diff options
| -rw-r--r-- | arch/x86/kernel/dumpstack_64.c | 89 |
1 files changed, 26 insertions, 63 deletions
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index 07373bec76f1..904fb46d7d65 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -16,83 +16,46 @@ #include <asm/stacktrace.h> +static char *exception_stack_names[N_EXCEPTION_STACKS] = { + [ DOUBLEFAULT_STACK-1 ] = "#DF", + [ NMI_STACK-1 ] = "NMI", + [ DEBUG_STACK-1 ] = "#DB", + [ MCE_STACK-1 ] = "#MC", +}; -#define N_EXCEPTION_STACKS_END \ - (N_EXCEPTION_STACKS + DEBUG_STKSZ/EXCEPTION_STKSZ - 2) - -static char x86_stack_ids[][8] = { - [ DEBUG_STACK-1 ] = "#DB", - [ NMI_STACK-1 ] = "NMI", - [ DOUBLEFAULT_STACK-1 ] = "#DF", - [ MCE_STACK-1 ] = "#MC", -#if DEBUG_STKSZ > EXCEPTION_STKSZ - [ N_EXCEPTION_STACKS ... - N_EXCEPTION_STACKS_END ] = "#DB[?]" -#endif +static unsigned long exception_stack_sizes[N_EXCEPTION_STACKS] = { + [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ, + [DEBUG_STACK - 1] = DEBUG_STKSZ }; static unsigned long *in_exception_stack(unsigned long stack, unsigned *usedp, char **idp) { + unsigned long begin, end; unsigned k; - /* - * Iterate over all exception stacks, and figure out whether - * 'stack' is in one of them: - */ + BUILD_BUG_ON(N_EXCEPTION_STACKS != 4); + for (k = 0; k < N_EXCEPTION_STACKS; k++) { - unsigned long end = raw_cpu_ptr(&orig_ist)->ist[k]; - /* - * Is 'stack' above this exception frame's end? - * If yes then skip to the next frame. - */ - if (stack >= end) + end = raw_cpu_ptr(&orig_ist)->ist[k]; + begin = end - exception_stack_sizes[k]; + + if (stack < begin || stack >= end) continue; + /* - * Is 'stack' above this exception frame's start address? - * If yes then we found the right frame. - */ - if (stack >= end - EXCEPTION_STKSZ) { - /* - * Make sure we only iterate through an exception - * stack once. If it comes up for the second time - * then there's something wrong going on - just - * break out and return NULL: - */ - if (*usedp & (1U << k)) - break; - *usedp |= 1U << k; - *idp = x86_stack_ids[k]; - return (unsigned long *)end; - } - /* - * If this is a debug stack, and if it has a larger size than - * the usual exception stacks, then 'stack' might still - * be within the lower portion of the debug stack: + * Make sure we only iterate through an exception stack once. + * If it comes up for the second time then there's something + * wrong going on - just break and return NULL: */ -#if DEBUG_STKSZ > EXCEPTION_STKSZ - if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) { - unsigned j = N_EXCEPTION_STACKS - 1; + if (*usedp & (1U << k)) + break; + *usedp |= 1U << k; - /* - * Black magic. A large debug stack is composed of - * multiple exception stack entries, which we - * iterate through now. Dont look: - */ - do { - ++j; - end -= EXCEPTION_STKSZ; - x86_stack_ids[j][4] = '1' + - (j - N_EXCEPTION_STACKS); - } while (stack < end - EXCEPTION_STKSZ); - if (*usedp & (1U << j)) - break; - *usedp |= 1U << j; - *idp = x86_stack_ids[j]; - return (unsigned long *)end; - } -#endif + *idp = exception_stack_names[k]; + return (unsigned long *)end; } + return NULL; } |