795* intr.c: Fix for xen on i386 (not currently supporting this).

.release

@@ -1,3 +1,3 @@
-date=Thu Nov 29 20:54:18 GMT 2012
-release=dtrace-20121129
-build=434
+date=Fri Nov 30 23:21:30 GMT 2012
+release=dtrace-20121130
+build=435

Changes

@@ -1,3 +1,7 @@
+Fri Nov 30 19:45:05 2012  fox
+
+     795* intr.c: Fix for xen on i386 (not currently supporting this).
+
 Thu Nov 29 20:53:05 2012  fox
 
      794* Add 'safe' support - make it work, but turn off by default.

driver/dtrace_isa.c

@@ -174,7 +174,8 @@ dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes,
     uint32_t *ignored)
 {
 	int	depth;
-#if 1 || !defined(HAVE_STACKTRACE_OPS)
+#if !defined(HAVE_STACKTRACE_OPS)
+	int	lim;
 	/***********************************************/
 	/*   This  is  a basic stack walker - we dont  */
 	/*   care  about  omit-frame-pointer,  and we  */
@@ -194,6 +195,7 @@ dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes,
 	/***********************************************/
 	cpu_core_t	*this_cpu = cpu_get_this();
 	struct pt_regs *regs = this_cpu->cpuc_regs;
+	struct thread_info *context;
 	uintptr_t *sp;
 	uintptr_t *spend;
 
@@ -204,26 +206,43 @@ dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes,
 	/*   syscall function.			       */
 	/***********************************************/
 	if (regs == NULL)
-		sp = (uintptr_t *) pcstack;
+		sp = (uintptr_t *) &depth;
 	else
 		sp = (uintptr_t *) regs->r_rsp;
 
 	/***********************************************/
-	/*   We  might walk off the end of the stack,  */
-	/*   so  protect  us  just in case. We should  */
-	/*   align   the   stack   against  the  page  */
-	/*   boundary  where  its allocated, but this  */
-	/*   suffices for now.			       */
+	/*   Daisy  chain the interrupt and any other  */
+	/*   stacks.  Limit  ourselves in case of bad  */
+	/*   corruptions.			       */
 	/***********************************************/
 	DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
-	spend = sp + THREAD_SIZE / sizeof(uintptr_t);
-	for (depth = 0; depth < pcstack_limit && sp < spend; sp++) {
-//if (*sp) printk("%d: %p: %p\n", i, sp, *sp);
-		if (*sp && is_kernel_text((unsigned long) *sp)) {
-			pcstack[depth++] = *sp;
+	depth = 0;
+	for (lim = 0; lim < 3 && depth < pcstack_limit; lim++) {
+		int	ndepth = depth;
+
+		context = (struct thread_info *) ((unsigned long) sp & (~(THREAD_SIZE - 1)));
+		spend = (uintptr_t *) ((unsigned long) sp | (THREAD_SIZE - 1));
+		for ( ; depth < pcstack_limit && sp < spend; sp++) {
+			if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAULT))
+				goto end_stack;
+			if (*sp && is_kernel_text((unsigned long) *sp)) {
+				pcstack[depth++] = *sp;
+			}
+		}
+		if (depth >= pcstack_limit || ndepth == depth)
+			break;
+		if ((sp = (uintptr_t *) context->previous_esp) == NULL)
+			break;
+		/***********************************************/
+		/*   Special signal to mark the IRQ stack.     */
+		/***********************************************/
+		if (depth < pcstack_limit) {
+			pcstack[depth++] = 1;
 		}
 	}
+end_stack:
 	DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
+	DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_FAULT);
 #else
 
