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()
  ...

6 files changed, 37 insertions, 56 deletions

diff --git a/arch/xtensa/include/asm/signal.h b/arch/xtensa/include/asm/signal.h
index 633ba73..7f201b9 100644
--- a/arch/xtensa/include/asm/signal.h
+++ b/arch/xtensa/include/asm/signal.h
@@ -120,13 +120,6 @@ typedef void (*__sighandler_t)(int);
 #define SIG_ERR	((__sighandler_t)-1)	/* error return from signal */
 
 #ifdef __KERNEL__
-struct old_sigaction {
-	__sighandler_t sa_handler;
-	old_sigset_t sa_mask;
-	unsigned long sa_flags;
-	void (*sa_restorer)(void);
-};
-
 struct sigaction {
 	__sighandler_t sa_handler;
 	unsigned long sa_flags;
diff --git a/arch/xtensa/include/asm/syscall.h b/arch/xtensa/include/asm/syscall.h
index efcf33b..0b9f2e1 100644
--- a/arch/xtensa/include/asm/syscall.h
+++ b/arch/xtensa/include/asm/syscall.h
@@ -15,10 +15,6 @@ asmlinkage long xtensa_clone(unsigned long, unsigned long, struct pt_regs*);
 asmlinkage long xtensa_ptrace(long, long, long, long);
 asmlinkage long xtensa_sigreturn(struct pt_regs*);
 asmlinkage long xtensa_rt_sigreturn(struct pt_regs*);
-asmlinkage long xtensa_sigsuspend(struct pt_regs*);
-asmlinkage long xtensa_rt_sigsuspend(struct pt_regs*);
-asmlinkage long xtensa_sigaction(int, const struct old_sigaction*,
-				 struct old_sigaction*);
 asmlinkage long xtensa_sigaltstack(struct pt_regs *regs);
 asmlinkage long sys_rt_sigaction(int,
 				 const struct sigaction __user *,
diff --git a/arch/xtensa/include/asm/thread_info.h b/arch/xtensa/include/asm/thread_info.h
index 6abbedd..81abfd5 100644
--- a/arch/xtensa/include/asm/thread_info.h
+++ b/arch/xtensa/include/asm/thread_info.h
@@ -131,6 +131,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_IRET		4	/* return with iret */
 #define TIF_MEMDIE		5	/* is terminating due to OOM killer */
 #define TIF_RESTORE_SIGMASK	6	/* restore signal mask in do_signal() */
+#define TIF_NOTIFY_RESUME	7	/* callback before returning to user */
 #define TIF_POLLING_NRFLAG	16	/* true if poll_idle() is polling TIF_NEED_RESCHED */
 
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
diff --git a/arch/xtensa/include/asm/unistd.h b/arch/xtensa/include/asm/unistd.h
index 798ee6d..bc7e005 100644
--- a/arch/xtensa/include/asm/unistd.h
+++ b/arch/xtensa/include/asm/unistd.h
@@ -507,7 +507,7 @@ __SYSCALL(229, sys_rt_sigtimedwait, 4)
 #define __NR_rt_sigqueueinfo 			230
 __SYSCALL(230, sys_rt_sigqueueinfo, 3)
 #define __NR_rt_sigsuspend 			231
-__SYSCALL(231, xtensa_rt_sigsuspend, 2)
+__SYSCALL(231, sys_rt_sigsuspend, 2)
 
 /* Message */
 
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 6223f33..7e62360 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -409,16 +409,16 @@ common_exception_return:
 	l32i	a4, a2, TI_FLAGS
 
 	_bbsi.l	a4, TIF_NEED_RESCHED, 3f
+	_bbsi.l	a4, TIF_NOTIFY_RESUME, 2f
 	_bbci.l	a4, TIF_SIGPENDING, 4f
 
-	l32i	a4, a1, PT_DEPC
+2:	l32i	a4, a1, PT_DEPC
 	bgeui	a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 4f
 
