Re: [uml-devel] Minor problems with interrupted systemcalls

[Jeff Dike <jdike@addtoit.com>]

Change the interface to handle_signal so that it doesn't take the system call
return value as an argument and eliminate its return value.
kern_do_signal also now doesn't return immediately after determining that
there is no signal to deliver.

Index: 2.6.9-rc/arch/um/kernel/signal_kern.c
===================================================================
--- 2.6.9-rc.orig/arch/um/kernel/signal_kern.c	2004-09-24 16:04:00.000000000 -0400
+++ 2.6.9-rc/arch/um/kernel/signal_kern.c	2004-09-24 16:17:04.000000000 -0400
@@ -38,16 +38,17 @@
 /*
  * OK, we're invoking a handler
  */	
-static int handle_signal(struct pt_regs *regs, unsigned long signr, 
-			 struct k_sigaction *ka, siginfo_t *info, 
-			 sigset_t *oldset, int error)
+static void handle_signal(struct pt_regs *regs, unsigned long signr, 
+			  struct k_sigaction *ka, siginfo_t *info, 
+			  sigset_t *oldset)
 {
         __sighandler_t handler;
 	void (*restorer)(void);
 	unsigned long sp;
 	sigset_t save;
-	int err, ret;
+	int error, err, ret;
 
+	error = PT_REGS_SYSCALL_RET(&current->thread.regs);
 	ret = 0;
 	/* Always make any pending restarted system calls return -EINTR */
 	current_thread_info()->restart_block.fn = do_no_restart_syscall;
@@ -109,31 +110,25 @@
 	else
 		err = setup_signal_stack_sc(sp, signr, (unsigned long) handler,
 					    restorer, regs, &save);
-	if(err) goto segv;
-
-	return(0);
- segv:
-	force_sigsegv(signr, current);
-	return(1);
+	if(err)
+		force_sigsegv(signr, current);
 }
 
-static int kern_do_signal(struct pt_regs *regs, sigset_t *oldset, int error)
+static int kern_do_signal(struct pt_regs *regs, sigset_t *oldset)
 {
 	struct k_sigaction ka_copy;
 	siginfo_t info;
-	int err, sig;
+	int sig;
 
 	if (!oldset)
 		oldset = &current->blocked;
 
 	sig = get_signal_to_deliver(&info, &ka_copy, regs, NULL);
-	if(sig == 0)
-		return(0);
-
-	/* Whee!  Actually deliver the signal.  */
-	err = handle_signal(regs, sig, &ka_copy, &info, oldset, error);
-	if(!err)
+	if(sig > 0){
+		/* Whee!  Actually deliver the signal.  */
+		handle_signal(regs, sig, &ka_copy, &info, oldset);
 		return(1);
+	}
 
 	/* Did we come from a system call? */
 	if(PT_REGS_SYSCALL_NR(regs) >= 0){
@@ -165,8 +160,7 @@
 
 int do_signal(void)
 {
-	return(kern_do_signal(&current->thread.regs, NULL,
-			      PT_REGS_SYSCALL_RET(&current->thread.regs)));
+	return(kern_do_signal(&current->thread.regs, NULL));
 }
 
 /*
@@ -183,10 +177,11 @@
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
+	PT_REGS_SYSCALL_RET(&current->thread.regs) = -EINTR;
 	while (1) {
 		current->state = TASK_INTERRUPTIBLE;
 		schedule();
-		if(kern_do_signal(&current->thread.regs, &saveset, -EINTR))
+		if(kern_do_signal(&current->thread.regs, &saveset))
 			return(-EINTR);
 	}
 }
@@ -209,10 +204,11 @@
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
+	PT_REGS_SYSCALL_RET(&current->thread.regs) = -EINTR;
 	while (1) {
 		current->state = TASK_INTERRUPTIBLE;
 		schedule();
-		if (kern_do_signal(&current->thread.regs, &saveset, -EINTR))
+		if (kern_do_signal(&current->thread.regs, &saveset))
 			return(-EINTR);
 	}
 }




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