linux/tools/perf/util/perf_regs.c
Alexis Berlemont 3b1f8311f6 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>
2017-03-21 10:59:01 -03:00

40 lines
680 B
C

#include <errno.h>
#include "perf_regs.h"
#include "event.h"
const struct sample_reg __weak sample_reg_masks[] = {
SMPL_REG_END
};
int __weak sdt_rename_register(char **pdesc __maybe_unused,
char *old_name __maybe_unused)
{
return 0;
}
#ifdef HAVE_PERF_REGS_SUPPORT
int perf_reg_value(u64 *valp, struct regs_dump *regs, int id)
{
int i, idx = 0;
u64 mask = regs->mask;
if (regs->cache_mask & (1ULL << id))
goto out;
if (!(mask & (1ULL << id)))
return -EINVAL;
for (i = 0; i < id; i++) {
if (mask & (1ULL << i))
idx++;
}
regs->cache_mask |= (1ULL << id);
regs->cache_regs[id] = regs->regs[idx];
out:
*valp = regs->cache_regs[id];
return 0;
}
#endif