| Message ID | 20170614211556.2062728-1-arnd@arndb.de |
|---|---|
| Headers | show |
| Series | bring back stack frame warning with KASAN | expand |
On Wed, 14 Jun 2017 23:15:40 +0200 Arnd Bergmann <arnd@arndb.de> 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 <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) 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;
On Fri, Aug 4, 2017 at 9:42 AM, Boris Brezillon <boris.brezillon@free-electrons.com> wrote: > On Wed, 14 Jun 2017 23:15:40 +0200 > Arnd Bergmann <arnd@arndb.de> 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 <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) > > 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? I'm pretty sure it doesn't need the 'inline' keywork. I see that the code was addedlike this in linux-2.4.0-test3pre3 along with the rest of the mtd layer, so it has always been 'inline' and nobody ever bothered to remove that during later cleanups. We could probably just mark this function as 'noinline' here and never inline it, but I would rather not add more than one variant of noinline_if_stackbloat: almost all other users of noinline_if_stackbloat are for functions that have to be inline in normal builds, so it is defined as being either 'inline' or 'noinline' depending on whether KASAN is active. >> 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. Right. Arnd
On Fri, 4 Aug 2017 11:09:53 +0200 Arnd Bergmann <arnd@arndb.de> wrote: > On Fri, Aug 4, 2017 at 9:42 AM, Boris Brezillon > <boris.brezillon@free-electrons.com> wrote: > > On Wed, 14 Jun 2017 23:15:40 +0200 > > Arnd Bergmann <arnd@arndb.de> 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 <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) > > > > 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? > > I'm pretty sure it doesn't need the 'inline' keywork. I see that the code was > addedlike this in linux-2.4.0-test3pre3 along with the rest of the mtd layer, > so it has always been 'inline' and nobody ever bothered to remove that > during later cleanups. > > We could probably just mark this function as 'noinline' here and never > inline it, > but I would rather not add more than one variant of noinline_if_stackbloat: > almost all other users of noinline_if_stackbloat are for functions that have > to be inline in normal builds, so it is defined as being either > 'inline' or 'noinline' > depending on whether KASAN is active. Okay. Let's keep it like that then.
On Wed, 14 Jun 2017 23:15:40 +0200 Arnd Bergmann <arnd@arndb.de> 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 <arnd@arndb.de> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com> > --- > 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;
This is a new version of patches I originally submitted back in March [1], this time reducing the size of the series even further. This minimal set of patches only makes sure that we do get frame size warnings in allmodconfig for x86_64 and arm64 again, even with KASAN enabled. The changes this time are reduced to: - I'm introducing "noinline_if_stackbloat" and use it in a number of places that suffer from inline functions with local variables - netlink, as used in various parts of the kernel - a number of drivers/media drivers - a handful of wireless network drivers - a rework for the brcmsmac driver - -fsanitize-address-use-after-scope is moved to a separate CONFIG_KASAN_EXTRA option that increases the warning limit - CONFIG_KASAN_EXTRA is disabled with CONFIG_COMPILE_TEST, improving compile speed and disabling code that leads to valid warnings on gcc-7.0.1 - kmemcheck conflicts with CONFIG_KASAN_EXTRA Compared to the previous version, I no longer have patches to fix all the CONFIG_KASAN_EXTRA warnings: - READ_ONCE/WRITE_ONCE cause problems in lots of code - typecheck() causes huge problems in a few places - many more uses of noinline_if_stackbloat This series lets us add back a stack frame warning for the regular 2048 bytes without CONFIG_KASAN_EXTRA. I set the warning limit with KASAN_EXTRA to 3072, since I have an additional set of patches to address all files that surpass that limit. We can debate whether we want to apply those as a follow-up, or instead remove the option entirely. Another follow-up series I have reduces the warning limit with KASAN to 1536, and without KASAN to 1280 for 64-bit architectures. I hope that Andrew can pick up the entire series for mmotm, and we can eventually backport most of it to stable kernels and address the warnings that kernelci still reports for this problem [2]. Arnd [1] https://lkml.org/lkml/2017/3/2/508 [2] https://kernelci.org/build/id/593f89a659b51463306b958d/logs/ kasan: rework Kconfig settings brcmsmac: reindent split functions brcmsmac: split up wlc_phy_workarounds_nphy brcmsmac: make some local variables 'static const' to reduce stack size r820t: mark register functions as noinline_if_stackbloat dvb-frontends: reduce stack size in i2c access mtd: cfi: reduce stack size with KASAN rocker: mark rocker_tlv_put_* functions as noinline_if_stackbloat tty: kbd: reduce stack size with KASAN netlink: mark nla_put_{u8,u16,u32} noinline_if_stackbloat compiler: introduce noinline_if_stackbloat annotation Arnd Bergmann (11): drivers/media/dvb-frontends/ascot2e.c | 3 +- drivers/media/dvb-frontends/cxd2841er.c | 4 +- drivers/media/dvb-frontends/drx39xyj/drxj.c | 14 +- drivers/media/dvb-frontends/helene.c | 4 +- drivers/media/dvb-frontends/horus3a.c | 2 +- drivers/media/dvb-frontends/itd1000.c | 2 +- drivers/media/dvb-frontends/mt312.c | 2 +- drivers/media/dvb-frontends/si2165.c | 14 +- drivers/media/dvb-frontends/stb0899_drv.c | 2 +- drivers/media/dvb-frontends/stb6100.c | 2 +- drivers/media/dvb-frontends/stv0367.c | 2 +- drivers/media/dvb-frontends/stv090x.c | 2 +- drivers/media/dvb-frontends/stv6110.c | 2 +- drivers/media/dvb-frontends/stv6110x.c | 2 +- drivers/media/dvb-frontends/tda8083.c | 2 +- drivers/media/dvb-frontends/zl10039.c | 2 +- drivers/media/tuners/r820t.c | 4 +- drivers/mtd/chips/cfi_cmdset_0020.c | 8 +- drivers/net/ethernet/rocker/rocker_tlv.h | 24 +- drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c | 1856 +++++++++++++++++++++++------------------------- drivers/tty/vt/keyboard.c | 6 +- include/linux/compiler.h | 11 + include/linux/mtd/map.h | 8 +- include/net/netlink.h | 36 +- lib/Kconfig.debug | 4 +- lib/Kconfig.kasan | 11 +- lib/Kconfig.kmemcheck | 1 + scripts/Makefile.kasan | 3 + 28 files changed, 986 insertions(+), 1047 deletions(-) -- 2.9.0