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Commit c7a7b814 authored by Tim Gardner's avatar Tim Gardner Committed by Ingo Molnar
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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: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarTim Gardner <tim.gardner@canonical.com>
Link: http://lkml.kernel.org/r/4DB99D2E.9080106@canonical.com


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 64d21fc1

arch/x86/mm/ioremap.c

+7 −7
Original line number Diff line number Diff line
@@ -90,13 +90,6 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, 
	if (is_ISA_range(phys_addr, last_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_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..

	 */
@@ -170,6 +163,13 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, 
	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);