prctl: Add force disable speculation

For certain use cases it is desired to enforce mitigations so they cannot
be undone afterwards. That's important for loader stubs which want to
prevent a child from disabling the mitigation again. Will also be used for
seccomp(). The extra state preserving of the prctl state for SSB is a
preparatory step for EBPF dymanic speculation control.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 303c155f9b04..d178a0236514 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -344,6 +344,9 @@ static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
         case PR_SPEC_NOT_AFFECTED:
                 seq_printf(m, "not vulnerable");
                 break;
+        case PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE:
+                seq_printf(m, "thread force mitigated");
+                break;
         case PR_SPEC_PRCTL | PR_SPEC_DISABLE:
                 seq_printf(m, "thread mitigated");
                 break;