From 63c95654d8256db8aed2a4699ad6eba359400ef8 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 2 Apr 2014 13:26:41 -0400 Subject: [PATCH] x86: Fix dumpstack_64 irq stack handling Commit 2223f6f6eeaa "x86: Clean up dumpstack_64.c code" changed the irq_stack processing a little from what it was before. The irq_stack_end variable needed to be cleared after its first use. By setting irq_stack to the per cpu irq_stack and passing that to analyze_stack(), and then clearing it after it is processed, we can get back the original behavior. Signed-off-by: Steven Rostedt Signed-off-by: Linus Torvalds --- arch/x86/kernel/dumpstack_64.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index 74c262a9b9f1..1abcb50b48ae 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -116,9 +116,9 @@ enum stack_type { static enum stack_type analyze_stack(int cpu, struct task_struct *task, unsigned long *stack, - unsigned long **stack_end, unsigned *used, char **id) + unsigned long **stack_end, unsigned long *irq_stack, + unsigned *used, char **id) { - unsigned long *irq_stack; unsigned long addr; addr = ((unsigned long)stack & (~(THREAD_SIZE - 1))); @@ -130,11 +130,11 @@ analyze_stack(int cpu, struct task_struct *task, unsigned long *stack, if (*stack_end) return STACK_IS_EXCEPTION; - *stack_end = (unsigned long *)per_cpu(irq_stack_ptr, cpu); - if (!*stack_end) - return STACK_IS_UNKNOWN; + if (!irq_stack) + return STACK_IS_NORMAL; - irq_stack = *stack_end - irq_stack_size; + *stack_end = irq_stack; + irq_stack = irq_stack - irq_stack_size; if (in_irq_stack(stack, irq_stack, *stack_end)) return STACK_IS_IRQ; @@ -155,7 +155,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, { const unsigned cpu = get_cpu(); struct thread_info *tinfo; - unsigned long *irq_stack; + unsigned long *irq_stack = (unsigned long *)per_cpu(irq_stack_ptr, cpu); unsigned long dummy; unsigned used = 0; int graph = 0; @@ -186,7 +186,8 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, enum stack_type stype; char *id; - stype = analyze_stack(cpu, task, stack, &stack_end, &used, &id); + stype = analyze_stack(cpu, task, stack, &stack_end, + irq_stack, &used, &id); /* Default finish unless specified to continue */ done = 1; @@ -226,7 +227,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, * pointer (index -1 to end) in the IRQ stack: */ stack = (unsigned long *) (stack_end[-1]); - irq_stack = stack_end - irq_stack_size; + irq_stack = NULL; ops->stack(data, "EOI"); done = 0; break; -- 2.39.2