[tip:perfcounters/core] perf report: Handle vDSO symbols properly

tip-bot for Ingo Molnar
2009-06-03T09:50:01Z

Commit-ID: ed966aac335a63083d3125198479447248637d9e
Gitweb: http://git.kernel.org/tip/ed966aac335a63083d3125198479447248637d9e
Author: Ingo Molnar <mingo@elte.hu>
AuthorDate: Wed, 3 Jun 2009 10:39:26 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 3 Jun 2009 10:39:26 +0200

perf report: Handle vDSO symbols properly

We were not looking up vDSO symbols properly, because they
are in the kallsyms but are user-mode entries.

Pass negative addresses to the kernel dso object, this
way we resolve them properly:

0.05% [kernel]: vread_tsc

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
Documentation/perf_counter/builtin-report.c | 15 +++++++++++++++
1 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/Documentation/perf_counter/builtin-report.c b/Documentation/perf_counter/builtin-report.c
index a8d3905..0f88d9e 100644
--- a/Documentation/perf_counter/builtin-report.c
+++ b/Documentation/perf_counter/builtin-report.c
@@ -728,6 +728,8 @@ more:
event->ip.pid,
(void *)(long)ip);

+ dprintf(" ... thread: %s:%d\n", thread->comm, thread->pid);
+
if (thread == NULL) {
fprintf(stderr, "problem processing %d event, skipping it.\n",
event->header.type);
@@ -740,6 +742,8 @@ more:

dso = kernel_dso;

+ dprintf(" ...... dso: %s\n", dso->name);
+
} else if (event->header.misc & PERF_EVENT_MISC_USER) {

show = SHOW_USER;
@@ -749,11 +753,22 @@ more:
if (map != NULL) {
dso = map->dso;
ip -= map->start + map->pgoff;
+ } else {
+ /*
+ * If this is outside of all known maps,
+ * and is a negative address, try to look it
+ * up in the kernel dso, as it might be a
+ * vsyscall (which executes in user-mode):
+ */
+ if ((long long)ip < 0)
+ dso = kernel_dso;
}
+ dprintf(" ...... dso: %s\n", dso ? dso->name : "<not found>");

} else {
show = SHOW_HV;
level = 'H';
+ dprintf(" ...... dso: [hypervisor]\n");
}

if (show & show_mask) {