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perf probe: Skip kernel symbols which is out of .text

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Skip the kernel symbols which is out of .text, e.g. the functions
in .inittext. Those are found in debuginfo/kallsyms, but already
freed from memory.

e.g.
  ----
  # perf probe vfs_caches_init
  vfs_caches_init+0 is out of .text, skip it.
  Probe point 'vfs_caches_init' not found.
    Error: Failed to add events.
  ----

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150506124649.4961.56249.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Masami Hiramatsu 2015-05-06 21:46:49 +09:00 committed by Arnaldo Carvalho de Melo
parent 573709fdfd
commit 5a51fcd1f3
1 changed files with 24 additions and 7 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

31
tools/perf/util/probe-event.c
View file

@ -557,8 +557,9 @@ static int post_process_probe_trace_events(struct probe_trace_event *tevs,
bool uprobe) bool uprobe)
{ {
struct ref_reloc_sym *reloc_sym; struct ref_reloc_sym *reloc_sym;
u64 etext_addr;
char *tmp; char *tmp;
int i; int i, skipped = 0;
if (uprobe) if (uprobe)
return add_exec_to_probe_trace_events(tevs, ntevs, module); return add_exec_to_probe_trace_events(tevs, ntevs, module);
@ -572,19 +573,29 @@ static int post_process_probe_trace_events(struct probe_trace_event *tevs,
pr_warning("Relocated base symbol is not found!\n"); pr_warning("Relocated base symbol is not found!\n");
return -EINVAL; return -EINVAL;
} }
/* Get the address of _etext for checking non-probable text symbol */
etext_addr = kernel_get_symbol_address_by_name("_etext", false);
for (i = 0; i < ntevs; i++) { for (i = 0; i < ntevs; i++) {
if (tevs[i].point.address && !tevs[i].point.retprobe) { if (tevs[i].point.address && !tevs[i].point.retprobe) {
tmp = strdup(reloc_sym->name); /* If we found a wrong one, mark it by NULL symbol */
if (!tmp) if (etext_addr < tevs[i].point.address) {
return -ENOMEM; pr_warning("%s+%lu is out of .text, skip it.\n",
tevs[i].point.symbol, tevs[i].point.offset);
tmp = NULL;
skipped++;
} else {
tmp = strdup(reloc_sym->name);
if (!tmp)
return -ENOMEM;
}
free(tevs[i].point.symbol); free(tevs[i].point.symbol);
tevs[i].point.symbol = tmp; tevs[i].point.symbol = tmp;
tevs[i].point.offset = tevs[i].point.address - tevs[i].point.offset = tevs[i].point.address -
reloc_sym->unrelocated_addr; reloc_sym->unrelocated_addr;
} }
} }
return 0; return skipped;
} }
/* Try to find perf_probe_event with debuginfo */ /* Try to find perf_probe_event with debuginfo */
@ -630,11 +641,14 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
pr_debug("Found %d probe_trace_events.\n", ntevs); pr_debug("Found %d probe_trace_events.\n", ntevs);
ret = post_process_probe_trace_events(*tevs, ntevs, ret = post_process_probe_trace_events(*tevs, ntevs,
target, pev->uprobes); target, pev->uprobes);
if (ret < 0) { if (ret < 0 || ret == ntevs) {
clear_probe_trace_events(*tevs, ntevs); clear_probe_trace_events(*tevs, ntevs);
zfree(tevs); zfree(tevs);
} }
return ret < 0 ? ret : ntevs; if (ret != ntevs)
return ret < 0 ? ret : ntevs;
ntevs = 0;
/* Fall through */
} }
if (ntevs == 0) { /* No error but failed to find probe point. */ if (ntevs == 0) { /* No error but failed to find probe point. */
@ -2403,6 +2417,9 @@ static int __add_probe_trace_events(struct perf_probe_event *pev,
pr_info("Added new event%s\n", (ntevs > 1) ? "s:" : ":"); pr_info("Added new event%s\n", (ntevs > 1) ? "s:" : ":");
for (i = 0; i < ntevs; i++) { for (i = 0; i < ntevs; i++) {
tev = &tevs[i]; tev = &tevs[i];
/* Skip if the symbol is out of .text (marked previously) */
if (!tev->point.symbol)
continue;
/* Ensure that the address is NOT blacklisted */ /* Ensure that the address is NOT blacklisted */
node = kprobe_blacklist__find_by_address(&blacklist, node = kprobe_blacklist__find_by_address(&blacklist,
tev->point.address); tev->point.address);