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()
  ...

1 files changed, 61 insertions, 114 deletions

diff --git a/arch/sparc/kernel/signal_32.c b/arch/sparc/kernel/signal_32.c
index 68f9c8650af4..7d5d8e1f8415 100644
--- a/arch/sparc/kernel/signal_32.c
+++ b/arch/sparc/kernel/signal_32.c
@@ -59,18 +59,6 @@ struct rt_signal_frame {
 #define SF_ALIGNEDSZ  (((sizeof(struct signal_frame) + 7) & (~7)))
 #define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame) + 7) & (~7)))
 
-static int _sigpause_common(old_sigset_t set)
-{
-	sigset_t blocked;
-	siginitset(&blocked, set);
-	return sigsuspend(&blocked);
-}
-
-asmlinkage int sys_sigsuspend(old_sigset_t set)
-{
-	return _sigpause_common(set);
-}
-
 asmlinkage void do_sigreturn(struct pt_regs *regs)
 {
 	struct signal_frame __user *sf;
@@ -141,9 +129,7 @@ asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
 	unsigned int psr, pc, npc;
 	__siginfo_fpu_t __user *fpu_save;
 	__siginfo_rwin_t __user *rwin_save;
-	mm_segment_t old_fs;
 	sigset_t set;
-	stack_t st;
 	int err;
 
 	synchronize_user_stack();
@@ -171,8 +157,7 @@ asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
 	if (!err && fpu_save)
 		err |= restore_fpu_state(regs, fpu_save);
 	err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
-	
-	err |= __copy_from_user(&st, &sf->stack, sizeof(stack_t));
+	err |= restore_altstack(&sf->stack);
 	
 	if (err)
 		goto segv;
@@ -180,14 +165,6 @@ asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
 	regs->pc = pc;
 	regs->npc = npc;
 	
-	/* It is more difficult to avoid calling this function than to
-	 * call it and ignore errors.
-	 */
-	old_fs = get_fs();
-	set_fs(KERNEL_DS);
-	do_sigaltstack((const stack_t __user *) &st, NULL, (unsigned long)sf);
-	set_fs(old_fs);
-
 	err |= __get_user(rwin_save, &sf->rwin_save);
 	if (!err && rwin_save) {
 		if (restore_rwin_state(rwin_save))
@@ -209,7 +186,7 @@ static inline int invalid_frame_pointer(void __user *fp, int fplen)
 	return 0;
 }
 
-static inline void __user *get_sigframe(struct sigaction *sa, struct pt_regs *regs, unsigned long framesize)
+static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
 {
 	unsigned long sp = regs->u_regs[UREG_FP];
 
@@ -221,12 +198,7 @@ static inline void __user *get_sigframe(struct sigaction *sa, struct pt_regs *re
 		return (void __user *) -1L;
 
 	/* This is the X/Open sanctioned signal stack switching.  */
-	if (sa->sa_flags & SA_ONSTACK) {
-		if (sas_ss_flags(sp) == 0)
-			sp = current->sas_ss_sp + current->sas_ss_size;
-	}
-
-	sp -= framesize;
+	sp = sigsp(sp, ksig) - framesize;
 
 	/* Always align the stack frame.  This handles two cases.  First,
 	 * sigaltstack need not be mindful of platform specific stack
@@ -239,8 +211,8 @@ static inline void __user *get_sigframe(struct sigaction *sa, struct pt_regs *re
 	return (void __user *) sp;
 }
 
-static int setup_frame(struct k_sigaction *ka, struct pt_regs *regs,
-		       int signo, sigset_t *oldset)
+static int setup_frame(struct ksignal *ksig, struct pt_regs *regs,
+		       sigset_t *oldset)
 {
 	struct signal_frame __user *sf;
 	int sigframe_size, err, wsaved;
@@ -258,10 +230,12 @@ static int setup_frame(struct k_sigaction *ka, struct pt_regs *regs,
 		sigframe_size += sizeof(__siginfo_rwin_t);
 
 	sf = (struct signal_frame __user *)
-		get_sigframe(&ka->sa, regs, sigframe_size);
+		get_sigframe(ksig, regs, sigframe_size);
 
-	if (invalid_frame_pointer(sf, sigframe_size))
-		goto sigill_and_return;
+	if (invalid_frame_pointer(sf, sigframe_size)) {
+		do_exit(SIGILL);
+		return -EINVAL;
+	}
 
 	tail = sf + 1;
 
@@ -300,21 +274,21 @@ static int setup_frame(struct k_sigaction *ka, struct pt_regs *regs,
 		err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
 	}
 	if (err)
-		goto sigsegv;
+		return err;
 	
 	/* 3. signal handler back-trampoline and parameters */
 	regs->u_regs[UREG_FP] = (unsigned long) sf;
-	regs->u_regs[UREG_I0] = signo;
+	regs->u_regs[UREG_I0] = ksig->sig;
 	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
 
 	/* 4. signal handler */
-	regs->pc = (unsigned long) ka->sa.sa_handler;
+	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
 	regs->npc = (regs->pc + 4);
 
 	/* 5. return to kernel instructions */
-	if (ka->ka_restorer)
-		regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
+	if (ksig->ka.ka_restorer)
+		regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
 	else {
 		regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
 
@@ -324,24 +298,16 @@ static int setup_frame(struct k_sigaction *ka, struct pt_regs *regs,
 		/* t 0x10 */
 		err |= __put_user(0x91d02010, &sf->insns[1]);
 		if (err)
-			goto sigsegv;
+			return err;
 
 		/* Flush instruction space. */
 		flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
 	}
 	return 0;
-
-sigill_and_return:
-	do_exit(SIGILL);
-	return -EINVAL;
-
-sigsegv:
-	force_sigsegv(signo, current);
-	return -EFAULT;
 }
 
