Re: [PATCH V1] um: Fix compilation warnings

From: Srinivasarao Pathipati
Date: Wed Feb 15 2023 - 03:15:10 EST


Hi Greert Uytterhoeven,

On 2/15/2023 1:37 PM, Geert Uytterhoeven wrote:
Hi Srinivasarao,

On Wed, Feb 15, 2023 at 6:36 AM Srinivasarao Pathipati
<quic_c_spathi@xxxxxxxxxxx> wrote:
On 2/15/2023 3:27 AM, Richard Weinberger wrote:
----- Ursprüngliche Mail -----
Von: "Srinivasarao Pathipati" <quic_c_spathi@xxxxxxxxxxx>
static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc)
{
- struct uml_pt_regs r;
+ struct uml_pt_regs *r;
int save_errno = errno;

- r.is_user = 0;
+ r = malloc(sizeof(struct uml_pt_regs));
I fear this is not correct since malloc() is not async-signal safe.
Thanks Richard for quick response. Could you please suggest alternative
function of malloc() with async-signal safe.

if that is not possible Is there any other way to fix this warning? OR
do we need to live with that warning?
Does this limit actually apply to this file, which calls into the host OS?

How come you even see this warning, as we have

CFLAGS_signal.o += -Wframe-larger-than=4096

since commit 517f60206ee5d5f7 ("um: Increase stack frame size threshold
for signal.c") in v5.11?

Gr{oetje,eeting}s,

Geert

We were testing this on 5.10 kernel.

We will back port this change.

Thanks