Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

Pull first series of signal handling cleanups from Al Viro:
 "This is just the first part of the queue (about a half of it);
  assorted fixes all over the place in signal handling.

  This one ends with all sigsuspend() implementations switched to
  generic one (->saved_sigmask-based).

  With this, a bunch of assorted old buglets are fixed and most of the
  missing bits of NOTIFY_RESUME hookup are in place.  Two more fixes sit
  in arm and um trees respectively, and there's a couple of broken ones
  that need obvious fixes - parisc and avr32 check TIF_NOTIFY_RESUME
  only on one of two codepaths; fixes for that will happen in the next
  series"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (55 commits)
  unicore32: if there's no handler we need to restore sigmask, syscall or no syscall
  xtensa: add handling of TIF_NOTIFY_RESUME
  microblaze: drop 'oldset' argument of do_notify_resume()
  microblaze: handle TIF_NOTIFY_RESUME
  score: add handling of NOTIFY_RESUME to do_notify_resume()
  m68k: add TIF_NOTIFY_RESUME and handle it.
  sparc: kill ancient comment in sparc_sigaction()
  h8300: missing checks of __get_user()/__put_user() return values
  frv: missing checks of __get_user()/__put_user() return values
  cris: missing checks of __get_user()/__put_user() return values
  powerpc: missing checks of __get_user()/__put_user() return values
  sh: missing checks of __get_user()/__put_user() return values
  sparc: missing checks of __get_user()/__put_user() return values
  avr32: struct old_sigaction is never used
  m32r: struct old_sigaction is never used
  xtensa: xtensa_sigaction doesn't exist
  alpha: tidy signal delivery up
  score: don't open-code force_sigsegv()
  cris: don't open-code force_sigsegv()
  blackfin: don't open-code force_sigsegv()
  ...

4 files changed, 41 insertions, 104 deletions

diff --git a/arch/sh/include/asm/syscalls_32.h b/arch/sh/include/asm/syscalls_32.h
index ae717e3c26d..6c1fa559753 100644
--- a/arch/sh/include/asm/syscalls_32.h
+++ b/arch/sh/include/asm/syscalls_32.h
@@ -23,9 +23,7 @@ asmlinkage int sys_execve(const char __user *ufilename,
 			  const char __user *const __user *uargv,
 			  const char __user *const __user *uenvp,
 			  unsigned long r7, struct pt_regs __regs);
-asmlinkage int sys_sigsuspend(old_sigset_t mask, unsigned long r5,
-			      unsigned long r6, unsigned long r7,
-			      struct pt_regs __regs);
+asmlinkage int sys_sigsuspend(old_sigset_t mask);
 asmlinkage int sys_sigaction(int sig, const struct old_sigaction __user *act,
 			     struct old_sigaction __user *oact);
 asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
diff --git a/arch/sh/include/asm/unistd.h b/arch/sh/include/asm/unistd.h
index a42a5610a36..e800a38c9f8 100644
--- a/arch/sh/include/asm/unistd.h
+++ b/arch/sh/include/asm/unistd.h
@@ -1,13 +1,11 @@
 #ifdef __KERNEL__
 # ifdef CONFIG_SUPERH32
-
 #  include "unistd_32.h"
-#  define __ARCH_WANT_SYS_RT_SIGSUSPEND
-
 # else
 #  include "unistd_64.h"
 # endif
 
+# define __ARCH_WANT_SYS_RT_SIGSUSPEND
 # define __ARCH_WANT_IPC_PARSE_VERSION
 # define __ARCH_WANT_OLD_READDIR
 # define __ARCH_WANT_OLD_STAT
diff --git a/arch/sh/kernel/signal_32.c b/arch/sh/kernel/signal_32.c
index 5901fba3176..cb4172c8af7 100644
--- a/arch/sh/kernel/signal_32.c
+++ b/arch/sh/kernel/signal_32.c
@@ -53,23 +53,11 @@ struct fdpic_func_descriptor {
  * Atomically swap in the new signal mask, and wait for a signal.
  */
 asmlinkage int
-sys_sigsuspend(old_sigset_t mask,
-	       unsigned long r5, unsigned long r6, unsigned long r7,
-	       struct pt_regs __regs)
+sys_sigsuspend(old_sigset_t mask)
 {
 	sigset_t blocked;
-
-	current->saved_sigmask = current->blocked;
-
-	mask &= _BLOCKABLE;
 	siginitset(&blocked, mask);
-	set_current_blocked(&blocked);
-
-	current->state = TASK_INTERRUPTIBLE;
-	schedule();
-	set_restore_sigmask();
-
-	return -ERESTARTNOHAND;
+	return sigsuspend(&blocked);
 }
 
