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

Pull signal handling cleanups from Al Viro:
 "This is the first pile; another one will come a bit later and will
  contain SYSCALL_DEFINE-related patches.

   - a bunch of signal-related syscalls (both native and compat)
     unified.

   - a bunch of compat syscalls switched to COMPAT_SYSCALL_DEFINE
     (fixing several potential problems with missing argument
     validation, while we are at it)

   - a lot of now-pointless wrappers killed

   - a couple of architectures (cris and hexagon) forgot to save
     altstack settings into sigframe, even though they used the
     (uninitialized) values in sigreturn; fixed.

   - microblaze fixes for delivery of multiple signals arriving at once

   - saner set of helpers for signal delivery introduced, several
     architectures switched to using those."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (143 commits)
  x86: convert to ksignal
  sparc: convert to ksignal
  arm: switch to struct ksignal * passing
  alpha: pass k_sigaction and siginfo_t using ksignal pointer
  burying unused conditionals
  make do_sigaltstack() static
  arm64: switch to generic old sigaction() (compat-only)
  arm64: switch to generic compat rt_sigaction()
  arm64: switch compat to generic old sigsuspend
  arm64: switch to generic compat rt_sigqueueinfo()
  arm64: switch to generic compat rt_sigpending()
  arm64: switch to generic compat rt_sigprocmask()
  arm64: switch to generic sigaltstack
  sparc: switch to generic old sigsuspend
  sparc: COMPAT_SYSCALL_DEFINE does all sign-extension as well as SYSCALL_DEFINE
  sparc: kill sign-extending wrappers for native syscalls
  kill sparc32_open()
  sparc: switch to use of generic old sigaction
  sparc: switch sys_compat_rt_sigaction() to COMPAT_SYSCALL_DEFINE
  mips: switch to generic sys_fork() and sys_clone()
  ...

6 files changed, 53 insertions, 136 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 38ec1f8df5a8..a955d89ed836 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -56,6 +56,8 @@ config ARM
 	select HAVE_MOD_ARCH_SPECIFIC if ARM_UNWIND
 	select MODULES_USE_ELF_REL
 	select CLONE_BACKWARDS
+	select OLD_SIGSUSPEND3
+	select OLD_SIGACTION
 	help
 	  The ARM series is a line of low-power-consumption RISC chip designs
 	  licensed by ARM Ltd and targeted at embedded applications and
diff --git a/arch/arm/include/asm/signal.h b/arch/arm/include/asm/signal.h
index 9a0ea6ab988f..c0eb412aff04 100644
--- a/arch/arm/include/asm/signal.h
+++ b/arch/arm/include/asm/signal.h
@@ -16,23 +16,7 @@ typedef struct {
 	unsigned long sig[_NSIG_WORDS];
 } sigset_t;
 
-struct old_sigaction {
-	__sighandler_t sa_handler;
-	old_sigset_t sa_mask;
-	unsigned long sa_flags;
-	__sigrestore_t sa_restorer;
-};
-
-struct sigaction {
-	__sighandler_t sa_handler;
-	unsigned long sa_flags;
-	__sigrestore_t sa_restorer;
-	sigset_t sa_mask;		/* mask last for extensibility */
-};
-
-struct k_sigaction {
-	struct sigaction sa;
-};
+#define __ARCH_HAS_SA_RESTORER
 
 #include <asm/sigcontext.h>
 #endif
diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h
index 21a2700d2957..e4ddfb39ca34 100644
--- a/arch/arm/include/asm/unistd.h
+++ b/arch/arm/include/asm/unistd.h
@@ -26,8 +26,6 @@
 #define __ARCH_WANT_SYS_NICE
 #define __ARCH_WANT_SYS_SIGPENDING
 #define __ARCH_WANT_SYS_SIGPROCMASK
-#define __ARCH_WANT_SYS_RT_SIGACTION
-#define __ARCH_WANT_SYS_RT_SIGSUSPEND
 #define __ARCH_WANT_SYS_OLD_MMAP
 #define __ARCH_WANT_SYS_OLD_SELECT
 
diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S
index a4fda4e7a372..0cc57611fc4f 100644
--- a/arch/arm/kernel/calls.S
+++ b/arch/arm/kernel/calls.S
@@ -195,7 +195,7 @@
 		CALL(sys_getcwd)
 		CALL(sys_capget)
 /* 185 */	CALL(sys_capset)
-		CALL(sys_sigaltstack_wrapper)
+		CALL(sys_sigaltstack)
 		CALL(sys_sendfile)
 		CALL(sys_ni_syscall)		/* getpmsg */
 		CALL(sys_ni_syscall)		/* putpmsg */
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index a6c301e90a3b..3248cde504ed 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -514,11 +514,6 @@ sys_rt_sigreturn_wrapper:
 		b	sys_rt_sigreturn
 ENDPROC(sys_rt_sigreturn_wrapper)
 
