<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel.git/tools/perf/arch/powerpc/util, branch linux-4.18.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.
</subtitle>
<id>https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-4.18.y</id>
<link rel='self' href='https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-4.18.y'/>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/'/>
<updated>2018-10-10T06:55:59Z</updated>
<entry>
<title>perf probe powerpc: Ignore SyS symbols irrespective of endianness</title>
<updated>2018-10-10T06:55:59Z</updated>
<author>
<name>Sandipan Das</name>
</author>
<published>2018-08-28T09:08:48Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=3cc1b441a4b9164c63620915f7b46b9edbd7158e'/>
<id>urn:sha1:3cc1b441a4b9164c63620915f7b46b9edbd7158e</id>
<content type='text'>
[ 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 &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Signed-off-by: Sandipan Das &lt;sandipan@linux.ibm.com&gt;
Reviewed-by: Kamalesh Babulal &lt;kamalesh@linux.vnet.ibm.com&gt;
Acked-by: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
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 &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>perf powerpc: Fix callchain ip filtering</title>
<updated>2018-09-26T06:39:25Z</updated>
<author>
<name>Sandipan Das</name>
</author>
<published>2018-07-10T13:58:13Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=b42c221e6c6f85bda8c32c4b3e0d2686f6e97f4c'/>
<id>urn:sha1:b42c221e6c6f85bda8c32c4b3e0d2686f6e97f4c</id>
<content type='text'>
[ 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 &lt;gaih_inet.constprop.7&gt;:
  ...
    10fa48:       78 bb e4 7e     mr      r4,r23
    10fa4c:       0a 00 60 38     li      r3,10
    10fa50:       d9 b4 04 48     bl      15af28 &lt;inet_pton+0x8&gt;
    10fa54:       00 00 00 60     nop
    10fa58:       ac f4 ff 4b     b       10ef04 &lt;gaih_inet.constprop.7+0x3f4&gt;
  ...
  0000000000110450 &lt;getaddrinfo&gt;:
  ...
    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 &lt;gaih_inet.constprop.7+0x8&gt;
    1105b4:       78 1b 71 7c     mr      r17,r3
    1105b8:       50 01 7f e8     ld      r3,336(r31)
  ...
  000000000015af20 &lt;inet_pton&gt;:
    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 &lt;_int_malloc&gt;:
     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 &lt;_int_malloc+0x180&gt;
     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 &lt;_int_malloc+0x6f0&gt;
  ...
  000000000009e3c0 &lt;tcache_init.part.4&gt;:
  ...
     9e420:       40 02 80 38     li      r4,576
     9e424:       78 fb e3 7f     mr      r3,r31
     9e428:       71 e9 ff 4b     bl      9cd98 &lt;_int_malloc+0x8&gt;
     9e42c:       00 00 a3 2f     cmpdi   cr7,r3,0
     9e430:       78 1b 7e 7c     mr      r30,r3
  ...
  000000000009f7a0 &lt;__libc_malloc&gt;:
  ...
     9f8f8:       00 00 89 2f     cmpwi   cr7,r9,0
     9f8fc:       1c ff 9e 40     bne     cr7,9f818 &lt;__libc_malloc+0x78&gt;
     9f900:       c9 ea ff 4b     bl      9e3c8 &lt;tcache_init.part.4+0x8&gt;
     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 &lt;sandipan@linux.ibm.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Maynard Johnson &lt;maynard@us.ibm.com&gt;
Cc: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@linux.vnet.ibm.com&gt;
Cc: Sukadev Bhattiprolu &lt;sukadev@linux.vnet.ibm.com&gt;
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 &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>perf powerpc: Fix callchain ip filtering when return address is in a register</title>
<updated>2018-09-26T06:39:25Z</updated>
<author>
<name>Sandipan Das</name>
</author>
<published>2018-07-10T13:58:14Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=0c664f04c204b1839b4869d2734e8c964090ef88'/>
<id>urn:sha1:0c664f04c204b1839b4869d2734e8c964090ef88</id>
<content type='text'>
[ 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 &lt;inet_pton&gt;:
    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 &lt;ravi.bangoria@linux.ibm.com&gt;
Signed-off-by: Sandipan Das &lt;sandipan@linux.ibm.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Maynard Johnson &lt;maynard@us.ibm.com&gt;
Cc: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@linux.vnet.ibm.com&gt;
Cc: Sukadev Bhattiprolu &lt;sukadev@linux.vnet.ibm.com&gt;
Link: http://lkml.kernel.org/r/66e848a7bdf2d43b39210a705ff6d828a0865661.1530724939.git.sandipan@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>perf probe powerpc: Fix trace event post-processing</title>
<updated>2018-09-15T07:46:51Z</updated>
<author>
<name>Sandipan Das</name>
</author>
<published>2018-08-09T16:19:29Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=c728031a35356c5c76be8b908f502384e225b18c'/>
<id>urn:sha1:c728031a35356c5c76be8b908f502384e225b18c</id>
<content type='text'>
[ 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 "&lt;__se_sys_open&gt;:"

