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-rw-r--r--arch/arm64/kernel/Makefile2
-rw-r--r--arch/arm64/kernel/proton-pack.c118
-rw-r--r--arch/arm64/kernel/ssbd.c129
3 files changed, 119 insertions, 130 deletions
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 15b0fcbb6883..bd12b9a2ab4a 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -19,7 +19,7 @@ obj-y := debug-monitors.o entry.o irq.o fpsimd.o \
return_address.o cpuinfo.o cpu_errata.o \
cpufeature.o alternative.o cacheinfo.o \
smp.o smp_spin_table.o topology.o smccc-call.o \
- ssbd.o syscall.o proton-pack.o
+ syscall.o proton-pack.o
targets += efi-entry.o
diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c
index 4f1411b45301..b373e4782ccd 100644
--- a/arch/arm64/kernel/proton-pack.c
+++ b/arch/arm64/kernel/proton-pack.c
@@ -20,6 +20,7 @@
#include <linux/arm-smccc.h>
#include <linux/cpu.h>
#include <linux/device.h>
+#include <linux/nospec.h>
#include <linux/prctl.h>
#include <asm/spectre.h>
@@ -318,3 +319,120 @@ void spectre_v2_enable_mitigation(const struct arm64_cpu_capabilities *__unused)
update_mitigation_state(&spectre_v2_state, state);
}
+
+/* Spectre v4 prctl */
+static void ssbd_ssbs_enable(struct task_struct *task)
+{
+ u64 val = is_compat_thread(task_thread_info(task)) ?
+ PSR_AA32_SSBS_BIT : PSR_SSBS_BIT;
+
+ task_pt_regs(task)->pstate |= val;
+}
+
+static void ssbd_ssbs_disable(struct task_struct *task)
+{
+ u64 val = is_compat_thread(task_thread_info(task)) ?
+ PSR_AA32_SSBS_BIT : PSR_SSBS_BIT;
+
+ task_pt_regs(task)->pstate &= ~val;
+}
+
+/*
+ * prctl interface for SSBD
+ */
+static int ssbd_prctl_set(struct task_struct *task, unsigned long ctrl)
+{
+ int state = arm64_get_ssbd_state();
+
+ /* Unsupported */
+ if (state == ARM64_SSBD_UNKNOWN)
+ return -ENODEV;
+
+ /* Treat the unaffected/mitigated state separately */
+ if (state == ARM64_SSBD_MITIGATED) {
+ switch (ctrl) {
+ case PR_SPEC_ENABLE:
+ return -EPERM;
+ case PR_SPEC_DISABLE:
+ case PR_SPEC_FORCE_DISABLE:
+ return 0;
+ }
+ }
+
+ /*
+ * Things are a bit backward here: the arm64 internal API
+ * *enables the mitigation* when the userspace API *disables
+ * speculation*. So much fun.
+ */
+ switch (ctrl) {
+ case PR_SPEC_ENABLE:
+ /* If speculation is force disabled, enable is not allowed */
+ if (state == ARM64_SSBD_FORCE_ENABLE ||
+ task_spec_ssb_force_disable(task))
+ return -EPERM;
+ task_clear_spec_ssb_disable(task);
+ clear_tsk_thread_flag(task, TIF_SSBD);
+ ssbd_ssbs_enable(task);
+ break;
+ case PR_SPEC_DISABLE:
+ if (state == ARM64_SSBD_FORCE_DISABLE)
+ return -EPERM;
+ task_set_spec_ssb_disable(task);
+ set_tsk_thread_flag(task, TIF_SSBD);
+ ssbd_ssbs_disable(task);
+ break;
+ case PR_SPEC_FORCE_DISABLE:
+ if (state == ARM64_SSBD_FORCE_DISABLE)
+ return -EPERM;
+ task_set_spec_ssb_disable(task);
+ task_set_spec_ssb_force_disable(task);
+ set_tsk_thread_flag(task, TIF_SSBD);
+ ssbd_ssbs_disable(task);
+ break;
+ default:
+ return -ERANGE;
+ }
+
+ return 0;
+}
+
+int arch_prctl_spec_ctrl_set(struct task_struct *task, unsigned long which,
+ unsigned long ctrl)
+{
+ switch (which) {
+ case PR_SPEC_STORE_BYPASS:
+ return ssbd_prctl_set(task, ctrl);
+ default:
+ return -ENODEV;
+ }
+}
+
+static int ssbd_prctl_get(struct task_struct *task)
+{
+ switch (arm64_get_ssbd_state()) {
+ case ARM64_SSBD_UNKNOWN:
+ return -ENODEV;
+ case ARM64_SSBD_FORCE_ENABLE:
+ return PR_SPEC_DISABLE;
+ case ARM64_SSBD_KERNEL:
+ if (task_spec_ssb_force_disable(task))
+ return PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE;
+ if (task_spec_ssb_disable(task))
+ return PR_SPEC_PRCTL | PR_SPEC_DISABLE;
+ return PR_SPEC_PRCTL | PR_SPEC_ENABLE;
+ case ARM64_SSBD_FORCE_DISABLE:
+ return PR_SPEC_ENABLE;
+ default:
+ return PR_SPEC_NOT_AFFECTED;
+ }
+}
+
+int arch_prctl_spec_ctrl_get(struct task_struct *task, unsigned long which)
+{
+ switch (which) {
+ case PR_SPEC_STORE_BYPASS:
+ return ssbd_prctl_get(task);
+ default:
+ return -ENODEV;
+ }
+}
diff --git a/arch/arm64/kernel/ssbd.c b/arch/arm64/kernel/ssbd.c
deleted file mode 100644
index b26955f56750..000000000000
--- a/arch/arm64/kernel/ssbd.c
+++ /dev/null
@@ -1,129 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (C) 2018 ARM Ltd, All Rights Reserved.
