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authorMark Rutland <mark.rutland@arm.com>2018-04-12 12:11:21 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-04-20 08:21:04 +0200
commitbad52d7979532b20bce7545c18fe7e443b7472f6 (patch)
tree6746a813efac1ac2928d2224367ed3442ded5250 /arch/arm64/kernel/bpi.S
parent4bcf61fa86cd8bb150fe89be782ded66e5ff11c3 (diff)
arm64: Implement branch predictor hardening for affected Cortex-A CPUs
From: Will Deacon <will.deacon@arm.com> commit aa6acde65e03186b5add8151e1ffe36c3c62639b upstream. Cortex-A57, A72, A73 and A75 are susceptible to branch predictor aliasing and can theoretically be attacked by malicious code. This patch implements a PSCI-based mitigation for these CPUs when available. The call into firmware will invalidate the branch predictor state, preventing any malicious entries from affecting other victim contexts. Co-developed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> [v4.9 backport] Tested-by: Greg Hackmann <ghackmann@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64/kernel/bpi.S')
-rw-r--r--arch/arm64/kernel/bpi.S24
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/arm64/kernel/bpi.S b/arch/arm64/kernel/bpi.S
index 06a931eb2673..dec95bd82e31 100644
--- a/arch/arm64/kernel/bpi.S
+++ b/arch/arm64/kernel/bpi.S
@@ -53,3 +53,27 @@ ENTRY(__bp_harden_hyp_vecs_start)
vectors __kvm_hyp_vector
.endr
ENTRY(__bp_harden_hyp_vecs_end)
+ENTRY(__psci_hyp_bp_inval_start)
+ sub sp, sp, #(8 * 18)
+ stp x16, x17, [sp, #(16 * 0)]
+ stp x14, x15, [sp, #(16 * 1)]
+ stp x12, x13, [sp, #(16 * 2)]
+ stp x10, x11, [sp, #(16 * 3)]
+ stp x8, x9, [sp, #(16 * 4)]
+ stp x6, x7, [sp, #(16 * 5)]
+ stp x4, x5, [sp, #(16 * 6)]
+ stp x2, x3, [sp, #(16 * 7)]
+ stp x0, x1, [sp, #(16 * 8)]
+ mov x0, #0x84000000
+ smc #0
+ ldp x16, x17, [sp, #(16 * 0)]
+ ldp x14, x15, [sp, #(16 * 1)]
+ ldp x12, x13, [sp, #(16 * 2)]
+ ldp x10, x11, [sp, #(16 * 3)]
+ ldp x8, x9, [sp, #(16 * 4)]
+ ldp x6, x7, [sp, #(16 * 5)]
+ ldp x4, x5, [sp, #(16 * 6)]
+ ldp x2, x3, [sp, #(16 * 7)]
+ ldp x0, x1, [sp, #(16 * 8)]
+ add sp, sp, #(8 * 18)
+ENTRY(__psci_hyp_bp_inval_end)