<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel.git/tools/perf/arch/powerpc, branch linux-5.0.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.
</subtitle>
<id>https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-5.0.y</id>
<link rel='self' href='https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-5.0.y'/>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/'/>
<updated>2019-02-04T14:32:14Z</updated>
<entry>
<title>perf mem/c2c: Fix perf_mem_events to support powerpc</title>
<updated>2019-02-04T14:32:14Z</updated>
<author>
<name>Ravi Bangoria</name>
</author>
<published>2019-01-29T13:24:12Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=f0fabf9c897327abd39018aefb5029aff8c7e133'/>
<id>urn:sha1:f0fabf9c897327abd39018aefb5029aff8c7e133</id>
<content type='text'>
PowerPC hardware does not have a builtin latency filter (--ldlat) for
the "mem-load" event and perf_mem_events by default includes
"/ldlat=30/" which is causing a failure on PowerPC. Refactor the code to
support "perf mem/c2c" on PowerPC.

This patch depends on kernel side changes done my Madhavan:
https://lists.ozlabs.org/pipermail/linuxppc-dev/2018-December/182596.html

Signed-off-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Dick Fowles &lt;fowles@inreach.com&gt;
Cc: Don Zickus &lt;dzickus@redhat.com&gt;
Cc: Joe Mario &lt;jmario@redhat.com&gt;
Cc: Madhavan Srinivasan &lt;maddy@linux.vnet.ibm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20190129132412.771-1-ravi.bangoria@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'powerpc-5.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux</title>
<updated>2019-01-18T17:55:42Z</updated>
<author>
<name>Linus Torvalds</name>
</author>
<published>2019-01-18T17:55:42Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=c5b709804ed7d36c45b5efa170d9e3ea8c29b865'/>
<id>urn:sha1:c5b709804ed7d36c45b5efa170d9e3ea8c29b865</id>
<content type='text'>
Pull powerpc fixes from Michael Ellerman:
 "A couple of weeks of fixes.

  There's one fix for an oops on Power9 machines with Open CAPI
  adapters.

  And a fix for probable memory corruption in some of the new NPU code,
  caught by smatch though and not seen in the wild.

  Plus a few other minor fixes.

  There's one non-fix which is the perf_regs change. That was sent
  during the merge window but I accidentally only merged the first of
  two patches in the series. It's been in linux-next so hopefully
  doesn't conflict with anything in acme's tree.

  Thanks to: Alexey Kardashevskiy, Andrew Donnellan, Breno Leitao,
  Christian Lamparter, Christophe Leroy, Dan Carpenter, Frederic Barrat,
  Greg Kurz, Jason A. Donenfeld, Madhavan Srinivasan"

* tag 'powerpc-5.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/syscalls: Fix syscall tracing
  powerpc/pseries: Fix build break due to pnv_npu2_init()
  powerpc/4xx/ocm: Fix fix for phys_addr_t printf warnings
  powerpc/powernv/npu: Fix oops in pnv_try_setup_npu_table_group()
  powerpc/tm: Limit TM code inside PPC_TRANSACTIONAL_MEM
  powerpc/8xx: fix setting of pagetable for Abatron BDI debug tool.
  powerpc/powernv/npu: Allocate enough memory in pnv_try_setup_npu_table_group()
  powerpc/perf: Update perf_regs structure to include MMCRA
</content>
</entry>
<entry>
<title>perf powerpc: Rework syscall table generation</title>
<updated>2019-01-10T13:34:52Z</updated>
<author>
<name>Ravi Bangoria</name>
</author>
<published>2019-01-10T09:49:35Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=0206131811fa6e4b3ed64b5f1c107e2815dcab42'/>
<id>urn:sha1:0206131811fa6e4b3ed64b5f1c107e2815dcab42</id>
<content type='text'>
Commit aff850393200 ("powerpc: add system call table generation
support") changed how systemcall table is generated for powerpc.
Incorporate these changes into perf as well.

