get_compat_sigset()

similar to put_compat_sigset()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/sparc/kernel/sys_sparc32.c

@@ -166,13 +166,11 @@ COMPAT_SYSCALL_DEFINE5(rt_sigaction, int, sig,
 
         if (act) {
 		u32 u_handler, u_restorer;
-		compat_sigset_t set32;
 
 		new_ka.ka_restorer = restorer;
 		ret = get_user(u_handler, &act->sa_handler);
 		new_ka.sa.sa_handler =  compat_ptr(u_handler);
-		ret |= copy_from_user(&set32, &act->sa_mask, sizeof(compat_sigset_t));
-		sigset_from_compat(&new_ka.sa.sa_mask, &set32);
+		ret |= get_compat_sigset(&new_ka.sa.sa_mask, &act->sa_mask);
 		ret |= get_user(new_ka.sa.sa_flags, &act->sa_flags);
 		ret |= get_user(u_restorer, &act->sa_restorer);
 		new_ka.sa.sa_restorer = compat_ptr(u_restorer);

fs/eventpoll.c

@@ -2259,7 +2259,6 @@ COMPAT_SYSCALL_DEFINE6(epoll_pwait, int, epfd,
 			compat_size_t, sigsetsize)
 {
 	long err;
-	compat_sigset_t csigmask;
 	sigset_t ksigmask, sigsaved;
 
 	/*
@@ -2269,9 +2268,8 @@ COMPAT_SYSCALL_DEFINE6(epoll_pwait, int, epfd,
 	if (sigmask) {
 		if (sigsetsize != sizeof(compat_sigset_t))
 			return -EINVAL;
-		if (copy_from_user(&csigmask, sigmask, sizeof(csigmask)))
+		if (get_compat_sigset(&ksigmask, sigmask))
 			return -EFAULT;
-		sigset_from_compat(&ksigmask, &csigmask);
 		sigsaved = current->blocked;
 		set_current_blocked(&ksigmask);
 	}

fs/select.c

@@ -1301,7 +1301,6 @@ static long do_compat_pselect(int n, compat_ulong_t __user *inp,
 	struct compat_timespec __user *tsp, compat_sigset_t __user *sigmask,
 	compat_size_t sigsetsize)
 {
-	compat_sigset_t ss32;
 	sigset_t ksigmask, sigsaved;
 	struct timespec64 ts, end_time, *to = NULL;
 	int ret;
@@ -1318,9 +1317,8 @@ static long do_compat_pselect(int n, compat_ulong_t __user *inp,
 	if (sigmask) {
 		if (sigsetsize != sizeof(compat_sigset_t))
 			return -EINVAL;
-		if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
+		if (get_compat_sigset(&ksigmask, sigmask))
 			return -EFAULT;
-		sigset_from_compat(&ksigmask, &ss32);
 
 		sigdelsetmask(&ksigmask, sigmask(SIGKILL)|sigmask(SIGSTOP));
 		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
@@ -1369,7 +1367,6 @@ COMPAT_SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds,
 	unsigned int,  nfds, struct compat_timespec __user *, tsp,
 	const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize)
 {
-	compat_sigset_t ss32;
 	sigset_t ksigmask, sigsaved;
 	struct timespec64 ts, end_time, *to = NULL;
 	int ret;
@@ -1386,9 +1383,8 @@ COMPAT_SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds,
 	if (sigmask) {
 		if (sigsetsize != sizeof(compat_sigset_t))
 			return -EINVAL;
-		if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
+		if (get_compat_sigset(&ksigmask, sigmask))
 			return -EFAULT;
-		sigset_from_compat(&ksigmask, &ss32);
 
 		sigdelsetmask(&ksigmask, sigmask(SIGKILL)|sigmask(SIGSTOP));
 		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);

