Commit 8efc0ab5 authored by David Howells's avatar David Howells Committed by Linus Torvalds
Browse files

[PATCH] frv: fix signal handling 



The attached patch makes FRV signal handling work properly:

 (1) After do_notify_resume() has been called, the work flags must be checked
     again (there may be another signal to deliver or the process might require
     rescheduling for instance).

 (2) After the signal frame is set up on the userspace stack, ptrace() should
     be given an opportunity to single-step into the signal handler.

 (3) The error state from setting up a signal frame should be passed back up
     the call chain.

 (4) The segfault handler shouldn't be preemptively reset in the arch if we
     fail to deliver a SEGV signal: force_sig() will take care of that.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 7ee1dd3f

arch/frv/kernel/entry.S

+1 −1
Original line number Diff line number Diff line
@@ -1076,7 +1076,7 @@ __entry_work_notifysig: 
	LEDS		0x6410

	ori.p		gr4,#0,gr8

	call		do_notify_resume

	bra		__entry_return_direct

	bra		__entry_resume_userspace



	# perform syscall entry tracing

__syscall_trace_entry:

arch/frv/kernel/signal.c

+45 −28
Original line number Diff line number Diff line
@@ -297,7 +297,8 @@ static inline void __user *get_sigframe(struct k_sigaction *ka, 
/*

 *

 */

static void setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs * regs)

static int setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,

		       struct pt_regs *regs)

{

	struct sigframe __user *frame;

	int rsig;
@@ -362,25 +363,29 @@ static void setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, struct p 


	set_fs(USER_DS);



	/* the tracer may want to single-step inside the handler */

	if (test_thread_flag(TIF_SINGLESTEP))

		ptrace_notify(SIGTRAP);



#if DEBUG_SIG

	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",

		sig, current->comm, current->pid, frame, regs->pc, frame->pretcode);

	       sig, current->comm, current->pid, frame, regs->pc,

	       frame->pretcode);

#endif



	return;

	return 1;



give_sigsegv:

	if (sig == SIGSEGV)

		ka->sa.sa_handler = SIG_DFL;



	force_sig(SIGSEGV, current);

	return 0;



} /* end setup_frame() */



/*****************************************************************************/

/*

 *

 */

static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,

static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,

			  sigset_t *set, struct pt_regs * regs)

{

	struct rt_sigframe __user *frame;
@@ -457,17 +462,21 @@ static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 


	set_fs(USER_DS);



	/* the tracer may want to single-step inside the handler */

	if (test_thread_flag(TIF_SINGLESTEP))

		ptrace_notify(SIGTRAP);



#if DEBUG_SIG

	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",

		sig, current->comm, current->pid, frame, regs->pc, frame->pretcode);

		sig, current->comm, current->pid, frame, regs->pc,

	       frame->pretcode);

#endif



	return;

	return 1;



give_sigsegv:

	if (sig == SIGSEGV)

		ka->sa.sa_handler = SIG_DFL;

	force_sig(SIGSEGV, current);

	return 0;



} /* end setup_rt_frame() */
@@ -475,10 +484,12 @@ give_sigsegv: 
/*

 * OK, we're invoking a handler

 */

static void handle_signal(unsigned long sig, siginfo_t *info,

static int handle_signal(unsigned long sig, siginfo_t *info,

			 struct k_sigaction *ka, sigset_t *oldset,

			 struct pt_regs *regs)

{

	int ret;



	/* Are we from a system call? */

	if (in_syscall(regs)) {

		/* If so, check system call restarting.. */
@@ -493,6 +504,7 @@ static void handle_signal(unsigned long sig, siginfo_t *info, 
				regs->gr8 = -EINTR;

				break;

			}



			/* fallthrough */

		case -ERESTARTNOINTR:

			regs->gr8 = regs->orig_gr8;
@@ -502,16 +514,22 @@ static void handle_signal(unsigned long sig, siginfo_t *info, 


	/* Set up the stack frame */

	if (ka->sa.sa_flags & SA_SIGINFO)

		setup_rt_frame(sig, ka, info, oldset, regs);

		ret = setup_rt_frame(sig, ka, info, oldset, regs);

	else

		setup_frame(sig, ka, oldset, regs);

		ret = setup_frame(sig, ka, oldset, regs);



	if (ret) {

		spin_lock_irq(&current->sighand->siglock);

	sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);

		sigorsets(&current->blocked, &current->blocked,

			  &ka->sa.sa_mask);

		if (!(ka->sa.sa_flags & SA_NODEFER))

			sigaddset(&current->blocked, sig);

		recalc_sigpending();

		spin_unlock_irq(&current->sighand->siglock);

	}



	return ret;



} /* end handle_signal() */



/*****************************************************************************/
@@ -542,10 +560,8 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset) 
		oldset = &current->blocked;



	signr = get_signal_to_deliver(&info, &ka, regs, NULL);

	if (signr > 0) {

		handle_signal(signr, &info, &ka, oldset, regs);

		return 1;

	}

	if (signr > 0)

		return handle_signal(signr, &info, &ka, oldset, regs);



no_signal:

	/* Did we come from a system call? */
@@ -565,6 +581,7 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset) 
	}



	return 0;



} /* end do_signal() */



/*****************************************************************************/

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