Re: [PATCH-4.19-stable 0/2] Backport ENCODE_FRAME_POINTER hint

From: Greg Kroah-Hartman
Date: Thu Feb 13 2020 - 10:02:00 EST


On Mon, Feb 10, 2020 at 02:05:41PM +0000, Dmitry Safonov wrote:
> On 4.19.93 the following warning was observed with CONFIG_FRAME_POINTER:
> > WARNING: kernel stack frame pointer at 00000000bceb5183 in Coronavirus:3282 has bad value (null)
> > unwind stack type:0 next_sp: (null) mask:0x2 graph_idx:0
> > 000000009630aa47: ffffc9000126fdb0 (0xffffc9000126fdb0)
> > 0000000020360f53: ffffffff81038e33 (__save_stack_trace+0xcb/0xee)
> > 00000000675081f2: 0000000000000000 ...
> > 0000000043198fe7: ffffc9000126c000 (0xffffc9000126c000)
> > 0000000008a46231: ffffc90001270000 (0xffffc90001270000)
> [..]
>
> It turns to be missing %rbp hint was making frame pointer unwinder
> a bit tipsy.
> The observed is WARN_ONCE(), so it one time per boot, but imho, worth to
> have in stable too.

All now queued up, thanks!

greg k-h