fs/signalfd.c

@@ -312,15 +312,13 @@ COMPAT_SYSCALL_DEFINE4(signalfd4, int, ufd,
 		     compat_size_t, sigsetsize,
 		     int, flags)
 {
-	compat_sigset_t ss32;
 	sigset_t tmp;
 	sigset_t __user *ksigmask;
 
 	if (sigsetsize != sizeof(compat_sigset_t))
 		return -EINVAL;
-	if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
+	if (get_compat_sigset(&tmp, sigmask))
 		return -EFAULT;
-	sigset_from_compat(&tmp, &ss32);
 	ksigmask = compat_alloc_user_space(sizeof(sigset_t));
 	if (copy_to_user(ksigmask, &tmp, sizeof(sigset_t)))
 		return -EFAULT;

include/linux/compat.h

@@ -450,7 +450,7 @@ asmlinkage long compat_sys_settimeofday(struct compat_timeval __user *tv,
 
 asmlinkage long compat_sys_adjtimex(struct compat_timex __user *utp);
 
-extern void sigset_from_compat(sigset_t *set, const compat_sigset_t *compat);
+extern int get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat);
 extern int put_compat_sigset(compat_sigset_t __user *compat,
 			     const sigset_t *set, unsigned int size);
 

kernel/compat.c

@@ -467,17 +467,26 @@ long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
 	return -EFAULT;
 }
 
-void
-sigset_from_compat(sigset_t *set, const compat_sigset_t *compat)
+int
+get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat)
 {
+#ifdef __BIG_ENDIAN
+	compat_sigset_t v;
+	if (copy_from_user(&v, compat, sizeof(compat_sigset_t)))
+		return -EFAULT;
 	switch (_NSIG_WORDS) {
-	case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32 );
-	case 3: set->sig[2] = compat->sig[4] | (((long)compat->sig[5]) << 32 );
-	case 2: set->sig[1] = compat->sig[2] | (((long)compat->sig[3]) << 32 );
-	case 1: set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 );
+	case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 );
+	case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 );
+	case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 );
+	case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 );
 	}
+#else
+	if (copy_from_user(set, compat, sizeof(compat_sigset_t)))
+		return -EFAULT;
+#endif
+	return 0;
 }
-EXPORT_SYMBOL_GPL(sigset_from_compat);
+EXPORT_SYMBOL_GPL(get_compat_sigset);
 
 int
 put_compat_sigset(compat_sigset_t __user *compat, const sigset_t *set,

kernel/signal.c

@@ -2600,7 +2600,6 @@ SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, nset,
 COMPAT_SYSCALL_DEFINE4(rt_sigprocmask, int, how, compat_sigset_t __user *, nset,
 		compat_sigset_t __user *, oset, compat_size_t, sigsetsize)
 {
-#ifdef __BIG_ENDIAN
 	sigset_t old_set = current->blocked;
 
 	/* XXX: Don't preclude handling different sized sigset_t's.  */
@@ -2608,13 +2607,10 @@ COMPAT_SYSCALL_DEFINE4(rt_sigprocmask, int, how, compat_sigset_t __user *, nset,
 		return -EINVAL;
 
 	if (nset) {
-		compat_sigset_t new32;
 		sigset_t new_set;
 		int error;
-		if (copy_from_user(&new32, nset, sizeof(compat_sigset_t)))
+		if (get_compat_sigset(&new_set, nset))
 			return -EFAULT;
-
-		sigset_from_compat(&new_set, &new32);
 		sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
 
 		error = sigprocmask(how, &new_set, NULL);
@@ -2622,10 +2618,6 @@ COMPAT_SYSCALL_DEFINE4(rt_sigprocmask, int, how, compat_sigset_t __user *, nset,
 			return error;
 	}
 	return oset ? put_compat_sigset(oset, &old_set, sizeof(*oset)) : 0;
-#else
-	return sys_rt_sigprocmask(how, (sigset_t __user *)nset,
-				  (sigset_t __user *)oset, sigsetsize);
-#endif
 }
 #endif
 