Committer testing:

  $ podman run --entrypoint=/bin/sh --privileged -v /home/acme/git:/git --rm -ti docker.io/acmel/linux-perf-tools-build-ubuntu:18.04-x-powerpc64
  perfbuilder@d7a7af166a80:/git/perf$ head -2 /etc/os-release
  NAME="Ubuntu"
  VERSION="18.04.1 LTS (Bionic Beaver)"
  perfbuilder@d7a7af166a80:/git/perf$
  perfbuilder@d7a7af166a80:/git/perf$ make ARCH=powerpc CROSS_COMPILE=powerpc64-linux-gnu- EXTRA_CFLAGS= -C /git/linux/tools/perf O=/tmp/build/perf
  make: Entering directory '/git/linux/tools/perf'
    BUILD:   Doing 'make -j8' parallel build
    HOSTCC   /tmp/build/perf/fixdep.o
    HOSTLD   /tmp/build/perf/fixdep-in.o
    LINK     /tmp/build/perf/fixdep
  Warning: Kernel ABI header at 'tools/include/uapi/linux/mman.h' differs from latest version at 'include/uapi/linux/mman.h'
  diff -u tools/include/uapi/linux/mman.h include/uapi/linux/mman.h
  sh: 1: command: Illegal option -c

  Auto-detecting system features:
  ...                         dwarf: [ on  ]
  ...            dwarf_getlocations: [ on  ]
  ...                         glibc: [ on  ]
  ...                          gtk2: [ OFF ]
  ...                      libaudit: [ OFF ]
  ...                        libbfd: [ OFF ]
  ...                        libelf: [ on  ]
  ...                       libnuma: [ OFF ]
  ...        numa_num_possible_cpus: [ OFF ]
  ...                       libperl: [ OFF ]
  ...                     libpython: [ OFF ]
  ...                      libslang: [ OFF ]
  ...                     libcrypto: [ OFF ]
  ...                     libunwind: [ OFF ]
  ...            libdw-dwarf-unwind: [ on  ]
  ...                          zlib: [ on  ]
  ...                          lzma: [ OFF ]
  ...                     get_cpuid: [ OFF ]
  ...                           bpf: [ on  ]

