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arm: ioremap: don't abuse pfn_valid() to check if pfn is in RAM

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The semantics of pfn_valid() is to check presence of the memory map for a
 PFN and not whether a PFN is in RAM. The memory map may be present for a
 hole in the physical memory and if such hole corresponds to an MMIO range,
 __arm_ioremap_pfn_caller() will produce a WARN() and fail:
 
 Use memblock_is_map_memory() instead of pfn_valid() to check if a PFN is in
 RAM or not.
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Merge tag 'fixes-2021-07-09' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

Pull memblock fix from Mike Rapoport:
 "This is a fix for the rework of ARM's pfn_valid() implementation
  merged during this merge window.

  Don't abuse pfn_valid() to check if pfn is in RAM

  The semantics of pfn_valid() is to check presence of the memory map
  for a PFN and not whether a PFN is in RAM. The memory map may be
  present for a hole in the physical memory and if such hole corresponds
  to an MMIO range, __arm_ioremap_pfn_caller() will produce a WARN() and
  fail.

  Use memblock_is_map_memory() instead of pfn_valid() to check if a PFN
  is in RAM or not"

* tag 'fixes-2021-07-09' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  arm: ioremap: don't abuse pfn_valid() to check if pfn is in RAM
This commit is contained in:
Linus Torvalds 2021-07-10 09:17:13 -07:00
commit b6fd9e2594
1 changed files with 3 additions and 1 deletions
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4
arch/arm/mm/ioremap.c
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@ -27,6 +27,7 @@
#include <linux/vmalloc.h>
#include <linux/io.h>
#include <linux/sizes.h>
#include <linux/memblock.h>
#include <asm/cp15.h>
#include <asm/cputype.h>
@ -284,7 +285,8 @@ static void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
* Don't allow RAM to be mapped with mismatched attributes - this
* causes problems with ARMv6+
*/
if (WARN_ON(pfn_valid(pfn) && mtype != MT_MEMORY_RW))
if (WARN_ON(memblock_is_map_memory(PFN_PHYS(pfn)) &&
mtype != MT_MEMORY_RW))
return NULL;
area = get_vm_area_caller(size, VM_IOREMAP, caller);