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authorAndrew Lutomirski <luto@mit.edu>2011-03-24 00:36:56 -0400
committerArnaldo Carvalho de Melo <acme@redhat.com>2011-03-28 14:44:15 -0300
commit6c6804fb2cef2d6aceb38b0eb0803210d77ff390 (patch)
treebb5a8a79c24f7f9f41b0ca076b9800cb3a840d7a /tools
parent18bcd0c8cb7d85a9063b88ec810dc1cdc0974518 (diff)
perf symbols: Fix vsyscall symbol lookup
Perf can't currently trace into the vsyscall page. It looks like it was meant to work. Tested on 2.6.38 and today's -git. The bug is easy to reproduce. Compile this: int main() { int i; struct timespec t; for(i = 0; i < 10000000; i++) clock_gettime(CLOCK_MONOTONIC, &t); return 0; } and run it through perf record; perf report. The top entry shows "[unknown]" and you can't zoom in. It looks like there are two issues. The first is a that a test for user mode executing in kernel space is backwards. (That's the first hunk below). The second (I think) is that something's wrong with the code that generates lots of little struct dso objects for different sections -- when it runs on vmlinux it results in bogus long_name values which cause objdump to fail. Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LPU-Reference: <AANLkTikxSw5+wJZUWNz++nL7mgivCh_Zf=2Kq6=f9Ce_@mail.gmail.com> Signed-off-by: Andy Lutomirski <luto@mit.edu> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/util/event.c2
-rw-r--r--tools/perf/util/symbol.c3
2 files changed, 4 insertions, 1 deletions
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 2b15c362ef56..1023f67633a4 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -710,7 +710,7 @@ try_again:
* in the whole kernel symbol list.
*/
if ((long long)al->addr < 0 &&
- cpumode == PERF_RECORD_MISC_KERNEL &&
+ cpumode == PERF_RECORD_MISC_USER &&
machine && mg != &machine->kmaps) {
mg = &machine->kmaps;
goto try_again;
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 17df793c8924..8f73907a959e 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1196,6 +1196,8 @@ static int dso__load_sym(struct dso *self, struct map *map, const char *name,
if (curr_dso == NULL)
goto out_elf_end;
curr_dso->kernel = self->kernel;
+ curr_dso->long_name = self->long_name;
+ curr_dso->long_name_len = self->long_name_len;
curr_map = map__new2(start, curr_dso,
map->type);
if (curr_map == NULL) {
@@ -1842,6 +1844,7 @@ int dso__load_vmlinux(struct dso *self, struct map *map,
if (fd < 0)
return -1;
+ dso__set_long_name(self, (char *)vmlinux);
dso__set_loaded(self, map->type);
err = dso__load_sym(self, map, symfs_vmlinux, fd, filter, 0, 0);
close(fd);

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