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authorDominik Brodowski <linux@dominikbrodowski.net>2018-03-11 11:34:41 +0100
committerDominik Brodowski <linux@dominikbrodowski.net>2018-04-02 20:15:51 +0200
commite7a3e8b2edf544ec28f689385c3adc2903f46ec0 (patch)
treef2fa667f8c2a6774aa466ab378a11e4c27cbd066 /fs/read_write.c
parenta16fe33ab5572e52ef4cb9719d6eb49623b2528a (diff)
downloadlinux-e7a3e8b2edf544ec28f689385c3adc2903f46ec0.tar.bz2
fs: add ksys_write() helper; remove in-kernel calls to sys_write()
Using this helper allows us to avoid the in-kernel calls to the sys_write() syscall. 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_write(). In the near future, the do_mounts / initramfs callers of ksys_write() should be converted to use filp_open() and vfs_write() instead. 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: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-s390@vger.kernel.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Diffstat (limited to 'fs/read_write.c')
-rw-r--r--fs/read_write.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/fs/read_write.c b/fs/read_write.c
index f8547b82dfb3..8e8f0b4f52e2 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -578,8 +578,7 @@ SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
return ret;
}
-SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
- size_t, count)
+ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count)
{
struct fd f = fdget_pos(fd);
ssize_t ret = -EBADF;
@@ -595,6 +594,12 @@ SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
return ret;
}
+SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
+ size_t, count)
+{
+ return ksys_write(fd, buf, count);
+}
+
SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
size_t, count, loff_t, pos)
{