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authorLinus Torvalds <torvalds@osdl.org>2006-04-18 20:59:27 +0000
committerGreg Kroah-Hartman <gregkh@suse.de>2006-04-24 09:56:04 -0700
commit3e5a2e956fff9e975e1b76c4de314cd077c6ec87 (patch)
treea6c44e27135735148fd0f332cf807f87ab71713e /fs
parent248c64d252a614b7d07ed85e1d714b25dd537d57 (diff)
[PATCH] x86: be careful about tailcall breakage for sys_open[at] too
x86: be careful about tailcall breakage for sys_open[at] too Came up through a quick grep for other cases similar to the ftruncate() one in commit 0a489cb3b6a7b277030cdbc97c2c65905db94536. Also, add a comment, so that people who read the code understand why we do what looks like a no-op. (Again, this won't actually matter to any sane user, since libc will save and restore the register gcc stomps on, but it's still wrong to stomp on it) Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs')
-rw-r--r--fs/open.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/fs/open.c b/fs/open.c
index b73623cdb575..f697914649e3 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -331,6 +331,7 @@ out:
asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length)
{
long ret = do_sys_ftruncate(fd, length, 1);
+ /* avoid REGPARM breakage on x86: */
prevent_tail_call(ret);
return ret;
}
@@ -345,6 +346,7 @@ asmlinkage long sys_truncate64(const char __user * path, loff_t length)
asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length)
{
long ret = do_sys_ftruncate(fd, length, 0);
+ /* avoid REGPARM breakage on x86: */
prevent_tail_call(ret);
return ret;
}
@@ -1087,20 +1089,30 @@ long do_sys_open(int dfd, const char __user *filename, int flags, int mode)
asmlinkage long sys_open(const char __user *filename, int flags, int mode)
{
+ long ret;
+
if (force_o_largefile())
flags |= O_LARGEFILE;
- return do_sys_open(AT_FDCWD, filename, flags, mode);
+ ret = do_sys_open(AT_FDCWD, filename, flags, mode);
+ /* avoid REGPARM breakage on x86: */
+ prevent_tail_call(ret);
+ return ret;
}
EXPORT_SYMBOL_GPL(sys_open);
asmlinkage long sys_openat(int dfd, const char __user *filename, int flags,
int mode)
{
+ long ret;
+
if (force_o_largefile())
flags |= O_LARGEFILE;
- return do_sys_open(dfd, filename, flags, mode);
+ ret = do_sys_open(dfd, filename, flags, mode);
+ /* avoid REGPARM breakage on x86: */
+ prevent_tail_call(ret);
+ return ret;
}
EXPORT_SYMBOL_GPL(sys_openat);