aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/kernel/perf_event.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/kernel/perf_event.c')
-rw-r--r--arch/arm/kernel/perf_event.c18
1 files changed, 12 insertions, 6 deletions
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 4238bcba9d60..266cba46db3e 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -560,11 +560,16 @@ user_backtrace(struct frame_tail __user *tail,
struct perf_callchain_entry *entry)
{
struct frame_tail buftail;
+ unsigned long err;
- /* Also check accessibility of one struct frame_tail beyond */
if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
return NULL;
- if (__copy_from_user_inatomic(&buftail, tail, sizeof(buftail)))
+
+ pagefault_disable();
+ err = __copy_from_user_inatomic(&buftail, tail, sizeof(buftail));
+ pagefault_enable();
+
+ if (err)
return NULL;
perf_callchain_store(entry, buftail.lr);
@@ -590,6 +595,10 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
}
perf_callchain_store(entry, regs->ARM_pc);
+
+ if (!current->mm)
+ return;
+
tail = (struct frame_tail __user *)regs->ARM_fp - 1;
while ((entry->nr < PERF_MAX_STACK_DEPTH) &&
@@ -621,10 +630,7 @@ perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
return;
}
- fr.fp = regs->ARM_fp;
- fr.sp = regs->ARM_sp;
- fr.lr = regs->ARM_lr;
- fr.pc = regs->ARM_pc;
+ arm_get_current_stackframe(regs, &fr);
walk_stackframe(&fr, callchain_trace, entry);
}