAP ... x [kernel.kallsyms]_text
Output after:
[tmricht@m83lp54 perf]$ ./perf report -D | fgrep MMAP
0 0x168 [0x50]: PERF_RECORD_MMAP ... x [kernel.kallsyms]_text
0 0x1b8 [0x98]: PERF_RECORD_MMAP ... x /lib/modules/.../autofs4.ko.xz
0 0x250 [0xa8]: PERF_RECORD_MMAP ... x /lib/modules/.../sha_common.ko.xz
0 0x2f8 [0x98]: PERF_RECORD_MMAP ... x /lib/modules/.../des_generic.ko.xz
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Link: http://lkml.kernel.org/r/20190522144601.50763-4-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4787eff3fa88f62fede6ed7afa06477ae6bf984d ] The tool perf is useful for the performance analysis on the Hygon Dhyana platform. But right now there is no Hygon support for it to analyze the KVM guest os data. So add Hygon Dhyana support to it by checking vendor string to share the code path of AMD. Signed-off-by: Pu Wen <puwen@hygon.cn> Acked-by: Borislav Petkov <bp@suse.de> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1542008451-31735-1-git-send-email-puwen@hygon.cn Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1c6f709b9f96366cc47af23c05ecec9b8c0c392d ] Users should never use 'pt=0', but if they do it may give a meaningless error: $ perf record -e intel_pt/pt=0/u uname Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (intel_pt/pt=0/u). Fix that by forcing 'pt=1'. Committer testing: # perf record -e intel_pt/pt=0/u uname Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (intel_pt/pt=0/u). /bin/dmesg | grep -i perf may provide additional information. # perf record -e intel_pt/pt=0/u uname pt=0 doesn't make sense, forcing pt=1 Linux [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.020 MB perf.data ] # Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/b7c5b4e5-9497-10e5-fd43-5f3e4a0fe51d@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fa694160cca6dbba17c57dc7efec5f93feaf8795 ]
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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c715fcfda5a08edabaa15508742be926b7ee51db ]
For powerpc64, redundant entries in the callchain are filtered out by
determining the state of the return address and the stack frame using
DWARF debug information.
For making these filtering decisions we must analyze the debug
information for the location corresponding to the program counter value,
i.e. the first entry in the callchain, and not the LR value; otherwise,
perf may filter out either the second or the third entry in the
callchain incorrectly.
This can be observed on a powerpc64le system running Fedora 27 as shown
below.
Case 1 - Attaching a probe at inet_pton+0x8 (binary offset 0x15af28).
Return address is still in LR and a new stack frame is not yet
allocated. The LR value, i.e. the second entry, should not be
filtered out.
# objdump -d /usr/lib64/libc-2.26.so | less
...
000000000010eb10 <gaih_inet.constprop.7>:
...
10fa48: 78 bb e4 7e mr r4,r23
10fa4c: 0a 00 60 38 li r3,10
10fa50: d9 b4 04 48 bl 15af28 <inet_pton+0x8>
10fa54: 00 00 00 60 nop
10fa58: ac f4 ff 4b b 10ef04 <gaih_inet.constprop.7+0x3f4>
...
0000000000110450 <getaddrinfo>:
...
1105a8: 54 00 ff 38 addi r7,r31,84
1105ac: 58 00 df 38 addi r6,r31,88
1105b0: 69 e5 ff 4b bl 10eb18 <gaih_inet.constprop.7+0x8>
1105b4: 78 1b 71 7c mr r17,r3
1105b8: 50 01 7f e8 ld r3,336(r31)
...
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)
...
# perf probe -x /usr/lib64/libc-2.26.so -a inet_pton+0x8
# perf record -e probe_libc:inet_pton -g ping -6 -c 1 ::1
# perf script
Before:
ping 4507 [002] 514985.546540: probe_libc:inet_pton: (7fffa7dbaf28)
7fffa7dbaf28 __GI___inet_pton+0x8 (/usr/lib64/libc-2.26.so)
7fffa7d705b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
13fb52d70 _init+0xbfc (/usr/bin/ping)
7fffa7c836a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
7fffa7c83898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
0 [unknown] ([unknown])
After:
ping 4507 [002] 514985.546540: probe_libc:inet_pton: (7fffa7dbaf28)
7fffa7dbaf28 __GI___inet_pton+0x8 (/usr/lib64/libc-2.26.so)
7fffa7d6fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)
7fffa7d705b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
13fb52d70 _init+0xbfc (/usr/bin/ping)
7fffa7c836a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
7fffa7c83898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
0 [unknown] ([unknown])
Case 2 - Attaching a probe at _int_malloc+0x180 (binary offset 0x9cf10).
