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Diffstat (limited to 'arch/arm64/kernel/ssbd.c')
-rw-r--r--arch/arm64/kernel/ssbd.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/arm64/kernel/ssbd.c b/arch/arm64/kernel/ssbd.c
index 0560738c1d5c..58de005cd756 100644
--- a/arch/arm64/kernel/ssbd.c
+++ b/arch/arm64/kernel/ssbd.c
@@ -3,13 +3,32 @@
* 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/compat.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
*/
@@ -45,12 +64,14 @@ static int ssbd_prctl_set(struct task_struct *task, unsigned long ctrl)
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)
@@ -58,6 +79,7 @@ static int ssbd_prctl_set(struct task_struct *task, unsigned long ctrl)
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;