From: Joe Perches <joe@perches.com>
To: Arnd Bergmann <arnd@arndb.de>, kasan-dev@googlegroups.com
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-media@vger.kernel.org, linux-wireless@vger.kernel.org,
kernel-build-reports@lists.linaro.org,
"David S . Miller" <davem@davemloft.net>
Subject: Re: [PATCH 24/26] ocfs2: reduce stack size with KASAN
Date: Thu, 02 Mar 2017 09:46:10 -0800 [thread overview]
Message-ID: <1488476770.2179.6.camel@perches.com> (raw)
In-Reply-To: <20170302163834.2273519-25-arnd@arndb.de>
On Thu, 2017-03-02 at 17:38 +0100, Arnd Bergmann wrote:
> The internal logging infrastructure in ocfs2 causes special warning code to be
> used with KASAN, which produces rather large stack frames:
> fs/ocfs2/super.c: In function 'ocfs2_fill_super':
> fs/ocfs2/super.c:1219:1: error: the frame size of 3264 bytes is larger than 3072 bytes [-Werror=frame-larger-than=]
At least by default it doesn't seem to.
gcc 6.2 allyesconfig, CONFIG_KASAN=y
with either CONFIG_KASAN_INLINE or CONFIG_KASAN_OUTLINE
gcc doesn't emit a stack warning
> By simply passing the mask by value instead of reference, we can avoid the
> problem completely.
Any idea why that's so?
> On 64-bit architectures, this is also more efficient,
Efficient true, but the same overall stack no?
> while on the less common (at least among ocfs2 users) 32-bit architectures,
> I'm guessing that the resulting code is comparable to what it was before.
>
> The current version was introduced by Joe Perches as an optimization, maybe
> he can see if my change regresses compared to his.
I don't see it.
> Cc: Joe Perches <joe@perches.com>
> Fixes: 7c2bd2f930ae ("ocfs2: reduce object size of mlog uses")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> fs/ocfs2/cluster/masklog.c | 10 +++++-----
> fs/o cfs2/cluster/masklog.h | 4 ++--
> 2 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/fs/ocfs2/cluster/masklog.c b/fs/ocfs2/cluster/masklog.c
> index d331c2386b94..9720c5443e4d 100644
> --- a/fs/ocfs2/cluster/masklog.c
> +++ b/fs/ocfs2/cluster/masklog.c
> @@ -64,7 +64,7 @@ static ssize_t mlog_mask_store(u64 mask, const char *buf, size_t count)
> return count;
> }
>
> -void __mlog_printk(const u64 *mask, const char *func, int line,
> +void __mlog_printk(const u64 mask, const char *func, int line,
> const char *fmt, ...)
> {
> struct va_format vaf;
> @@ -72,14 +72,14 @@ void __mlog_printk(const u64 *mask, const char *func, int line,
> const char *level;
> const char *prefix = "";
>
> - if (!__mlog_test_u64(*mask, mlog_and_bits) ||
> - __mlog_test_u64(*mask, mlog_not_bits))
> + if (!__mlog_test_u64(mask, mlog_and_bits) ||
> + __mlog_test_u64(mask, mlog_not_bits))
> return;
>
> - if (*mask & ML_ERROR) {
> + if (mask & ML_ERROR) {
> level = KERN_ERR;
> prefix = "ERROR: ";
> - } else if (*mask & ML_NOTICE) {
> + } else if (mask & ML_NOTICE) {
> level = KERN_NOTICE;
> } else {
> level = KERN_INFO;
> diff --git a/fs/ocfs2/cluster/masklog.h b/fs/ocfs2/cluster/masklog.h
> index 308ea0eb35fd..0d0f4bf2c3d8 100644
> --- a/fs/ocfs2/cluster/masklog.h
> +++ b/fs/ocfs2/cluster/masklog.h
> @@ -163,7 +163,7 @@ extern struct mlog_bits mlog_and_bits, mlog_not_bits;
> #endif
>
> __printf(4, 5)
> -void __mlog_printk(const u64 *m, const char *func, int line,
> +void __mlog_printk(const u64 m, const char *func, int line,
> const char *fmt, ...);
>
> /*
> @@ -174,7 +174,7 @@ void __mlog_printk(const u64 *m, const char *func, int line,
> do { \
> u64 _m = MLOG_MASK_PREFIX | (mask); \
> if (_m & ML_ALLOWED_BITS) \
> - __mlog_printk(&_m, __func__, __LINE__, fmt, \
> + __mlog_printk(_m, __func__, __LINE__, fmt, \
> ##__VA_ARGS__); \
> } while (0)
>
next prev parent reply other threads:[~2017-03-02 17:50 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-02 16:38 [PATCH 00/26] bring back stack frame warning with KASAN Arnd Bergmann
