From b9bc36704cca500e2b41be4c5bf615c1d7ddc3ce Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Sat, 31 Oct 2020 11:43:45 +0200 Subject: 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 Co-developed-by: Mike Rapoport Signed-off-by: Mike Rapoport Acked-by: Max Filippov --- arch/arm/mm/init.c | 4 ++-- arch/xtensa/mm/init.c | 4 ++-- 2 files changed, 4 insertions(+), 4 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) diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c index c6fc83efee0c..8731b7ad9308 100644 --- a/arch/xtensa/mm/init.c +++ b/arch/xtensa/mm/init.c @@ -89,8 +89,8 @@ 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) -- cgit v1.2.3