- */
-
-#include <linux/compat.h>
-#include <linux/errno.h>
-#include <linux/prctl.h>
-#include <linux/sched.h>
-#include <linux/sched/task_stack.h>
-#include <linux/thread_info.h>
-
-#include <asm/cpufeature.h>
-
-static void ssbd_ssbs_enable(struct task_struct *task)
-{
- u64 val = is_compat_thread(task_thread_info(task)) ?
- PSR_AA32_SSBS_BIT : PSR_SSBS_BIT;
-
- task_pt_regs(task)->pstate |= val;
-}
-
-static void ssbd_ssbs_disable(struct task_struct *task)
-{
- u64 val = is_compat_thread(task_thread_info(task)) ?
- PSR_AA32_SSBS_BIT : PSR_SSBS_BIT;
-
- task_pt_regs(task)->pstate &= ~val;
-}
-
-/*
- * prctl interface for SSBD
- */
-static int ssbd_prctl_set(struct task_struct *task, unsigned long ctrl)
-{
- int state = arm64_get_ssbd_state();
-
- /* Unsupported */
- if (state == ARM64_SSBD_UNKNOWN)
- return -ENODEV;
-
- /* Treat the unaffected/mitigated state separately */
- if (state == ARM64_SSBD_MITIGATED) {
- switch (ctrl) {
- case PR_SPEC_ENABLE:
- return -EPERM;
- case PR_SPEC_DISABLE:
- case PR_SPEC_FORCE_DISABLE:
- return 0;
- }
- }
-
- /*
- * Things are a bit backward here: the arm64 internal API
- * *enables the mitigation* when the userspace API *disables
- * speculation*. So much fun.
- */
- switch (ctrl) {
- case PR_SPEC_ENABLE:
- /* If speculation is force disabled, enable is not allowed */
- if (state == ARM64_SSBD_FORCE_ENABLE ||
- task_spec_ssb_force_disable(task))
- return -EPERM;
- task_clear_spec_ssb_disable(task);
- clear_tsk_thread_flag(task, TIF_SSBD);
- ssbd_ssbs_enable(task);
- break;
- case PR_SPEC_DISABLE:
- if (state == ARM64_SSBD_FORCE_DISABLE)
- return -EPERM;
- task_set_spec_ssb_disable(task);
- set_tsk_thread_flag(task, TIF_SSBD);
- ssbd_ssbs_disable(task);
- break;
- case PR_SPEC_FORCE_DISABLE:
- if (state == ARM64_SSBD_FORCE_DISABLE)
- return -EPERM;
- task_set_spec_ssb_disable(task);
- task_set_spec_ssb_force_disable(task);
- set_tsk_thread_flag(task, TIF_SSBD);
- ssbd_ssbs_disable(task);
- break;
- default:
- return -ERANGE;
- }
-
- return 0;
-}
-
-int arch_prctl_spec_ctrl_set(struct task_struct *task, unsigned long which,
- unsigned long ctrl)
-{
- switch (which) {
- case PR_SPEC_STORE_BYPASS:
- return ssbd_prctl_set(task, ctrl);
- default:
- return -ENODEV;
- }
-}
-
-static int ssbd_prctl_get(struct task_struct *task)
-{
- switch (arm64_get_ssbd_state()) {
- case ARM64_SSBD_UNKNOWN:
- return -ENODEV;
- case ARM64_SSBD_FORCE_ENABLE:
- return PR_SPEC_DISABLE;
- case ARM64_SSBD_KERNEL:
- if (task_spec_ssb_force_disable(task))
- return PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE;
- if (task_spec_ssb_disable(task))
- return PR_SPEC_PRCTL | PR_SPEC_DISABLE;
- return PR_SPEC_PRCTL | PR_SPEC_ENABLE;
- case ARM64_SSBD_FORCE_DISABLE:
- return PR_SPEC_ENABLE;
- default:
- return PR_SPEC_NOT_AFFECTED;
- }
-}
-
-int arch_prctl_spec_ctrl_get(struct task_struct *task, unsigned long which)
-{
- switch (which) {
- case PR_SPEC_STORE_BYPASS:
- return ssbd_prctl_get(task);
- default:
- return -ENODEV;
- }
-}
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