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Diffstat (limited to 'arch/x86/kernel/unwind_orc.c')
-rw-r--r--arch/x86/kernel/unwind_orc.c20
1 files changed, 11 insertions, 9 deletions
diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
index 3bbb399f7ead..b698468f726b 100644
--- a/arch/x86/kernel/unwind_orc.c
+++ b/arch/x86/kernel/unwind_orc.c
@@ -90,9 +90,6 @@ static struct orc_entry null_orc_entry = {
static struct orc_entry *orc_find(unsigned long ip)
{
- if (!orc_init)
- return NULL;
-
if (ip == 0)
return &null_orc_entry;
@@ -460,7 +457,7 @@ bool unwind_next_frame(struct unwind_state *state)
default:
orc_warn("unknown .orc_unwind entry type %d for ip %pB\n",
orc->type, (void *)orig_ip);
- break;
+ goto done;
}
/* Find BP: */
@@ -511,17 +508,20 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task,
memset(state, 0, sizeof(*state));
state->task = task;
+ if (!orc_init)
+ goto err;
+
/*
* Refuse to unwind the stack of a task while it's executing on another
* CPU. This check is racy, but that's ok: the unwinder has other
* checks to prevent it from going off the rails.
*/
if (task_on_another_cpu(task))
- goto done;
+ goto err;
if (regs) {
if (user_mode(regs))
- goto done;
+ goto the_end;
state->ip = regs->ip;
state->sp = kernel_stack_pointer(regs);
@@ -554,6 +554,7 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task,
* generate some kind of backtrace if this happens.
*/
void *next_page = (void *)PAGE_ALIGN((unsigned long)state->sp);
+ state->error = true;
if (get_stack_info(next_page, state->task, &state->stack_info,
&state->stack_mask))
return;
@@ -574,13 +575,14 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task,
/* Otherwise, skip ahead to the user-specified starting frame: */
while (!unwind_done(state) &&
(!on_stack(&state->stack_info, first_frame, sizeof(long)) ||
- state->sp <= (unsigned long)first_frame))
+ state->sp < (unsigned long)first_frame))
unwind_next_frame(state);
return;
-done:
+err:
+ state->error = true;
+the_end:
state->stack_info.type = STACK_TYPE_UNKNOWN;
- return;
}
EXPORT_SYMBOL_GPL(__unwind_start);