[PATCH 15/45] fs: add do_compat_futimesat() helper; remove in-kernel call to comapt syscall

From: Dominik Brodowski
Date: Thu Mar 22 2018 - 05:04:30 EST


Using the fs-internal do_compat_futimesat() helper allows us to get rid of
the fs-internal call to the compat_sys_futimesat() syscall.

This patch is part of a series which tries to remove in-kernel calls to
syscalls. On this basis, the syscall entry path can be streamlined.

Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
---
fs/utimes.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/fs/utimes.c b/fs/utimes.c
index 5be035ed26c0..69d4b6ba1bfb 100644
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -260,7 +260,8 @@ COMPAT_SYSCALL_DEFINE4(utimensat, unsigned int, dfd, const char __user *, filena
return do_utimes(dfd, filename, t ? tv : NULL, flags);
}

-COMPAT_SYSCALL_DEFINE3(futimesat, unsigned int, dfd, const char __user *, filename, struct compat_timeval __user *, t)
+static long do_compat_futimesat(unsigned int dfd, const char __user *filename,
+ struct compat_timeval __user *t)
{
struct timespec64 tv[2];

@@ -279,8 +280,15 @@ COMPAT_SYSCALL_DEFINE3(futimesat, unsigned int, dfd, const char __user *, filena
return do_utimes(dfd, filename, t ? tv : NULL, 0);
}

+COMPAT_SYSCALL_DEFINE3(futimesat, unsigned int, dfd,
+ const char __user *, filename,
+ struct compat_timeval __user *, t)
+{
+ return do_compat_futimesat(dfd, filename, t);
+}
+
COMPAT_SYSCALL_DEFINE2(utimes, const char __user *, filename, struct compat_timeval __user *, t)
{
- return compat_sys_futimesat(AT_FDCWD, filename, t);
+ return do_compat_futimesat(AT_FDCWD, filename, t);
}
#endif
--
2.16.2