From: Matt Fleming <matt@codeblueprint.co.uk>
To: Joe Perches <joe@perches.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ferruh Yigit <fery@cypress.com>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: possible krealloc with __GFP_ZERO defects
Date: Fri, 5 Aug 2016 12:37:01 +0100 [thread overview]
Message-ID: <20160805113701.GO3636@codeblueprint.co.uk> (raw)
In-Reply-To: <1469729491.3998.58.camel@perches.com>
On Thu, 28 Jul, at 11:11:31AM, Joe Perches wrote:
> (forwarding to the maintainers of other uses)
>
> On Thu, 2016-07-28 at 10:27 -0700, Joe Perches wrote:
> > There is a defect in krealloc with __GFP_ZERO so this code in
> > drivers/chat/tile-srom.c may not work properly:
> >
> > drivers/char/tile-srom.c- for (i = 0; ; i++) {
> > drivers/char/tile-srom.c- int devhdl;
> > drivers/char/tile-srom.c- char buf[20];
> > drivers/char/tile-srom.c- struct srom_dev *new_srom_devices =
> > drivers/char/tile-srom.c- krealloc(srom_devices, (i+1) * sizeof(struct srom_dev),
> > drivers/char/tile-srom.c: GFP_KERNEL | __GFP_ZERO);
> > drivers/char/tile-srom.c- if (!new_srom_devices) {
> > drivers/char/tile-srom.c- result = -ENOMEM;
> > drivers/char/tile-srom.c- goto fail_mem;
> > drivers/char/tile-srom.c- }
> > drivers/char/tile-srom.c- srom_devices = new_srom_devices;
> >
> > http://linux-kernel.vger.kernel.narkive.com/xyiQV3vf/slab-krealloc-with-gfp-zero-defect
>
> Here are the other in-tree uses that may not work properly
>
> $ grep-2.5.4 -rP --include=*.[ch] -n "krealloc[^;]+__GFP_ZERO" *
> drivers/firmware/efi/capsule-loader.c:87: temp_page = krealloc(cap_info->pages,
> pages_needed * sizeof(void *),
> GFP_KERNEL | __GFP_ZERO);
> drivers/char/tile-srom.c:375: krealloc(srom_devices, (i+1) * sizeof(struct srom_dev),
> GFP_KERNEL | __GFP_ZERO);
> drivers/input/touchscreen/cyttsp4_core.c:521: p = krealloc(si->btn, si->si_ofs.btn_keys_size,
> GFP_KERNEL|__GFP_ZERO);
> drivers/input/touchscreen/cyttsp4_core.c:565: p = krealloc(si->xy_mode, si->si_ofs.mode_size, GFP_KERNEL|__GFP_ZERO);
> drivers/input/touchscreen/cyttsp4_core.c:570: p = krealloc(si->xy_data, si->si_ofs.data_size, GFP_KERNEL|__GFP_ZERO);
> drivers/input/touchscreen/cyttsp4_core.c:575: p = krealloc(si->btn_rec_data,
> si->si_ofs.btn_rec_size * si->si_ofs.num_btns,
> GFP_KERNEL|__GFP_ZERO);
> sound/hda/array.c:28: nlist = krealloc(array->list, size, GFP_KERNEL | __GFP_ZERO);
> sound/core/info.c:342: char *nbuf = krealloc(buf->buffer, PAGE_ALIGN(next),
> GFP_KERNEL | __GFP_ZERO);
Isn't this a bug in krealloc()?
next prev parent reply other threads:[~2016-08-05 11:37 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-28 17:27 tile-srom and krealloc with __GFP_ZERO defect Joe Perches
2016-07-28 18:11 ` possible krealloc with __GFP_ZERO defects Joe Perches
2016-07-28 19:07 ` [PATCH] tile-srom: avoid krealloc(... __GFP_ZERO) pattern Chris Metcalf
2016-08-05 11:37 ` Matt Fleming [this message]
2016-08-05 15:25 ` possible krealloc with __GFP_ZERO defects Joe Perches
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