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author | Linus Torvalds <torvalds@g5.osdl.org> | 2006-04-18 22:22:59 +0200 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-04-18 22:22:59 +0200 |
commit | 385910f2b275a636238f70844f1b6da9fda6f2da (patch) | |
tree | 284f31a897d1ae9d02598ccb2f1d108ba62a079c /fs | |
parent | x86: don't allow tail-calls in sys_ftruncate[64]() (diff) | |
download | linux-385910f2b275a636238f70844f1b6da9fda6f2da.tar.xz linux-385910f2b275a636238f70844f1b6da9fda6f2da.zip |
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>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/open.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/fs/open.c b/fs/open.c index 8279c65d3bef..53ec28c36777 100644 --- a/fs/open.c +++ b/fs/open.c @@ -332,6 +332,7 @@ 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; } @@ -346,6 +347,7 @@ 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; } @@ -1097,20 +1099,30 @@ 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); |