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authorAndi Kleen <ak@suse.de>2005-04-16 15:25:17 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:25:17 -0700
commit0a65800243742480b4b594b619b759749a3cfef4 (patch)
tree72f9a3b376c604e7619ef265c7dc351644f45359
parent635186447d0e6f3b35895fda993a266a1315d2a7 (diff)
downloadop-kernel-dev-0a65800243742480b4b594b619b759749a3cfef4.zip
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[PATCH] x86_64: Rewrite exception stack backtracing
Exceptions and hardware interrupts can, to a certain degree, nest, so when attempting to follow the sequence of stacks used in order to dump their contents this has to be accounted for. Also, IST stacks have their tops stored in the TSS, so there's no need to add the stack size to get to their ends. Minor changes from AK. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--arch/x86_64/kernel/traps.c147
1 files changed, 79 insertions, 68 deletions
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index f6ccf15..65a37f5 100644
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -120,95 +120,106 @@ int printk_address(unsigned long address)
}
#endif
-unsigned long *in_exception_stack(int cpu, unsigned long stack)
-{
- int k;
+static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
+ unsigned *usedp, const char **idp)
+{
+ static const char ids[N_EXCEPTION_STACKS][8] = {
+ [DEBUG_STACK - 1] = "#DB",
+ [NMI_STACK - 1] = "NMI",
+ [DOUBLEFAULT_STACK - 1] = "#DF",
+ [STACKFAULT_STACK - 1] = "#SS",
+ [MCE_STACK - 1] = "#MC",
+ };
+ unsigned k;
+
for (k = 0; k < N_EXCEPTION_STACKS; k++) {
- struct tss_struct *tss = &per_cpu(init_tss, cpu);
- unsigned long start = tss->ist[k] - EXCEPTION_STKSZ;
+ unsigned long end;
- if (stack >= start && stack < tss->ist[k])
- return (unsigned long *)tss->ist[k];
+ end = per_cpu(init_tss, cpu).ist[k];
+ if (stack >= end)
+ continue;
+ if (stack >= end - EXCEPTION_STKSZ) {
+ if (*usedp & (1U << k))
+ break;
+ *usedp |= 1U << k;
+ *idp = ids[k];
+ return (unsigned long *)end;
+ }
}
return NULL;
-}
+}
/*
* x86-64 can have upto three kernel stacks:
* process stack
* interrupt stack
- * severe exception (double fault, nmi, stack fault) hardware stack
- * Check and process them in order.
+ * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
*/
void show_trace(unsigned long *stack)
{
unsigned long addr;
- unsigned long *irqstack, *irqstack_end, *estack_end;
- const int cpu = safe_smp_processor_id();
+ const unsigned cpu = safe_smp_processor_id();
+ unsigned long *irqstack_end = (unsigned long *)cpu_pda[cpu].irqstackptr;
int i;
+ unsigned used = 0;
printk("\nCall Trace:");
- i = 0;
-
- estack_end = in_exception_stack(cpu, (unsigned long)stack);
- if (estack_end) {
- while (stack < estack_end) {
- addr = *stack++;
- if (__kernel_text_address(addr)) {
- i += printk_address(addr);
- i += printk(" ");
- if (i > 50) {
- printk("\n");
- i = 0;
- }
- }
+
+#define HANDLE_STACK(cond) \
+ do while (cond) { \
+ addr = *stack++; \
+ if (kernel_text_address(addr)) { \
+ /* \
+ * If the address is either in the text segment of the \
+ * kernel, or in the region which contains vmalloc'ed \
+ * memory, it *may* be the address of a calling \
+ * routine; if so, print it so that someone tracing \
+ * down the cause of the crash will be able to figure \
+ * out the call path that was taken. \
+ */ \
+ i += printk_address(addr); \
+ if (i > 50) { \
+ printk("\n "); \
+ i = 0; \
+ } \
+ else \
+ i += printk(" "); \
+ } \
+ } while (0)
+
+ for(i = 0; ; ) {
+ const char *id;
+ unsigned long *estack_end;
+ estack_end = in_exception_stack(cpu, (unsigned long)stack,
+ &used, &id);
+
+ if (estack_end) {
+ i += printk(" <%s> ", id);
+ HANDLE_STACK (stack < estack_end);
+ i += printk(" <EOE> ");
+ stack = (unsigned long *) estack_end[-2];
+ continue;
}
- i += printk(" <EOE> ");
- i += 7;
- stack = (unsigned long *) estack_end[-2];
- }
-
- irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
- irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE + 64);
-
- if (stack >= irqstack && stack < irqstack_end) {
- printk("<IRQ> ");
- while (stack < irqstack_end) {
- addr = *stack++;
- /*
- * If the address is either in the text segment of the
- * kernel, or in the region which contains vmalloc'ed
- * memory, it *may* be the address of a calling
- * routine; if so, print it so that someone tracing
- * down the cause of the crash will be able to figure
- * out the call path that was taken.
- */
- if (__kernel_text_address(addr)) {
- i += printk_address(addr);
- i += printk(" ");
- if (i > 50) {
- printk("\n ");
- i = 0;
- }
+ if (irqstack_end) {
+ unsigned long *irqstack;
+ irqstack = irqstack_end -
+ (IRQSTACKSIZE - 64) / sizeof(*irqstack);
+
+ if (stack >= irqstack && stack < irqstack_end) {
+ i += printk(" <IRQ> ");
+ HANDLE_STACK (stack < irqstack_end);
+ stack = (unsigned long *) (irqstack_end[-1]);
+ irqstack_end = NULL;
+ i += printk(" <EOI> ");
+ continue;
}
- }
- stack = (unsigned long *) (irqstack_end[-1]);
- printk(" <EOI> ");
- i += 7;
- }
-
- while (((long) stack & (THREAD_SIZE-1)) != 0) {
- addr = *stack++;
- if (__kernel_text_address(addr)) {
- i += printk_address(addr);
- i += printk(" ");
- if (i > 50) {
- printk("\n ");
- i = 0;
- }
}
+ break;
}
+
+ HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
+#undef HANDLE_STACK
printk("\n");
}
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