From: Al Viro <viro@zeniv.linux.org.uk>
To: linux-fsdevel@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>, Christoph Hellwig <hch@lst.de>,
Matthew Wilcox <willy@infradead.org>
Subject: [PATCH 1/9] No need of likely/unlikely on calls of check_copy_size()
Date: Tue, 7 Jun 2022 04:09:23 +0000 [thread overview]
Message-ID: <Yp7Pc2PFBke5FyWa@zeniv-ca.linux.org.uk> (raw)
In-Reply-To: <Yp7PTZ2nckKDTkKu@zeniv-ca.linux.org.uk>
it's inline and unlikely() inside of it (including the implicit one
in WARN_ON_ONCE()) suffice to convince the compiler that getting
false from check_copy_size() is unlikely.
Spotted-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
arch/powerpc/include/asm/uaccess.h | 2 +-
arch/s390/include/asm/uaccess.h | 4 ++--
include/linux/uaccess.h | 4 ++--
include/linux/uio.h | 15 ++++++---------
4 files changed, 11 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 9b82b38ff867..105f200b1e31 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -348,7 +348,7 @@ copy_mc_to_kernel(void *to, const void *from, unsigned long size)
static inline unsigned long __must_check
copy_mc_to_user(void __user *to, const void *from, unsigned long n)
{
- if (likely(check_copy_size(from, n, true))) {
+ if (check_copy_size(from, n, true)) {
if (access_ok(to, n)) {
allow_write_to_user(to, n);
n = copy_mc_generic((void *)to, from, n);
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index f4511e21d646..c2c9995466e0 100644
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -39,7 +39,7 @@ _copy_from_user_key(void *to, const void __user *from, unsigned long n, unsigned
static __always_inline unsigned long __must_check
copy_from_user_key(void *to, const void __user *from, unsigned long n, unsigned long key)
{
- if (likely(check_copy_size(to, n, false)))
+ if (check_copy_size(to, n, false))
n = _copy_from_user_key(to, from, n, key);
return n;
}
@@ -50,7 +50,7 @@ _copy_to_user_key(void __user *to, const void *from, unsigned long n, unsigned l
static __always_inline unsigned long __must_check
copy_to_user_key(void __user *to, const void *from, unsigned long n, unsigned long key)
{
- if (likely(check_copy_size(from, n, true)))
+ if (check_copy_size(from, n, true))
n = _copy_to_user_key(to, from, n, key);
return n;
}
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 5a328cf02b75..47e5d374c7eb 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -148,7 +148,7 @@ _copy_to_user(void __user *, const void *, unsigned long);
static __always_inline unsigned long __must_check
copy_from_user(void *to, const void __user *from, unsigned long n)
{
- if (likely(check_copy_size(to, n, false)))
+ if (check_copy_size(to, n, false))
n = _copy_from_user(to, from, n);
return n;
}
@@ -156,7 +156,7 @@ copy_from_user(void *to, const void __user *from, unsigned long n)
static __always_inline unsigned long __must_check
copy_to_user(void __user *to, const void *from, unsigned long n)
{
- if (likely(check_copy_size(from, n, true)))
+ if (check_copy_size(from, n, true))
n = _copy_to_user(to, from, n);
return n;
}
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 739285fe5a2f..76d305f3d4c2 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -156,19 +156,17 @@ static inline size_t copy_folio_to_iter(struct folio *folio, size_t offset,
static __always_inline __must_check
size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
{
- if (unlikely(!check_copy_size(addr, bytes, true)))
- return 0;
- else
+ if (check_copy_size(addr, bytes, true))
return _copy_to_iter(addr, bytes, i);
