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| author | Mark Rutland <mark.rutland@arm.com> | 2016-03-15 11:22:57 +0000 |
|---|---|---|
| committer | Jeff Vander Stoep <jeffv@google.com> | 2016-09-22 13:38:22 -0700 |
| commit | b6d54c720c294dd973ddff2d111a4f3a0d35dc74 (patch) | |
| tree | 509cb42bdba9cc4e845bef5215c55b320aa3c3d7 /arch/arm64/kernel/head.S | |
| parent | 46debe0769bb9597eaeb460f8dd0c3a85ad76af1 (diff) | |
UPSTREAM: 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>
Bug: 30369029
Patchset: kaslr-arm64-4.4
(cherry picked from commit b90b4a608ea2401cc491828f7a385edd2e236e37)
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
Change-Id: Ic66b5fec29867b86782ad6c3243642afc1f40080
Diffstat (limited to 'arch/arm64/kernel/head.S')
| -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 319f896c6e74..a88a15447c3b 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -740,8 +740,9 @@ __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 |