1 files changed, 106 insertions, 92 deletions

diff --git a/arch/openrisc/kernel/signal.c b/arch/openrisc/kernel/signal.c
index ae167f7e081a..c277ec82783d 100644
--- a/arch/openrisc/kernel/signal.c
+++ b/arch/openrisc/kernel/signal.c
@@ -28,24 +28,24 @@
 #include <linux/tracehook.h>
 
 #include <asm/processor.h>
+#include <asm/syscall.h>
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
 
 #define DEBUG_SIG 0
 
 struct rt_sigframe {
-	struct siginfo *pinfo;
-	void *puc;
 	struct siginfo info;
 	struct ucontext uc;
 	unsigned char retcode[16];	/* trampoline code */
 };
 
-static int restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc)
+static int restore_sigcontext(struct pt_regs *regs,
+			      struct sigcontext __user *sc)
 {
-	unsigned int err = 0;
+	int err = 0;
 
-	/* Alwys make any pending restarted system call return -EINTR */
+	/* Always make any pending restarted system calls return -EINTR */
 	current_thread_info()->restart_block.fn = do_no_restart_syscall;
 
 	/*
@@ -53,25 +53,21 @@ static int restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc)
 	 * (sc is already checked for VERIFY_READ since the sigframe was
 	 *  checked in sys_sigreturn previously)
 	 */
-	if (__copy_from_user(regs, sc->regs.gpr, 32 * sizeof(unsigned long)))
-		goto badframe;
-	if (__copy_from_user(&regs->pc, &sc->regs.pc, sizeof(unsigned long)))
-		goto badframe;
-	if (__copy_from_user(&regs->sr, &sc->regs.sr, sizeof(unsigned long)))
-		goto badframe;
+	err |= __copy_from_user(regs, sc->regs.gpr, 32 * sizeof(unsigned long));
+	err |= __copy_from_user(&regs->pc, &sc->regs.pc, sizeof(unsigned long));
+	err |= __copy_from_user(&regs->sr, &sc->regs.sr, sizeof(unsigned long));
 
 	/* make sure the SM-bit is cleared so user-mode cannot fool us */
 	regs->sr &= ~SPR_SR_SM;
 
+	regs->orig_gpr11 = -1;	/* Avoid syscall restart checks */
+
 	/* TODO: the other ports use regs->orig_XX to disable syscall checks
 	 * after this completes, but we don't use that mechanism. maybe we can
 	 * use it now ?
 	 */
 
 	return err;
-
-badframe:
-	return 1;
 }
 
 asmlinkage long _sys_rt_sigreturn(struct pt_regs *regs)
@@ -111,21 +107,18 @@ badframe:
  * Set up a signal frame.
  */
 
-static int setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
-			    unsigned long mask)
+static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 {
 	int err = 0;
 
 	/* copy the regs */
-
+	/* There should be no need to save callee-saved registers here...
+	 * ...but we save them anyway.  Revisit this
+	 */
 	err |= __copy_to_user(sc->regs.gpr, regs, 32 * sizeof(unsigned long));
 	err |= __copy_to_user(&sc->regs.pc, &regs->pc, sizeof(unsigned long));
 	err |= __copy_to_user(&sc->regs.sr, &regs->sr, sizeof(unsigned long));
 
-	/* then some other stuff */
-
-	err |= __put_user(mask, &sc->oldmask);
-
 	return err;
 }
 
@@ -181,24 +174,18 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	int err = 0;
 
 	frame = get_sigframe(ka, regs, sizeof(*frame));
-
 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 		goto give_sigsegv;
 
-	err |= __put_user(&frame->info, &frame->pinfo);
-	err |= __put_user(&frame->uc, &frame->puc);
-
+	/* Create siginfo.  */
 	if (ka->sa.sa_flags & SA_SIGINFO)
 		err |= copy_siginfo_to_user(&frame->info, info);
-	if (err)
-		goto give_sigsegv;
 
-	/* Clear all the bits of the ucontext we don't use.  */
-	err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
+	/* Create the ucontext.  */
 	err |= __put_user(0, &frame->uc.uc_flags);
 	err |= __put_user(NULL, &frame->uc.uc_link);
 	err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
-	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
+	err |= setup_sigcontext(regs, &frame->uc.uc_mcontext);
 
 	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 
@@ -207,9 +194,12 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 
 	/* trampoline - the desired return ip is the retcode itself */
 	return_ip = (unsigned long)&frame->retcode;
-	/* This is l.ori r11,r0,__NR_sigreturn, l.sys 1 */
-	err |= __put_user(0xa960, (short *)(frame->retcode + 0));
-	err |= __put_user(__NR_rt_sigreturn, (short *)(frame->retcode + 2));
+	/* This is:
+		l.ori r11,r0,__NR_sigreturn
+		l.sys 1
+	 */
+	err |= __put_user(0xa960,             (short *)(frame->retcode + 0));
+	err |= __put_user(__NR_rt_sigreturn,  (short *)(frame->retcode + 2));
 	err |= __put_user(0x20000001, (unsigned long *)(frame->retcode + 4));
 	err |= __put_user(0x15000000, (unsigned long *)(frame->retcode + 8));
 
