x86: janitor stack overflow warning patch
Add KERN_WARNING to the printk as this could not be done in the original patch, which allegedly only moves code around. Un#ifdef do_IRQ. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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1 changed files with 80 additions and 66 deletions
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@ -48,6 +48,29 @@ void ack_bad_irq(unsigned int irq)
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#endif
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}
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#ifdef CONFIG_DEBUG_STACKOVERFLOW
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/* Debugging check for stack overflow: is there less than 1KB free? */
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static int check_stack_overflow(void)
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{
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long sp;
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__asm__ __volatile__("andl %%esp,%0" :
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"=r" (sp) : "0" (THREAD_SIZE - 1));
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return sp < (sizeof(struct thread_info) + STACK_WARN);
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}
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static void print_stack_overflow(void)
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{
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printk(KERN_WARNING "low stack detected by irq handler\n");
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dump_stack();
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}
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#else
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static inline int check_stack_overflow(void) { return 0; }
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static inline void print_stack_overflow(void) { }
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#endif
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#ifdef CONFIG_4KSTACKS
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/*
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* per-CPU IRQ handling contexts (thread information and stack)
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@ -59,18 +82,12 @@ union irq_ctx {
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static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly;
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static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
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#endif
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static void stack_overflow(void)
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{
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printk("low stack detected by irq handler\n");
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dump_stack();
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}
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static inline void call_on_stack2(void *func, void *stack,
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unsigned long arg1, unsigned long arg2)
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static inline void call_on_stack(void *func, void *stack,
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unsigned long arg1, void *arg2)
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{
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unsigned long bx;
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asm volatile(
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" xchgl %%ebx,%%esp \n"
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" call *%%edi \n"
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@ -81,44 +98,11 @@ static inline void call_on_stack2(void *func, void *stack,
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: "memory", "cc", "ecx");
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}
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/*
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* do_IRQ handles all normal device IRQ's (the special
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* SMP cross-CPU interrupts have their own specific
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* handlers).
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*/
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unsigned int do_IRQ(struct pt_regs *regs)
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{
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struct pt_regs *old_regs;
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/* high bit used in ret_from_ code */
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int irq = ~regs->orig_ax;
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struct irq_desc *desc = irq_desc + irq;
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#ifdef CONFIG_4KSTACKS
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static inline int
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execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq)
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{
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union irq_ctx *curctx, *irqctx;
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u32 *isp;
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#endif
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int overflow = 0;
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if (unlikely((unsigned)irq >= NR_IRQS)) {
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printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
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__func__, irq);
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BUG();
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}
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old_regs = set_irq_regs(regs);
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irq_enter();
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#ifdef CONFIG_DEBUG_STACKOVERFLOW
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/* Debugging check for stack overflow: is there less than 1KB free? */
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{
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long sp;
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__asm__ __volatile__("andl %%esp,%0" :
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"=r" (sp) : "0" (THREAD_SIZE - 1));
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if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN)))
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overflow = 1;
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}
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#endif
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#ifdef CONFIG_4KSTACKS
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curctx = (union irq_ctx *) current_thread_info();
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irqctx = hardirq_ctx[smp_processor_id()];
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@ -129,31 +113,61 @@ unsigned int do_IRQ(struct pt_regs *regs)
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* handler) we can't do that and just have to keep using the
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* current stack (which is the irq stack already after all)
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*/
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if (curctx != irqctx) {
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/* build the stack frame on the IRQ stack */
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isp = (u32*) ((char*)irqctx + sizeof(*irqctx));
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irqctx->tinfo.task = curctx->tinfo.task;
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irqctx->tinfo.previous_esp = current_stack_pointer;
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if (unlikely(curctx == irqctx))
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return 0;
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/*
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* Copy the softirq bits in preempt_count so that the
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* softirq checks work in the hardirq context.
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*/
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irqctx->tinfo.preempt_count =
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(irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
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(curctx->tinfo.preempt_count & SOFTIRQ_MASK);
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/* build the stack frame on the IRQ stack */
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isp = (u32 *) ((char*)irqctx + sizeof(*irqctx));
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irqctx->tinfo.task = curctx->tinfo.task;
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irqctx->tinfo.previous_esp = current_stack_pointer;
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/* Execute warning on interrupt stack */
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if (unlikely(overflow))
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call_on_stack2(stack_overflow, isp, 0, 0);
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/*
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* Copy the softirq bits in preempt_count so that the
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* softirq checks work in the hardirq context.
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*/
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irqctx->tinfo.preempt_count =
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(irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
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(curctx->tinfo.preempt_count & SOFTIRQ_MASK);
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call_on_stack2(desc->handle_irq, isp, irq, (unsigned long)desc);
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} else
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if (unlikely(overflow))
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call_on_stack(print_stack_overflow, isp, 0, NULL);
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call_on_stack(desc->handle_irq, isp, irq, desc);
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return 1;
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}
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#else
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static inline int
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execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq) { return 0; }
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#endif
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{
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/* AK: Slightly bogus here */
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if (overflow)
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stack_overflow();
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/*
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* do_IRQ handles all normal device IRQ's (the special
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* SMP cross-CPU interrupts have their own specific
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* handlers).
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*/
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unsigned int do_IRQ(struct pt_regs *regs)
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{
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struct pt_regs *old_regs;
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/* high bit used in ret_from_ code */
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int overflow, irq = ~regs->orig_ax;
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struct irq_desc *desc = irq_desc + irq;
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if (unlikely((unsigned)irq >= NR_IRQS)) {
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printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
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__func__, irq);
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BUG();
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}
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old_regs = set_irq_regs(regs);
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irq_enter();
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overflow = check_stack_overflow();
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if (!execute_on_irq_stack(overflow, desc, irq)) {
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if (unlikely(overflow))
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print_stack_overflow();
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desc->handle_irq(irq, desc);
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}
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