Messages in this thread Patch in this message | | | From | Jun Yao <> | Subject | [PATCH v2 2/2] arm64/mm: make tramp_pg_dir read-only | Date | Thu, 31 May 2018 18:31:22 +0800 |
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Make tramp_pg_dir read-only.
Signed-off-by: Jun Yao <yaojun8558363@gmail.com> --- arch/arm64/mm/mmu.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index a675fb88914e..2c6e6433090c 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -542,6 +542,7 @@ static int __init map_entry_trampoline(void) { pgprot_t prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC; phys_addr_t pa_start = __pa_symbol(__entry_tramp_text_start); + int segment_size; /* The trampoline is always mapped and can therefore be global */ pgprot_val(prot) &= ~PTE_NG; @@ -551,6 +552,11 @@ static int __init map_entry_trampoline(void) __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE, prot, pgd_pgtable_alloc, 0); + segment_size = __tramp_pgdir_segment_end - __tramp_pgdir_segment_start; + update_mapping_prot(__pa_symbol(__tramp_pgdir_segment_start), + (unsigned long)__tramp_pgdir_segment_start, + segment_size, PAGE_KERNEL_RO); + /* Map both the text and data into the kernel page table */ __set_fixmap(FIX_ENTRY_TRAMP_TEXT, pa_start, prot); if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { -- 2.17.0
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