x86: kmap_atomic() debugging (022eb434) · Commits · 戴 / test

arch/x86/mm/highmem_32.c

+46 −1

Original line number	Diff line number	Diff line
		@@ -18,6 +18,49 @@ void kunmap(struct page *page)
		kunmap_high(page);
		}

		static void debug_kmap_atomic_prot(enum km_type type)
		{
		#ifdef CONFIG_DEBUG_HIGHMEM
		static unsigned warn_count = 10;

		if (unlikely(warn_count == 0))
		return;

		if (unlikely(in_interrupt())) {
		if (in_irq()) {
		if (type != KM_IRQ0 && type != KM_IRQ1 &&
		type != KM_BIO_SRC_IRQ && type != KM_BIO_DST_IRQ &&
		type != KM_BOUNCE_READ) {
		WARN_ON(1);
		warn_count--;
		}
		} else if (!irqs_disabled()) { /* softirq */
		if (type != KM_IRQ0 && type != KM_IRQ1 &&
		type != KM_SOFTIRQ0 && type != KM_SOFTIRQ1 &&
		type != KM_SKB_SUNRPC_DATA &&
		type != KM_SKB_DATA_SOFTIRQ &&
		type != KM_BOUNCE_READ) {
		WARN_ON(1);
		warn_count--;
		}
		}
		}

		if (type == KM_IRQ0 \|\| type == KM_IRQ1 \|\| type == KM_BOUNCE_READ \|\|
		type == KM_BIO_SRC_IRQ \|\| type == KM_BIO_DST_IRQ) {
		if (!irqs_disabled()) {
		WARN_ON(1);
		warn_count--;
		}
		} else if (type == KM_SOFTIRQ0 \|\| type == KM_SOFTIRQ1) {
		if (irq_count() == 0 && !irqs_disabled()) {
		WARN_ON(1);
		warn_count--;
		}
		}
		#endif
		}

		/*
		* kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
		* no global lock is needed and because the kmap code must perform a global TLB
		@@ -30,8 +73,10 @@ void kmap_atomic_prot(struct page page, enum km_type type, pgprot_t prot)
		{
		enum fixed_addresses idx;
		unsigned long vaddr;

		/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */

		debug_kmap_atomic_prot(type);

		pagefault_disable();

		if (!PageHighMem(page))