X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=arch%2Fx86%2Fmm%2Fphysaddr.c;h=e666cbbb926191e18995e0cc30c955a726bf462b;hb=a25b9316841c5afa226f8f70a457861b35276a92;hp=c73feddd518d475f94756b84b453d992f66c36ab;hpb=7b5c4a65cc27f017c170b025f8d6d75dabb11c6f;p=deliverable%2Flinux.git

diff --git a/arch/x86/mm/physaddr.c b/arch/x86/mm/physaddr.c
index c73feddd518d..e666cbbb9261 100644
--- a/arch/x86/mm/physaddr.c
+++ b/arch/x86/mm/physaddr.c
@@ -1,3 +1,4 @@
+#include <linux/bootmem.h>
 #include <linux/mmdebug.h>
 #include <linux/module.h>
 #include <linux/mm.h>
@@ -68,10 +69,16 @@ EXPORT_SYMBOL(__virt_addr_valid);
 #ifdef CONFIG_DEBUG_VIRTUAL
 unsigned long __phys_addr(unsigned long x)
 {
+	unsigned long phys_addr = x - PAGE_OFFSET;
 	/* VMALLOC_* aren't constants  */
 	VIRTUAL_BUG_ON(x < PAGE_OFFSET);
 	VIRTUAL_BUG_ON(__vmalloc_start_set && is_vmalloc_addr((void *) x));
-	return x - PAGE_OFFSET;
+	/* max_low_pfn is set early, but not _that_ early */
+	if (max_low_pfn) {
+		VIRTUAL_BUG_ON((phys_addr >> PAGE_SHIFT) > max_low_pfn);
+		BUG_ON(slow_virt_to_phys((void *)x) != phys_addr);
+	}
+	return phys_addr;
 }
 EXPORT_SYMBOL(__phys_addr);
 #endif