[LV-commit] kernel-2.4/arch/vax/kernel signal.c,1.11,1.12

[<ai...@us...>]

Update of /cvsroot/linux-vax/kernel-2.4/arch/vax/kernel
In directory sc8-pr-cvs1:/tmp/cvs-serv16019

Modified Files:
	signal.c 
Log Message:
DA: this is better than what was there already - still not tested,
I'd say there is still some work left to do


Index: signal.c
===================================================================
RCS file: /cvsroot/linux-vax/kernel-2.4/arch/vax/kernel/signal.c,v
retrieving revision 1.11
retrieving revision 1.12
diff -u -d -r1.11 -r1.12
--- signal.c	16 Feb 2003 23:28:02 -0000	1.11
+++ signal.c	16 Sep 2003 12:34:15 -0000	1.12
@@ -32,7 +32,7 @@
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
 
-#undef DEBUG_SIG
+#undef DEBUG_SIG 
 
 /* FIXME: Check this & fixup other regs, like r0 */
 #define RESTART_VAX_SYSCALL(regs) { (regs)->pc -= 4; } 
@@ -188,12 +188,10 @@
 
 /* FIXME: this dont work ... */
 struct rt_sigframe {
-   	char *pretcode;
-	struct siginfo *pinfo;
-	void *puc;
+	int sig;
 	struct siginfo info;
 	struct ucontext uc;
-	unsigned char retcode[8];  /* trampoline code */
+	unsigned char retcode[20];  /* trampoline code */
 };
 
 
@@ -526,17 +524,14 @@
 			   sigset_t *set, struct pt_regs * regs)
 {
 	struct rt_sigframe *frame;
-	unsigned long return_ip;
 	int err = 0;
 
-   	machine_halt();
+	//   	machine_halt();
 	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);
 	err |= copy_siginfo_to_user(&frame->info, info);
 	if (err)
 		goto give_sigsegv;
@@ -553,17 +548,54 @@
 
 	/* Set up to return from userspace.  If provided, use a stub
 	   already in userspace.  */
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+   
+        /* We do this differently to other ports. Each function has a two byte RSM.
+	 * (due to the calling convention).  Each sighandler will expect to be 
+	 * CALLS'd and will RET from that. So we cant just muck about with PC's on the
+	 * stack like the i386. So we use the trampoline code on the stack a bit more.
+	 * The easiest way to skip around all this is to calls the signal
+	 * handler, and then either calls the restorer, or chmk to sys_sigreturn */
+   
+        /* 	 CALLS $1, */
+        err |= __put_user(0xfb, (char *)(frame->retcode+0));
+        err |= __put_user(0x01, (char *)(frame->retcode+1));
+        /*             (absolute address)*/
+        err |= __put_user(0x9f,   (char  *)(frame->retcode+2));
+        /*				     sighandler */
+        err |= __put_user(((unsigned long) ka->sa.sa_handler), (unsigned long *)(frame->retcode + 3));
+        
 	if (ka->sa.sa_flags & SA_RESTORER) {
-		return_ip = (unsigned long)ka->sa.sa_restorer;
+	        /*  CALLS $0,*/
+                err |= __put_user(0xfb, (char *)(frame->retcode+7));
+                err |= __put_user(0x00, (char *)(frame->retcode+8));
+                /*             (absolute address)*/
+                err |= __put_user(0x9f,   (char  *)(frame->retcode+9));
+                /*				     restorer */
+                err |= __put_user(((unsigned long) ka->sa.sa_restorer), (unsigned long *)(frame->retcode + 10));
+		/* plus a halt */
+	        err |= __put_user(0x00,   (char *)(frame->retcode+14));
 	} else {
-		/* trampoline - the desired return ip is the retcode itself */
-		return_ip = (unsigned long)&frame->retcode;
-		/* TODO: check byteorder */
-		err |= __put_user(0xbc8f,         (short *)(frame->retcode+0));
-		err |= __put_user(__NR_sigreturn, (short *)(frame->retcode+2));
+	        /* perform a syscall to sys_sigreturn. First set up the 
+		 * argument list to avoid confusing it */
+	   
+		/* pushl $0x0 */	   
+		err |= __put_user(0xdd,         (char *)(frame->retcode+7));
+		err |= __put_user(0x00,         (char *)(frame->retcode+8));
+	        /* movl sp, ap */
+		err |= __put_user(0xd0,         (char *)(frame->retcode+9));
+		err |= __put_user(0x5e,         (char *)(frame->retcode+10));
+		err |= __put_user(0x5c,         (char *)(frame->retcode+11));
+		/* chmk __NR_sigreturn; */
+		err |= __put_user(0xbc,         (char *)(frame->retcode+12));
+		err |= __put_user(0x8f,         (char *)(frame->retcode+13));
+		err |= __put_user(__NR_sigreturn, (short *)(frame->retcode+14));
+		/* plus a halt */
+	        err |= __put_user(0x00,   (char *)(frame->retcode+16));
 	}
 
-        err |= __put_user(return_ip, &frame->pretcode);
 	if (err)
 		goto give_sigsegv;
 
@@ -572,7 +604,9 @@
 	/* Set up registers for signal handler */
 
 	regs->pc = (unsigned long) ka->sa.sa_handler;  /* what we enter NOW   */
-	regs->sp = (unsigned int)frame;                          /* what we enter LATER */
+	regs->fp = regs->sp;
+	regs->sp = (unsigned int)frame;                /* what we enter LATER */
+	__mtpr(frame, PR_USP);
 
 	return;
 
@@ -657,7 +691,7 @@
 		return 1;
 
         /* FIXME: */
-   	canrestart=0;
+   	canrestart=regs->r0;
 #ifdef DEBUG_SIG   
 	printk("do_signal: pid %d,canrestart %d, current->sigpending %d,current->blocked %d ", current->pid,canrestart,current->sigpending,current->blocked);
 #endif