perf report: Add validation of call-chain entries

Add boundary checks for call-chain events. In case of corrupted
entries we could crash otherwise.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 10 insertions, 10 deletions

diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index eccae437fe37..a7d3a61a59b7 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -337,6 +337,16 @@ enum perf_event_type {
          */
 };
 
+#define MAX_STACK_DEPTH                 255
+
+struct perf_callchain_entry {
+        __u16                           nr;
+        __u16                           hv;
+        __u16                           kernel;
+        __u16                           user;
+        __u64                           ip[MAX_STACK_DEPTH];
+};
+
 #ifdef __KERNEL__
 /*
  * Kernel-internal data types and definitions:
@@ -652,16 +662,6 @@ extern void perf_counter_fork(struct task_struct *tsk);
 
 extern void perf_counter_task_migration(struct task_struct *task, int cpu);
 
-#define MAX_STACK_DEPTH                 255
-
-struct perf_callchain_entry {
-        u16                             nr;
-        u16                             hv;
-        u16                             kernel;
-        u16                             user;
-        u64                             ip[MAX_STACK_DEPTH];
-};
-
 extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs);
 
 extern int sysctl_perf_counter_paranoid;