 	/* Call do_signal() */
 
-	movi	a4, do_signal	# int do_signal(struct pt_regs*, sigset_t*)
+	movi	a4, do_notify_resume	# int do_notify_resume(struct pt_regs*)
 	mov	a6, a1
-	movi	a7, 0
 	callx4	a4
 	j	1b
 
diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c
index d78869a..c5e4ec0 100644
--- a/arch/xtensa/kernel/signal.c
+++ b/arch/xtensa/kernel/signal.c
@@ -20,6 +20,7 @@
 #include <linux/ptrace.h>
 #include <linux/personality.h>
 #include <linux/freezer.h>
+#include <linux/tracehook.h>
 
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
@@ -31,8 +32,6 @@
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
-asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
-
 extern struct task_struct *coproc_owners[];
 
 struct rt_sigframe
@@ -248,6 +247,9 @@ asmlinkage long xtensa_rt_sigreturn(long a0, long a1, long a2, long a3,
 	sigset_t set;
 	int ret;
 
+	/* Always make any pending restarted system calls return -EINTR */
+	current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
 	if (regs->depc > 64)
 		panic("rt_sigreturn in double exception!\n");
 
@@ -426,37 +428,6 @@ give_sigsegv:
 	return -EFAULT;
 }
 
-/*
- * Atomically swap in the new signal mask, and wait for a signal.
- */
-
-asmlinkage long xtensa_rt_sigsuspend(sigset_t __user *unewset, 
-    				     size_t sigsetsize,
-    				     long a2, long a3, long a4, long a5, 
-				     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);
-
-	regs->areg[2] = -EINTR;
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		if (do_signal(regs, &saveset))
-			return -EINTR;
-	}
-}
-
 asmlinkage long xtensa_sigaltstack(const stack_t __user *uss, 
 				   stack_t __user *uoss,
     				   long a2, long a3, long a4, long a5,
@@ -476,19 +447,19 @@ asmlinkage long xtensa_sigaltstack(const stack_t __user *uss,
  * the kernel can handle, and then we build all the user-level signal handling
  * stack-frames in one go after that.
  */
-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;
-
-	if (!user_mode(regs))
-		return 0;
+	sigset_t oldset;
 
 	if (try_to_freeze())
 		goto no_signal;
 
-	if (!oldset)
+	if (test_thread_flag(TIF_RESTORE_SIGMASK))
+		oldset = &current->saved_sigmask;
+	else
 		oldset = &current->blocked;
 
 	task_pt_regs(current)->icountlevel = 0;
@@ -532,13 +503,14 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset)
 		/* Set up the stack frame */
 		ret = setup_frame(signr, &ka, &info, oldset, regs);
 		if (ret)
-			return ret;
+			return;
 
+		clear_thread_flag(TIF_RESTORE_SIGMASK);
 		block_sigmask(&ka, signr);
 		if (current->ptrace & PT_SINGLESTEP)
 			task_pt_regs(current)->icountlevel = 1;
 
-		return 1;
+		return;
 	}
 
 no_signal:
@@ -558,8 +530,27 @@ no_signal:
 			break;
 		}
 	}
+
+	/* If there's no signal to deliver, we just restore the saved mask.  */
+	if (test_and_clear_thread_flag(TIF_RESTORE_SIGMASK))
+		set_current_blocked(&current->saved_sigmask);
+
 	if (current->ptrace & PT_SINGLESTEP)
 		task_pt_regs(current)->icountlevel = 1;
-	return 0;
+	return;
 }
 
+void do_notify_resume(struct pt_regs *regs)
+{
+	if (!user_mode(regs))
+		return;
+
+	if (test_thread_flag(TIF_SIGPENDING))
+		do_signal(regs);
+
+	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) {
+		tracehook_notify_resume(regs);
+		if (current->replacement_session_keyring)
+			key_replace_session_keyring();
+	}
+}