[tip:perf/core] perf symbols: Load kernel maps before using

From: tip-bot for Adrian Hunter
Date: Mon Aug 12 2013 - 06:21:45 EST

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Commit-ID: 5b7ba82a75915e739709d0ace4bb559cb280db09
Gitweb: http://git.kernel.org/tip/5b7ba82a75915e739709d0ace4bb559cb280db09
Author: Adrian Hunter <adrian.hunter@xxxxxxxxx>
AuthorDate: Wed, 7 Aug 2013 14:38:46 +0300
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 7 Aug 2013 17:35:31 -0300

perf symbols: Load kernel maps before using

In order to use kernel maps to read object code, those maps must be
adjusted to map to the dso file offset. Because lazy-initialization is
used, that is not done until symbols are loaded. However the maps are
first used by thread__find_addr_map() before symbols are loaded. So
this patch changes thread__find_addr() to "load" kernel maps before
using them.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1375875537-4509-3-git-send-email-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-inject.c | 2 +-
tools/perf/builtin-script.c | 4 ++--
tools/perf/tests/code-reading.c | 2 +-
tools/perf/util/build-id.c | 2 +-
tools/perf/util/event.c | 18 ++++++++++++++----
tools/perf/util/thread.h | 2 +-
tools/perf/util/unwind.c | 4 ++--
7 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index 1d8de2e..f012a98 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -206,7 +206,7 @@ static int perf_event__inject_buildid(struct perf_tool *tool,
}

thread__find_addr_map(thread, machine, cpumode, MAP__FUNCTION,
- event->ip.ip, &al);
+ event->ip.ip, &al, NULL);

if (al.map != NULL) {
if (!al.map->dso->hit) {
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 1cad370..cd616ff 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -341,10 +341,10 @@ static void print_sample_addr(union perf_event *event,
return;

thread__find_addr_map(thread, machine, cpumode, MAP__FUNCTION,
- sample->addr, &al);
+ sample->addr, &al, NULL);
if (!al.map)
thread__find_addr_map(thread, machine, cpumode, MAP__VARIABLE,
- sample->addr, &al);
+ sample->addr, &al, NULL);

al.cpu = sample->cpu;
al.sym = NULL;
diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
index 28bee62..0c7b052 100644
--- a/tools/perf/tests/code-reading.c
+++ b/tools/perf/tests/code-reading.c
@@ -138,7 +138,7 @@ static int read_object_code(u64 addr, size_t len, u8 cpumode,
pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);

thread__find_addr_map(thread, machine, cpumode, MAP__FUNCTION, addr,
- &al);
+ &al, NULL);
if (!al.map || !al.map->dso) {
pr_debug("thread__find_addr_map failed\n");
return -1;
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 5295625..3a0f508 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -33,7 +33,7 @@ int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused,
}

thread__find_addr_map(thread, machine, cpumode, MAP__FUNCTION,
- event->ip.ip, &al);
+ event->ip.ip, &al, NULL);

if (al.map != NULL)
al.map->dso->hit = 1;
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 9541270..cc7c0c9 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -592,9 +592,10 @@ int perf_event__process(struct perf_tool *tool __maybe_unused,
void thread__find_addr_map(struct thread *self,
struct machine *machine, u8 cpumode,
enum map_type type, u64 addr,
- struct addr_location *al)
+ struct addr_location *al, symbol_filter_t filter)
{
struct map_groups *mg = &self->mg;
+ bool load_map = false;

al->thread = self;
al->addr = addr;
@@ -609,11 +610,13 @@ void thread__find_addr_map(struct thread *self,
if (cpumode == PERF_RECORD_MISC_KERNEL && perf_host) {
al->level = 'k';
mg = &machine->kmaps;
+ load_map = true;
} else if (cpumode == PERF_RECORD_MISC_USER && perf_host) {
al->level = '.';
} else if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL && perf_guest) {
al->level = 'g';
mg = &machine->kmaps;
+ load_map = true;
} else {
/*
* 'u' means guest os user space.
@@ -654,8 +657,15 @@ try_again:
mg = &machine->kmaps;
goto try_again;
}
- } else
+ } else {
+ /*
+ * Kernel maps might be changed when loading symbols so loading
+ * must be done prior to using kernel maps.
+ */
+ if (load_map)
+ map__load(al->map, filter);
al->addr = al->map->map_ip(al->map, al->addr);
+ }
}

void thread__find_addr_location(struct thread *thread, struct machine *machine,
@@ -663,7 +673,7 @@ void thread__find_addr_location(struct thread *thread, struct machine *machine,
struct addr_location *al,
symbol_filter_t filter)
{
- thread__find_addr_map(thread, machine, cpumode, type, addr, al);
+ thread__find_addr_map(thread, machine, cpumode, type, addr, al, filter);
if (al->map != NULL)
al->sym = map__find_symbol(al->map, al->addr, filter);
else
@@ -699,7 +709,7 @@ int perf_event__preprocess_sample(const union perf_event *event,
machine__create_kernel_maps(machine);

thread__find_addr_map(thread, machine, cpumode, MAP__FUNCTION,
- event->ip.ip, al);
+ event->ip.ip, al, filter);
dump_printf(" ...... dso: %s\n",
al->map ? al->map->dso->long_name :
al->level == 'H' ? "[hypervisor]" : "<not found>");
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index 0fe1f9c..f98d1d9 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -41,7 +41,7 @@ static inline struct map *thread__find_map(struct thread *self,

void thread__find_addr_map(struct thread *thread, struct machine *machine,
u8 cpumode, enum map_type type, u64 addr,
- struct addr_location *al);
+ struct addr_location *al, symbol_filter_t filter);

void thread__find_addr_location(struct thread *thread, struct machine *machine,
u8 cpumode, enum map_type type, u64 addr,
diff --git a/tools/perf/util/unwind.c b/tools/perf/util/unwind.c
index 958723b..5bbd494 100644
--- a/tools/perf/util/unwind.c
+++ b/tools/perf/util/unwind.c
@@ -272,7 +272,7 @@ static struct map *find_map(unw_word_t ip, struct unwind_info *ui)
struct addr_location al;

thread__find_addr_map(ui->thread, ui->machine, PERF_RECORD_MISC_USER,
- MAP__FUNCTION, ip, &al);
+ MAP__FUNCTION, ip, &al, NULL);
return al.map;
}

@@ -349,7 +349,7 @@ static int access_dso_mem(struct unwind_info *ui, unw_word_t addr,
ssize_t size;

thread__find_addr_map(ui->thread, ui->machine, PERF_RECORD_MISC_USER,
- MAP__FUNCTION, addr, &al);
+ MAP__FUNCTION, addr, &al, NULL);
if (!al.map) {
pr_debug("unwind: no map for %lx\n", (unsigned long)addr);
return -1;
--
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Next message: tip-bot for Adrian Hunter: "[tip:perf/core] perf tools: Make it possible to read object code from vmlinux"
Previous message: tip-bot for Adrian Hunter: "[tip:perf/core] perf tests: Add test for reading object code"
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