  c000000000414290 &lt;__se_sys_open&gt;:
  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 &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Signed-off-by: Sandipan Das &lt;sandipan@linux.ibm.com&gt;
Acked-by: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Cc: Aneesh Kumar &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
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 &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>perf report powerpc: Fix crash if callchain is empty</title>
<updated>2018-06-25T14:59:35Z</updated>
<author>
<name>Sandipan Das</name>
</author>
<published>2018-06-11T10:40:49Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=143c99f6ac6812d23254e80844d6e34be897d3e1'/>
<id>urn:sha1:143c99f6ac6812d23254e80844d6e34be897d3e1</id>
<content type='text'>
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 &lt;ravi.bangoria@linux.ibm.com&gt;
Signed-off-by: Sandipan Das &lt;sandipan@linux.ibm.com&gt;
Acked-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Cc: Sukadev Bhattiprolu &lt;sukadev@linux.vnet.ibm.com&gt;
Link: http://lkml.kernel.org/r/20180611104049.11048-1-sandipan@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf thread: Introduce thread__find_symbol()</title>
<updated>2018-04-26T16:47:07Z</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
</author>
<published>2018-04-24T14:24:49Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=4546263d72e22ea84b49dafad26d8ca679d5e83d'/>
<id>urn:sha1:4546263d72e22ea84b49dafad26d8ca679d5e83d</id>
<content type='text'>
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 &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: https://lkml.kernel.org/n/tip-n7528en9e08yd3flzmb26tth@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf probe: Find versioned symbols from map</title>
<updated>2017-12-27T15:15:54Z</updated>
<author>
<name>Masami Hiramatsu</name>
</author>
<published>2017-12-08T16:28:12Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=4b3a2716dd785fabb9f6ac80c1d53cb29a88169d'/>
<id>urn:sha1:4b3a2716dd785fabb9f6ac80c1d53cb29a88169d</id>
<content type='text'>
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 &lt;mhiramat@kernel.org&gt;
Reviewed-by: Thomas Richter &lt;tmricht@linux.vnet.ibm.com&gt;
Acked-by: Ravi Bangoria &lt;ravi.bangoria@linux.vnet.ibm.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Paul Clarke &lt;pc@us.ibm.com&gt;
Cc: bhargavb &lt;bhargavaramudu@gmail.com&gt;
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 &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf pmu: Pass pmu as a parameter to get_cpuid_str()</title>
<updated>2017-12-05T13:24:33Z</updated>
<author>
<name>Ganapatrao Kulkarni</name>
</author>
<published>2017-10-16T18:32:18Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=54e32dc0f89ec7fcb87df6c45b096e57f050f22b'/>
<id>urn:sha1:54e32dc0f89ec7fcb87df6c45b096e57f050f22b</id>
<content type='text'>
The cpuid string will not be same on all CPUs on heterogeneous platforms
like ARM's big.LITTLE, adding provision(using pmu-&gt;cpus) to find cpuid
string from associated CPUs of PMU CORE device.

Also optimise arguments to function pmu_add_cpu_aliases.

Signed-off-by: Ganapatrao Kulkarni &lt;ganapatrao.kulkarni@cavium.com&gt;
Acked-by: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Jayachandran C &lt;jnair@caviumnetworks.com&gt;
Cc: Jonathan Cameron &lt;jonathan.cameron@huawei.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Robert Richter &lt;robert.richter@cavium.com&gt;
Cc: Shaokun Zhang &lt;zhangshaokun@hisilicon.com&gt;
Link: http://lkml.kernel.org/r/20171016183222.25750-2-ganapatrao.kulkarni@cavium.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>License cleanup: add SPDX GPL-2.0 license identifier to files with no license</title>
<updated>2017-11-02T10:10:55Z</updated>
<author>
<name>Greg Kroah-Hartman</name>
</author>
<published>2017-11-01T14:07:57Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=b24413180f5600bcb3bb70fbed5cf186b60864bd'/>
<id>urn:sha1:b24413180f5600bcb3bb70fbed5cf186b60864bd</id>
<content type='text'>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode &amp; Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained &gt;5
   lines of source
 - File already had some variant of a license header in it (even if &lt;5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>perf probe: Allow placing uprobes in alternate namespaces.</title>
<updated>2017-07-19T02:14:10Z</updated>
<author>
<name>Krister Johansen</name>
</author>
<published>2017-07-06T01:48:10Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=544abd44c7064c8a58a6bd2073d757f6b91d98c5'/>
<id>urn:sha1:544abd44c7064c8a58a6bd2073d757f6b91d98c5</id>
<content type='text'>
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 &lt;kjlx@templeofstupid.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Brendan Gregg &lt;brendan.d.gregg@gmail.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@linux.vnet.ibm.com&gt;
[ 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 &lt;tmricht@linux.vnet.ibm.com&gt;
[ 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 &lt;acme@redhat.com&gt;
</content>
</entry>
</feed>
