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authorArd Biesheuvel <ardb@kernel.org>2020-10-31 12:43:45 +0300
committerMike Rapoport <rppt@linux.ibm.com>2020-11-04 11:42:57 +0300
commitb9bc36704cca500e2b41be4c5bf615c1d7ddc3ce (patch)
tree16687fb5437c2cc2d7bcd6ea5d41d525a6817b17 /arch/arm/mm
parent4ef8451b332662d004df269d4cdeb7d9f31419b5 (diff)
downloadlinux-b9bc36704cca500e2b41be4c5bf615c1d7ddc3ce.tar.xz
ARM, xtensa: highmem: avoid clobbering non-page aligned memory reservations
free_highpages() iterates over the free memblock regions in high memory, and marks each page as available for the memory management system. Until commit cddb5ddf2b76 ("arm, xtensa: simplify initialization of high memory pages") it rounded beginning of each region upwards and end of each region downwards. However, after that commit free_highmem() rounds the beginning and end of each region downwards, and we may end up freeing a page that is memblock_reserve()d, resulting in memory corruption. Restore the original rounding of the region boundaries to avoid freeing reserved pages. Fixes: cddb5ddf2b76 ("arm, xtensa: simplify initialization of high memory pages") Link: https://lore.kernel.org/r/20201029110334.4118-1-ardb@kernel.org/ Link: https://lore.kernel.org/r/20201031094345.6984-1-rppt@kernel.org Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Co-developed-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/arm/mm')
-rw-r--r--arch/arm/mm/init.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index d57112a276f5..c23dbf8bebee 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -354,8 +354,8 @@ static void __init free_highpages(void)
/* set highmem page free */
for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
&range_start, &range_end, NULL) {
- unsigned long start = PHYS_PFN(range_start);
- unsigned long end = PHYS_PFN(range_end);
+ unsigned long start = PFN_UP(range_start);
+ unsigned long end = PFN_DOWN(range_end);
/* Ignore complete lowmem entries */
if (end <= max_low)