sparc64: Like x86 we should check current->mm during perf backtrace generation.
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 <davem@davemloft.net>
diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c
index e48651d..9e96f84 100644
--- a/arch/sparc/kernel/perf_event.c
+++ b/arch/sparc/kernel/perf_event.c
@@ -1738,8 +1738,6 @@
{
unsigned long ufp;
- perf_callchain_store(entry, regs->tpc);
-
ufp = regs->u_regs[UREG_I6] + STACK_BIAS;
do {
struct sparc_stackf *usf, sf;
@@ -1760,8 +1758,6 @@
{
unsigned long ufp;
- perf_callchain_store(entry, regs->tpc);
-
ufp = regs->u_regs[UREG_I6] & 0xffffffffUL;
do {
struct sparc_stackf32 *usf, sf;
@@ -1780,6 +1776,11 @@
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);
