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-rw-r--r--arch/x86/mm/ioremap.c6
-rw-r--r--include/linux/ioport.h1
-rw-r--r--kernel/resource.c33
3 files changed, 40 insertions, 0 deletions
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index d4b6e6a..c818b45 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -150,6 +150,12 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr,
return (__force void __iomem *)phys_to_virt(phys_addr);
/*
+ * Check if the request spans more than any BAR in the iomem resource
+ * tree.
+ */
+ WARN_ON(iomem_map_sanity_check(phys_addr, size));
+
+ /*
* Don't allow anybody to remap normal RAM that we're using..
*/
for (pfn = phys_addr >> PAGE_SHIFT;
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index fded376..01712cf 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -169,6 +169,7 @@ extern struct resource * __devm_request_region(struct device *dev,
extern void __devm_release_region(struct device *dev, struct resource *parent,
resource_size_t start, resource_size_t n);
+extern int iomem_map_sanity_check(resource_size_t addr, unsigned long size);
#endif /* __ASSEMBLY__ */
#endif /* _LINUX_IOPORT_H */
diff --git a/kernel/resource.c b/kernel/resource.c
index fc59dcc..1d003a5 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -827,3 +827,36 @@ static int __init reserve_setup(char *str)
}
__setup("reserve=", reserve_setup);
+
+/*
+ * Check if the requested addr and size spans more than any slot in the
+ * iomem resource tree.
+ */
+int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
+{
+ struct resource *p = &iomem_resource;
+ int err = 0;
+ loff_t l;
+
+ read_lock(&resource_lock);
+ for (p = p->child; p ; p = r_next(NULL, p, &l)) {
+ /*
+ * We can probably skip the resources without
+ * IORESOURCE_IO attribute?
+ */
+ if (p->start >= addr + size)
+ continue;
+ if (p->end < addr)
+ continue;
+ if (p->start <= addr && (p->end >= addr + size - 1))
+ continue;
+ printk(KERN_WARNING "resource map sanity check conflict: "
+ "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
+ addr, addr + size - 1, p->start, p->end, p->name);
+ err = -1;
+ break;
+ }
+ read_unlock(&resource_lock);
+
+ return err;
+}
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