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authorDominik Brodowski <linux@dominikbrodowski.net>2018-03-19 17:38:31 +0100
committerDominik Brodowski <linux@dominikbrodowski.net>2018-04-02 20:16:09 +0200
commit36028d5dd71175c332ab634e089e16dbdfe3812b (patch)
treed25084dfe2fe7c0a070cad40333a365af076695c /fs
parentdf260e21e6cd5d2dfc1fe9b6a3bbf747e72b3bed (diff)
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')
-rw-r--r--fs/read_write.c20
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)
{