+ return 0;
}
static __always_inline __must_check
size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{
- if (unlikely(!check_copy_size(addr, bytes, false)))
- return 0;
- else
+ if (check_copy_size(addr, bytes, false))
return _copy_from_iter(addr, bytes, i);
+ return 0;
}
static __always_inline __must_check
@@ -184,10 +182,9 @@ bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
static __always_inline __must_check
size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
{
- if (unlikely(!check_copy_size(addr, bytes, false)))
- return 0;
- else
+ if (check_copy_size(addr, bytes, false))
return _copy_from_iter_nocache(addr, bytes, i);
+ return 0;
}
static __always_inline __must_check
--
2.30.2
next prev parent reply other threads:[~2022-06-07 4:09 UTC|newest]
Thread overview: 93+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-07 4:08 [RFC][PATCHES] iov_iter stuff Al Viro
2022-06-07 4:09 ` Al Viro [this message]
2022-06-07 4:41 ` [PATCH 1/9] No need of likely/unlikely on calls of check_copy_size() Christoph Hellwig
2022-06-07 11:49 ` Christian Brauner
2022-06-07 4:09 ` [PATCH 2/9] btrfs_direct_write(): cleaner way to handle generic_write_sync() suppression Al Viro
2022-06-07 4:42 ` Christoph Hellwig
2022-06-07 16:06 ` Al Viro
2022-06-07 23:27 ` Al Viro
2022-06-07 23:31 ` [PATCH 01/10] No need of likely/unlikely on calls of check_copy_size() Al Viro
2022-06-07 23:31 ` [PATCH 02/10] teach iomap_dio_rw() to suppress dsync Al Viro
2022-06-08 6:18 ` Christoph Hellwig
2022-06-08 15:17 ` Darrick J. Wong
2022-06-10 11:38 ` Christian Brauner
2022-06-07 23:31 ` [PATCH 03/10] btrfs: use IOMAP_DIO_NOSYNC Al Viro
2022-06-08 6:18 ` Christoph Hellwig
2022-06-10 11:09 ` Christian Brauner
2022-06-07 23:31 ` [PATCH 04/10] struct file: use anonymous union member for rcuhead and llist Al Viro
2022-06-07 23:31 ` [PATCH 05/10] iocb: delay evaluation of IS_SYNC(...) until we want to check IOCB_DSYNC Al Viro
2022-06-10 11:41 ` Christian Brauner
2022-06-07 23:31 ` [PATCH 06/10] keep iocb_flags() result cached in struct file Al Viro
2022-06-09 0:35 ` Dave Chinner
2022-06-10 11:43 ` Christian Brauner
2022-06-07 23:31 ` [PATCH 07/10] copy_page_{to,from}_iter(): switch iovec variants to generic Al Viro
2022-06-07 23:31 ` [PATCH 08/10] new iov_iter flavour - ITER_UBUF Al Viro
2022-06-07 23:31 ` [PATCH 09/10] switch new_sync_{read,write}() to ITER_UBUF Al Viro
2022-06-10 11:11 ` Christian Brauner
2022-06-07 23:31 ` [PATCH 10/10] iov_iter_bvec_advance(): don't bother with bvec_iter Al Viro
2022-06-08 6:16 ` [PATCH 2/9] btrfs_direct_write(): cleaner way to handle generic_write_sync() suppression Christoph Hellwig
2022-06-07 14:49 ` Matthew Wilcox
2022-06-07 20:17 ` Al Viro
2022-06-07 4:10 ` [PATCH 3/9] struct file: use anonymous union member for rcuhead and llist Al Viro
2022-06-07 10:18 ` Jan Kara
2022-06-07 11:46 ` Christian Brauner
2022-06-07 4:11 ` [PATCH 4/9] iocb: delay evaluation of IS_SYNC(...) until we want to check IOCB_DSYNC Al Viro
2022-06-07 10:34 ` Jan Kara
2022-06-07 15:34 ` Al Viro
2022-06-07 4:11 ` [PATCH 5/9] keep iocb_flags() result cached in struct file Al Viro
2022-06-07 4:12 ` [PATCH 6/9] copy_page_{to,from}_iter(): switch iovec variants to generic Al Viro
2022-06-07 4:12 ` [PATCH 7/9] new iov_iter flavour - ITER_UBUF Al Viro
2022-06-07 4:13 ` [PATCH 8/9] switch new_sync_{read,write}() to ITER_UBUF Al Viro
2022-06-07 4:13 ` [PATCH 9/9] iov_iter_bvec_advance(): don't bother with bvec_iter Al Viro
