sw64: fix sys_rt_sigaction

Sunway inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I56XYC

--------------------------------

__ARCH_HAS_SA_RESTORER was defined to fix compile error in the past.
However, this changed the offset of sa_mask in struct sigaction and
made sys_rt_sigaction unable to get sa_mask passed from user.

To fix this problem, the old sigaction and the related structs are
added back, macro define __ARCH_HAS_SA_RESTORER is removed.
Signed-off-by: NMao Minkai <maominkai@wxiat.com>
Signed-off-by: NGu Zitao <guzitao@wxiat.com>

arch/sw_64/Kconfig

@@ -23,7 +23,6 @@ config SW64
 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_SECCOMP_FILTER
-	select OLD_SIGACTION
 	select OLD_SIGSUSPEND
 	select GENERIC_STRNCPY_FROM_USER
 	select GENERIC_STRNLEN_USER

arch/sw_64/include/asm/signal.h

@@ -14,9 +14,11 @@ typedef struct {
 	unsigned long sig[_NSIG_WORDS];
 } sigset_t;
 
-#ifdef CONFIG_OLD_SIGACTION
-#define __ARCH_HAS_SA_RESTORER
-#endif
+struct odd_sigaction {
+	__sighandler_t	sa_handler;
+	old_sigset_t	sa_mask;
+	int		sa_flags;
+};
 
 #include <asm/sigcontext.h>
 #endif

arch/sw_64/kernel/signal.c

@@ -38,6 +38,36 @@ SYSCALL_DEFINE2(odd_sigprocmask, int, how, unsigned long, newmask)
 	return res;
 }
 
+SYSCALL_DEFINE3(odd_sigaction, int, sig,
+		const struct odd_sigaction __user *, act,
+		struct odd_sigaction __user *, oact)
+{
+	struct k_sigaction new_ka, old_ka;
+	old_sigset_t mask;
+	int ret;
+
+	if (act) {
+		if (!access_ok(act, sizeof(*act)) ||
+		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
+		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
+		    __get_user(mask, &act->sa_mask))
+			return -EFAULT;
+		siginitset(&new_ka.sa.sa_mask, mask);
+	}
+
+	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
+
+	if (!ret && oact) {
+		if (!access_ok(oact, sizeof(*oact)) ||
+		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
+		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
+		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
+			return -EFAULT;
+	}
+
+	return ret;
+}
+
 /*
  * Do a signal return; undo the signal stack.
  */

arch/sw_64/kernel/syscalls/syscall.tbl

@@ -163,7 +163,7 @@
 #153 is unused
 #154 is unused
 #155 is unused
-156	common	sigaction			sys_sigaction
+156	common	sigaction			sys_odd_sigaction
 #157 is unused
 #158 is unused
 #159 is unused