-sys_sigaltstack_wrapper:
-		ldr	r2, [sp, #S_OFF + S_SP]
-		b	do_sigaltstack
-ENDPROC(sys_sigaltstack_wrapper)
-
 sys_statfs64_wrapper:
 		teq	r1, #88
 		moveq	r1, #84
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 56f72d257ebd..296786bdbb73 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -45,48 +45,6 @@ const unsigned long sigreturn_codes[7] = {
 	MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,
 };
 
-/*
- * atomically swap in the new signal mask, and wait for a signal.
- */
-asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask)
-{
-	sigset_t blocked;
-	siginitset(&blocked, mask);
-	return sigsuspend(&blocked);
-}
-
-asmlinkage int 
-sys_sigaction(int sig, const struct old_sigaction __user *act,
-	      struct old_sigaction __user *oact)
-{
-	struct k_sigaction new_ka, old_ka;
-	int ret;
-
-	if (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_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(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_flags, &oact->sa_flags) ||
-		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
-			return -EFAULT;
-	}
-
-	return ret;
-}
-
 #ifdef CONFIG_CRUNCH
 static int preserve_crunch_context(struct crunch_sigframe __user *frame)
 {
@@ -300,7 +258,7 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
 	if (restore_sigframe(regs, &frame->sig))
 		goto badframe;
 
-	if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT)
+	if (restore_altstack(&frame->sig.uc.uc_stack))
 		goto badframe;
 
 	return regs->ARM_r0;
@@ -360,18 +318,12 @@ setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set)
 }
 
 static inline void __user *
-get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
+get_sigframe(struct ksignal *ksig, struct pt_regs *regs, int framesize)
 {
-	unsigned long sp = regs->ARM_sp;
+	unsigned long sp = sigsp(regs->ARM_sp, ksig);
 	void __user *frame;
 
 	/*
-	 * This is the X/Open sanctioned signal stack switching.
-	 */
-	if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
-		sp = current->sas_ss_sp + current->sas_ss_size;
-
-	/*
 	 * ATPCS B01 mandates 8-byte alignment
 	 */
 	frame = (void __user *)((sp - framesize) & ~7);
@@ -385,11 +337,22 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
 	return frame;
 }
 
+/*
+ * translate the signal
+ */
+static inline int map_sig(int sig)
+{
+	struct thread_info *thread = current_thread_info();
+	if (sig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
+		sig = thread->exec_domain->signal_invmap[sig];
+	return sig;
+}
+
 static int
-setup_return(struct pt_regs *regs, struct k_sigaction *ka,
-	     unsigned long __user *rc, void __user *frame, int usig)
+setup_return(struct pt_regs *regs, struct ksignal *ksig,
+	     unsigned long __user *rc, void __user *frame)
 {
-	unsigned long handler = (unsigned long)ka->sa.sa_handler;
+	unsigned long handler = (unsigned long)ksig->ka.sa.sa_handler;
 	unsigned long retcode;
 	int thumb = 0;
 	unsigned long cpsr = regs->ARM_cpsr & ~(PSR_f | PSR_E_BIT);
@@ -399,7 +362,7 @@ setup_return(struct pt_regs *regs, struct k_sigaction *ka,
 	/*
 	 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
 	 */
-	if (ka->sa.sa_flags & SA_THIRTYTWO)
+	if (ksig->ka.sa.sa_flags & SA_THIRTYTWO)
 		cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
 
 #ifdef CONFIG_ARM_THUMB
@@ -421,12 +384,12 @@ setup_return(struct pt_regs *regs, struct k_sigaction *ka,
 	}
 #endif
 
-	if (ka->sa.sa_flags & SA_RESTORER) {
-		retcode = (unsigned long)ka->sa.sa_restorer;
+	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+		retcode = (unsigned long)ksig->ka.sa.sa_restorer;
 	} else {
 		unsigned int idx = thumb << 1;
 
-		if (ka->sa.sa_flags & SA_SIGINFO)
+		if (ksig->ka.sa.sa_flags & SA_SIGINFO)
 			idx += 3;
 
 		if (__put_user(sigreturn_codes[idx],   rc) ||
@@ -451,7 +414,7 @@ setup_return(struct pt_regs *regs, struct k_sigaction *ka,
 		}
 	}
 