2022-06-08 19:28 ` [RFC][PATCHES] iov_iter stuff Sedat Dilek
2022-06-08 20:39 ` Al Viro
2022-06-09 19:10 ` Sedat Dilek
2022-06-09 19:22 ` Matthew Wilcox
2022-06-09 19:58 ` Matthew Wilcox
2022-06-09 19:45 ` Al Viro
2022-06-17 22:30 ` Jens Axboe
2022-06-17 22:48 ` Al Viro
2022-06-18 5:27 ` Al Viro
2022-06-18 5:35 ` [PATCH 01/31] splice: stop abusing iov_iter_advance() to flush a pipe Al Viro
2022-06-18 5:35 ` [PATCH 02/31] ITER_PIPE: helper for getting pipe buffer by index Al Viro
2022-06-18 5:35 ` [PATCH 03/31] ITER_PIPE: helpers for adding pipe buffers Al Viro
2022-06-18 5:35 ` [PATCH 04/31] ITER_PIPE: allocate buffers as we go in copy-to-pipe primitives Al Viro
2022-06-19 1:34 ` Al Viro
2022-06-18 5:35 ` [PATCH 05/31] ITER_PIPE: fold push_pipe() into __pipe_get_pages() Al Viro
2022-06-18 5:35 ` [PATCH 06/31] ITER_PIPE: lose iter_head argument of __pipe_get_pages() Al Viro
2022-06-18 5:35 ` [PATCH 07/31] ITER_PIPE: clean pipe_advance() up Al Viro
2022-06-18 5:35 ` [PATCH 08/31] ITER_PIPE: clean iov_iter_revert() Al Viro
2022-06-18 5:35 ` [PATCH 09/31] ITER_PIPE: cache the type of last buffer Al Viro
2022-06-18 5:35 ` [PATCH 10/10] iov_iter_bvec_advance(): don't bother with bvec_iter Al Viro
2022-06-18 5:35 ` [PATCH 10/31] ITER_PIPE: fold data_start() and pipe_space_for_user() together Al Viro
2022-06-19 2:25 ` Al Viro
2022-06-18 5:35 ` [PATCH 11/31] iov_iter_get_pages{,_alloc}(): cap the maxsize with LONG_MAX Al Viro
2022-06-18 5:35 ` [PATCH 12/31] iov_iter_get_pages_alloc(): lift freeing pages array on failure exits into wrapper Al Viro
2022-06-18 5:35 ` [PATCH 13/31] iov_iter_get_pages(): sanity-check arguments Al Viro
2022-06-19 3:07 ` Al Viro
2022-06-18 5:35 ` [PATCH 14/31] unify pipe_get_pages() and pipe_get_pages_alloc() Al Viro
2022-06-18 5:35 ` [PATCH 15/31] unify xarray_get_pages() and xarray_get_pages_alloc() Al Viro
2022-06-18 5:35 ` [PATCH 16/31] unify the rest of iov_iter_get_pages()/iov_iter_get_pages_alloc() guts Al Viro
2022-06-19 3:56 ` Al Viro
2022-06-18 5:35 ` [PATCH 17/31] ITER_XARRAY: don't open-code DIV_ROUND_UP() Al Viro
2022-06-18 5:35 ` [PATCH 18/31] iov_iter: lift dealing with maxpages out of first_{iovec,bvec}_segment() Al Viro
2022-06-18 5:35 ` [PATCH 19/31] iov_iter: massage calling conventions for first_{iovec,bvec}_segment() Al Viro
2022-06-18 11:13 ` Al Viro
2022-06-18 11:18 ` Al Viro
2022-06-18 5:35 ` [PATCH 20/31] found_iovec_segment(): just return address Al Viro
2022-06-18 5:35 ` [PATCH 21/31] fold __pipe_get_pages() into pipe_get_pages() Al Viro
2022-06-18 5:35 ` [PATCH 22/31] iov_iter: saner helper for page array allocation Al Viro
2022-06-18 11:14 ` Al Viro
2022-06-18 5:35 ` [PATCH 23/31] iov_iter: advancing variants of iov_iter_get_pages{,_alloc}() Al Viro
2022-06-18 5:35 ` [PATCH 24/31] block: convert to " Al Viro
2022-06-18 5:35 ` [PATCH 25/31] iter_to_pipe(): switch to advancing variant of iov_iter_get_pages() Al Viro
2022-06-18 5:35 ` [PATCH 26/31] af_alg_make_sg(): " Al Viro
2022-06-18 5:35 ` [PATCH 27/31] 9p: convert to advancing variant of iov_iter_get_pages_alloc() Al Viro
2022-06-18 5:35 ` [PATCH 28/31] ceph: switch the last caller " Al Viro
2022-06-18 5:35 ` [PATCH 29/31] get rid of non-advancing variants Al Viro
2022-06-18 11:14 ` Al Viro
2022-06-18 5:35 ` [PATCH 30/31] pipe_get_pages(): switch to append_pipe() Al Viro
2022-06-19 4:01 ` Al Viro
2022-06-19 4:09 ` Al Viro
2022-06-18 5:35 ` [PATCH 31/31] expand those iov_iter_advance() Al Viro
2022-06-18 11:14 ` Al Viro
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