Return address in still in LR and a new stack frame has already
been allocated but not used. The caller's caller, i.e. the third
entry, is invalid and should be filtered out and not the second
one.
# objdump -d /usr/lib64/libc-2.26.so | less
...
000000000009cd90 <_int_malloc>:
9cd90: 17 00 4c 3c addis r2,r12,23
9cd94: 70 a3 42 38 addi r2,r2,-23696
9cd98: 26 00 80 7d mfcr r12
9cd9c: f8 ff e1 fb std r31,-8(r1)
9cda0: 17 00 e4 3b addi r31,r4,23
9cda4: d8 ff 61 fb std r27,-40(r1)
9cda8: 78 23 9b 7c mr r27,r4
9cdac: 1f 00 bf 2b cmpldi cr7,r31,31
9cdb0: f0 ff c1 fb std r30,-16(r1)
9cdb4: b0 ff c1 fa std r22,-80(r1)
9cdb8: 78 1b 7e 7c mr r30,r3
9cdbc: 08 00 81 91 stw r12,8(r1)
9cdc0: 11 ff 21 f8 stdu r1,-240(r1)
9cdc4: 4c 01 9d 41 bgt cr7,9cf10 <_int_malloc+0x180>
9cdc8: 20 00 a4 2b cmpldi cr7,r4,32
...
9cf08: 00 00 00 60 nop
9cf0c: 00 00 42 60 ori r2,r2,0
9cf10: e4 06 ff 7b rldicr r31,r31,0,59
9cf14: 40 f8 a4 7f cmpld cr7,r4,r31
9cf18: 68 05 9d 41 bgt cr7,9d480 <_int_malloc+0x6f0>
...
000000000009e3c0 <tcache_init.part.4>:
...
9e420: 40 02 80 38 li r4,576
9e424: 78 fb e3 7f mr r3,r31
9e428: 71 e9 ff 4b bl 9cd98 <_int_malloc+0x8>
9e42c: 00 00 a3 2f cmpdi cr7,r3,0
9e430: 78 1b 7e 7c mr r30,r3
...
000000000009f7a0 <__libc_malloc>:
...
9f8f8: 00 00 89 2f cmpwi cr7,r9,0
9f8fc: 1c ff 9e 40 bne cr7,9f818 <__libc_malloc+0x78>
9f900: c9 ea ff 4b bl 9e3c8 <tcache_init.part.4+0x8>
9f904: 00 00 00 60 nop
9f908: e8 90 22 e9 ld r9,-28440(r2)
...
# perf probe -x /usr/lib64/libc-2.26.so -a _int_malloc+0x180
# perf record -e probe_libc:_int_malloc -g ./test-malloc
# perf script
Before:
test-malloc 6554 [009] 515975.797403: probe_libc:_int_malloc: (7fffa6e6cf10)
7fffa6e6cf10 _int_malloc+0x180 (/usr/lib64/libc-2.26.so)
7fffa6dd0000 [unknown] (/usr/lib64/libc-2.26.so)
7fffa6e6f904 malloc+0x164 (/usr/lib64/libc-2.26.so)
7fffa6e6f9fc malloc+0x25c (/usr/lib64/libc-2.26.so)
100006b4 main+0x38 (/home/testuser/test-malloc)
7fffa6df36a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
7fffa6df3898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
0 [unknown] ([unknown])
After:
test-malloc 6554 [009] 515975.797403: probe_libc:_int_malloc: (7fffa6e6cf10)
7fffa6e6cf10 _int_malloc+0x180 (/usr/lib64/libc-2.26.so)
7fffa6e6e42c tcache_init.part.4+0x6c (/usr/lib64/libc-2.26.so)
7fffa6e6f904 malloc+0x164 (/usr/lib64/libc-2.26.so)
7fffa6e6f9fc malloc+0x25c (/usr/lib64/libc-2.26.so)
100006b4 main+0x38 (/home/sandipan/test-malloc)
7fffa6df36a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
7fffa6df3898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
0 [unknown] ([unknown])
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>
Fixes: a60335ba3298 ("perf tools powerpc: Adjust callchain based on DWARF debug info")
Link: http://lkml.kernel.org/r/24bb726d91ed173aebc972ec3f41a2ef2249434e.1530724939.git.sandipan@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9068533e4f470daf2b0f29c71d865990acd8826e ]
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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 354b064b8ebc1e1ede58550ca9e08bfa81e6af43 ]
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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 143c99f6ac6812d23254e80844d6e34be897d3e1 ]
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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>