2017-03-02 16:38 ` [PATCH 01/26] compiler: introduce noinline_for_kasan annotation Arnd Bergmann
2017-03-03 13:50 ` Andrey Ryabinin
2017-03-03 13:55 ` Alexander Potapenko
2017-03-03 14:30 ` Arnd Bergmann
2017-03-03 14:33 ` Alexander Potapenko
2017-03-03 14:51 ` Arnd Bergmann
2017-03-03 16:34 ` David Laight
2017-03-02 16:38 ` [PATCH 02/26] rewrite READ_ONCE/WRITE_ONCE Arnd Bergmann
2017-03-02 16:51 ` Christian Borntraeger
2017-03-02 17:55 ` Arnd Bergmann
2017-03-02 19:00 ` Christian Borntraeger
2017-03-02 21:45 ` Arnd Bergmann
2017-03-03 8:26 ` Christian Borntraeger
2017-03-03 9:54 ` Arnd Bergmann
2017-03-03 14:49 ` Peter Zijlstra
2017-03-03 14:57 ` Peter Zijlstra
2017-03-02 16:38 ` [PATCH 03/26] typecheck.h: avoid local variables in typecheck() macro Arnd Bergmann
2017-03-02 16:38 ` [PATCH 04/26] tty: kbd: reduce stack size with KASAN Arnd Bergmann
2017-03-02 16:38 ` [PATCH 05/26] netlink: mark nla_put_{u8,u16,u32} noinline_for_kasan Arnd Bergmann
2017-03-02 16:38 ` [PATCH 06/26] rocker: mark rocker_tlv_put_* functions as noinline_for_kasan Arnd Bergmann
2017-03-02 16:38 ` [PATCH 07/26] brcmsmac: reduce stack size with KASAN Arnd Bergmann
2017-03-06 9:16 ` Arend Van Spriel
2017-03-06 10:38 ` Arnd Bergmann
2017-03-06 11:02 ` Arend Van Spriel
2017-03-06 11:16 ` Arnd Bergmann
2017-03-06 11:18 ` Arnd Bergmann
2017-03-02 16:38 ` [PATCH 08/26] brcmsmac: make some local variables 'static const' to reduce stack size Arnd Bergmann
2017-03-06 9:30 ` Arend Van Spriel
2017-03-06 16:19 ` Kalle Valo
2017-03-06 21:34 ` Arnd Bergmann
2017-03-07 9:44 ` Kalle Valo
2017-03-07 9:55 ` Arend Van Spriel
2017-03-02 16:38 ` [PATCH 09/26] brcmsmac: split up wlc_phy_workarounds_nphy Arnd Bergmann
2017-03-06 9:31 ` Arend Van Spriel
2017-03-02 16:38 ` [PATCH 10/26] brcmsmac: reindent split functions Arnd Bergmann
2017-03-06 9:33 ` Arend Van Spriel
2017-03-06 16:24 ` Kalle Valo
2017-03-02 16:38 ` [PATCH 11/26] rtlwifi: reduce stack usage for KASAN Arnd Bergmann
2017-03-02 16:38 ` [PATCH 12/26] wl3501_cs: reduce stack size " Arnd Bergmann
2017-03-02 16:38 ` [PATCH 13/26] rtl8180: " Arnd Bergmann
2017-03-02 16:38 ` [PATCH 14/26] [media] dvb-frontends: reduce stack size in i2c access Arnd Bergmann
2017-03-02 16:38 ` [PATCH 15/26] [media] tuners: i2c: reduce stack usage for tuner_i2c_xfer_* Arnd Bergmann
2017-03-02 16:38 ` [PATCH 16/26] [media] i2c: adv7604: mark register access as noinline_for_kasan Arnd Bergmann
2017-03-02 16:38 ` [PATCH 17/26] [media] i2c: ks0127: reduce stack frame size for KASAN Arnd Bergmann
2017-03-02 16:38 ` [PATCH 18/26] [media] i2c: cx25840: avoid stack overflow with KASAN Arnd Bergmann
2017-03-02 16:38 ` [PATCH 19/26] [media] r820t: mark register functions as noinline_for_kasan Arnd Bergmann
2017-03-02 16:38 ` [PATCH 20/26] [media] em28xx: split up em28xx_dvb_init to reduce stack size Arnd Bergmann
2017-03-02 16:38 ` [PATCH 21/26] drm/bridge: ps8622: reduce stack size for KASAN Arnd Bergmann
2017-03-02 16:38 ` [PATCH 22/26] drm/i915/gvt: don't overflow the kernel stack with KASAN Arnd Bergmann
2017-03-02 16:38 ` [PATCH 23/26] mtd: cfi: reduce stack size " Arnd Bergmann
2017-03-02 16:38 ` [PATCH 24/26] ocfs2: " Arnd Bergmann
2017-03-02 17:46 ` Joe Perches [this message]
2017-03-02 22:22 ` Arnd Bergmann
2017-03-02 22:40 ` Joe Perches
2017-03-02 22:59 ` Arnd Bergmann
2017-03-02 23:58 ` Joe Perches
2017-03-02 16:38 ` [PATCH 25/26] isdn: eicon: mark divascapi incompatible with kasan Arnd Bergmann
2017-03-03 14:20 ` Andrey Ryabinin
2017-03-03 14:54 ` Arnd Bergmann
2017-03-03 15:22 ` Andrey Ryabinin
2017-03-03 15:37 ` Arnd Bergmann
2017-03-02 16:38 ` [PATCH 26/26] kasan: rework Kconfig settings Arnd Bergmann
2017-03-03 14:51 ` Andrey Ryabinin
2017-03-03 15:03 ` Arnd Bergmann
2017-03-03 12:25 ` [PATCH 00/26] bring back stack frame warning with KASAN Alexander Potapenko
2017-03-03 12:54 ` Arnd Bergmann
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