aboutsummaryrefslogtreecommitdiff
path: root/kernel/uid16.c
diff options
context:
space:
mode:
authorOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>2006-04-20 06:41:39 +0900
committerLinus Torvalds <torvalds@g5.osdl.org>2006-04-19 16:27:18 -0700
commit5a7b46b369419493bab4de67b1526e9f76b22a7f (patch)
treec6c25e52dfd063db53db93d756da77ab67550ec6 /kernel/uid16.c
parent52824b6b5fa0533e2b2adc9df396d0e9ff6fb02a (diff)
downloadvexpress-lsk-5a7b46b369419493bab4de67b1526e9f76b22a7f.tar.gz
[PATCH] Add more prevent_tail_call()
Those also break userland regs like following. 00000000 <sys_chown16>: 0: 0f b7 44 24 0c movzwl 0xc(%esp),%eax 5: 83 ca ff or $0xffffffff,%edx 8: 0f b7 4c 24 08 movzwl 0x8(%esp),%ecx d: 66 83 f8 ff cmp $0xffffffff,%ax 11: 0f 44 c2 cmove %edx,%eax 14: 66 83 f9 ff cmp $0xffffffff,%cx 18: 0f 45 d1 cmovne %ecx,%edx 1b: 89 44 24 0c mov %eax,0xc(%esp) 1f: 89 54 24 08 mov %edx,0x8(%esp) 23: e9 fc ff ff ff jmp 24 <sys_chown16+0x24> where the tailcall at the end overwrites the incoming stack-frame. Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> [ I would _really_ like to have a way to tell gcc about calling conventions. The "prevent_tail_call()" macro is pretty ugly ] Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/uid16.c')
-rw-r--r--kernel/uid16.c59
1 files changed, 46 insertions, 13 deletions
diff --git a/kernel/uid16.c b/kernel/uid16.c
index aa25605027c..187e2a42387 100644
--- a/kernel/uid16.c
+++ b/kernel/uid16.c
@@ -20,43 +20,67 @@
asmlinkage long sys_chown16(const char __user * filename, old_uid_t user, old_gid_t group)
{
- return sys_chown(filename, low2highuid(user), low2highgid(group));
+ long ret = sys_chown(filename, low2highuid(user), low2highgid(group));
+ /* avoid REGPARM breakage on x86: */
+ prevent_tail_call(ret);
+ return ret;
}
asmlinkage long sys_lchown16(const char __user * filename, old_uid_t user, old_gid_t group)
{
- return sys_lchown(filename, low2highuid(user), low2highgid(group));
+ long ret = sys_lchown(filename, low2highuid(user), low2highgid(group));
+ /* avoid REGPARM breakage on x86: */
+ prevent_tail_call(ret);
+ return ret;
}
asmlinkage long sys_fchown16(unsigned int fd, old_uid_t user, old_gid_t group)
{
- return sys_fchown(fd, low2highuid(user), low2highgid(group));
+ long ret = sys_fchown(fd, low2highuid(user), low2highgid(group));
+ /* avoid REGPARM breakage on x86: */
+ prevent_tail_call(ret);
+ return ret;
}
asmlinkage long sys_setregid16(old_gid_t rgid, old_gid_t egid)
{
- return sys_setregid(low2highgid(rgid), low2highgid(egid));
+ long ret = sys_setregid(low2highgid(rgid), low2highgid(egid));
+ /* avoid REGPARM breakage on x86: */
+ prevent_tail_call(ret);
+ return ret;
}
asmlinkage long sys_setgid16(old_gid_t gid)
{
- return sys_setgid(low2highgid(gid));
+ long ret = sys_setgid(low2highgid(gid));
+ /* avoid REGPARM breakage on x86: */
+ prevent_tail_call(ret);
+ return ret;
}
asmlinkage long sys_setreuid16(old_uid_t ruid, old_uid_t euid)
{
- return sys_setreuid(low2highuid(ruid), low2highuid(euid));
+ long ret = sys_setreuid(low2highuid(ruid), low2highuid(euid));
+ /* avoid REGPARM breakage on x86: */
+ prevent_tail_call(ret);
+ return ret;
}
asmlinkage long sys_setuid16(old_uid_t uid)
{
- return sys_setuid(low2highuid(uid));
+ long ret = sys_setuid(low2highuid(uid));
+ /* avoid REGPARM breakage on x86: */
+ prevent_tail_call(ret);
+ return ret;
}
asmlinkage long sys_setresuid16(old_uid_t ruid, old_uid_t euid, old_uid_t suid)
{
- return sys_setresuid(low2highuid(ruid), low2highuid(euid),
- low2highuid(suid));
+ long ret = sys_setresuid(low2highuid(ruid), low2highuid(euid),
+ low2highuid(suid));
+ /* avoid REGPARM breakage on x86: */
+ prevent_tail_call(ret);
+ return ret;
}
asmlinkage long sys_getresuid16(old_uid_t __user *ruid, old_uid_t __user *euid, old_uid_t __user *suid)
@@ -72,8 +96,11 @@ asmlinkage long sys_getresuid16(old_uid_t __user *ruid, old_uid_t __user *euid,
asmlinkage long sys_setresgid16(old_gid_t rgid, old_gid_t egid, old_gid_t sgid)
{
- return sys_setresgid(low2highgid(rgid), low2highgid(egid),
- low2highgid(sgid));
+ long ret = sys_setresgid(low2highgid(rgid), low2highgid(egid),
+ low2highgid(sgid));
+ /* avoid REGPARM breakage on x86: */
+ prevent_tail_call(ret);
+ return ret;
}
asmlinkage long sys_getresgid16(old_gid_t __user *rgid, old_gid_t __user *egid, old_gid_t __user *sgid)
@@ -89,12 +116,18 @@ asmlinkage long sys_getresgid16(old_gid_t __user *rgid, old_gid_t __user *egid,
asmlinkage long sys_setfsuid16(old_uid_t uid)
{
- return sys_setfsuid(low2highuid(uid));
+ long ret = sys_setfsuid(low2highuid(uid));
+ /* avoid REGPARM breakage on x86: */
+ prevent_tail_call(ret);
+ return ret;
}
asmlinkage long sys_setfsgid16(old_gid_t gid)
{
- return sys_setfsgid(low2highgid(gid));
+ long ret = sys_setfsgid(low2highgid(gid));
+ /* avoid REGPARM breakage on x86: */
+ prevent_tail_call(ret);
+ return ret;
}
static int groups16_to_user(old_gid_t __user *grouplist,