diff options
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/trace_sysprof.c | 28 |
1 files changed, 19 insertions, 9 deletions
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c index 7f6fcccffb8..f9a09fe705b 100644 --- a/kernel/trace/trace_sysprof.c +++ b/kernel/trace/trace_sysprof.c @@ -37,21 +37,26 @@ struct stack_frame { static int copy_stack_frame(const void __user *fp, struct stack_frame *frame) { + int ret; + if (!access_ok(VERIFY_READ, fp, sizeof(*frame))) return 0; - if (__copy_from_user_inatomic(frame, frame_pointer, sizeof(*frame))) - return 0; + ret = 1; + pagefault_disable(); + if (__copy_from_user_inatomic(frame, fp, sizeof(*frame))) + ret = 0; + pagefault_enable(); - return 1; + return ret; } static void timer_notify(struct pt_regs *regs, int cpu) { - const void __user *frame_pointer; struct trace_array_cpu *data; struct stack_frame frame; struct trace_array *tr; + const void __user *fp; int is_user; int i; @@ -77,21 +82,26 @@ static void timer_notify(struct pt_regs *regs, int cpu) trace_special(tr, data, 0, current->pid, regs->ip); - frame_pointer = (void __user *)regs->bp; + fp = (void __user *)regs->bp; for (i = 0; i < sample_max_depth; i++) { - if (!copy_stack_frame(frame_pointer, &frame)) + frame.next_fp = 0; + frame.return_address = 0; + if (!copy_stack_frame(fp, &frame)) break; - if ((unsigned long)frame_pointer < regs->sp) + if ((unsigned long)fp < regs->sp) break; trace_special(tr, data, 1, frame.return_address, - (unsigned long)frame_pointer); - frame_pointer = frame.next_fp; + (unsigned long)fp); + fp = frame.next_fp; } trace_special(tr, data, 2, current->pid, i); + /* + * Special trace entry if we overflow the max depth: + */ if (i == sample_max_depth) trace_special(tr, data, -1, -1, -1); } |