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authorDominik Brodowski <linux@dominikbrodowski.net>2018-03-13 21:56:26 +0100
committerDominik Brodowski <linux@dominikbrodowski.net>2018-04-02 20:16:04 +0200
commit3ce4a7bf66263748194b77ccefd284be963c6304 (patch)
tree69ff6bec0f1186e6e4662c628449c5ced2f8b0d3 /fs/read_write.c
parentfs: add ksys_lseek() helper; remove in-kernel calls to sys_lseek() (diff)
downloadlinux-3ce4a7bf66263748194b77ccefd284be963c6304.tar.xz
linux-3ce4a7bf66263748194b77ccefd284be963c6304.zip
fs: add ksys_read() helper; remove in-kernel calls to sys_read()
Using this helper allows us to avoid the in-kernel calls to the sys_read() 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_read(). 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> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Diffstat (limited to 'fs/read_write.c')
-rw-r--r--fs/read_write.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/fs/read_write.c b/fs/read_write.c
index b38b008a078e..fc441e1ac683 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -568,7 +568,7 @@ static inline void file_pos_write(struct file *file, loff_t pos)
file->f_pos = pos;
}
-SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
+ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count)
{
struct fd f = fdget_pos(fd);
ssize_t ret = -EBADF;
@@ -583,6 +583,11 @@ SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
return ret;
}
+SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
+{
+ return ksys_read(fd, buf, count);
+}
+
ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count)
{
struct fd f = fdget_pos(fd);