 asmlinkage int
@@ -83,10 +71,10 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
 		old_sigset_t mask;
 		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
 		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
-		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
+		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
+		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
+		    __get_user(mask, &act->sa_mask))
 			return -EFAULT;
-		__get_user(new_ka.sa.sa_flags, &act->sa_flags);
-		__get_user(mask, &act->sa_mask);
 		siginitset(&new_ka.sa.sa_mask, mask);
 	}
 
@@ -95,10 +83,10 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
 	if (!ret && oact) {
 		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
 		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
-		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
+		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
+		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
+		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
 			return -EFAULT;
-		__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
-		__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
 	}
 
 	return ret;
@@ -162,12 +150,11 @@ static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
 	if (!(boot_cpu_data.flags & CPU_HAS_FPU))
 		return 0;
 
-	if (!used_math()) {
-		__put_user(0, &sc->sc_ownedfp);
-		return 0;
-	}
+	if (!used_math())
+		return __put_user(0, &sc->sc_ownedfp);
 
-	__put_user(1, &sc->sc_ownedfp);
+	if (__put_user(1, &sc->sc_ownedfp))
+		return -EFAULT;
 
 	/* This will cause a "finit" to be triggered by the next
 	   attempted FPU operation by the 'current' process.
@@ -207,7 +194,7 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p
 		regs->sr |= SR_FD; /* Release FPU */
 		clear_fpu(tsk, regs);
 		clear_used_math();
-		__get_user (owned_fp, &sc->sc_ownedfp);
+		err |= __get_user (owned_fp, &sc->sc_ownedfp);
 		if (owned_fp)
 			err |= restore_sigcontext_fpu(sc);
 	}
@@ -398,11 +385,14 @@ static int setup_frame(int sig, struct k_sigaction *ka,
 		struct fdpic_func_descriptor __user *funcptr =
 			(struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
 
-		__get_user(regs->pc, &funcptr->text);
-		__get_user(regs->regs[12], &funcptr->GOT);
+		err |= __get_user(regs->pc, &funcptr->text);
+		err |= __get_user(regs->regs[12], &funcptr->GOT);
 	} else
 		regs->pc = (unsigned long)ka->sa.sa_handler;
 
+	if (err)
+		goto give_sigsegv;
+
 	set_fs(USER_DS);
 
 	pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
@@ -482,11 +472,14 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 		struct fdpic_func_descriptor __user *funcptr =
 			(struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
 
-		__get_user(regs->pc, &funcptr->text);
-		__get_user(regs->regs[12], &funcptr->GOT);
+		err |= __get_user(regs->pc, &funcptr->text);
+		err |= __get_user(regs->regs[12], &funcptr->GOT);
 	} else
 		regs->pc = (unsigned long)ka->sa.sa_handler;
 
+	if (err)
+		goto give_sigsegv;
+
 	set_fs(USER_DS);
 
 	pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
diff --git a/arch/sh/kernel/signal_64.c b/arch/sh/kernel/signal_64.c
index 3c9a6f7dcdc..b589a354c06 100644
--- a/arch/sh/kernel/signal_64.c
+++ b/arch/sh/kernel/signal_64.c
@@ -83,11 +83,12 @@ handle_syscall_restart(struct pt_regs *regs, struct sigaction *sa)
  * the kernel can handle, and then we build all the user-level signal handling
  * stack-frames in one go after that.
  */
-static int do_signal(struct pt_regs *regs, sigset_t *oldset)
+static void do_signal(struct pt_regs *regs)
 {
 	siginfo_t info;
 	int signr;
 	struct k_sigaction ka;
+	sigset_t *oldset;
 
