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

Pull third pile of kernel_execve() patches from Al Viro:
 "The last bits of infrastructure for kernel_thread() et.al., with
  alpha/arm/x86 use of those.  Plus sanitizing the asm glue and
  do_notify_resume() on alpha, fixing the "disabled irq while running
  task_work stuff" breakage there.

  At that point the rest of kernel_thread/kernel_execve/sys_execve work
  can be done independently for different architectures.  The only
  pending bits that do depend on having all architectures converted are
  restrictred to fs/* and kernel/* - that'll obviously have to wait for
  the next cycle.

  I thought we'd have to wait for all of them done before we start
  eliminating the longjump-style insanity in kernel_execve(), but it
  turned out there's a very simple way to do that without flagday-style
  changes."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
  alpha: switch to saner kernel_execve() semantics
  arm: switch to saner kernel_execve() semantics
  x86, um: convert to saner kernel_execve() semantics
  infrastructure for saner ret_from_kernel_thread semantics
  make sure that kernel_thread() callbacks call do_exit() themselves
  make sure that we always have a return path from kernel_execve()
  ppc: eeh_event should just use kthread_run()
  don't bother with kernel_thread/kernel_execve for launching linuxrc
  alpha: get rid of switch_stack argument of do_work_pending()
  alpha: don't bother passing switch_stack separately from regs
  alpha: take SIGPENDING/NOTIFY_RESUME loop into signal.c
  alpha: simplify TIF_NEED_RESCHED handling

1 files changed, 28 insertions, 20 deletions

diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c
index a8c97d42ec8..32575f85507 100644
--- a/arch/alpha/kernel/signal.c
+++ b/arch/alpha/kernel/signal.c
@@ -298,8 +298,9 @@ get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
 
 static long
 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, 
-		 struct switch_stack *sw, unsigned long mask, unsigned long sp)
+		 unsigned long mask, unsigned long sp)
 {
+	struct switch_stack *sw = (struct switch_stack *)regs - 1;
 	long i, err = 0;
 
 	err |= __put_user(on_sig_stack((unsigned long)sc), &sc->sc_onstack);
@@ -354,7 +355,7 @@ setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 
 static int
 setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
-	    struct pt_regs *regs, struct switch_stack * sw)
+	    struct pt_regs *regs)
 {
 	unsigned long oldsp, r26, err = 0;
 	struct sigframe __user *frame;
@@ -364,7 +365,7 @@ setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 		return -EFAULT;
 
-	err |= setup_sigcontext(&frame->sc, regs, sw, set->sig[0], oldsp);
+	err |= setup_sigcontext(&frame->sc, regs, set->sig[0], oldsp);
 	if (err)
 		return -EFAULT;
 
@@ -401,7 +402,7 @@ setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
 
 static int
 setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
-	       sigset_t *set, struct pt_regs *regs, struct switch_stack * sw)
+	       sigset_t *set, struct pt_regs *regs)
 {
 	unsigned long oldsp, r26, err = 0;
 	struct rt_sigframe __user *frame;
@@ -420,7 +421,7 @@ setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 	err |= __put_user(sas_ss_flags(oldsp), &frame->uc.uc_stack.ss_flags);
 	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
-	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, sw,
+	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, 
 				set->sig[0], oldsp);
 	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 	if (err)
@@ -464,15 +465,15 @@ setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
  */
 static inline void
 handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
-	      struct pt_regs * regs, struct switch_stack *sw)
+	      struct pt_regs * regs)
 {
 	sigset_t *oldset = sigmask_to_save();
 	int ret;
 
 	if (ka->sa.sa_flags & SA_SIGINFO)
-		ret = setup_rt_frame(sig, ka, info, oldset, regs, sw);
+		ret = setup_rt_frame(sig, ka, info, oldset, regs);
 	else
-		ret = setup_frame(sig, ka, oldset, regs, sw);
+		ret = setup_frame(sig, ka, oldset, regs);
 
 	if (ret) {
 		force_sigsegv(sig, current);
@@ -519,8 +520,7 @@ syscall_restart(unsigned long r0, unsigned long r19,
  * all (if we get here from anything but a syscall return, it will be 0)
  */
 static void
-do_signal(struct pt_regs * regs, struct switch_stack * sw,
-	  unsigned long r0, unsigned long r19)
+do_signal(struct pt_regs *regs, unsigned long r0, unsigned long r19)
 {
 	siginfo_t info;
 	int signr;
@@ -537,7 +537,7 @@ do_signal(struct pt_regs * regs, struct switch_stack * sw,
 		/* Whee!  Actually deliver the signal.  */
 		if (r0)
 			syscall_restart(r0, r19, regs, &ka);
-		handle_signal(signr, &ka, &info, regs, sw);
+		handle_signal(signr, &ka, &info, regs);
 		if (single_stepping) 
 			ptrace_set_bpt(current); /* re-set bpt */
 		return;
@@ -568,15 +568,23 @@ do_signal(struct pt_regs * regs, struct switch_stack * sw,
 }
 
 void
-do_notify_resume(struct pt_regs *regs, struct switch_stack *sw,
-		 unsigned long thread_info_flags,
+do_work_pending(struct pt_regs *regs, unsigned long thread_flags,
 		 unsigned long r0, unsigned long r19)
 {
-	if (thread_info_flags & _TIF_SIGPENDING)
-		do_signal(regs, sw, r0, r19);
-
-	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
-		clear_thread_flag(TIF_NOTIFY_RESUME);
-		tracehook_notify_resume(regs);
-	}
+	do {
+		if (thread_flags & _TIF_NEED_RESCHED) {
+			schedule();
+		} else {
+			local_irq_enable();
+			if (thread_flags & _TIF_SIGPENDING) {
+				do_signal(regs, r0, r19);
+				r0 = 0;
+			} else {
+				clear_thread_flag(TIF_NOTIFY_RESUME);
+				tracehook_notify_resume(regs);
+			}
+		}
+		local_irq_disable();
+		thread_flags = current_thread_info()->flags;
+	} while (thread_flags & _TIF_WORK_MASK);
 }