Kernel/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2024-12-29 17:23:36 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

[PATCH] x86_64: Rewrite exception stack backtracing

Browse Source 
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>
This commit is contained in:
Andi Kleen 2005-04-16 15:25:17 -07:00 committed by Linus Torvalds
parent 635186447d
commit 0a65800243
1 changed files with 81 additions and 70 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

151
arch/x86_64/kernel/traps.c
View File

@ -120,95 +120,106 @@ int printk_address(unsigned long address)
}
#endif
unsigned long *in_exception_stack(int cpu, unsigned long stack)
{
int 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;
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;
if (stack >= start && stack < tss->ist[k])
return (unsigned long *)tss->ist[k];
for (k = 0; k < N_EXCEPTION_STACKS; k++) {
unsigned long end;
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;
}
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;
}
}
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;
}
}
}
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");
}