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| author |   Dominik Brodowski <linux@dominikbrodowski.net> | 2018-03-19 17:38:31 +0100 |
|---|---|---|
| committer | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-04-02 20:16:09 +0200 |
| commit | 36028d5dd71175c332ab634e089e16dbdfe3812b (patch) | |
| tree | d25084dfe2fe7c0a070cad40333a365af076695c /fs/read_write.c | |
| parent | fs: add ksys_truncate() wrapper; remove in-kernel calls to sys_truncate() (diff) | |
| download | wireguard-linux-36028d5dd71175c332ab634e089e16dbdfe3812b.tar.xz wireguard-linux-36028d5dd71175c332ab634e089e16dbdfe3812b.zip | |
fs: add ksys_p{read,write}64() helpers; remove in-kernel calls to syscalls
Using the ksys_p{read,write}64() wrappers allows us to get rid of
in-kernel calls to the sys_pread64() and sys_pwrite64() syscalls.
The ksys_ prefix denotes that this function is meant as a drop-in
replacement for the syscall. In particular, it uses the same calling
convention as sys_p{read,write}64().
This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Diffstat (limited to 'fs/read_write.c')
| -rw-r--r-- | fs/read_write.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index fc441e1ac683..c4eabbfc90df 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -610,8 +610,8 @@ SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, return ksys_write(fd, buf, count); } -SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, - size_t, count, loff_t, pos) +ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count, + loff_t pos) { struct fd f; ssize_t ret = -EBADF; @@ -630,8 +630,14 @@ SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, return ret; } -SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, - size_t, count, loff_t, pos) +SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, + size_t, count, loff_t, pos) +{ + return ksys_pread64(fd, buf, count, pos); +} + +ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf, + size_t count, loff_t pos) { struct fd f; ssize_t ret = -EBADF; @@ -650,6 +656,12 @@ SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, return ret; } +SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, + size_t, count, loff_t, pos) +{ + return ksys_pwrite64(fd, buf, count, pos); +} + static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, loff_t *ppos, int type, rwf_t flags) { |