3.2-stable review patch. If anyone has any objections, please let me know.
------------------
From: "David S. Miller" <da...@davemloft.net>
[ Upstream commit 08280e6c4c2e8049ac61d9e8e3536ec1df629c0d ]
If the MM is not active, only report the top-level PC. Do not try to
access the address space.
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
arch/sparc/kernel/perf_event.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c
index 614da62..5331ae1 100644
--- a/arch/sparc/kernel/perf_event.c
+++ b/arch/sparc/kernel/perf_event.c
@@ -1422,8 +1422,6 @@ static void perf_callchain_user_64(struct
perf_callchain_entry *entry,
{
unsigned long ufp;
- perf_callchain_store(entry, regs->tpc);
-
ufp = regs->u_regs[UREG_I6] + STACK_BIAS;
do {
struct sparc_stackf *usf, sf;
@@ -1444,8 +1442,6 @@ static void perf_callchain_user_32(struct
perf_callchain_entry *entry,
{
unsigned long ufp;
- perf_callchain_store(entry, regs->tpc);
-
ufp = regs->u_regs[UREG_I6] & 0xffffffffUL;
do {
struct sparc_stackf32 *usf, sf;
@@ -1464,6 +1460,11 @@ static void perf_callchain_user_32(struct
perf_callchain_entry *entry,
void
perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
{
+ perf_callchain_store(entry, regs->tpc);
+
+ if (!current->mm)
+ return;
+
flushw_user();
if (test_thread_flag(TIF_32BIT))
perf_callchain_user_32(entry, regs);
--
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