From 4205a89b8060141ac0216a507b9f70728f056a10 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 13 Mar 2018 12:40:39 +0000 Subject: arm64: Make BP hardening slot counter available We're about to need to allocate hardening slots from other parts of the kernel (in order to support ARM64_HARDEN_EL2_VECTORS). Turn the counter into an atomic_t and make it available to the rest of the kernel. Also add BP_HARDEN_EL2_SLOTS as the number of slots instead of the hardcoded 4... Acked-by: Catalin Marinas Reviewed-by: Andrew Jones Signed-off-by: Marc Zyngier --- arch/arm64/kernel/bpi.S | 3 ++- arch/arm64/kernel/cpu_errata.c | 9 ++++----- 2 files changed, 6 insertions(+), 6 deletions(-) (limited to 'arch/arm64/kernel') diff --git a/arch/arm64/kernel/bpi.S b/arch/arm64/kernel/bpi.S index dc51ef2ce98a..bb0b67722e86 100644 --- a/arch/arm64/kernel/bpi.S +++ b/arch/arm64/kernel/bpi.S @@ -20,6 +20,7 @@ #include #include +#include .macro hyp_ventry .align 7 @@ -66,7 +67,7 @@ alternative_cb_end .align 11 ENTRY(__bp_harden_hyp_vecs_start) - .rept 4 + .rept BP_HARDEN_EL2_SLOTS generate_vectors .endr ENTRY(__bp_harden_hyp_vecs_end) diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 52f15cd896e1..8cf6b60a085a 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -60,6 +60,8 @@ static int cpu_enable_trap_ctr_access(void *__unused) return 0; } +atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1); + #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR #include #include @@ -90,7 +92,6 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn, const char *hyp_vecs_start, const char *hyp_vecs_end) { - static int last_slot = -1; static DEFINE_SPINLOCK(bp_lock); int cpu, slot = -1; @@ -103,10 +104,8 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn, } if (slot == -1) { - last_slot++; - BUG_ON(((__bp_harden_hyp_vecs_end - __bp_harden_hyp_vecs_start) - / SZ_2K) <= last_slot); - slot = last_slot; + slot = atomic_inc_return(&arm64_el2_vector_last_slot); + BUG_ON(slot >= BP_HARDEN_EL2_SLOTS); __copy_hyp_vect_bpi(slot, hyp_vecs_start, hyp_vecs_end); } -- cgit v1.2.3-55-g7522