Re: ppc64le reliable stack unwinder and scheduled tasks

From: Joe Lawrence
Date: Mon Jan 14 2019 - 12:54:56 EST


On 1/14/19 12:09 PM, Josh Poimboeuf wrote:
On Mon, Jan 14, 2019 at 11:46:59AM -0500, Joe Lawrence wrote:
@@ -158,11 +158,21 @@ save_stack_trace_tsk_reliable(struct task_struct *tsk,
return 1; /* invalid backlink, too far up. */
}
+ /* We can only trust the bottom frame's backlink, the rest
+ * of the frame may be uninitialized, continue to the next. */
+ if (firstframe--)
+ goto next;

Won't this decrement firstframe on every iteration, so when firstframe
is 0, it will decrement it to -1, causing it to 'goto next' on all
future iterations?


Argg, yes, that should be:

if (!firstframe) {
firstframe = 0;
goto next;
}

Apologies for the monday-morning crap-patch.

/runsoff to find some more caffeine

-- Joe