 	/***********************************************/

driver/dtrace_linux.c

@@ -85,7 +85,6 @@ enum {
 	OFFSET_print_modules,
 	OFFSET_task_exit_notifier,
 	OFFSET_xtime,
-	OFFSET_kernel_text_address,
 	OFFSET_ia32_sys_call_table,
 	OFFSET_END_SYMS,
 	};
@@ -103,7 +102,6 @@ static struct map {
 			 	  /* find the modules table. 		  */
 {"task_exit_notifier",     NULL},
 {"xtime",     		   NULL}, /* Needed for dtrace_gethrtime, if 2.6.9 */
-{"kernel_text_address",    NULL}, /* Used for stack walking when no dump_trace available */
 {"ia32_sys_call_table",    NULL}, /* On 64b kernel, the 32b syscall table. */
 {"END_SYMS",               NULL}, /* This is a sentinel so we know we are done. */
 	{0}
@@ -1134,16 +1132,23 @@ extern caddr_t ktext;
 extern caddr_t ketext;
 int
 is_kernel_text(unsigned long p)
-{
-	int (*func)(unsigned long);
+{static int first_time = TRUE;
+static caddr_t stext;
+static caddr_t etext;
 
 //printk("ktext=%p..%p %p\n", ktext, ketext, p);
 	if (ktext <= (caddr_t) p && (caddr_t) p < ketext)
 		return 1;
+	if (first_time) {
+		first_time = FALSE;
+		stext = get_proc_addr("_stext");
+		etext = get_proc_addr("_etext");
+	}
+	if (stext <= (caddr_t) p && (caddr_t) p < etext)
+		return 1;
 
-	func = (int (*)(unsigned long)) syms[OFFSET_kernel_text_address].m_ptr;
-	if (func) {
-		return func(p);
+	if (kernel_text_address_fn) {
+		return kernel_text_address_fn(p);
 	}
 	return 0;
 }

driver/intr.c

@@ -7,7 +7,7 @@
 /*   								      */
 /*   License: CDDL						      */
 /*   								      */
-/*   $Header: Last edited: 07-Nov-2012 1.16 $ 			      */
+/*   $Header: Last edited: 30-Nov-2012 1.17 $ 			      */
 /**********************************************************************/
 
 #include <linux/mm.h>
@@ -157,7 +157,7 @@ int dtrace_int_ipi(void);
 int dtrace_int_nmi(void);
 int dtrace_int_dtrace_ret(void);
 
-#ifdef CONFIG_PARAVIRT
+#if defined(CONFIG_PARAVIRT) && defined(__amd64)
 int dtrace_int1_xen(void);
 int dtrace_int3_xen(void);
 int dtrace_page_fault_xen(void);
@@ -1311,7 +1311,7 @@ static	struct x86_descriptor desc1;
 	set_idt_entry(8, (unsigned long) dtrace_double_fault);
 #endif
 
-#ifdef CONFIG_PARAVIRT
+#if defined(CONFIG_PARAVIRT) && defined(__amd64)
 	if (dtrace_is_xen()) {
 		set_idt_entry(1, (unsigned long) dtrace_int1_xen); // single-step
 		set_idt_entry(3, (unsigned long) dtrace_int3_xen); // breakpoint

driver/xen.c

@@ -32,10 +32,13 @@ extern int nr_cpus;
 int
 dtrace_is_xen(void)
 {	static void **xen_start_info;
+static int first_time = TRUE;
 
 //	return xen_domain();
-	if (xen_start_info == NULL)
+	if (first_time && xen_start_info == NULL) {
 		xen_start_info = get_proc_addr("xen_start_info");
+		first_time = FALSE;
+	}
 
 	if (xen_start_info && *xen_start_info)
 		return TRUE;

tools/load.pl

@@ -99,8 +99,15 @@ sub main
 	#   Safely remove the old driver.	      #
 	###############################################
 	if ( -e "/dev/dtrace" ) {
-		my $rmmod = "/sbin/rmmod";
-		$rmmod = "/usr/sbin/rmmod" if -x "/usr/sbin/rmmod";
+		my $rmmod;
+		foreach my $p ("/sbin", "/usr/sbin", "/usr/bin") {
+			my $p1 = "$p/rmmod";
+			$rmmod = $p1 if -x $p1;
+		}
+		if (!$rmmod) {
+			print "ERROR: Strange..cannot locate 'rmmod'\n";
+			exit(0);
+		}
 		spawn("$SUDO $rmmod dtracedrv");
 		spawn("sync ; sync");
 		exit(0) if $opts{unload};
@@ -235,7 +242,6 @@ sub main
 		ia32_sys_call_table:amd64
 		syscall_call:optional
 		xtime:optional
-		kernel_text_address
 		__module_text_address
 		add_timer_on
 		/) {