-	regs->ARM_r0 = usig;
+	regs->ARM_r0 = map_sig(ksig->sig);
 	regs->ARM_sp = (unsigned long)frame;
 	regs->ARM_lr = retcode;
 	regs->ARM_pc = handler;
@@ -461,9 +424,9 @@ setup_return(struct pt_regs *regs, struct k_sigaction *ka,
 }
 
 static int
-setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs)
+setup_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
 {
-	struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
+	struct sigframe __user *frame = get_sigframe(ksig, regs, sizeof(*frame));
 	int err = 0;
 
 	if (!frame)
@@ -476,36 +439,29 @@ setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *reg
 
 	err |= setup_sigframe(frame, regs, set);
 	if (err == 0)
-		err = setup_return(regs, ka, frame->retcode, frame, usig);
+		err = setup_return(regs, ksig, frame->retcode, frame);
 
 	return err;
 }
 
 static int
-setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
-	       sigset_t *set, struct pt_regs *regs)
+setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
 {
-	struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
-	stack_t stack;
+	struct rt_sigframe __user *frame = get_sigframe(ksig, regs, sizeof(*frame));
 	int err = 0;
 
 	if (!frame)
 		return 1;
 
-	err |= copy_siginfo_to_user(&frame->info, info);
+	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
 
 	__put_user_error(0, &frame->sig.uc.uc_flags, err);
 	__put_user_error(NULL, &frame->sig.uc.uc_link, err);
 
-	memset(&stack, 0, sizeof(stack));
-	stack.ss_sp = (void __user *)current->sas_ss_sp;
-	stack.ss_flags = sas_ss_flags(regs->ARM_sp);
-	stack.ss_size = current->sas_ss_size;
-	err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack));
-
+	err |= __save_altstack(&frame->sig.uc.uc_stack, regs->ARM_sp);
 	err |= setup_sigframe(&frame->sig, regs, set);
 	if (err == 0)
-		err = setup_return(regs, ka, frame->sig.retcode, frame, usig);
+		err = setup_return(regs, ksig, frame->sig.retcode, frame);
 
 	if (err == 0) {
 		/*
@@ -523,40 +479,25 @@ setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
 /*
  * OK, we're invoking a handler
  */	
-static void
-handle_signal(unsigned long sig, struct k_sigaction *ka,
-	      siginfo_t *info, struct pt_regs *regs)
+static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 {
-	struct thread_info *thread = current_thread_info();
-	struct task_struct *tsk = current;
 	sigset_t *oldset = sigmask_to_save();
-	int usig = sig;
 	int ret;
 
 	/*
-	 * translate the signal
-	 */
-	if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
-		usig = thread->exec_domain->signal_invmap[usig];
-
-	/*
 	 * Set up the stack frame
 	 */
-	if (ka->sa.sa_flags & SA_SIGINFO)
-		ret = setup_rt_frame(usig, ka, info, oldset, regs);
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+		ret = setup_rt_frame(ksig, oldset, regs);
 	else
-		ret = setup_frame(usig, ka, oldset, regs);
+		ret = setup_frame(ksig, oldset, regs);
 
 	/*
 	 * Check that the resulting registers are actually sane.
 	 */
 	ret |= !valid_user_regs(regs);
 
-	if (ret != 0) {
-		force_sigsegv(sig, tsk);
-		return;
-	}
-	signal_delivered(sig, info, ka, regs, 0);
+	signal_setup_done(ret, ksig, 0);
 }
 
 /*
@@ -571,9 +512,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
 static int do_signal(struct pt_regs *regs, int syscall)
 {
 	unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
-	struct k_sigaction ka;
-	siginfo_t info;
-	int signr;
+	struct ksignal ksig;
 	int restart = 0;
 
 	/*
@@ -605,33 +544,32 @@ static int do_signal(struct pt_regs *regs, int syscall)
 	 * Get the signal to deliver.  When running under ptrace, at this
 	 * point the debugger may change all our registers ...
 	 */
-	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 	/*
 	 * Depending on the signal settings we may need to revert the
 	 * decision to restart the system call.  But skip this if a
 	 * debugger has chosen to restart at a different PC.
 	 */
-	if (regs->ARM_pc != restart_addr)
-		restart = 0;
-	if (signr > 0) {
-		if (unlikely(restart)) {
+	if (get_signal(&ksig)) {
+		/* handler */
+		if (unlikely(restart) && regs->ARM_pc == restart_addr) {
 			if (retval == -ERESTARTNOHAND ||
 			    retval == -ERESTART_RESTARTBLOCK
 			    || (retval == -ERESTARTSYS
-				&& !(ka.sa.sa_flags & SA_RESTART))) {
+				&& !(ksig.ka.sa.sa_flags & SA_RESTART))) {
 				regs->ARM_r0 = -EINTR;
 				regs->ARM_pc = continue_addr;
 			}
 		}
-
-		handle_signal(signr, &ka, &info, regs);
-		return 0;
+		handle_signal(&ksig, regs);
+	} else {
+		/* no handler */
+		restore_saved_sigmask();
+		if (unlikely(restart) && regs->ARM_pc == restart_addr) {
+			regs->ARM_pc = continue_addr;
+			return restart;
+		}
 	}
-
-	restore_saved_sigmask();
-	if (unlikely(restart))
-		regs->ARM_pc = continue_addr;
-	return restart;
+	return 0;
 }
 
 asmlinkage int