diff options
Diffstat (limited to 'arch/arm64/kernel/ssbd.c')
| -rw-r--r-- | arch/arm64/kernel/ssbd.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/arch/arm64/kernel/ssbd.c b/arch/arm64/kernel/ssbd.c index 3432e5ef9f41..885f13e58708 100644 --- a/arch/arm64/kernel/ssbd.c +++ b/arch/arm64/kernel/ssbd.c @@ -3,17 +3,33 @@ * Copyright (C) 2018 ARM Ltd, All Rights Reserved. */ +#include <linux/compat.h> #include <linux/errno.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 - * FIXME: Drop the below ifdefery once merged in 4.18. */ -#ifdef PR_SPEC_STORE_BYPASS static int ssbd_prctl_set(struct task_struct *task, unsigned long ctrl) { int state = arm64_get_ssbd_state(); @@ -46,12 +62,14 @@ 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) @@ -59,6 +77,7 @@ 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; @@ -107,4 +126,3 @@ int arch_prctl_spec_ctrl_get(struct task_struct *task, unsigned long which) return -ENODEV; } } -#endif /* PR_SPEC_STORE_BYPASS */ |