leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Merge branch 'kvm-arm64/vector-rework' into kvmarm-master/next

Browse Source 
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Marc Zyngier
2020-11-27 11:47:08 +00:00
parent 6e5d8c713d 4f6a36fed7
commit dc2286f397
13 changed files with 222 additions and 267 deletions
Download Patch File Download Diff File Expand all files Collapse all files

84
arch/arm64/kernel/proton-pack.c
View File

@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Handle detection, reporting and mitigation of Spectre v1, v2 and v4, as
* Handle detection, reporting and mitigation of Spectre v1, v2, v3a and v4, as
* detailed at:
*
* https://developer.arm.com/support/arm-security-updates/speculative-processor-vulnerability
@@ -26,6 +26,7 @@
#include <asm/spectre.h>
#include <asm/traps.h>
#include <asm/virt.h>
/*
* We try to ensure that the mitigation state can never change as the result of
@@ -170,72 +171,26 @@ bool has_spectre_v2(const struct arm64_cpu_capabilities *entry, int scope)
return true;
}
DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
enum mitigation_state arm64_get_spectre_v2_state(void)
{
return spectre_v2_state;
}
#ifdef CONFIG_KVM
#include <asm/cacheflush.h>
#include <asm/kvm_asm.h>
atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1);
static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start,
const char *hyp_vecs_end)
{
void *dst = lm_alias(__bp_harden_hyp_vecs + slot * SZ_2K);
int i;
for (i = 0; i < SZ_2K; i += 0x80)
memcpy(dst + i, hyp_vecs_start, hyp_vecs_end - hyp_vecs_start);
__flush_icache_range((uintptr_t)dst, (uintptr_t)dst + SZ_2K);
}
DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
static void install_bp_hardening_cb(bp_hardening_cb_t fn)
{
static DEFINE_RAW_SPINLOCK(bp_lock);
int cpu, slot = -1;
const char *hyp_vecs_start = __smccc_workaround_1_smc;
const char *hyp_vecs_end = __smccc_workaround_1_smc +
__SMCCC_WORKAROUND_1_SMC_SZ;
__this_cpu_write(bp_hardening_data.fn, fn);
/*
* Vinz Clortho takes the hyp_vecs start/end "keys" at
* the door when we're a guest. Skip the hyp-vectors work.
*/
if (!is_hyp_mode_available()) {
__this_cpu_write(bp_hardening_data.fn, fn);
if (!is_hyp_mode_available())
return;
}
raw_spin_lock(&bp_lock);
for_each_possible_cpu(cpu) {
if (per_cpu(bp_hardening_data.fn, cpu) == fn) {
slot = per_cpu(bp_hardening_data.hyp_vectors_slot, cpu);
break;
}
}
if (slot == -1) {
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);
}
__this_cpu_write(bp_hardening_data.hyp_vectors_slot, slot);
__this_cpu_write(bp_hardening_data.fn, fn);
raw_spin_unlock(&bp_lock);
__this_cpu_write(bp_hardening_data.slot, HYP_VECTOR_SPECTRE_DIRECT);
}
#else
static void install_bp_hardening_cb(bp_hardening_cb_t fn)
{
__this_cpu_write(bp_hardening_data.fn, fn);
}
#endif /* CONFIG_KVM */
static void call_smc_arch_workaround_1(void)
{
@@ -316,6 +271,33 @@ void spectre_v2_enable_mitigation(const struct arm64_cpu_capabilities *__unused)
update_mitigation_state(&spectre_v2_state, state);
}
/*
* Spectre-v3a.
*
* Phew, there's not an awful lot to do here! We just instruct EL2 to use
* an indirect trampoline for the hyp vectors so that guests can't read
* VBAR_EL2 to defeat randomisation of the hypervisor VA layout.
*/
bool has_spectre_v3a(const struct arm64_cpu_capabilities *entry, int scope)
{
static const struct midr_range spectre_v3a_unsafe_list[] = {
MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
{},
};
WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
return is_midr_in_range_list(read_cpuid_id(), spectre_v3a_unsafe_list);
}
void spectre_v3a_enable_mitigation(const struct arm64_cpu_capabilities *__unused)
{
struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data);
if (this_cpu_has_cap(ARM64_SPECTRE_V3A))
data->slot += HYP_VECTOR_INDIRECT;
}
/*
* Spectre v4.
*