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| author | Will Deacon <will.deacon@arm.com> | 2017-12-06 14:24:02 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-16 22:22:48 +0300 |
| commit | 3882b5f63f3cfff225cee691dcb8357bf6714d07 (patch) | |
| tree | b8a6f86f14d7208e824b4de6d74a6bfcc8c920fe /arch/arm64/mm | |
| parent | 7fafcbb04f94d4709a5c8b7fb2c196b5bdf4fd7b (diff) | |
| download | linux-3882b5f63f3cfff225cee691dcb8357bf6714d07.tar.xz | |
arm64: kaslr: Put kernel vectors address in separate data page
Commit 6c27c4082f4f upstream.
The literal pool entry for identifying the vectors base is the only piece
of information in the trampoline page that identifies the true location
of the kernel.
This patch moves it into a page-aligned region of the .rodata section
and maps this adjacent to the trampoline text via an additional fixmap
entry, which protects against any accidental leakage of the trampoline
contents.
Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64/mm')
| -rw-r--r-- | arch/arm64/mm/mmu.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 3b9af178f791..606c3654186f 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -541,8 +541,16 @@ static int __init map_entry_trampoline(void) __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE, prot, pgd_pgtable_alloc, 0); - /* ...as well as the kernel page table */ + /* 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)) { + extern char __entry_tramp_data_start[]; + + __set_fixmap(FIX_ENTRY_TRAMP_DATA, + __pa_symbol(__entry_tramp_data_start), + PAGE_KERNEL_RO); + } + return 0; } core_initcall(map_entry_trampoline); |