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>
This commit is contained in:
David S. Miller 2012-10-14 17:59:40 -07:00
parent ddffeb8c4d
commit 08280e6c4c

View File

@ -1738,8 +1738,6 @@ 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;
@ -1760,8 +1758,6 @@ 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;
@ -1780,6 +1776,11 @@ 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);