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| author | Mark Rutland <mark.rutland@arm.com> | 2016-03-15 14:22:57 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2016-03-21 15:08:50 +0300 |
| commit | b90b4a608ea2401cc491828f7a385edd2e236e37 (patch) | |
| tree | 5776ae101d27c4eb38dd0a09781a8c6ff284ddbd /arch/arm64 | |
| parent | b660950c60a7278f9d8deb7c32a162031207c758 (diff) | |
| download | linux-b90b4a608ea2401cc491828f7a385edd2e236e37.tar.xz | |
arm64: fix KASLR boot-time I-cache maintenance
Commit f80fb3a3d50843a4 ("arm64: add support for kernel ASLR") missed a
DSB necessary to complete I-cache maintenance in the primary boot path,
and hence stale instructions may still be present in the I-cache and may
be executed until the I-cache maintenance naturally completes.
Since commit 8ec41987436d566f ("arm64: mm: ensure patched kernel text is
fetched from PoU"), all CPUs invalidate their I-caches after their MMU
is enabled. Prior a CPU's MMU having been enabled, arbitrary lines may
have been fetched from the PoC into I-caches. We never patch text
expected to be executed with the MMU off. Thus, it is unnecessary to
perform broadcast I-cache maintenance in the primary boot path.
This patch reduces the scope of the I-cache maintenance to the local
CPU, and adds the missing DSB with similar scope, matching prior
maintenance in the primary boot path.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Ard Biesehvuel <ard.biesheuvel@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kernel/head.S | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 50c2134a4aaf..1672ca9e963b 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -766,8 +766,9 @@ __enable_mmu: msr sctlr_el1, x19 // re-enable the MMU isb - ic ialluis // flush instructions fetched - isb // via old mapping + ic iallu // flush instructions fetched + dsb nsh // via old mapping + isb add x27, x27, x23 // relocated __mmap_switched #endif br x27 |