Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Tue, 12 Dec 2017 15:58:00 +0100 | Subject | Re: [PATCH] drivers: base: power: Fix GFP_KERNEL in spinlock context |
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Hi Shrikant,
On Tue, Dec 12, 2017 at 2:45 PM, <shrikant.maurya@techveda.org> wrote: > From: Shrikant Maurya <shrikant.maurya@techveda.org> > > As reported by Jia-Ju Bai (https://lkml.org/lkml/2017/12/11/872): > API's are using GFP_KERNEL to allocate memory which may sleep. > > To ensure atomicity such allocations must be avoided in critical > sections under spinlock. > Fixed by replacing GFP_KERNEL to GFP_ATOMIC. > > Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com> > Signed-off-by: Shrikant Maurya <shrikant.maurya@techveda.org> > Signed-off-by: Suniel Mahesh <sunil.m@techveda.org> > Signed-off-by: Raghu Bharadwaj <raghu@techveda.org> > Signed-off-by: Karthik Tummala <karthik@techveda.org>
Can't the call to device_init_wakeup() in isp116x_start() just be moved below the spinlock release?
> --- a/drivers/base/power/wakeup.c > +++ b/drivers/base/power/wakeup.c > @@ -92,11 +92,11 @@ struct wakeup_source *wakeup_source_create(const char *name) > { > struct wakeup_source *ws; > > - ws = kmalloc(sizeof(*ws), GFP_KERNEL); > + ws = kmalloc(sizeof(*ws), GFP_ATOMIC);
With GFP_ATOMIC, allocation failure is much more likely to occur. So IMHO it's better to fix the isp116x, than to impose this burden on every user.
> if (!ws) > return NULL; > > - wakeup_source_prepare(ws, name ? kstrdup_const(name, GFP_KERNEL) : NULL); > + wakeup_source_prepare(ws, name ? kstrdup_const(name, GFP_ATOMIC) : NULL); > return ws; > } > EXPORT_SYMBOL_GPL(wakeup_source_create);
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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