Merge branch 'android-4.4-p' of https://android.googlesource.com/kernel/common into lineage-18.1-caf-msm8998

This brings LA.UM.9.2.r1-02700-SDMxx0.0 up to date with
https://android.googlesource.com/kernel/common/ android-4.4-p at commit:
58bc8e0469d08 Merge 4.4.261 into android-4.4-p

Conflicts:
	drivers/block/zram/zram_drv.c
	drivers/block/zram/zram_drv.h
	mm/zsmalloc.c

Change-Id: I451bffa685eaaea04938bc6d0b8e3f4bb0f869e9

1 files changed, 64 insertions, 16 deletions

diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index eda85bbf1c2e..a1f9be703002 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -59,6 +59,12 @@ struct tp_probes {
 	struct tracepoint_func probes[0];
 };
 
+/* Called in removal of a func but failed to allocate a new tp_funcs */
+static void tp_stub_func(void)
+{
+	return;
+}
+
 static inline void *allocate_probes(int count)
 {
 	struct tp_probes *p  = kmalloc(count * sizeof(struct tracepoint_func)
@@ -97,6 +103,7 @@ func_add(struct tracepoint_func **funcs, struct tracepoint_func *tp_func,
 {
 	struct tracepoint_func *old, *new;
 	int nr_probes = 0;
+	int stub_funcs = 0;
 	int pos = -1;
 
 	if (WARN_ON(!tp_func->func))
@@ -113,14 +120,34 @@ func_add(struct tracepoint_func **funcs, struct tracepoint_func *tp_func,
 			if (old[nr_probes].func == tp_func->func &&
 			    old[nr_probes].data == tp_func->data)
 				return ERR_PTR(-EEXIST);
+			if (old[nr_probes].func == tp_stub_func)
+				stub_funcs++;
 		}
 	}
-	/* + 2 : one for new probe, one for NULL func */
-	new = allocate_probes(nr_probes + 2);
+	/* + 2 : one for new probe, one for NULL func - stub functions */
+	new = allocate_probes(nr_probes + 2 - stub_funcs);
 	if (new == NULL)
 		return ERR_PTR(-ENOMEM);
 	if (old) {
-		if (pos < 0) {
+		if (stub_funcs) {
+			/* Need to copy one at a time to remove stubs */
+			int probes = 0;
+
+			pos = -1;
+			for (nr_probes = 0; old[nr_probes].func; nr_probes++) {
+				if (old[nr_probes].func == tp_stub_func)
+					continue;
+				if (pos < 0 && old[nr_probes].prio < prio)
+					pos = probes++;
+				new[probes++] = old[nr_probes];
+			}
+			nr_probes = probes;
+			if (pos < 0)
+				pos = probes;
+			else
+				nr_probes--; /* Account for insertion */
+
+		} else if (pos < 0) {
 			pos = nr_probes;
 			memcpy(new, old, nr_probes * sizeof(struct tracepoint_func));
 		} else {
@@ -154,8 +181,9 @@ static void *func_remove(struct tracepoint_func **funcs,
 	/* (N -> M), (N > 1, M >= 0) probes */
 	if (tp_func->func) {
 		for (nr_probes = 0; old[nr_probes].func; nr_probes++) {
-			if (old[nr_probes].func == tp_func->func &&
-			     old[nr_probes].data == tp_func->data)
+			if ((old[nr_probes].func == tp_func->func &&
+			     old[nr_probes].data == tp_func->data) ||
+			    old[nr_probes].func == tp_stub_func)
 				nr_del++;
 		}
 	}
@@ -174,14 +202,32 @@ static void *func_remove(struct tracepoint_func **funcs,
 		/* N -> M, (N > 1, M > 0) */
 		/* + 1 for NULL */
 		new = allocate_probes(nr_probes - nr_del + 1);
-		if (new == NULL)
-			return ERR_PTR(-ENOMEM);
-		for (i = 0; old[i].func; i++)
-			if (old[i].func != tp_func->func
-					|| old[i].data != tp_func->data)
-				new[j++] = old[i];
-		new[nr_probes - nr_del].func = NULL;
-		*funcs = new;
+		if (new) {
+			for (i = 0; old[i].func; i++)
+				if ((old[i].func != tp_func->func
+				     || old[i].data != tp_func->data)
+				    && old[i].func != tp_stub_func)
+					new[j++] = old[i];
+			new[nr_probes - nr_del].func = NULL;
+			*funcs = new;
+		} else {
+			/*
+			 * Failed to allocate, replace the old function
+			 * with calls to tp_stub_func.
+			 */
+			for (i = 0; old[i].func; i++)
+				if (old[i].func == tp_func->func &&
+				    old[i].data == tp_func->data) {
+					old[i].func = tp_stub_func;
+					/* Set the prio to the next event. */
+					if (old[i + 1].func)
+						old[i].prio =
+							old[i + 1].prio;
+					else
+						old[i].prio = -1;
+				}
+			*funcs = old;
+		}
 	}
 	debug_print_probes(*funcs);
 	return old;
@@ -234,10 +280,12 @@ static int tracepoint_remove_func(struct tracepoint *tp,
 	tp_funcs = rcu_dereference_protected(tp->funcs,
 			lockdep_is_held(&tracepoints_mutex));
 	old = func_remove(&tp_funcs, func);
-	if (IS_ERR(old)) {
-		WARN_ON_ONCE(PTR_ERR(old) != -ENOMEM);
+	if (WARN_ON_ONCE(IS_ERR(old)))
 		return PTR_ERR(old);
-	}
+
+	if (tp_funcs == old)
+		/* Failed allocating new tp_funcs, replaced func with stub */
+		return 0;
 
 	if (!tp_funcs) {
 		/* Removed last function */