Merge "Merge android-4.4.145 (05670d3) into msm-4.4"

2 files changed, 35 insertions, 6 deletions

diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index efd384f3f852..9a9203b15cde 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -16,6 +16,8 @@
 #include <linux/atomic.h>
 #include <linux/audit.h>
 #include <linux/compat.h>
+#include <linux/nospec.h>
+#include <linux/prctl.h>
 #include <linux/sched.h>
 #include <linux/seccomp.h>
 #include <linux/slab.h>
@@ -214,8 +216,11 @@ static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode)
 	return true;
 }
 
+void __weak arch_seccomp_spec_mitigate(struct task_struct *task) { }
+
 static inline void seccomp_assign_mode(struct task_struct *task,
-				       unsigned long seccomp_mode)
+				       unsigned long seccomp_mode,
+				       unsigned long flags)
 {
 	assert_spin_locked(&task->sighand->siglock);
 
@@ -225,6 +230,9 @@ static inline void seccomp_assign_mode(struct task_struct *task,
 	 * filter) is set.
 	 */
 	smp_mb__before_atomic();
+	/* Assume default seccomp processes want spec flaw mitigation. */
+	if ((flags & SECCOMP_FILTER_FLAG_SPEC_ALLOW) == 0)
+		arch_seccomp_spec_mitigate(task);
 	set_tsk_thread_flag(task, TIF_SECCOMP);
 }
 
@@ -292,7 +300,7 @@ static inline pid_t seccomp_can_sync_threads(void)
  * without dropping the locks.
  *
  */
-static inline void seccomp_sync_threads(void)
+static inline void seccomp_sync_threads(unsigned long flags)
 {
 	struct task_struct *thread, *caller;
 
@@ -333,7 +341,8 @@ static inline void seccomp_sync_threads(void)
 		 * allow one thread to transition the other.
 		 */
 		if (thread->seccomp.mode == SECCOMP_MODE_DISABLED)
-			seccomp_assign_mode(thread, SECCOMP_MODE_FILTER);
+			seccomp_assign_mode(thread, SECCOMP_MODE_FILTER,
+					    flags);
 	}
 }
 
@@ -452,7 +461,7 @@ static long seccomp_attach_filter(unsigned int flags,
 
 	/* Now that the new filter is in place, synchronize to all threads. */
 	if (flags & SECCOMP_FILTER_FLAG_TSYNC)
-		seccomp_sync_threads();
+		seccomp_sync_threads(flags);
 
 	return 0;
 }
@@ -747,7 +756,7 @@ static long seccomp_set_mode_strict(void)
 #ifdef TIF_NOTSC
 	disable_TSC();
 #endif
-	seccomp_assign_mode(current, seccomp_mode);
+	seccomp_assign_mode(current, seccomp_mode, 0);
 	ret = 0;
 
 out:
@@ -805,7 +814,7 @@ static long seccomp_set_mode_filter(unsigned int flags,
 	/* Do not free the successfully attached filter. */
 	prepared = NULL;
 
-	seccomp_assign_mode(current, seccomp_mode);
+	seccomp_assign_mode(current, seccomp_mode, flags);
 out:
 	spin_unlock_irq(&current->sighand->siglock);
 	if (flags & SECCOMP_FILTER_FLAG_TSYNC)
diff --git a/kernel/sys.c b/kernel/sys.c
index cf40663a54c2..3195435462a6 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -2224,6 +2224,17 @@ static int prctl_set_vma(unsigned long opt, unsigned long start,
 }
 #endif
 
+int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
+{
+	return -EINVAL;
+}
+
+int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
+				    unsigned long ctrl)
+{
+	return -EINVAL;
+}
+
 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 		unsigned long, arg4, unsigned long, arg5)
 {
@@ -2444,6 +2455,15 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 		break;
 	case PR_SET_VMA:
 		error = prctl_set_vma(arg2, arg3, arg4, arg5);
+	case PR_GET_SPECULATION_CTRL:
+		if (arg3 || arg4 || arg5)
+			return -EINVAL;
+		error = arch_prctl_spec_ctrl_get(me, arg2);
+		break;
+	case PR_SET_SPECULATION_CTRL:
+		if (arg4 || arg5)
+			return -EINVAL;
+		error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
 		break;
 	default:
 		error = -EINVAL;