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  1. 19 7月, 2017 10 次提交
  3. 12 7月, 2017 1 次提交
    • A
      perf symbols: Accept zero as the kernel base address · 4b1303d0
      由 Arnaldo Carvalho de Melo 提交于 
      Which is the case in S/390, where symbols were not being resolved
because machine__get_kernel_start was only setting machine->kernel_start
when the just successfully loaded kernel symtab had its map->start set
to !0, when it was left at (1ULL << 63) assuming a partitioning of the
address space for user/kernel, which is not the case in S/390 nor in
Sparc.

So just check if map__load() was successfull and set
machine->kernel_start to zero, fixing kernel symbol resolution on S/390.

Test performed by Thomas:

 ----

  I like this patch. I have done a new build and removed all my debug output to start
  from scratch. Without your patch I get this:

  # Samples: 4  of event 'cpu-clock'
  # Event count (approx.): 1000000
  #
  # Children      Self  Command  Shared Object     Symbol
  # ........  ........  .......  ................  ........................
      75.00%     0.00%  true     [unknown]         [k] 0x00000000004bedda
              |
              ---0x4bedda
                 |
                 |--50.00%--0x42693a
                 |          |
                 |           --25.00%--0x2a72e0
                 |                     0x2af0ca
                 |                     0x3d1003fe4c0
                 |
                  --25.00%--0x4272bc
                            0x26fa84

  and with your patch (I just rebuilt the perf tool, nothing else and used the same
  perf.data file as input):

  # Samples: 4  of event 'cpu-clock'
  # Event count (approx.): 1000000
  #
  # Children      Self  Command  Shared Object               Symbol
  # ........  ........  .......  ..........................  ..................................
      75.00%     0.00%  true     [kernel.vmlinux]            [k] pgm_check_handler
              |
              ---pgm_check_handler
                 do_dat_exception
                 handle_mm_fault
                 __handle_mm_fault
                 filemap_map_pages
                 |
                 |--25.00%--rcu_read_lock_held
                 |          rcu_lockdep_current_cpu_online
                 |          0x3d1003ff4c0
                 |
                  --25.00%--lock_release

  Looks good to me....
 ----
Reported-and-Tested-by: NThomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zvonko Kosic <zvonko.kosic@de.ibm.com>
Link: http://lkml.kernel.org/n/tip-dk0n1uzmbe0tbthrpfqlx6bz@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      4b1303d0
  5. 11 7月, 2017 3 次提交
  7. 04 7月, 2017 2 次提交
    • J
      perf unwind: Do not fail due to missing unwind support · 1934adf7
      由 Jiri Olsa 提交于 
      We currently fail the MMAP event processing if we don't have the MMAP
event's specific arch unwind support compiled in.

That's wrong and can lead to unresolved mmaps in report output for 32bit
binaries on 64bit server, like in this example on x86_64 server:

  $ cat ex.c
  int main(int argc, char **argv)
  {
          while (1) {}
  }
  $ gcc -o ex -m32 ex.c
  $ perf record ./ex
  ^C[ perf record: Woken up 2 times to write data ]
  [ perf record: Captured and wrote 0.371 MB perf.data (9322 samples) ]

Before:
  $ perf report --stdio

  SNIP

  # Overhead  Command  Shared Object     Symbol
  # ........  .......  ................  ......................
  #
     100.00%  ex       [unknown]         [.] 0x00000000080483de
       0.00%  ex       [unknown]         [.] 0x00000000f76dba4f
       0.00%  ex       [unknown]         [.] 0x00000000f76e4c11
       0.00%  ex       [unknown]         [.] 0x00000000f76daa30

After:
  $ perf report --stdio

  SNIP

  # Overhead  Command  Shared Object  Symbol
  # ........  .......  .............  ...............
  #
     100.00%  ex       ex             [.] main
       0.00%  ex       ld-2.24.so     [.] _dl_start
       0.00%  ex       ld-2.24.so     [.] do_lookup_x
       0.00%  ex       ld-2.24.so     [.] _start

The fix is not to fail, just warn if there's not unwind support compiled
in.
Reported-by: NMichael Lyle <mlyle@lyle.org>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20170704131131.27508-1-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      1934adf7
    • A
      perf evsel: Set attr.exclude_kernel when probing max attr.precise_ip · 97365e81
      由 Arnaldo Carvalho de Melo 提交于 
      We should set attr.exclude_kernel when probing for attr.precise_ip
level, otherwise !CAP_SYS_ADMIN users will not default to skidless
samples in capable hardware.

The increase in the paranoid level in commit 0161028b ("perf/core:
Change the default paranoia level to 2") broke this, fix it by excluding
kernel samples when probing.

Before:

  $ perf record usleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.018 MB perf.data (6 samples) ]
  $ perf evlist -v
  cycles:u: sample_freq: 4000, sample_type: IP|TID|TIME|PERIOD, exclude_kernel: 1

After:

  $ perf record usleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.018 MB perf.data (8 samples) ]
  $ perf evlist -v
  cycles:ppp: sample_freq: 4000, sample_type: IP|TID|TIME|PERIOD, exclude_kernel: 1, precise_ip: 3
                                                                                     ^^^^^^^^^^^^^
                                                                                     ^^^^^^^^^^^^^
                                                                                     ^^^^^^^^^^^^^
  $

To further clarify: we always set .exclude_kernel when non !CAP_SYS_ADMIN
users profile, its just on the attr.precise_ip probing that we weren't doing
so, fix it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 7f8d1ade ("perf tools: By default use the most precise "cycles" hw counter available")
Link: http://lkml.kernel.org/n/tip-t2qttwhbnua62o5gt75cueml@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      97365e81
  9. 01 7月, 2017 1 次提交
    • J
      objtool: Silence warnings for functions which use IRET · 2513cbf9
      由 Josh Poimboeuf 提交于 
      Previously, objtool ignored functions which have the IRET instruction
in them.  That's because it assumed that such functions know what
they're doing with respect to frame pointers.

With the new "objtool 2.0" changes, it stopped ignoring such functions,
and started complaining about them:

  arch/x86/kernel/alternative.o: warning: objtool: do_sync_core()+0x1b: unsupported instruction in callable function
  arch/x86/kernel/alternative.o: warning: objtool: text_poke()+0x1a8: unsupported instruction in callable function
  arch/x86/kernel/ftrace.o: warning: objtool: do_sync_core()+0x16: unsupported instruction in callable function
  arch/x86/kernel/cpu/mcheck/mce.o: warning: objtool: machine_check_poll()+0x166: unsupported instruction in callable function
  arch/x86/kernel/cpu/mcheck/mce.o: warning: objtool: do_machine_check()+0x147: unsupported instruction in callable function

Silence those warnings for now.  They can be re-enabled later, once we
have unwind hints which will allow the code to annotate the IRET usages.
Reported-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Fixes: baa41469 ("objtool: Implement stack validation 2.0")
Link: http://lkml.kernel.org/r/20170630140934.mmwtpockvpupahro@trebleSigned-off-by: NIngo Molnar <mingo@kernel.org>
      2513cbf9
  11. 30 6月, 2017 16 次提交
  13. 27 6月, 2017 7 次提交