linux_dsm_epyc7002/arch/arm64/kernel/cpu_errata.c
Shanker Donthineni ec82b567a7 arm64: Implement branch predictor hardening for Falkor
Falkor is susceptible to branch predictor aliasing and can
theoretically be attacked by malicious code. This patch
implements a mitigation for these attacks, preventing any
malicious entries from affecting other victim contexts.

Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
[will: fix label name when !CONFIG_KVM and remove references to MIDR_FALKOR]
Signed-off-by: Will Deacon <will.deacon@arm.com>

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-08 18:47:07 +00:00

375 lines
9.9 KiB
C

/*
* Contains CPU specific errata definitions
*
* Copyright (C) 2014 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/types.h>
#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/cpufeature.h>
static bool __maybe_unused
is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope)
{
WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
return MIDR_IS_CPU_MODEL_RANGE(read_cpuid_id(), entry->midr_model,
entry->midr_range_min,
entry->midr_range_max);
}
static bool
has_mismatched_cache_line_size(const struct arm64_cpu_capabilities *entry,
int scope)
{
WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
return (read_cpuid_cachetype() & arm64_ftr_reg_ctrel0.strict_mask) !=
(arm64_ftr_reg_ctrel0.sys_val & arm64_ftr_reg_ctrel0.strict_mask);
}
static int cpu_enable_trap_ctr_access(void *__unused)
{
/* Clear SCTLR_EL1.UCT */
config_sctlr_el1(SCTLR_EL1_UCT, 0);
return 0;
}
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>
DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
#ifdef CONFIG_KVM
extern char __psci_hyp_bp_inval_start[], __psci_hyp_bp_inval_end[];
extern char __qcom_hyp_sanitize_link_stack_start[];
extern char __qcom_hyp_sanitize_link_stack_end[];
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_start + 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);
}
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;
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) {
last_slot++;
BUG_ON(((__bp_harden_hyp_vecs_end - __bp_harden_hyp_vecs_start)
/ SZ_2K) <= last_slot);
slot = last_slot;
__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);
spin_unlock(&bp_lock);
}
#else
#define __psci_hyp_bp_inval_start NULL
#define __psci_hyp_bp_inval_end NULL
#define __qcom_hyp_sanitize_link_stack_start NULL
#define __qcom_hyp_sanitize_link_stack_end NULL
static void __install_bp_hardening_cb(bp_hardening_cb_t fn,
const char *hyp_vecs_start,
const char *hyp_vecs_end)
{
__this_cpu_write(bp_hardening_data.fn, fn);
}
#endif /* CONFIG_KVM */
static void install_bp_hardening_cb(const struct arm64_cpu_capabilities *entry,
bp_hardening_cb_t fn,
const char *hyp_vecs_start,
const char *hyp_vecs_end)
{
u64 pfr0;
if (!entry->matches(entry, SCOPE_LOCAL_CPU))
return;
pfr0 = read_cpuid(ID_AA64PFR0_EL1);
if (cpuid_feature_extract_unsigned_field(pfr0, ID_AA64PFR0_CSV2_SHIFT))
return;
__install_bp_hardening_cb(fn, hyp_vecs_start, hyp_vecs_end);
}
#include <linux/psci.h>
static int enable_psci_bp_hardening(void *data)
{
const struct arm64_cpu_capabilities *entry = data;
if (psci_ops.get_version)
install_bp_hardening_cb(entry,
(bp_hardening_cb_t)psci_ops.get_version,
__psci_hyp_bp_inval_start,
__psci_hyp_bp_inval_end);
return 0;
}
static void qcom_link_stack_sanitization(void)
{
u64 tmp;
asm volatile("mov %0, x30 \n"
".rept 16 \n"
"bl . + 4 \n"
".endr \n"
"mov x30, %0 \n"
: "=&r" (tmp));
}
static int qcom_enable_link_stack_sanitization(void *data)
{
const struct arm64_cpu_capabilities *entry = data;
install_bp_hardening_cb(entry, qcom_link_stack_sanitization,
__qcom_hyp_sanitize_link_stack_start,
__qcom_hyp_sanitize_link_stack_end);
return 0;
}
#endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */
#define MIDR_RANGE(model, min, max) \
.def_scope = SCOPE_LOCAL_CPU, \
.matches = is_affected_midr_range, \
.midr_model = model, \
.midr_range_min = min, \
.midr_range_max = max
#define MIDR_ALL_VERSIONS(model) \
.def_scope = SCOPE_LOCAL_CPU, \
.matches = is_affected_midr_range, \
.midr_model = model, \
.midr_range_min = 0, \
.midr_range_max = (MIDR_VARIANT_MASK | MIDR_REVISION_MASK)
const struct arm64_cpu_capabilities arm64_errata[] = {
#if defined(CONFIG_ARM64_ERRATUM_826319) || \
defined(CONFIG_ARM64_ERRATUM_827319) || \
defined(CONFIG_ARM64_ERRATUM_824069)
{
/* Cortex-A53 r0p[012] */
.desc = "ARM errata 826319, 827319, 824069",
.capability = ARM64_WORKAROUND_CLEAN_CACHE,
MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x02),
.enable = cpu_enable_cache_maint_trap,
},
#endif
#ifdef CONFIG_ARM64_ERRATUM_819472
{
/* Cortex-A53 r0p[01] */
.desc = "ARM errata 819472",
.capability = ARM64_WORKAROUND_CLEAN_CACHE,
MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x01),
.enable = cpu_enable_cache_maint_trap,
},
#endif
#ifdef CONFIG_ARM64_ERRATUM_832075
{
/* Cortex-A57 r0p0 - r1p2 */
.desc = "ARM erratum 832075",
.capability = ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE,
MIDR_RANGE(MIDR_CORTEX_A57,
MIDR_CPU_VAR_REV(0, 0),
MIDR_CPU_VAR_REV(1, 2)),
},
#endif
#ifdef CONFIG_ARM64_ERRATUM_834220
{
/* Cortex-A57 r0p0 - r1p2 */
.desc = "ARM erratum 834220",
.capability = ARM64_WORKAROUND_834220,
MIDR_RANGE(MIDR_CORTEX_A57,
MIDR_CPU_VAR_REV(0, 0),
MIDR_CPU_VAR_REV(1, 2)),
},
#endif
#ifdef CONFIG_ARM64_ERRATUM_845719
{
/* Cortex-A53 r0p[01234] */
.desc = "ARM erratum 845719",
.capability = ARM64_WORKAROUND_845719,
MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x04),
},
#endif
#ifdef CONFIG_CAVIUM_ERRATUM_23154
{
/* Cavium ThunderX, pass 1.x */
.desc = "Cavium erratum 23154",
.capability = ARM64_WORKAROUND_CAVIUM_23154,
MIDR_RANGE(MIDR_THUNDERX, 0x00, 0x01),
},
#endif
#ifdef CONFIG_CAVIUM_ERRATUM_27456
{
/* Cavium ThunderX, T88 pass 1.x - 2.1 */
.desc = "Cavium erratum 27456",
.capability = ARM64_WORKAROUND_CAVIUM_27456,
MIDR_RANGE(MIDR_THUNDERX,
MIDR_CPU_VAR_REV(0, 0),
MIDR_CPU_VAR_REV(1, 1)),
},
{
/* Cavium ThunderX, T81 pass 1.0 */
.desc = "Cavium erratum 27456",
.capability = ARM64_WORKAROUND_CAVIUM_27456,
MIDR_RANGE(MIDR_THUNDERX_81XX, 0x00, 0x00),
},
#endif
#ifdef CONFIG_CAVIUM_ERRATUM_30115
{
/* Cavium ThunderX, T88 pass 1.x - 2.2 */
.desc = "Cavium erratum 30115",
.capability = ARM64_WORKAROUND_CAVIUM_30115,
MIDR_RANGE(MIDR_THUNDERX, 0x00,
(1 << MIDR_VARIANT_SHIFT) | 2),
},
{
/* Cavium ThunderX, T81 pass 1.0 - 1.2 */
.desc = "Cavium erratum 30115",
.capability = ARM64_WORKAROUND_CAVIUM_30115,
MIDR_RANGE(MIDR_THUNDERX_81XX, 0x00, 0x02),
},
{
/* Cavium ThunderX, T83 pass 1.0 */
.desc = "Cavium erratum 30115",
.capability = ARM64_WORKAROUND_CAVIUM_30115,
MIDR_RANGE(MIDR_THUNDERX_83XX, 0x00, 0x00),
},
#endif
{
.desc = "Mismatched cache line size",
.capability = ARM64_MISMATCHED_CACHE_LINE_SIZE,
.matches = has_mismatched_cache_line_size,
.def_scope = SCOPE_LOCAL_CPU,
.enable = cpu_enable_trap_ctr_access,
},
#ifdef CONFIG_QCOM_FALKOR_ERRATUM_1003
{
.desc = "Qualcomm Technologies Falkor erratum 1003",
.capability = ARM64_WORKAROUND_QCOM_FALKOR_E1003,
MIDR_RANGE(MIDR_QCOM_FALKOR_V1,
MIDR_CPU_VAR_REV(0, 0),
MIDR_CPU_VAR_REV(0, 0)),
},
#endif
#ifdef CONFIG_QCOM_FALKOR_ERRATUM_1009
{
.desc = "Qualcomm Technologies Falkor erratum 1009",
.capability = ARM64_WORKAROUND_REPEAT_TLBI,
MIDR_RANGE(MIDR_QCOM_FALKOR_V1,
MIDR_CPU_VAR_REV(0, 0),
MIDR_CPU_VAR_REV(0, 0)),
},
#endif
#ifdef CONFIG_ARM64_ERRATUM_858921
{
/* Cortex-A73 all versions */
.desc = "ARM erratum 858921",
.capability = ARM64_WORKAROUND_858921,
MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
},
#endif
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
.enable = enable_psci_bp_hardening,
},
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
.enable = enable_psci_bp_hardening,
},
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
.enable = enable_psci_bp_hardening,
},
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
MIDR_ALL_VERSIONS(MIDR_CORTEX_A75),
.enable = enable_psci_bp_hardening,
},
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
.enable = qcom_enable_link_stack_sanitization,
},
{
.capability = ARM64_HARDEN_BP_POST_GUEST_EXIT,
MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
},
#endif
{
}
};
/*
* The CPU Errata work arounds are detected and applied at boot time
* and the related information is freed soon after. If the new CPU requires
* an errata not detected at boot, fail this CPU.
*/
void verify_local_cpu_errata_workarounds(void)
{
const struct arm64_cpu_capabilities *caps = arm64_errata;
for (; caps->matches; caps++)
if (!cpus_have_cap(caps->capability) &&
caps->matches(caps, SCOPE_LOCAL_CPU)) {
pr_crit("CPU%d: Requires work around for %s, not detected"
" at boot time\n",
smp_processor_id(),
caps->desc ? : "an erratum");
cpu_die_early();
}
}
void update_cpu_errata_workarounds(void)
{
update_cpu_capabilities(arm64_errata, "enabling workaround for");
}
void __init enable_errata_workarounds(void)
{
enable_cpu_capabilities(arm64_errata);
}