#include <asm/stacktrace.h>
-static void *is_irq_stack(void *p, void *irq)
+void stack_type_str(enum stack_type type, const char **begin, const char **end)
{
- if (p < irq || p >= (irq + THREAD_SIZE))
- return NULL;
- return irq + THREAD_SIZE;
+ switch (type) {
+ case STACK_TYPE_IRQ:
+ case STACK_TYPE_SOFTIRQ:
+ *begin = "IRQ";
+ *end = "EOI";
+ break;
+ default:
+ *begin = NULL;
+ *end = NULL;
+ }
}
-
-static void *is_hardirq_stack(unsigned long *stack, int cpu)
+static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info)
{
- void *irq = per_cpu(hardirq_stack, cpu);
+ unsigned long *begin = (unsigned long *)this_cpu_read(hardirq_stack);
+ unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
- return is_irq_stack(stack, irq);
-}
+ /*
+ * This is a software stack, so 'end' can be a valid stack pointer.
+ * It just means the stack is empty.
+ */
+ if (stack < begin || stack > end)
+ return false;
-static void *is_softirq_stack(unsigned long *stack, int cpu)
-{
- void *irq = per_cpu(softirq_stack, cpu);
+ info->type = STACK_TYPE_IRQ;
+ info->begin = begin;
+ info->end = end;
- return is_irq_stack(stack, irq);
+ /*
+ * See irq_32.c -- the next stack pointer is stored at the beginning of
+ * the stack.
+ */
+ info->next_sp = (unsigned long *)*begin;
+
+ return true;
}
-void dump_trace(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data)
+static bool in_softirq_stack(unsigned long *stack, struct stack_info *info)
{
- const unsigned cpu = get_cpu();
- int graph = 0;
- u32 *prev_esp;
+ unsigned long *begin = (unsigned long *)this_cpu_read(softirq_stack);
+ unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
- if (!task)
- task = current;
+ /*
+ * This is a software stack, so 'end' can be a valid stack pointer.
+ * It just means the stack is empty.
+ */
+ if (stack < begin || stack > end)
+ return false;
- if (!stack) {
- unsigned long dummy;
+ info->type = STACK_TYPE_SOFTIRQ;
+ info->begin = begin;
+ info->end = end;
- stack = &dummy;
- if (task != current)
- stack = (unsigned long *)task->thread.sp;
- }
+ /*
+ * The next stack pointer is stored at the beginning of the stack.
+ * See irq_32.c.
+ */
+ info->next_sp = (unsigned long *)*begin;
- if (!bp)
- bp = stack_frame(task, regs);
+ return true;
+}
- for (;;) {
- void *end_stack;
+int get_stack_info(unsigned long *stack, struct task_struct *task,
+ struct stack_info *info, unsigned long *visit_mask)
+{
+ if (!stack)
+ goto unknown;
- end_stack = is_hardirq_stack(stack, cpu);
- if (!end_stack)
- end_stack = is_softirq_stack(stack, cpu);
+ task = task ? : current;
- bp = ops->walk_stack(task, stack, bp, ops, data,
- end_stack, &graph);
+ if (in_task_stack(stack, task, info))
+ goto recursion_check;
- /* Stop if not on irq stack */
- if (!end_stack)
- break;
+ if (task != current)
+ goto unknown;
- /* The previous esp is saved on the bottom of the stack */
- prev_esp = (u32 *)(end_stack - THREAD_SIZE);
- stack = (unsigned long *)*prev_esp;
- if (!stack)
- break;
+ if (in_hardirq_stack(stack, info))
+ goto recursion_check;
- if (ops->stack(data, "IRQ") < 0)
- break;
- touch_nmi_watchdog();
+ if (in_softirq_stack(stack, info))
+ goto recursion_check;
+
+ goto unknown;
+
+recursion_check:
+ /*
+ * Make sure we don't iterate through any given 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 (visit_mask) {
+ if (*visit_mask & (1UL << info->type))
+ goto unknown;
+ *visit_mask |= 1UL << info->type;
}
- put_cpu();
+
+ return 0;
+
+unknown:
+ info->type = STACK_TYPE_UNKNOWN;
+ return -EINVAL;
}
-EXPORT_SYMBOL(dump_trace);
-void
-show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *sp, unsigned long bp, char *log_lvl)
+void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+ unsigned long *sp, char *log_lvl)
{
unsigned long *stack;
int i;
- if (sp == NULL) {
- if (regs)
- sp = (unsigned long *)regs->sp;
- else if (task)
- sp = (unsigned long *)task->thread.sp;
- else
- sp = (unsigned long *)&sp;
- }
+ if (!try_get_task_stack(task))
+ return;
+
+ sp = sp ? : get_stack_pointer(task, regs);
stack = sp;
for (i = 0; i < kstack_depth_to_print; i++) {
touch_nmi_watchdog();
}
pr_cont("\n");
- show_trace_log_lvl(task, regs, sp, bp, log_lvl);
+ show_trace_log_lvl(task, regs, sp, log_lvl);
+
+ put_task_stack(task);
}
u8 *ip;
pr_emerg("Stack:\n");
- show_stack_log_lvl(NULL, regs, ®s->sp, 0, KERN_EMERG);
+ show_stack_log_lvl(current, regs, NULL, KERN_EMERG);
pr_emerg("Code:");
projects / cascardo / linux.git / blobdiff