6 files changed, 44 insertions, 22 deletions

diff --git a/arch/x86/kernel/tls.c b/arch/x86/kernel/tls.c
index 022bcaa3b42e..ab6bf375a307 100644
--- a/arch/x86/kernel/tls.c
+++ b/arch/x86/kernel/tls.c
@@ -92,7 +92,7 @@ int do_set_thread_area(struct task_struct *p, int idx,
 asmlinkage int sys_set_thread_area(struct user_desc __user *u_info)
 {
         int ret = do_set_thread_area(current, -1, u_info, 1);
-        prevent_tail_call(ret);
+        asmlinkage_protect(1, ret, u_info);
         return ret;
 }
 
@@ -142,7 +142,7 @@ int do_get_thread_area(struct task_struct *p, int idx,
 asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
 {
         int ret = do_get_thread_area(current, -1, u_info);
-        prevent_tail_call(ret);
+        asmlinkage_protect(1, ret, u_info);
         return ret;
 }
 
diff --git a/fs/open.c b/fs/open.c
index a4b12022edaa..3fa4e4ffce4c 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -335,7 +335,7 @@ 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);
+        asmlinkage_protect(2, ret, fd, length);
         return ret;
 }
 
@@ -350,7 +350,7 @@ 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);
+        asmlinkage_protect(2, ret, fd, length);
         return ret;
 }
 #endif
@@ -1067,7 +1067,7 @@ asmlinkage long sys_open(const char __user *filename, int flags, int mode)
 
         ret = do_sys_open(AT_FDCWD, filename, flags, mode);
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(3, ret, filename, flags, mode);
         return ret;
 }
 
@@ -1081,7 +1081,7 @@ asmlinkage long sys_openat(int dfd, const char __user *filename, int flags,
 
         ret = do_sys_open(dfd, filename, flags, mode);
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(4, ret, dfd, filename, flags, mode);
         return ret;
 }
 
diff --git a/include/asm-x86/linkage.h b/include/asm-x86/linkage.h
index 31739c7d66a9..d605eeba0f70 100644
--- a/include/asm-x86/linkage.h
+++ b/include/asm-x86/linkage.h
@@ -8,12 +8,34 @@
 
 #ifdef CONFIG_X86_32
 #define asmlinkage CPP_ASMLINKAGE __attribute__((regparm(0)))
-#define prevent_tail_call(ret) __asm__ ("" : "=r" (ret) : "0" (ret))
 /*
  * For 32-bit UML - mark functions implemented in assembly that use
  * regparm input parameters:
  */
 #define asmregparm __attribute__((regparm(3)))
+
+#define asmlinkage_protect(n, ret, args...) \
+        __asmlinkage_protect##n(ret, ##args)
+#define __asmlinkage_protect_n(ret, args...) \
+        __asm__ __volatile__ ("" : "=r" (ret) : "0" (ret), ##args)
+#define __asmlinkage_protect0(ret) \
+        __asmlinkage_protect_n(ret)
+#define __asmlinkage_protect1(ret, arg1) \
+        __asmlinkage_protect_n(ret, "g" (arg1))
+#define __asmlinkage_protect2(ret, arg1, arg2) \
+        __asmlinkage_protect_n(ret, "g" (arg1), "g" (arg2))
+#define __asmlinkage_protect3(ret, arg1, arg2, arg3) \
+        __asmlinkage_protect_n(ret, "g" (arg1), "g" (arg2), "g" (arg3))
+#define __asmlinkage_protect4(ret, arg1, arg2, arg3, arg4) \
+        __asmlinkage_protect_n(ret, "g" (arg1), "g" (arg2), "g" (arg3), \
+                              "g" (arg4))
+#define __asmlinkage_protect5(ret, arg1, arg2, arg3, arg4, arg5) \
+        __asmlinkage_protect_n(ret, "g" (arg1), "g" (arg2), "g" (arg3), \
+                              "g" (arg4), "g" (arg5))
+#define __asmlinkage_protect6(ret, arg1, arg2, arg3, arg4, arg5, arg6) \
+        __asmlinkage_protect_n(ret, "g" (arg1), "g" (arg2), "g" (arg3), \
+                              "g" (arg4), "g" (arg5), "g" (arg6))
+
 #endif
 
