sparc64: Like x86 we should check current->mm during perf backtrace generation.

[ Upstream commit 08280e6c4c ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
David S. Miller 2012-10-14 17:59:40 -07:00 committed by Greg Kroah-Hartman
parent 01afdbe150
commit 846514fcb8

View file

@ -1428,8 +1428,6 @@ 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;
@ -1450,8 +1448,6 @@ 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;
@ -1470,6 +1466,11 @@ 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);