perf probe: Add sdt probes arguments into the uprobe cmd string

An sdt probe can be associated with arguments but they were not passed
to the user probe tracing interface (uprobe_events); this patch adapts
the sdt argument descriptors according to the uprobe input format.

As the uprobe parser does not support scaled address mode, perf will
skip arguments which cannot be adapted to the uprobe format.

Here are the results:

  $ perf buildid-cache -v --add test_sdt
  $ perf probe -x test_sdt sdt_libfoo:table_frob
  $ perf probe -x test_sdt sdt_libfoo:table_diddle
  $ perf record -e sdt_libfoo:table_frob -e sdt_libfoo:table_diddle test_sdt
  $ perf script
  test_sdt  ...   666.255678:   sdt_libfoo:table_frob: (4004d7) arg0=0 arg1=0
  test_sdt  ...   666.255683: sdt_libfoo:table_diddle: (40051a) arg0=0 arg1=0
  test_sdt  ...   666.255686:   sdt_libfoo:table_frob: (4004d7) arg0=1 arg1=2
  test_sdt  ...   666.255689: sdt_libfoo:table_diddle: (40051a) arg0=3 arg1=4
  test_sdt  ...   666.255692:   sdt_libfoo:table_frob: (4004d7) arg0=2 arg1=4
  test_sdt  ...   666.255694: sdt_libfoo:table_diddle: (40051a) arg0=6 arg1=8

Signed-off-by: Alexis Berlemont <alexis.berlemont@gmail.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20161214000732.1710-3-alexis.berlemont@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Alexis Berlemont
2016-12-14 01:07:32 +01:00
committed by Arnaldo Carvalho de Melo
parent be88184b1c
commit 3b1f8311f6
4 changed files with 261 additions and 4 deletions

View File

@@ -15,6 +15,12 @@ struct sample_reg {
extern const struct sample_reg sample_reg_masks[];
/*
* The table sdt_reg_renamings is used for adjusting gcc/gas-generated
* registers before filling the uprobe tracer interface.
*/
int sdt_rename_register(char **pdesc, char *old_name);
#ifdef HAVE_PERF_REGS_SUPPORT
#include <perf_regs.h>