path: root/arch
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authorYueyi Li <liyueyi@live.com>2018-12-24 07:40:07 +0000
committerWill Deacon <will.deacon@arm.com>2019-01-03 18:03:54 +0000
commitc8a43c18a97845e7f94ed7d181c11f41964976a2 (patch)
tree14356b37f98932e6fe44a0befaa184d1734442be /arch
parentacafce48b07bf5f9994a38e7fe237193d43d092e (diff)
arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region
When KASLR is enabled (CONFIG_RANDOMIZE_BASE=y), the top 4K of kernel virtual address space may be mapped to physical addresses despite being reserved for ERR_PTR values. Fix the randomization of the linear region so that we avoid mapping the last page of the virtual address space. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: liyueyi <liyueyi@live.com> [will: rewrote commit message; merged in suggestion from Ard] Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch')
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 4bfe0fc9edac..124be28e4e16 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -457,7 +457,7 @@ void __init arm64_memblock_init(void)
* memory spans, randomize the linear region as well.
if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) {
- range = range / ARM64_MEMSTART_ALIGN + 1;
+ range /= ARM64_MEMSTART_ALIGN;
memstart_addr -= ARM64_MEMSTART_ALIGN *
((range * memstart_offset_seed) >> 16);