linux.git/tools/perf/util/machine.c, branch v4.18-rc2

perf machine: Synthesize and process mmap events for x86 PTI entry trampolines

2018-05-23T13:26:39+00:00

Like the kernel text, the location of x86 PTI entry trampolines must be
recorded in the perf.data file. Like the kernel, synthesize a mmap event
for that, and add processing for it.

Signed-off-by: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Andy Lutomirski 
Cc: Dave Hansen 
Cc: H. Peter Anvin 
Cc: Jiri Olsa 
Cc: Joerg Roedel 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1526986485-6562-10-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Create maps for x86 PTI entry trampolines

2018-05-23T13:24:08+00:00

Create maps for x86 PTI entry trampolines, based on symbols found in
kallsyms. It is also necessary to keep track of whether the trampolines
have been mapped particularly when the kernel dso is kcore.

Signed-off-by: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Andy Lutomirski 
Cc: Dave Hansen 
Cc: H. Peter Anvin 
Cc: Jiri Olsa 
Cc: Joerg Roedel 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1526986485-6562-9-git-send-email-adrian.hunter@intel.com
[ Fix extra_kernel_map_info.cnt designed struct initializer on gcc 4.4.7 (centos:6, etc) ]
Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Allow for extra kernel maps

2018-05-22T13:59:22+00:00

Identify extra kernel maps by name so that they can be distinguished
from the kernel map and module maps.

Signed-off-by: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Andy Lutomirski 
Cc: Dave Hansen 
Cc: H. Peter Anvin 
Cc: Jiri Olsa 
Cc: Joerg Roedel 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1526986485-6562-8-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Workaround missing maps for x86 PTI entry trampolines

2018-05-22T13:54:22+00:00

On x86_64 the PTI entry trampolines are not in the kernel map created by
perf tools. That results in the addresses having no symbols and prevents
annotation.  It also causes Intel PT to have decoding errors at the
trampoline addresses.

Workaround that by creating maps for the trampolines.

At present the kernel does not export information revealing where the
trampolines are.  Until that happens, the addresses are hardcoded.

Signed-off-by: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Andy Lutomirski 
Cc: Dave Hansen 
Cc: H. Peter Anvin 
Cc: Jiri Olsa 
Cc: Joerg Roedel 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1526986485-6562-6-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Add nr_cpus_avail()

2018-05-22T13:52:49+00:00

Add a function to return the number of the machine's available CPUs.

Signed-off-by: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Andy Lutomirski 
Cc: Dave Hansen 
Cc: H. Peter Anvin 
Cc: Jiri Olsa 
Cc: Joerg Roedel 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1526986485-6562-5-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix kernel_start for PTI on x86

2018-05-19T09:42:51+00:00

Opickn x86_64, PTI entry trampolines are less than the start of kernel text,
but still above 2^63. So leave kernel_start = 1ULL << 63 for x86_64.

Signed-off-by: Adrian Hunter 
Tested-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Andy Lutomirski 
Cc: Dave Hansen 
Cc: H. Peter Anvin 
Cc: Joerg Roedel 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1526548928-20790-7-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Add machine__is() to identify machine arch

2018-05-19T09:42:50+00:00

Add a function to identify the machine architecture.

Signed-off-by: Adrian Hunter 
Tested-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Andy Lutomirski 
Cc: Dave Hansen 
Cc: H. Peter Anvin 
Cc: Joerg Roedel 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1526548928-20790-6-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf script: Show virtual addresses instead of offsets

2018-05-17T19:55:29+00:00

When perf data is recorded with the call-graph option enabled, the
callchain shown by perf script shows the binary offsets of the symbols
as the ip. This is incorrect for kernel symbols as the ip values are
always off by a fixed offset depending on the architecture. If the
offsets from the start of the symbols are printed, they are also
incorrect for both kernel and userspace symbols.

Without the call-graph option, the callchain shows the virtual addresses
of the symbols rather than their binary offsets. The offsets printed in
this case are also correct.

This fixes the inconsistency in perf script's output.

This can be verified on a powerpc64le system running Fedora 27 as
follows:

  # cat /proc/kallsyms | grep sys_write
  ...
  c0000000004025a0 T sys_write
  c0000000004025a0 T __se_sys_write
  ...

  # perf probe -a sys_write

Before applying this patch:

  # perf record -e probe:sys_write -g ~/test
  # perf script -F ip,sym,symoff

                    4125b0 sys_write+0x8000000000008010
                     1b9e0 system_call+0x8000000000008058
                    118234 __GI___libc_write+0xffff0000f52c0024
                     92c74 _IO_file_write@@GLIBC_2.17+0xffff0000f52c0044
                  5afbfd8a [unknown]
                     91a60 new_do_write+0xffff0000f52c0090
                     94638 _IO_do_write@@GLIBC_2.17+0xffff0000f52c0038
                     94bbc _IO_file_overflow@@GLIBC_2.17+0xffff0000f52c014c
                     95a24 __overflow+0xffff0000f52c0064
                     84548 _IO_puts+0xffff0000f52c0218
                       440 main+0xffffffffe0000020
                     236a0 generic_start_main.isra.0+0xffff0000f52c0140
                     23898 __libc_start_main+0xffff0000f52c00b8
                         0 [unknown]
  ...

  # perf record -e probe:sys_write ~/test
  # perf script -F ip,sym,symoff

  c0000000004025b0 sys_write+0x10
  ...

After applying this patch:

  # perf record -e probe:sys_write -g ~/test
  # perf script -F ip,sym,symoff

          c0000000004025b0 sys_write+0x10
          c00000000000b9e0 system_call+0x58
              7fffb70d8234 __GI___libc_write+0x24
              7fffb7052c74 _IO_file_write@@GLIBC_2.17+0x44
                  5afc1818 [unknown]
              7fffb7051a60 new_do_write+0x90
              7fffb7054638 _IO_do_write@@GLIBC_2.17+0x38
              7fffb7054bbc _IO_file_overflow@@GLIBC_2.17+0x14c
              7fffb7055a24 __overflow+0x64
              7fffb7044548 _IO_puts+0x218
                  10000440 main+0x20
              7fffb6fe36a0 generic_start_main.isra.0+0x140
              7fffb6fe3898 __libc_start_main+0xb8
                         0 [unknown]
  ...

  # perf record -e probe:sys_write ~/test
  # perf script -F ip,sym,symoff

  c0000000004025b0 sys_write+0x10
  ...

Signed-off-by: Sandipan Das 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Naveen N. Rao 
Cc: Ravi Bangoria 
Link: http://lkml.kernel.org/r/20180517063326.6319-1-sandipan@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Ditch find_kernel_function variants

2018-04-30T15:20:54+00:00

Since we do not have split symtabs anymore, no need to have explicit
find_kernel_function variants, use the find_kernel_symbol ones.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-hiw2ryflju000f6wl62128it@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Unify symbol maps

2018-04-27T13:47:06+00:00

Remove the split of symbol tables for data (MAP__VARIABLE) and for
functions (MAP__FUNCTION), its unneeded and there were various places
doing two lookups to find a symbol, so simplify this.

We still will consider only the symbols that matched the filters in
place, i.e. see the (elf_(sec,sym)|symbol_type)__filter() routines in
the patch, just so that we consider only the same symbols as before,
to reduce the possibility of regressions.

All the tests on 50-something build environments, in varios versions
of lots of distros and cross build environments were performed without
build regressions, as usual with all pull requests the other tests were
also performed: 'perf test' and 'make -C tools/perf build-test'.

Also this was done at a great granularity so that regressions can be
bisected more easily.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-hiq0fy2rsleupnqqwuojo1ne@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo