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| author | Jun Yao <yaojun8558363@gmail.com> | 2018-09-24 17:56:18 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2018-09-25 15:10:55 +0100 |
| commit | 8eb7e28d4c642c310f25c18f80a44dd4b01c694e (patch) | |
| tree | 931df13e61148dfd777a5244cbceded4a5fad955 /arch/arm64/kernel | |
| parent | 2330b7ca78350efcb1a3b919ea4b3e0e4c57d99f (diff) | |
| download | linux-stable-8eb7e28d4c642c310f25c18f80a44dd4b01c694e.tar.gz linux-stable-8eb7e28d4c642c310f25c18f80a44dd4b01c694e.tar.bz2 linux-stable-8eb7e28d4c642c310f25c18f80a44dd4b01c694e.zip | |
arm64/mm: move runtime pgds to rodata
Now that deliberate writes to swapper_pg_dir are made via the fixmap, we
can defend against errant writes by moving it into the rodata section.
Since tramp_pg_dir and reserved_ttbr0 must be at a fixed offset from
swapper_pg_dir, and are not modified at runtime, these are also moved
into the rodata section. Likewise, idmap_pg_dir is not modified at
runtime, and is moved into rodata.
Signed-off-by: Jun Yao <yaojun8558363@gmail.com>
Reviewed-by: James Morse <james.morse@arm.com>
[Mark: simplify linker script, commit message]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/head.S | 12 | ||||
| -rw-r--r-- | arch/arm64/kernel/vmlinux.lds.S | 33 |
2 files changed, 24 insertions, 21 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 7bf52ee0a805..4471f570a295 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -287,18 +287,20 @@ __create_page_tables: mov x28, lr /* - * Invalidate the idmap and swapper page tables to avoid potential - * dirty cache lines being evicted. + * Invalidate the init page tables to avoid potential dirty cache lines + * being evicted. Other page tables are allocated in rodata as part of + * the kernel image, and thus are clean to the PoC per the boot + * protocol. */ - adrp x0, idmap_pg_dir + adrp x0, init_pg_dir adrp x1, init_pg_end sub x1, x1, x0 bl __inval_dcache_area /* - * Clear the idmap and swapper page tables. + * Clear the init page tables. */ - adrp x0, idmap_pg_dir + adrp x0, init_pg_dir adrp x1, init_pg_end sub x1, x1, x0 1: stp xzr, xzr, [x0], #16 diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index ac4c10351b17..ab29c06a7d4b 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -138,6 +138,23 @@ SECTIONS EXCEPTION_TABLE(8) /* __init_begin will be marked RO NX */ NOTES + . = ALIGN(PAGE_SIZE); + idmap_pg_dir = .; + . += IDMAP_DIR_SIZE; + +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 + tramp_pg_dir = .; + . += PAGE_SIZE; +#endif + +#ifdef CONFIG_ARM64_SW_TTBR0_PAN + reserved_ttbr0 = .; + . += RESERVED_TTBR0_SIZE; +#endif + swapper_pg_dir = .; + . += PAGE_SIZE; + swapper_pg_end = .; + . = ALIGN(SEGMENT_ALIGN); __init_begin = .; __inittext_begin = .; @@ -216,22 +233,6 @@ SECTIONS BSS_SECTION(0, 0, 0) . = ALIGN(PAGE_SIZE); - idmap_pg_dir = .; - . += IDMAP_DIR_SIZE; - -#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 - tramp_pg_dir = .; - . += PAGE_SIZE; -#endif - -#ifdef CONFIG_ARM64_SW_TTBR0_PAN - reserved_ttbr0 = .; - . += RESERVED_TTBR0_SIZE; -#endif - swapper_pg_dir = .; - . += PAGE_SIZE; - swapper_pg_end = .; - init_pg_dir = .; . += INIT_DIR_SIZE; init_pg_end = .; |