diff options
Diffstat (limited to 'arch/x86/kernel/cpu/bugs.c')
-rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 1a5a1b085eaa..ecfca3bbcd96 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1252,6 +1252,24 @@ static void task_update_spec_tif(struct task_struct *tsk) speculation_ctrl_update_current(); } +static int l1d_flush_prctl_set(struct task_struct *task, unsigned long ctrl) +{ + + if (!static_branch_unlikely(&switch_mm_cond_l1d_flush)) + return -EPERM; + + switch (ctrl) { + case PR_SPEC_ENABLE: + set_ti_thread_flag(&task->thread_info, TIF_SPEC_L1D_FLUSH); + return 0; + case PR_SPEC_DISABLE: + clear_ti_thread_flag(&task->thread_info, TIF_SPEC_L1D_FLUSH); + return 0; + default: + return -ERANGE; + } +} + static int ssb_prctl_set(struct task_struct *task, unsigned long ctrl) { if (ssb_mode != SPEC_STORE_BYPASS_PRCTL && @@ -1361,6 +1379,8 @@ int arch_prctl_spec_ctrl_set(struct task_struct *task, unsigned long which, return ssb_prctl_set(task, ctrl); case PR_SPEC_INDIRECT_BRANCH: return ib_prctl_set(task, ctrl); + case PR_SPEC_L1D_FLUSH: + return l1d_flush_prctl_set(task, ctrl); default: return -ENODEV; } @@ -1377,6 +1397,17 @@ void arch_seccomp_spec_mitigate(struct task_struct *task) } #endif +static int l1d_flush_prctl_get(struct task_struct *task) +{ + if (!static_branch_unlikely(&switch_mm_cond_l1d_flush)) + return PR_SPEC_FORCE_DISABLE; + + if (test_ti_thread_flag(&task->thread_info, TIF_SPEC_L1D_FLUSH)) + return PR_SPEC_PRCTL | PR_SPEC_ENABLE; + else + return PR_SPEC_PRCTL | PR_SPEC_DISABLE; +} + static int ssb_prctl_get(struct task_struct *task) { switch (ssb_mode) { @@ -1427,6 +1458,8 @@ int arch_prctl_spec_ctrl_get(struct task_struct *task, unsigned long which) return ssb_prctl_get(task); case PR_SPEC_INDIRECT_BRANCH: return ib_prctl_get(task); + case PR_SPEC_L1D_FLUSH: + return l1d_flush_prctl_get(task); default: return -ENODEV; } |