 	/*
 	 * We want the common case to go fast, which
@@ -96,11 +97,11 @@ static int do_signal(struct pt_regs *regs, sigset_t *oldset)
 	 * if so.
 	 */
 	if (!user_mode(regs))
-		return 1;
+		return;
 
 	if (current_thread_info()->status & TS_RESTORE_SIGMASK)
 		oldset = &current->saved_sigmask;
-	else if (!oldset)
+	else
 		oldset = &current->blocked;
 
 	signr = get_signal_to_deliver(&info, &ka, regs, 0);
@@ -118,7 +119,7 @@ static int do_signal(struct pt_regs *regs, sigset_t *oldset)
 
 			tracehook_signal_handler(signr, &info, &ka, regs,
 					test_thread_flag(TIF_SINGLESTEP));
-			return 1;
+			return;
 		}
 	}
 
@@ -147,71 +148,18 @@ static int do_signal(struct pt_regs *regs, sigset_t *oldset)
 		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 	}
 
-	return 0;
+	return;
 }
 
 /*
  * Atomically swap in the new signal mask, and wait for a signal.
  */
 asmlinkage int
-sys_sigsuspend(old_sigset_t mask,
-	       unsigned long r3, unsigned long r4, unsigned long r5,
-	       unsigned long r6, unsigned long r7,
-	       struct pt_regs * regs)
+sys_sigsuspend(old_sigset_t mask)
 {
-	sigset_t saveset, blocked;
-
-	saveset = current->blocked;
-
-	mask &= _BLOCKABLE;
+	sigset_t blocked;
 	siginitset(&blocked, mask);
-	set_current_blocked(&blocked);
-
-	REF_REG_RET = -EINTR;
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		set_restore_sigmask();
-		regs->pc += 4;    /* because sys_sigreturn decrements the pc */
-		if (do_signal(regs, &saveset)) {
-			/* pc now points at signal handler. Need to decrement
-			   it because entry.S will increment it. */
-			regs->pc -= 4;
-			return -EINTR;
-		}
-	}
-}
-
-asmlinkage int
-sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
-	          unsigned long r4, unsigned long r5, unsigned long r6,
-	          unsigned long r7,
-	          struct pt_regs * regs)
-{
-	sigset_t saveset, newset;
-
-	/* XXX: Don't preclude handling different sized sigset_t's.  */
-	if (sigsetsize != sizeof(sigset_t))
-		return -EINVAL;
-
-	if (copy_from_user(&newset, unewset, sizeof(newset)))
-		return -EFAULT;
-	sigdelsetmask(&newset, ~_BLOCKABLE);
-	saveset = current->blocked;
-	set_current_blocked(&newset);
-
-	REF_REG_RET = -EINTR;
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		regs->pc += 4;    /* because sys_sigreturn decrements the pc */
-		if (do_signal(regs, &saveset)) {
-			/* pc now points at signal handler. Need to decrement
-			   it because entry.S will increment it. */
-			regs->pc -= 4;
-			return -EINTR;
-		}
-	}
+	return sigsuspend(&blocked);
 }
 
 asmlinkage int
@@ -225,10 +173,10 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
 		old_sigset_t mask;
 		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
 		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
-		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
+		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
+		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
+		    __get_user(mask, &act->sa_mask))
 			return -EFAULT;
-		__get_user(new_ka.sa.sa_flags, &act->sa_flags);
-		__get_user(mask, &act->sa_mask);
 		siginitset(&new_ka.sa.sa_mask, mask);
 	}
 
@@ -237,10 +185,10 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
 	if (!ret && oact) {
 		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
 		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
-		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
+		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
+		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
+		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
 			return -EFAULT;
-		__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
-		__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
 	}
 
 	return ret;
@@ -732,7 +680,7 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
 {
 	if (thread_info_flags & _TIF_SIGPENDING)
-		do_signal(regs, 0);
+		do_signal(regs);
 
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);