@@ -262,82 +252,106 @@ handle_signal(unsigned long sig,
  * mode below.
  */
 
-void do_signal(struct pt_regs *regs)
+int do_signal(struct pt_regs *regs, int syscall)
 {
 	siginfo_t info;
 	int signr;
 	struct k_sigaction ka;
-
-	/*
-	 * We want the common case to go fast, which
-	 * is why we may in certain cases get here from
-	 * kernel mode. Just return without doing anything
-	 * if so.
-	 */
-	if (!user_mode(regs))
-		return;
-
-	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
-
-	/* If we are coming out of a syscall then we need
-	 * to check if the syscall was interrupted and wants to be
-	 * restarted after handling the signal.  If so, the original
-	 * syscall number is put back into r11 and the PC rewound to
-	 * point at the l.sys instruction that resulted in the
-	 * original syscall.  Syscall results other than the four
-	 * below mean that the syscall executed to completion and no
-	 * restart is necessary.
-	 */
-	if (regs->orig_gpr11) {
-		int restart = 0;
-
-		switch (regs->gpr[11]) {
+	unsigned long continue_addr = 0;
+	unsigned long restart_addr = 0;
+	unsigned long retval = 0;
+	int restart = 0;
+
+	if (syscall) {
+		continue_addr = regs->pc;
+		restart_addr = continue_addr - 4;
+		retval = regs->gpr[11];
+
+		/*
+		 * Setup syscall restart here so that a debugger will
+		 * see the already changed PC.
+		 */
+		switch (retval) {
 		case -ERESTART_RESTARTBLOCK:
+			restart = -2;
+			/* Fall through */
 		case -ERESTARTNOHAND:
-			/* Restart if there is no signal handler */
-			restart = (signr <= 0);
-			break;
 		case -ERESTARTSYS:
-			/* Restart if there no signal handler or
-			 * SA_RESTART flag is set */
-			restart = (signr <= 0 || (ka.sa.sa_flags & SA_RESTART));
-			break;
 		case -ERESTARTNOINTR:
-			/* Always restart */
-			restart = 1;
+			restart++;
+			regs->gpr[11] = regs->orig_gpr11;
+			regs->pc = restart_addr;
 			break;
 		}
+	}
 
-		if (restart) {
-			if (regs->gpr[11] == -ERESTART_RESTARTBLOCK)
-				regs->gpr[11] = __NR_restart_syscall;
-			else
-				regs->gpr[11] = regs->orig_gpr11;
-			regs->pc -= 4;
-		} else {
-			regs->gpr[11] = -EINTR;
+	/*
+	 * 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 (signr > 0) {
+		if (unlikely(restart) && regs->pc == restart_addr) {
+			if (retval == -ERESTARTNOHAND ||
+			    retval == -ERESTART_RESTARTBLOCK
+			    || (retval == -ERESTARTSYS
+			        && !(ka.sa.sa_flags & SA_RESTART))) {
+				/* No automatic restart */
+				regs->gpr[11] = -EINTR;
+				regs->pc = continue_addr;
+			}
 		}
-	}
 
-	if (signr <= 0) {
-		/* no signal to deliver so we just put the saved sigmask
-		 * back */
-		restore_saved_sigmask();
-	} else {		/* signr > 0 */
-		/* Whee!  Actually deliver the signal.  */
 		handle_signal(signr, &info, &ka, regs);
+	} else {
+		/* no handler */
+		restore_saved_sigmask();
+		/*
+		 * Restore pt_regs PC as syscall restart will be handled by
+		 * kernel without return to userspace
+		 */
+		if (unlikely(restart) && regs->pc == restart_addr) {
+			regs->pc = continue_addr;
+			return restart;
+		}
 	}
 
-	return;
+	return 0;
 }
 
-asmlinkage void do_notify_resume(struct pt_regs *regs)
+asmlinkage int
+do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
 {
-	if (current_thread_info()->flags & _TIF_SIGPENDING)
-		do_signal(regs);
-
-	if (current_thread_info()->flags & _TIF_NOTIFY_RESUME) {
-		clear_thread_flag(TIF_NOTIFY_RESUME);
-		tracehook_notify_resume(regs);
-	}
+	do {
+		if (likely(thread_flags & _TIF_NEED_RESCHED)) {
+			schedule();
+		} else {
+			if (unlikely(!user_mode(regs)))
+				return 0;
+			local_irq_enable();
+			if (thread_flags & _TIF_SIGPENDING) {
+				int restart = do_signal(regs, syscall);
+				if (unlikely(restart)) {
+					/*
+					 * Restart without handlers.
+					 * Deal with it without leaving
+					 * the kernel space.
+					 */
+					return restart;
+				}
+				syscall = 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);
+	return 0;
 }