diff options
| author | James Morse <james.morse@arm.com> | 2018-01-15 19:38:54 +0000 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2018-02-07 15:47:14 +0000 |
| commit | 116d4aa3ee75008caef20f98d5d51f06dba70c11 (patch) | |
| tree | 57d5b372c6a246392a79cc65929c346b3b5c25d0 | |
| parent | 208ead4bd8949b46374d1876fe917c9c5e34a4e0 (diff) | |
[Variant 2/Spectre-v2] arm64: cpufeature: __this_cpu_has_cap() shouldn't stop early
Commit edf298cfce47 upstream.
this_cpu_has_cap() tests caps->desc not caps->matches, so it stops
walking the list when it finds a 'silent' feature, instead of
walking to the end of the list.
Prior to v4.6's 644c2ae198412 ("arm64: cpufeature: Test 'matches' pointer
to find the end of the list") we always tested desc to find the end of
a capability list. This was changed for dubious things like PAN_NOT_UAO.
v4.7's e3661b128e53e ("arm64: Allow a capability to be checked on
single CPU") added this_cpu_has_cap() using the old desc style test.
CC: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 4aeadb4c0831..c38d91434e26 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1173,9 +1173,8 @@ static bool __this_cpu_has_cap(const struct arm64_cpu_capabilities *cap_array, if (WARN_ON(preemptible())) return false; - for (caps = cap_array; caps->desc; caps++) + for (caps = cap_array; caps->matches; caps++) if (caps->capability == cap && - caps->matches && caps->matches(caps, SCOPE_LOCAL_CPU)) return true; return false; |