diff options
Diffstat (limited to 'arch/x86/kernel/dumpstack_64.c')
-rw-r--r-- | arch/x86/kernel/dumpstack_64.c | 169 |
1 files changed, 91 insertions, 78 deletions
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index 904fb46d7d65..41813abc7380 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -28,76 +28,109 @@ static unsigned long exception_stack_sizes[N_EXCEPTION_STACKS] = { [DEBUG_STACK - 1] = DEBUG_STKSZ }; -static unsigned long *in_exception_stack(unsigned long stack, unsigned *usedp, - char **idp) +void stack_type_str(enum stack_type type, const char **begin, const char **end) { - unsigned long begin, end; + BUILD_BUG_ON(N_EXCEPTION_STACKS != 4); + + switch (type) { + case STACK_TYPE_IRQ: + *begin = "IRQ"; + *end = "EOI"; + break; + case STACK_TYPE_EXCEPTION ... STACK_TYPE_EXCEPTION_LAST: + *begin = exception_stack_names[type - STACK_TYPE_EXCEPTION]; + *end = "EOE"; + break; + default: + *begin = NULL; + *end = NULL; + } +} + +static bool in_exception_stack(unsigned long *stack, struct stack_info *info, + unsigned long *visit_mask) +{ + unsigned long *begin, *end; + struct pt_regs *regs; unsigned k; BUILD_BUG_ON(N_EXCEPTION_STACKS != 4); for (k = 0; k < N_EXCEPTION_STACKS; k++) { - end = raw_cpu_ptr(&orig_ist)->ist[k]; - begin = end - exception_stack_sizes[k]; + end = (unsigned long *)raw_cpu_ptr(&orig_ist)->ist[k]; + begin = end - (exception_stack_sizes[k] / sizeof(long)); + regs = (struct pt_regs *)end - 1; if (stack < begin || stack >= end) continue; /* - * 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: + * Make sure we don't iterate through an exception stack more + * than once. If it comes up a second time then there's + * something wrong going on - just break out and report an + * unknown stack type. */ - if (*usedp & (1U << k)) + if (*visit_mask & (1U << k)) break; - *usedp |= 1U << k; + *visit_mask |= 1U << k; - *idp = exception_stack_names[k]; - return (unsigned long *)end; + info->type = STACK_TYPE_EXCEPTION + k; + info->begin = begin; + info->end = end; + info->next_sp = (unsigned long *)regs->sp; + + return true; } - return NULL; + return false; } -static inline int -in_irq_stack(unsigned long *stack, unsigned long *irq_stack, - unsigned long *irq_stack_end) +static bool in_irq_stack(unsigned long *stack, struct stack_info *info) { - return (stack >= irq_stack && stack < irq_stack_end); -} + unsigned long *end = (unsigned long *)this_cpu_read(irq_stack_ptr); + unsigned long *begin = end - (IRQ_STACK_SIZE / sizeof(long)); -enum stack_type { - STACK_IS_UNKNOWN, - STACK_IS_NORMAL, - STACK_IS_EXCEPTION, - STACK_IS_IRQ, -}; + if (stack < begin || stack >= end) + return false; + + info->type = STACK_TYPE_IRQ; + info->begin = begin; + info->end = end; + + /* + * The next stack pointer is the first thing pushed by the entry code + * after switching to the irq stack. + */ + info->next_sp = (unsigned long *)*(end - 1); + + return true; +} -static enum stack_type -analyze_stack(struct task_struct *task, unsigned long *stack, - unsigned long **stack_end, unsigned long *irq_stack, - unsigned *used, char **id) +int get_stack_info(unsigned long *stack, struct task_struct *task, + struct stack_info *info, unsigned long *visit_mask) { - unsigned long addr; + if (!stack) + goto unknown; - addr = ((unsigned long)stack & (~(THREAD_SIZE - 1))); - if ((unsigned long)task_stack_page(task) == addr) - return STACK_IS_NORMAL; + task = task ? : current; + + if (in_task_stack(stack, task, info)) + return 0; - *stack_end = in_exception_stack((unsigned long)stack, used, id); - if (*stack_end) - return STACK_IS_EXCEPTION; + if (task != current) + goto unknown; - if (!irq_stack) - return STACK_IS_NORMAL; + if (in_exception_stack(stack, info, visit_mask)) + return 0; - *stack_end = irq_stack; - irq_stack -= (IRQ_STACK_SIZE / sizeof(long)); + if (in_irq_stack(stack, info)) + return 0; - if (in_irq_stack(stack, irq_stack, *stack_end)) - return STACK_IS_IRQ; + return 0; - return STACK_IS_UNKNOWN; +unknown: + info->type = STACK_TYPE_UNKNOWN; + return -EINVAL; } /* @@ -111,8 +144,8 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, unsigned long *stack, unsigned long bp, const struct stacktrace_ops *ops, void *data) { - unsigned long *irq_stack = (unsigned long *)this_cpu_read(irq_stack_ptr); - unsigned used = 0; + unsigned long visit_mask = 0; + struct stack_info info; int graph = 0; int done = 0; @@ -126,57 +159,37 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, * exceptions */ while (!done) { - unsigned long *stack_end; - enum stack_type stype; - char *id; + const char *begin_str, *end_str; - stype = analyze_stack(task, stack, &stack_end, irq_stack, &used, - &id); + get_stack_info(stack, task, &info, &visit_mask); /* Default finish unless specified to continue */ done = 1; - switch (stype) { + switch (info.type) { /* Break out early if we are on the thread stack */ - case STACK_IS_NORMAL: + case STACK_TYPE_TASK: break; - case STACK_IS_EXCEPTION: + case STACK_TYPE_IRQ: + case STACK_TYPE_EXCEPTION ... STACK_TYPE_EXCEPTION_LAST: + + stack_type_str(info.type, &begin_str, &end_str); - if (ops->stack(data, id) < 0) + if (ops->stack(data, begin_str) < 0) break; bp = ops->walk_stack(task, stack, bp, ops, - data, stack_end, &graph); - ops->stack(data, "EOE"); - /* - * We link to the next stack via the - * second-to-last pointer (index -2 to end) in the - * exception stack: - */ - stack = (unsigned long *) stack_end[-2]; - done = 0; - break; + data, &info, &graph); - case STACK_IS_IRQ: + ops->stack(data, end_str); - if (ops->stack(data, "IRQ") < 0) - break; - bp = ops->walk_stack(task, stack, bp, - ops, data, stack_end, &graph); - /* - * We link to the next stack (which would be - * the process stack normally) the last - * pointer (index -1 to end) in the IRQ stack: - */ - stack = (unsigned long *) (stack_end[-1]); - irq_stack = NULL; - ops->stack(data, "EOI"); + stack = info.next_sp; done = 0; break; - case STACK_IS_UNKNOWN: + default: ops->stack(data, "UNK"); break; } @@ -185,7 +198,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, /* * This handles the process stack: */ - bp = ops->walk_stack(task, stack, bp, ops, data, NULL, &graph); + bp = ops->walk_stack(task, stack, bp, ops, data, &info, &graph); } EXPORT_SYMBOL(dump_trace); |