sanitize rt_sigaction() situation a bit

Switch from __ARCH_WANT_SYS_RT_SIGACTION to opposite
(!CONFIG_ODD_RT_SIGACTION); the only two architectures that
need it are alpha and sparc.  The reason for use of CONFIG_...
instead of __ARCH_... is that it's needed only kernel-side
and doing it that way avoids a mess with include order on many
architectures.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/Kconfig

@@ -373,4 +373,9 @@ config CLONE_BACKWARDS2
 	help
 	  Architecture has the first two arguments of clone(2) swapped.
 
+config ODD_RT_SIGACTION
+	bool
+	help
+	  Architecture has unusual rt_sigaction(2) arguments
+
 source "kernel/gcov/Kconfig"

arch/alpha/Kconfig

@@ -23,6 +23,7 @@ config ALPHA
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
 	select GENERIC_SIGALTSTACK
+	select ODD_RT_SIGACTION
 	help
 	  The Alpha is a 64-bit general-purpose processor designed and
 	  marketed by the Digital Equipment Corporation of blessed memory,

arch/ia64/include/asm/unistd.h

@@ -49,10 +49,6 @@ asmlinkage unsigned long sys_mmap2(
 struct pt_regs;
 struct sigaction;
 asmlinkage long sys_ia64_pipe(void);
-asmlinkage long sys_rt_sigaction(int sig,
-				 const struct sigaction __user *act,
-				 struct sigaction __user *oact,
-				 size_t sigsetsize);
 
 /*
  * "Conditional" syscalls

arch/powerpc/include/asm/syscalls.h

@@ -19,9 +19,6 @@ asmlinkage unsigned long sys_mmap2(unsigned long addr, size_t len,
 		unsigned long fd, unsigned long pgoff);
 asmlinkage long sys_pipe(int __user *fildes);
 asmlinkage long sys_pipe2(int __user *fildes, int flags);
-asmlinkage long sys_rt_sigaction(int sig,
-		const struct sigaction __user *act,
-		struct sigaction __user *oact, size_t sigsetsize);
 asmlinkage long ppc64_personality(unsigned long personality);
 asmlinkage int ppc_rtas(struct rtas_args __user *uargs);
 asmlinkage time_t sys64_time(time_t __user * tloc);

arch/sparc/Kconfig

@@ -41,6 +41,7 @@ config SPARC
 	select GENERIC_STRNCPY_FROM_USER
 	select GENERIC_STRNLEN_USER
 	select MODULES_USE_ELF_RELA
+	select ODD_RT_SIGACTION
 
 config SPARC32
 	def_bool !64BIT

arch/sparc/kernel/sys_sparc_32.c

@@ -197,12 +197,11 @@ sparc_sigaction (int sig, const struct old_sigaction __user *act,
 	return ret;
 }
 
-asmlinkage long
-sys_rt_sigaction(int sig,
-		 const struct sigaction __user *act,
-		 struct sigaction __user *oact,
-		 void __user *restorer,
-		 size_t sigsetsize)
+SYSCALL_DEFINE5(rt_sigaction, int, sig,
+		 const struct sigaction __user *, act,
+		 struct sigaction __user *, oact,
+		 void __user *, restorer,
+		 size_t, sigsetsize)
 {
 	struct k_sigaction new_ka, old_ka;
 	int ret;

arch/x86/um/shared/sysdep/syscalls_32.h

@@ -8,11 +8,6 @@
 
 typedef long syscall_handler_t(struct pt_regs);
 
-/* Not declared on x86, incompatible declarations on x86_64, so these have
- * to go here rather than in sys_call_table.c
- */
-extern syscall_handler_t sys_rt_sigaction;
-
 extern syscall_handler_t *sys_call_table[];
 
 #define EXECUTE_SYSCALL(syscall, regs) \

arch/xtensa/include/asm/syscall.h

@@ -9,15 +9,10 @@
  */
 
 struct pt_regs;
-struct sigaction;
 asmlinkage long xtensa_ptrace(long, long, long, long);
 asmlinkage long xtensa_sigreturn(struct pt_regs*);
 asmlinkage long xtensa_rt_sigreturn(struct pt_regs*);
 asmlinkage long xtensa_sigaltstack(struct pt_regs *regs);
-asmlinkage long sys_rt_sigaction(int,
-				 const struct sigaction __user *,
-				 struct sigaction __user *,
-				 size_t);
 asmlinkage long xtensa_shmat(int, char __user *, int);
 asmlinkage long xtensa_fadvise64_64(int, int,
 				    unsigned long long, unsigned long long);

include/asm-generic/syscalls.h

@@ -36,9 +36,4 @@ asmlinkage long sys_rt_sigreturn(struct pt_regs *regs);
 asmlinkage long sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize);
 #endif
 
-#ifndef sys_rt_sigaction
-asmlinkage long sys_rt_sigaction(int sig, const struct sigaction __user *act,
-			 struct sigaction __user *oact, size_t sigsetsize);
-#endif
-
 #endif /* __ASM_GENERIC_SYSCALLS_H */

include/linux/syscalls.h

@@ -377,6 +377,12 @@ asmlinkage long sys_init_module(void __user *umod, unsigned long len,
 asmlinkage long sys_delete_module(const char __user *name_user,
 				unsigned int flags);
 
+#ifndef CONFIG_ODD_RT_SIGACTION
+asmlinkage long sys_rt_sigaction(int,
+				 const struct sigaction __user *,
+				 struct sigaction __user *,
+				 size_t);
+#endif
 asmlinkage long sys_rt_sigprocmask(int how, sigset_t __user *set,
 				sigset_t __user *oset, size_t sigsetsize);
 asmlinkage long sys_rt_sigpending(sigset_t __user *set, size_t sigsetsize);

kernel/signal.c

@@ -3231,7 +3231,7 @@ SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, nset,
 }
 #endif /* __ARCH_WANT_SYS_SIGPROCMASK */
 
-#ifdef __ARCH_WANT_SYS_RT_SIGACTION
+#ifndef CONFIG_ODD_RT_SIGACTION
 /**
  *  sys_rt_sigaction - alter an action taken by a process
  *  @sig: signal to be sent
@@ -3265,7 +3265,7 @@ SYSCALL_DEFINE4(rt_sigaction, int, sig,
 out:
 	return ret;
 }
-#endif /* __ARCH_WANT_SYS_RT_SIGACTION */
+#endif /* !CONFIG_ODD_RT_SIGACTION */
 
 #ifdef __ARCH_WANT_SYS_SGETMASK