From: Arnd Bergmann <arnd@arndb.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: kasan-dev@googlegroups.com, Dmitry Vyukov <dvyukov@google.com>,
        Alexander Potapenko <glider@google.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Arend van Spriel <arend.vanspriel@broadcom.com>,
        Arnd Bergmann <arnd@arndb.de>, David Woodhouse <dwmw2@infradead.org>,
        Brian Norris <computersforpeace@gmail.com>,
        Boris Brezillon <boris.brezillon@free-electrons.com>,
        Marek Vasut <marek.vasut@gmail.com>,
        Richard Weinberger <richard@nod.at>,
        Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>,
        linux-mtd@lists.infradead.org
Subject: [PATCH v2 05/11] mtd: cfi: reduce stack size with KASAN
Date: Wed, 14 Jun 2017 23:15:40 +0200
Message-Id: <20170614211556.2062728-6-arnd@arndb.de>
In-Reply-To: <20170614211556.2062728-1-arnd@arndb.de>
References: <20170614211556.2062728-1-arnd@arndb.de>
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 4282
Lines: 100

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 <arnd@arndb.de>
---
 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)
 {
 	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)
 {
 	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;
-- 
2.9.0