  Makefile.config:445: No sys/sdt.h found, no SDT events are defined, please install systemtap-sdt-devel or systemtap-sdt-dev
  Makefile.config:491: No libunwind found. Please install libunwind-dev[el] &gt;= 1.1 and/or set LIBUNWIND_DIR
  Makefile.config:583: No libcrypto.h found, disables jitted code injection, please install libssl-devel or libssl-dev
  Makefile.config:598: slang not found, disables TUI support. Please install slang-devel, libslang-dev or libslang2-dev
  Makefile.config:612: GTK2 not found, disables GTK2 support. Please install gtk2-devel or libgtk2.0-dev
  Makefile.config:639: Missing perl devel files. Disabling perl scripting support, please install perl-ExtUtils-Embed/libperl-dev
  Makefile.config:666: No python interpreter was found: disables Python support - please install python-devel/python-dev
  Makefile.config:721: No bfd.h/libbfd found, please install binutils-dev[el]/zlib-static/libiberty-dev to gain symbol demangling
  Makefile.config:750: No liblzma found, disables xz kernel module decompression, please install xz-devel/liblzma-dev
  Makefile.config:763: No numa.h found, disables 'perf bench numa mem' benchmark, please install numactl-devel/libnuma-devel/libnuma-dev
  Makefile.config:814: No libbabeltrace found, disables 'perf data' CTF format support, please install libbabeltrace-dev[el]/libbabeltrace-ctf-dev
  Makefile.config:840: No alternatives command found, you need to set JDIR= to point to the root of your Java directory
    GEN      /tmp/build/perf/common-cmds.h
  &lt;SNIP&gt;
    CC       /tmp/build/perf/util/syscalltbl.o
  &lt;SNIP&gt;
    LD       /tmp/build/perf/libperf-in.o
    AR       /tmp/build/perf/libperf.a
    LINK     /tmp/build/perf/perf
  make: Leaving directory '/git/linux/tools/perf'
  perfbuilder@d7a7af166a80:/git/perf$ head /tmp/build/perf/arch/powerpc/include/generated/asm/syscalls_64.c
  static const char *syscalltbl_powerpc_64[] = {
  	[0] = "restart_syscall",
  	[1] = "exit",
  	[2] = "fork",
  	[3] = "read",
  	[4] = "write",
  	[5] = "open",
  	[6] = "close",
  	[7] = "waitpid",
  	[8] = "creat",
  perfbuilder@d7a7af166a80:/git/perf$ tail /tmp/build/perf/arch/powerpc/include/generated/asm/syscalls_64.c
  	[381] = "pwritev2",
  	[382] = "kexec_file_load",
  	[383] = "statx",
  	[384] = "pkey_alloc",
  	[385] = "pkey_free",
  	[386] = "pkey_mprotect",
  	[387] = "rseq",
  	[388] = "io_pgetevents",
  };
  #define SYSCALLTBL_POWERPC_64_MAX_ID 388
  perfbuilder@d7a7af166a80:/git/perf$ head /tmp/build/perf/arch/powerpc/include/generated/asm/syscalls_32.c
  static const char *syscalltbl_powerpc_32[] = {
  	[0] = "restart_syscall",
  	[1] = "exit",
  	[2] = "fork",
  	[3] = "read",
  	[4] = "write",
  	[5] = "open",
  	[6] = "close",
  	[7] = "waitpid",
  	[8] = "creat",
  perfbuilder@d7a7af166a80:/git/perf$ tail /tmp/build/perf/arch/powerpc/include/generated/asm/syscalls_32.c
  	[381] = "pwritev2",
  	[382] = "kexec_file_load",
  	[383] = "statx",
  	[384] = "pkey_alloc",
  	[385] = "pkey_free",
  	[386] = "pkey_mprotect",
  	[387] = "rseq",
  	[388] = "io_pgetevents",
  };
  #define SYSCALLTBL_POWERPC_32_MAX_ID 388
  perfbuilder@d7a7af166a80:/git/perf$

Signed-off-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Reported-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20190110094936.3132-1-ravi.bangoria@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>powerpc/perf: Update perf_regs structure to include MMCRA</title>
<updated>2019-01-08T08:22:47Z</updated>
<author>
<name>Madhavan Srinivasan</name>
</author>
<published>2018-12-09T09:25:36Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=6529870cb0323823f49b3e95d1760383910f96cd'/>
<id>urn:sha1:6529870cb0323823f49b3e95d1760383910f96cd</id>
<content type='text'>
On each sample, Monitor Mode Control Register A (MMCRA) content is
saved in pt_regs. MMCRA does not have a entry as-is in the pt_regs but
instead, MMCRA content is saved in the "dsisr" register of pt_regs.

Patch adds another entry to the perf_regs structure to include the
"MMCRA" printing which internally maps to the "dsisr" of pt_regs.

It also check for the MMCRA availability in the platform and present
value accordingly

mpe: This was the 2nd patch in a series with commit 333804dc3b7a
("powerpc/perf: Update perf_regs structure to include SIER") but I
accidentally only merged the 1st patch, so merge this one now.

Signed-off-by: Madhavan Srinivasan &lt;maddy@linux.vnet.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
</entry>
<entry>
<title>powerpc/perf: Update perf_regs structure to include SIER</title>
<updated>2018-12-20T09:53:11Z</updated>
<author>
<name>Madhavan Srinivasan</name>
</author>
<published>2018-12-09T09:25:35Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=333804dc3b7a92158ab63a48febff0d8ef89ada3'/>
<id>urn:sha1:333804dc3b7a92158ab63a48febff0d8ef89ada3</id>
<content type='text'>
On each sample, Sample Instruction Event Register (SIER) content
is saved in pt_regs. SIER does not have a entry as-is in the pt_regs
but instead, SIER content is saved in the "dar" register of pt_regs.

