Commit d9b62aba authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo

perf tools: Adjust kallsyms for relocated kernel

If the kernel is relocated at boot time, kallsyms will not match data
recorded previously.

That does not matter for modules because they are corrected anyway.  It
also does not matter if vmlinux is being used for symbols. But if perf
tools has only kallsyms then the symbols will not match.

Fix by applying the delta gained by comparing the old and current
addresses of the relocation reference symbol.
Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Tested-by: default avatarJiri Olsa <jolsa@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1391004884-10334-9-git-send-email-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent c080f727
...@@ -627,7 +627,7 @@ static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map, ...@@ -627,7 +627,7 @@ static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map,
* kernel range is broken in several maps, named [kernel].N, as we don't have * kernel range is broken in several maps, named [kernel].N, as we don't have
* the original ELF section names vmlinux have. * the original ELF section names vmlinux have.
*/ */
static int dso__split_kallsyms(struct dso *dso, struct map *map, static int dso__split_kallsyms(struct dso *dso, struct map *map, u64 delta,
symbol_filter_t filter) symbol_filter_t filter)
{ {
struct map_groups *kmaps = map__kmap(map)->kmaps; struct map_groups *kmaps = map__kmap(map)->kmaps;
...@@ -692,6 +692,12 @@ static int dso__split_kallsyms(struct dso *dso, struct map *map, ...@@ -692,6 +692,12 @@ static int dso__split_kallsyms(struct dso *dso, struct map *map,
char dso_name[PATH_MAX]; char dso_name[PATH_MAX];
struct dso *ndso; struct dso *ndso;
if (delta) {
/* Kernel was relocated at boot time */
pos->start -= delta;
pos->end -= delta;
}
if (count == 0) { if (count == 0) {
curr_map = map; curr_map = map;
goto filter_symbol; goto filter_symbol;
...@@ -721,6 +727,10 @@ static int dso__split_kallsyms(struct dso *dso, struct map *map, ...@@ -721,6 +727,10 @@ static int dso__split_kallsyms(struct dso *dso, struct map *map,
curr_map->map_ip = curr_map->unmap_ip = identity__map_ip; curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
map_groups__insert(kmaps, curr_map); map_groups__insert(kmaps, curr_map);
++kernel_range; ++kernel_range;
} else if (delta) {
/* Kernel was relocated at boot time */
pos->start -= delta;
pos->end -= delta;
} }
filter_symbol: filter_symbol:
if (filter && filter(curr_map, pos)) { if (filter && filter(curr_map, pos)) {
...@@ -1130,15 +1140,41 @@ static int dso__load_kcore(struct dso *dso, struct map *map, ...@@ -1130,15 +1140,41 @@ static int dso__load_kcore(struct dso *dso, struct map *map,
return -EINVAL; return -EINVAL;
} }
/*
* If the kernel is relocated at boot time, kallsyms won't match. Compute the
* delta based on the relocation reference symbol.
*/
static int kallsyms__delta(struct map *map, const char *filename, u64 *delta)
{
struct kmap *kmap = map__kmap(map);
u64 addr;
if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
return 0;
addr = kallsyms__get_function_start(filename,
kmap->ref_reloc_sym->name);
if (!addr)
return -1;
*delta = addr - kmap->ref_reloc_sym->addr;
return 0;
}
int dso__load_kallsyms(struct dso *dso, const char *filename, int dso__load_kallsyms(struct dso *dso, const char *filename,
struct map *map, symbol_filter_t filter) struct map *map, symbol_filter_t filter)
{ {
u64 delta = 0;
if (symbol__restricted_filename(filename, "/proc/kallsyms")) if (symbol__restricted_filename(filename, "/proc/kallsyms"))
return -1; return -1;
if (dso__load_all_kallsyms(dso, filename, map) < 0) if (dso__load_all_kallsyms(dso, filename, map) < 0)
return -1; return -1;
if (kallsyms__delta(map, filename, &delta))
return -1;
symbols__fixup_duplicate(&dso->symbols[map->type]); symbols__fixup_duplicate(&dso->symbols[map->type]);
symbols__fixup_end(&dso->symbols[map->type]); symbols__fixup_end(&dso->symbols[map->type]);
...@@ -1150,7 +1186,7 @@ int dso__load_kallsyms(struct dso *dso, const char *filename, ...@@ -1150,7 +1186,7 @@ int dso__load_kallsyms(struct dso *dso, const char *filename,
if (!dso__load_kcore(dso, map, filename)) if (!dso__load_kcore(dso, map, filename))
return dso__split_kallsyms_for_kcore(dso, map, filter); return dso__split_kallsyms_for_kcore(dso, map, filter);
else else
return dso__split_kallsyms(dso, map, filter); return dso__split_kallsyms(dso, map, delta, filter);
} }
static int dso__load_perf_map(struct dso *dso, struct map *map, static int dso__load_perf_map(struct dso *dso, struct map *map,
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment