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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2017-03-09 23:52:05 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2017-03-23 16:55:21 +0300 |
| commit | eccc1bff1b0d168a136ecd51c6091cf0ba02151b (patch) | |
| tree | 700abaf93030403d41e86fc7cacb92369e0db561 | |
| parent | e393cf40aecfe7e872ea630b5b9ecb8c05a78c7c (diff) | |
| download | linux-eccc1bff1b0d168a136ecd51c6091cf0ba02151b.tar.xz | |
arm64/mmu: ignore debug_pagealloc for kernel segments
The debug_pagealloc facility manipulates kernel mappings in the linear
region at page granularity to detect out of bounds or use-after-free
accesses. Since the kernel segments are not allocated dynamically,
there is no point in taking the debug_pagealloc_enabled flag into
account for them, and we can use block mappings unconditionally.
Note that this applies equally to the linear alias of text/rodata:
we will never have dynamic allocations there given that the same
memory is statically in use by the kernel image.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | arch/arm64/mm/mmu.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index bb9179084217..ec23aec6433f 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -328,8 +328,7 @@ static void update_mapping_prot(phys_addr_t phys, unsigned long virt, return; } - __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, - NULL, debug_pagealloc_enabled()); + __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL, false); /* flush the TLBs after updating live kernel mappings */ flush_tlb_kernel_range(virt, virt + size); @@ -381,7 +380,7 @@ static void __init __map_memblock(pgd_t *pgd, phys_addr_t start, phys_addr_t end */ __create_pgd_mapping(pgd, kernel_start, __phys_to_virt(kernel_start), kernel_end - kernel_start, PAGE_KERNEL, - early_pgtable_alloc, debug_pagealloc_enabled()); + early_pgtable_alloc, false); } void __init mark_linear_text_alias_ro(void) @@ -437,7 +436,7 @@ static void __init map_kernel_segment(pgd_t *pgd, void *va_start, void *va_end, BUG_ON(!PAGE_ALIGNED(size)); __create_pgd_mapping(pgd, pa_start, (unsigned long)va_start, size, prot, - early_pgtable_alloc, debug_pagealloc_enabled()); + early_pgtable_alloc, false); vma->addr = va_start; vma->phys_addr = pa_start; |