Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752048AbdHDHm6 (ORCPT ); Fri, 4 Aug 2017 03:42:58 -0400 Received: from mail.free-electrons.com ([62.4.15.54]:50187 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751278AbdHDHm4 (ORCPT ); Fri, 4 Aug 2017 03:42:56 -0400 Date: Fri, 4 Aug 2017 09:42:54 +0200 From: Boris Brezillon To: Arnd Bergmann Cc: Andrew Morton , kasan-dev@googlegroups.com, Dmitry Vyukov , Alexander Potapenko , Andrey Ryabinin , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Arend van Spriel , David Woodhouse , Brian Norris , Marek Vasut , Richard Weinberger , Cyrille Pitchen , linux-mtd@lists.infradead.org Subject: Re: [PATCH v2 05/11] mtd: cfi: reduce stack size with KASAN Message-ID: <20170804094254.369140c0@bbrezillon> In-Reply-To: <20170614211556.2062728-6-arnd@arndb.de> References: <20170614211556.2062728-1-arnd@arndb.de> <20170614211556.2062728-6-arnd@arndb.de> X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4738 Lines: 108 On Wed, 14 Jun 2017 23:15:40 +0200 Arnd Bergmann wrote: > When CONFIG_KASAN is used, we consume a lot of extra stack space: > > drivers/mtd/chips/cfi_cmdset_0020.c: In function 'do_write_buffer': > drivers/mtd/chips/cfi_cmdset_0020.c:603:1: error: the frame size of 2184 bytes is larger than 1536 bytes [-Werror=frame-larger-than=] > drivers/mtd/chips/cfi_cmdset_0020.c: In function 'cfi_staa_erase_varsize': > drivers/mtd/chips/cfi_cmdset_0020.c:972:1: error: the frame size of 1936 bytes is larger than 1536 bytes [-Werror=frame-larger-than=] > drivers/mtd/chips/cfi_cmdset_0001.c: In function 'do_write_buffer': > drivers/mtd/chips/cfi_cmdset_0001.c:1841:1: error: the frame size of 1776 bytes is larger than 1536 bytes [-Werror=frame-larger-than=] > > This marks some functions as noinline_if_stackbloat to keep reduce the > overall stack size. > > Signed-off-by: Arnd Bergmann > --- > drivers/mtd/chips/cfi_cmdset_0020.c | 8 ++++---- > include/linux/mtd/map.h | 8 ++++---- > 2 files changed, 8 insertions(+), 8 deletions(-) > > diff --git a/drivers/mtd/chips/cfi_cmdset_0020.c b/drivers/mtd/chips/cfi_cmdset_0020.c > index 7d342965f392..5eee5e883f55 100644 > --- a/drivers/mtd/chips/cfi_cmdset_0020.c > +++ b/drivers/mtd/chips/cfi_cmdset_0020.c > @@ -244,7 +244,7 @@ static struct mtd_info *cfi_staa_setup(struct map_info *map) > } > > > -static inline int do_read_onechip(struct map_info *map, struct flchip *chip, loff_t adr, size_t len, u_char *buf) > +static noinline_if_stackbloat int do_read_onechip(struct map_info *map, struct flchip *chip, loff_t adr, size_t len, u_char *buf) Why do we even need to mark those functions inline in the first place? Isn't the compiler smart enough to decide when it should inline things? > { > map_word status, status_OK; > unsigned long timeo; > @@ -728,7 +728,7 @@ cfi_staa_writev(struct mtd_info *mtd, const struct kvec *vecs, > } > > > -static inline int do_erase_oneblock(struct map_info *map, struct flchip *chip, unsigned long adr) > +static noinline_if_stackbloat int do_erase_oneblock(struct map_info *map, struct flchip *chip, unsigned long adr) > { > struct cfi_private *cfi = map->fldrv_priv; > map_word status, status_OK; > @@ -1029,7 +1029,7 @@ static void cfi_staa_sync (struct mtd_info *mtd) > } > } > > -static inline int do_lock_oneblock(struct map_info *map, struct flchip *chip, unsigned long adr) > +static noinline_if_stackbloat int do_lock_oneblock(struct map_info *map, struct flchip *chip, unsigned long adr) > { > struct cfi_private *cfi = map->fldrv_priv; > map_word status, status_OK; > @@ -1175,7 +1175,7 @@ static int cfi_staa_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) > } > return 0; > } > -static inline int do_unlock_oneblock(struct map_info *map, struct flchip *chip, unsigned long adr) > +static noinline_if_stackbloat int do_unlock_oneblock(struct map_info *map, struct flchip *chip, unsigned long adr) > { > struct cfi_private *cfi = map->fldrv_priv; > map_word status, status_OK; > diff --git a/include/linux/mtd/map.h b/include/linux/mtd/map.h > index 3aa56e3104bb..29db74314db8 100644 > --- a/include/linux/mtd/map.h > +++ b/include/linux/mtd/map.h > @@ -316,7 +316,7 @@ static inline map_word map_word_or(struct map_info *map, map_word val1, map_word > return r; > } > > -static inline int map_word_andequal(struct map_info *map, map_word val1, map_word val2, map_word val3) > +static noinline_if_stackbloat int map_word_andequal(struct map_info *map, map_word val1, map_word val2, map_word val3) It's indeed needed for those defined in a header. > { > int i; > > @@ -328,7 +328,7 @@ static inline int map_word_andequal(struct map_info *map, map_word val1, map_wor > return 1; > } > > -static inline int map_word_bitsset(struct map_info *map, map_word val1, map_word val2) > +static noinline_if_stackbloat int map_word_bitsset(struct map_info *map, map_word val1, map_word val2) > { > int i; > > @@ -362,7 +362,7 @@ static inline map_word map_word_load(struct map_info *map, const void *ptr) > return r; > } > > -static inline map_word map_word_load_partial(struct map_info *map, map_word orig, const unsigned char *buf, int start, int len) > +static noinline_if_stackbloat map_word map_word_load_partial(struct map_info *map, map_word orig, const unsigned char *buf, int start, int len) > { > int i; > > @@ -392,7 +392,7 @@ static inline map_word map_word_load_partial(struct map_info *map, map_word orig > #define MAP_FF_LIMIT 8 > #endif > > -static inline map_word map_word_ff(struct map_info *map) > +static noinline_if_stackbloat map_word map_word_ff(struct map_info *map) > { > map_word r; > int i;