fs/compat: fix lookup_dcookie() parameter handling

heicarst · torvalds · commit d8d14bd09cdd · 2014-01-29T16:22:40.000-08:00
Commit d5dc77b ("consolidate compat lookup_dcookie()") coverted all architectures to the new compat_sys_lookup_dcookie() syscall. The "len" paramater of the new compat syscall must have the type compat_size_t in order to enforce zero extension for architectures where the ABI requires that the caller of a function performed zero and/or sign extension to 64 bit of all parameters. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ingo Molnar <mingo@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: <stable@vger.kernel.org> [v3.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/dcookies.c b/fs/dcookies.c
@@ -204,7 +204,7 @@ SYSCALL_DEFINE3(lookup_dcookie, u64, cookie64, char __user *, buf, size_t, len)
 }
 
 #ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE4(lookup_dcookie, u32, w0, u32, w1, char __user *, buf, size_t, len)
+COMPAT_SYSCALL_DEFINE4(lookup_dcookie, u32, w0, u32, w1, char __user *, buf, compat_size_t, len)
 {
 #ifdef __BIG_ENDIAN
 	return sys_lookup_dcookie(((u64)w0 << 32) | w1, buf, len);
diff --git a/include/linux/compat.h b/include/linux/compat.h
@@ -422,7 +422,7 @@ extern long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
 				  compat_long_t addr, compat_long_t data);
 
-asmlinkage long compat_sys_lookup_dcookie(u32, u32, char __user *, size_t);
+asmlinkage long compat_sys_lookup_dcookie(u32, u32, char __user *, compat_size_t);
 /*
  * epoll (fs/eventpoll.c) compat bits follow ...
  */

Original file line number	Diff line number	Diff line change
`@@ -204,7 +204,7 @@ SYSCALL_DEFINE3(lookup_dcookie, u64, cookie64, char __user *, buf, size_t, len)`
`204`	`204`	`}`
`205`	`205`
`206`	`206`	`#ifdef CONFIG_COMPAT`
`207`		`-COMPAT_SYSCALL_DEFINE4(lookup_dcookie, u32, w0, u32, w1, char __user *, buf, size_t, len)`
	`207`	`+COMPAT_SYSCALL_DEFINE4(lookup_dcookie, u32, w0, u32, w1, char __user *, buf, compat_size_t, len)`
`208`	`208`	`{`
`209`	`209`	`#ifdef __BIG_ENDIAN`
`210`	`210`	`return sys_lookup_dcookie(((u64)w0 << 32) \| w1, buf, len);`