-static int setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
-			  int signo, sigset_t *oldset, siginfo_t *info)
+static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs,
+			  sigset_t *oldset)
 {
 	struct rt_signal_frame __user *sf;
 	int sigframe_size, wsaved;
@@ -357,9 +323,11 @@ static int setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
 	if (wsaved)
 		sigframe_size += sizeof(__siginfo_rwin_t);
 	sf = (struct rt_signal_frame __user *)
-		get_sigframe(&ka->sa, regs, sigframe_size);
-	if (invalid_frame_pointer(sf, sigframe_size))
-		goto sigill;
+		get_sigframe(ksig, regs, sigframe_size);
+	if (invalid_frame_pointer(sf, sigframe_size)) {
+		do_exit(SIGILL);
+		return -EINVAL;
+	}
 
 	tail = sf + 1;
 	err  = __put_user(regs->pc, &sf->regs.pc);
@@ -391,9 +359,7 @@ static int setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
 	err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
 	
 	/* Setup sigaltstack */
-	err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
-	err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
-	err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);
+	err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
 	
 	if (!wsaved) {
 		err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
@@ -405,21 +371,21 @@ static int setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
 		err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
 	}
 
-	err |= copy_siginfo_to_user(&sf->info, info);
+	err |= copy_siginfo_to_user(&sf->info, &ksig->info);
 
 	if (err)
-		goto sigsegv;
+		return err;
 
 	regs->u_regs[UREG_FP] = (unsigned long) sf;
-	regs->u_regs[UREG_I0] = signo;
+	regs->u_regs[UREG_I0] = ksig->sig;
 	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 	regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
 
-	regs->pc = (unsigned long) ka->sa.sa_handler;
+	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
 	regs->npc = (regs->pc + 4);
 
-	if (ka->ka_restorer)
-		regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
+	if (ksig->ka.ka_restorer)
+		regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
 	else {
 		regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
 
@@ -429,38 +395,25 @@ static int setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
 		/* t 0x10 */
 		err |= __put_user(0x91d02010, &sf->insns[1]);
 		if (err)
-			goto sigsegv;
+			return err;
 
 		/* Flush instruction space. */
 		flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
 	}
 	return 0;
-
-sigill:
-	do_exit(SIGILL);
-	return -EINVAL;
-
-sigsegv:
-	force_sigsegv(signo, current);
-	return -EFAULT;
 }
 
 static inline void
-handle_signal(unsigned long signr, struct k_sigaction *ka,
-	      siginfo_t *info, struct pt_regs *regs)
+handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 {
 	sigset_t *oldset = sigmask_to_save();
 	int err;
 
-	if (ka->sa.sa_flags & SA_SIGINFO)
-		err = setup_rt_frame(ka, regs, signr, oldset, info);
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+		err = setup_rt_frame(ksig, regs, oldset);
 	else
-		err = setup_frame(ka, regs, signr, oldset);
-
-	if (err)
-		return;
-
-	signal_delivered(signr, info, ka, regs, 0);
+		err = setup_frame(ksig, regs, oldset);
+	signal_setup_done(err, ksig, 0);
 }
 
 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
@@ -490,10 +443,9 @@ static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
  */
 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 {
-	struct k_sigaction ka;
+	struct ksignal ksig;
 	int restart_syscall;
-	siginfo_t info;
-	int signr;
+	bool has_handler;
 
 	/* It's a lot of work and synchronization to add a new ptrace
 	 * register for GDB to save and restore in order to get
@@ -516,7 +468,7 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
 		regs->u_regs[UREG_G6] = orig_i0;
 
-	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+	has_handler = get_signal(&ksig);
 
 	/* If the debugger messes with the program counter, it clears
 	 * the software "in syscall" bit, directing us to not perform
@@ -528,35 +480,30 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 		orig_i0 = regs->u_regs[UREG_G6];
 	}
 
-
-	if (signr > 0) {
+	if (has_handler) {
 		if (restart_syscall)
-			syscall_restart(orig_i0, regs, &ka.sa);
-		handle_signal(signr, &ka, &info, regs);
-		return;
-	}
-	if (restart_syscall &&
-	    (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
-	     regs->u_regs[UREG_I0] == ERESTARTSYS ||
-	     regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
-		/* replay the system call when we are done */
-		regs->u_regs[UREG_I0] = orig_i0;
-		regs->pc -= 4;
-		regs->npc -= 4;
-		pt_regs_clear_syscall(regs);
-	}
-	if (restart_syscall &&
-	    regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
-		regs->u_regs[UREG_G1] = __NR_restart_syscall;
-		regs->pc -= 4;
-		regs->npc -= 4;
-		pt_regs_clear_syscall(regs);
+			syscall_restart(orig_i0, regs, &ksig.ka.sa);
+		handle_signal(&ksig, regs);
+	} else {
+		if (restart_syscall) {
+			switch (regs->u_regs[UREG_I0]) {
+			case ERESTARTNOHAND:
+	     		case ERESTARTSYS:
+			case ERESTARTNOINTR:
+				/* replay the system call when we are done */
+				regs->u_regs[UREG_I0] = orig_i0;
+				regs->pc -= 4;
+				regs->npc -= 4;
+				pt_regs_clear_syscall(regs);
+			case ERESTART_RESTARTBLOCK:
+				regs->u_regs[UREG_G1] = __NR_restart_syscall;
+				regs->pc -= 4;
+				regs->npc -= 4;
+				pt_regs_clear_syscall(regs);
+			}
+		}
+		restore_saved_sigmask();
 	}
-
-	/* if there's no signal to deliver, we just put the saved sigmask
-	 * back
-	 */
-	restore_saved_sigmask();
 }
 
 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,