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; }