From: Martin Wilck <mwilck@suse•com>
To: Stephen Rothwell <sfr@canb•auug.org.au>,
Christoph Hellwig <hch@lst•de>, Jens Axboe <axboe@kernel•dk>,
Andrew Morton <akpm@linux-foundation•org>
Cc: Sagi Grimberg <sagi@grimberg•me>,
Kees Cook <keescook@chromium•org>,
linux-kernel@vger•kernel.org, linux-next@vger•kernel.org,
Martin Wilck <mwilck@suse•de>
Subject: [PATCH] string.h: un-fortify memcpy_and_pad
Date: Wed, 6 Sep 2017 14:36:57 +0200 [thread overview]
Message-ID: <20170906123657.25534-1-mwilck@suse.com> (raw)
In-Reply-To: <20170831182101.0e4ad9a2@canb.auug.org.au>
The way I'd implemented the new helper memcpy_and_pad with
__FORTIFY_INLINE caused compiler warnings for certain kernel
configurations.
This helper is only used in a single place at this time, and thus
doesn't benefit much from fortification. So simplify the code
by dropping fortification support for now.
Fixes: 01f33c336e2d "string.h: add memcpy_and_pad()"
Signed-off-by: Martin Wilck <mwilck@suse•com>
Acked-by: Arnd Bergmann <arnd@arndb•de>
---
include/linux/string.h | 15 ++-------------
1 file changed, 2 insertions(+), 13 deletions(-)
diff --git a/include/linux/string.h b/include/linux/string.h
index e1eeb0a8a9693..54d21783e18dd 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -434,20 +434,9 @@ __FORTIFY_INLINE char *strcpy(char *p, const char *q)
* @count: The number of bytes to copy
* @pad: Character to use for padding if space is left in destination.
*/
-__FORTIFY_INLINE void memcpy_and_pad(void *dest, size_t dest_len,
- const void *src, size_t count, int pad)
+static inline void memcpy_and_pad(void *dest, size_t dest_len,
+ const void *src, size_t count, int pad)
{
- size_t dest_size = __builtin_object_size(dest, 0);
- size_t src_size = __builtin_object_size(src, 0);
-
- if (__builtin_constant_p(dest_len) && __builtin_constant_p(count)) {
- if (dest_size < dest_len && dest_size < count)
- __write_overflow();
- else if (src_size < dest_len && src_size < count)
- __read_overflow3();
- }
- if (dest_size < dest_len)
- fortify_panic(__func__);
if (dest_len > count) {
memcpy(dest, src, count);
memset(dest + count, pad, dest_len - count);
--
2.14.0
next prev parent reply other threads:[~2017-09-06 12:36 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-31 8:21 linux-next: build failure after merge of the akpm-current tree Stephen Rothwell
2017-09-06 12:32 ` Martin Wilck
2017-09-06 12:36 ` Martin Wilck [this message]
2017-09-11 9:44 ` [PATCH] string.h: un-fortify memcpy_and_pad Martin Wilck
2017-09-11 11:57 ` Christoph Hellwig
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