 #ifdef CONFIG_X86_ALIGNMENT_16
diff --git a/include/linux/linkage.h b/include/linux/linkage.h
index 0592936344c4..fe2a39c489b6 100644
--- a/include/linux/linkage.h
+++ b/include/linux/linkage.h
@@ -17,8 +17,8 @@
 # define asmregparm
 #endif
 
-#ifndef prevent_tail_call
-# define prevent_tail_call(ret) do { } while (0)
+#ifndef asmlinkage_protect
+# define asmlinkage_protect(n, ret, args...)    do { } while (0)
 #endif
 
 #ifndef __ALIGN
diff --git a/kernel/exit.c b/kernel/exit.c
index 53872bf993fa..073005b1cfb2 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1608,7 +1608,7 @@ asmlinkage long sys_waitid(int which, pid_t upid,
         put_pid(pid);
 
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(5, ret, which, upid, infop, options, ru);
         return ret;
 }
 
@@ -1640,7 +1640,7 @@ asmlinkage long sys_wait4(pid_t upid, int __user *stat_addr,
         put_pid(pid);
 
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(4, ret, upid, stat_addr, options, ru);
         return ret;
 }
 
diff --git a/kernel/uid16.c b/kernel/uid16.c
index dd308ba4e03b..3e41c1673e2f 100644
--- a/kernel/uid16.c
+++ b/kernel/uid16.c
@@ -21,7 +21,7 @@ asmlinkage long sys_chown16(const char __user * filename, old_uid_t user, old_gi
 {
         long ret = sys_chown(filename, low2highuid(user), low2highgid(group));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(3, ret, filename, user, group);
         return ret;
 }
 
@@ -29,7 +29,7 @@ asmlinkage long sys_lchown16(const char __user * filename, old_uid_t user, old_g
 {
         long ret = sys_lchown(filename, low2highuid(user), low2highgid(group));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(3, ret, filename, user, group);
         return ret;
 }
 
@@ -37,7 +37,7 @@ asmlinkage long sys_fchown16(unsigned int fd, old_uid_t user, old_gid_t group)
 {
         long ret = sys_fchown(fd, low2highuid(user), low2highgid(group));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(3, ret, fd, user, group);
         return ret;
 }
 
@@ -45,7 +45,7 @@ asmlinkage long sys_setregid16(old_gid_t rgid, old_gid_t egid)
 {
         long ret = sys_setregid(low2highgid(rgid), low2highgid(egid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(2, ret, rgid, egid);
         return ret;
 }
 
@@ -53,7 +53,7 @@ asmlinkage long sys_setgid16(old_gid_t gid)
 {
         long ret = sys_setgid(low2highgid(gid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(1, ret, gid);
         return ret;
 }
 
@@ -61,7 +61,7 @@ asmlinkage long sys_setreuid16(old_uid_t ruid, old_uid_t euid)
 {
         long ret = sys_setreuid(low2highuid(ruid), low2highuid(euid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(2, ret, ruid, euid);
         return ret;
 }
 
@@ -69,7 +69,7 @@ asmlinkage long sys_setuid16(old_uid_t uid)
 {
         long ret = sys_setuid(low2highuid(uid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(1, ret, uid);
         return ret;
 }
 
@@ -78,7 +78,7 @@ asmlinkage long sys_setresuid16(old_uid_t ruid, old_uid_t euid, old_uid_t suid)
         long ret = sys_setresuid(low2highuid(ruid), low2highuid(euid),
                                  low2highuid(suid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(3, ret, ruid, euid, suid);
         return ret;
 }
 
@@ -98,7 +98,7 @@ asmlinkage long sys_setresgid16(old_gid_t rgid, old_gid_t egid, old_gid_t sgid)
         long ret = sys_setresgid(low2highgid(rgid), low2highgid(egid),
                                  low2highgid(sgid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(3, ret, rgid, egid, sgid);
         return ret;
 }
 
@@ -117,7 +117,7 @@ asmlinkage long sys_setfsuid16(old_uid_t uid)
 {
         long ret = sys_setfsuid(low2highuid(uid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(1, ret, uid);
         return ret;
 }
 
@@ -125,7 +125,7 @@ asmlinkage long sys_setfsgid16(old_gid_t gid)
 {
         long ret = sys_setfsgid(low2highgid(gid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(1, ret, gid);
         return ret;
 }