@@ -2908,7 +2900,6 @@ COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
 		struct compat_siginfo __user *, uinfo,
 		struct compat_timespec __user *, uts, compat_size_t, sigsetsize)
 {
-	compat_sigset_t s32;
 	sigset_t s;
 	struct timespec t;
 	siginfo_t info;
@@ -2917,9 +2908,8 @@ COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
 	if (sigsetsize != sizeof(sigset_t))
 		return -EINVAL;
 
-	if (copy_from_user(&s32, uthese, sizeof(compat_sigset_t)))
+	if (get_compat_sigset(&s, uthese))
 		return -EFAULT;
-	sigset_from_compat(&s, &s32);
 
 	if (uts) {
 		if (compat_get_timespec(&t, uts))
@@ -3450,18 +3440,16 @@ COMPAT_SYSCALL_DEFINE4(rt_sigaction, int, sig,
 
 	if (act) {
 		compat_uptr_t handler;
-		compat_sigset_t mask;
 		ret = get_user(handler, &act->sa_handler);
 		new_ka.sa.sa_handler = compat_ptr(handler);
 #ifdef __ARCH_HAS_SA_RESTORER
 		ret |= get_user(restorer, &act->sa_restorer);
 		new_ka.sa.sa_restorer = compat_ptr(restorer);
 #endif
-		ret |= copy_from_user(&mask, &act->sa_mask, sizeof(mask));
+		ret |= get_compat_sigset(&new_ka.sa.sa_mask, &act->sa_mask);
 		ret |= get_user(new_ka.sa.sa_flags, &act->sa_flags);
 		if (ret)
 			return -EFAULT;
-		sigset_from_compat(&new_ka.sa.sa_mask, &mask);
 	}
 
 	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
@@ -3649,22 +3637,15 @@ SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize)
 #ifdef CONFIG_COMPAT
 COMPAT_SYSCALL_DEFINE2(rt_sigsuspend, compat_sigset_t __user *, unewset, compat_size_t, sigsetsize)
 {
-#ifdef __BIG_ENDIAN
 	sigset_t newset;
-	compat_sigset_t newset32;
 
 	/* XXX: Don't preclude handling different sized sigset_t's.  */
 	if (sigsetsize != sizeof(sigset_t))
 		return -EINVAL;
 
-	if (copy_from_user(&newset32, unewset, sizeof(compat_sigset_t)))
+	if (get_compat_sigset(&newset, unewset))
 		return -EFAULT;
-	sigset_from_compat(&newset, &newset32);
 	return sigsuspend(&newset);
-#else
-	/* on little-endian bitmaps don't care about granularity */
-	return sys_rt_sigsuspend((sigset_t __user *)unewset, sigsetsize);
-#endif
 }
 #endif
 

virt/kvm/kvm_main.c

@@ -2724,7 +2724,6 @@ static long kvm_vcpu_compat_ioctl(struct file *filp,
 	case KVM_SET_SIGNAL_MASK: {
 		struct kvm_signal_mask __user *sigmask_arg = argp;
 		struct kvm_signal_mask kvm_sigmask;
-		compat_sigset_t csigset;
 		sigset_t sigset;
 
 		if (argp) {
@@ -2733,13 +2732,11 @@ static long kvm_vcpu_compat_ioctl(struct file *filp,
 					   sizeof(kvm_sigmask)))
 				goto out;
 			r = -EINVAL;
-			if (kvm_sigmask.len != sizeof(csigset))
+			if (kvm_sigmask.len != sizeof(compat_sigset_t))
 				goto out;
 			r = -EFAULT;
-			if (copy_from_user(&csigset, sigmask_arg->sigset,
-					   sizeof(csigset)))
+			if (get_compat_sigset(&sigset, (void *)sigmask_arg->sigset))
 				goto out;
-			sigset_from_compat(&sigset, &csigset);
 			r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
 		} else
 			r = kvm_vcpu_ioctl_set_sigmask(vcpu, NULL);