Patch adds another entry to the perf_regs structure to include the "SIER"
printing which internally maps to the "dar" of pt_regs.

It also check for the SIER availability in the platform and present
value accordingly

Signed-off-by: Madhavan Srinivasan &lt;maddy@linux.vnet.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
</entry>
<entry>
<title>Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-next</title>
<updated>2018-10-09T05:13:20Z</updated>
<author>
<name>Paul Mackerras</name>
</author>
<published>2018-10-09T05:13:20Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=9d67121a4fce20e0f7f127d40cd824fbbf5297dc'/>
<id>urn:sha1:9d67121a4fce20e0f7f127d40cd824fbbf5297dc</id>
<content type='text'>
This merges in the "ppc-kvm" topic branch of the powerpc tree to get a
series of commits that touch both general arch/powerpc code and KVM
code.  These commits will be merged both via the KVM tree and the
powerpc tree.

Signed-off-by: Paul Mackerras &lt;paulus@ozlabs.org&gt;
</content>
</entry>
<entry>
<title>KVM: PPC: Book3S: Simplify external interrupt handling</title>
<updated>2018-10-09T05:04:27Z</updated>
<author>
<name>Paul Mackerras</name>
</author>
<published>2018-10-08T05:30:48Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=d24ea8a7336a2c392728e2cf909d607a680feb7b'/>
<id>urn:sha1:d24ea8a7336a2c392728e2cf909d607a680feb7b</id>
<content type='text'>
Currently we use two bits in the vcpu pending_exceptions bitmap to
indicate that an external interrupt is pending for the guest, one
for "one-shot" interrupts that are cleared when delivered, and one
for interrupts that persist until cleared by an explicit action of
the OS (e.g. an acknowledge to an interrupt controller).  The
BOOK3S_IRQPRIO_EXTERNAL bit is used for one-shot interrupt requests
and BOOK3S_IRQPRIO_EXTERNAL_LEVEL is used for persisting interrupts.

In practice BOOK3S_IRQPRIO_EXTERNAL never gets used, because our
Book3S platforms generally, and pseries in particular, expect
external interrupt requests to persist until they are acknowledged
at the interrupt controller.  That combined with the confusion
introduced by having two bits for what is essentially the same thing
makes it attractive to simplify things by only using one bit.  This
patch does that.

With this patch there is only BOOK3S_IRQPRIO_EXTERNAL, and by default
it has the semantics of a persisting interrupt.  In order to avoid
breaking the ABI, we introduce a new "external_oneshot" flag which
preserves the behaviour of the KVM_INTERRUPT ioctl with the
KVM_INTERRUPT_SET argument.

Reviewed-by: David Gibson &lt;david@gibson.dropbear.id.au&gt;
Signed-off-by: Paul Mackerras &lt;paulus@ozlabs.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
</entry>
<entry>
<title>perf probe powerpc: Ignore SyS symbols irrespective of endianness</title>
<updated>2018-08-30T18:15:11Z</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=fa694160cca6dbba17c57dc7efec5f93feaf8795'/>
<id>urn:sha1:fa694160cca6dbba17c57dc7efec5f93feaf8795</id>
<content type='text'>
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;
</content>
</entry>
<entry>
<title>perf probe powerpc: Fix trace event post-processing</title>
<updated>2018-08-09T17:40:11Z</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=354b064b8ebc1e1ede58550ca9e08bfa81e6af43'/>
<id>urn:sha1:354b064b8ebc1e1ede58550ca9e08bfa81e6af43</id>
<content type='text'>
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;
</content>
</entry>
<entry>
<title>perf powerpc: Fix callchain ip filtering when return address is in a register</title>
<updated>2018-07-24T17:50:44Z</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=9068533e4f470daf2b0f29c71d865990acd8826e'/>
<id>urn:sha1:9068533e4f470daf2b0f29c71d865990acd8826e</id>
<content type='text'>
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;
</content>
</entry>
</feed>
