ioremap: Delay sanity check until after a successful mapping
While tracking down the reason for an ioremap() failure I was
distracted by the WARN_ONCE() in __ioremap_caller().
Performing a WARN_ONCE() sanity check before the mapping
is successful seems pointless if the caller sends bad values.
A case in point is when the BIOS provides erroneous screen_info
values causing vesafb_probe() to request an outrageuous size.
The WARN_ONCE is then wasted on bogosity. Move the warning to a
point where the mapping has been successfully allocated.
Addresses:
http://bugs.launchpad.net/bugs/772042
Reviewed-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Link: http://lkml.kernel.org/r/4DB99D2E.9080106@canonical.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 0369843..be1ef57 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -91,13 +91,6 @@
return (__force void __iomem *)phys_to_virt(phys_addr);
/*
- * Check if the request spans more than any BAR in the iomem resource
- * tree.
- */
- WARN_ONCE(iomem_map_sanity_check(phys_addr, size),
- KERN_INFO "Info: mapping multiple BARs. Your kernel is fine.");
-
- /*
* Don't allow anybody to remap normal RAM that we're using..
*/
last_pfn = last_addr >> PAGE_SHIFT;
@@ -170,6 +163,13 @@
ret_addr = (void __iomem *) (vaddr + offset);
mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr);
+ /*
+ * Check if the request spans more than any BAR in the iomem resource
+ * tree.
+ */
+ WARN_ONCE(iomem_map_sanity_check(unaligned_phys_addr, unaligned_size),
+ KERN_INFO "Info: mapping multiple BARs. Your kernel is fine.");
+
return ret_addr;
err_free_area:
free_vm_area(area);
