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

4 files changed, 102 insertions, 36 deletions

diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index 533e04e75a9c..f51b762d6886 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -234,7 +234,7 @@ extern struct task_struct *kdb_curr_task(int);
 #define	kdb_do_each_thread(g, p) do_each_thread(g, p)
 #define	kdb_while_each_thread(g, p) while_each_thread(g, p)
 
-#define GFP_KDB (in_interrupt() ? GFP_ATOMIC : GFP_KERNEL)
+#define GFP_KDB (in_dbg_master() ? GFP_ATOMIC : GFP_KERNEL)
 
 extern void *debug_kmalloc(size_t size, gfp_t flags);
 extern void debug_kfree(void *);
diff --git a/kernel/futex.c b/kernel/futex.c
index dcc7d0e9138f..cb96565ad7c0 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -874,7 +874,9 @@ static void free_pi_state(struct futex_pi_state *pi_state)
 	 * and has cleaned up the pi_state already
 	 */
 	if (pi_state->owner) {
+		raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);
 		pi_state_update_owner(pi_state, NULL);
+		raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);
 		rt_mutex_proxy_unlock(&pi_state->pi_mutex);
 	}
 
@@ -1406,7 +1408,7 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this,
 	if (pi_state->owner != current)
 		return -EINVAL;
 
-	raw_spin_lock(&pi_state->pi_mutex.wait_lock);
+	raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);
 	new_owner = rt_mutex_next_owner(&pi_state->pi_mutex);
 
 	/*
@@ -2248,10 +2250,6 @@ static int __fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
 
 	oldowner = pi_state->owner;
 
-	/* Owner died? */
-	if (!pi_state->owner)
-		newtid |= FUTEX_OWNER_DIED;
-
 	/*
 	 * We are here because either:
 	 *
@@ -2287,7 +2285,7 @@ retry:
 		}
 
 		if (__rt_mutex_futex_trylock(&pi_state->pi_mutex)) {
-			/* We got the lock after all, nothing to fix. */
+			/* We got the lock. pi_state is correct. Tell caller */
 			return 1;
 		}
 
@@ -2309,6 +2307,9 @@ retry:
 	}
 
 	newtid = task_pid_vnr(newowner) | FUTEX_WAITERS;
+	/* Owner died? */
+	if (!pi_state->owner)
+		newtid |= FUTEX_OWNER_DIED;
 
 	if (get_futex_value_locked(&uval, uaddr))
 		goto handle_fault;
@@ -2329,7 +2330,7 @@ retry:
 	 */
 	pi_state_update_owner(pi_state, newowner);
 
-	return 0;
+	return argowner == current;
 
 	/*
 	 * To handle the page fault we need to drop the hash bucket
@@ -2412,8 +2413,6 @@ static long futex_wait_restart(struct restart_block *restart);
  */
 static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked)
 {
-	int ret = 0;
-
 	if (locked) {
 		/*
 		 * Got the lock. We might not be the anticipated owner if we
@@ -2424,8 +2423,8 @@ static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked)
 		 * stable state, anything else needs more attention.
 		 */
 		if (q->pi_state->owner != current)
-			ret = fixup_pi_state_owner(uaddr, q, current);
-		goto out;
+			return fixup_pi_state_owner(uaddr, q, current);
+		return 1;
 	}
 
 	/*
@@ -2436,10 +2435,8 @@ static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked)
 	 * Another speculative read; pi_state->owner == current is unstable
 	 * but needs our attention.
 	 */
-	if (q->pi_state->owner == current) {
-		ret = fixup_pi_state_owner(uaddr, q, NULL);
-		goto out;
-	}
+	if (q->pi_state->owner == current)
+		return fixup_pi_state_owner(uaddr, q, NULL);
 
 	/*
 	 * Paranoia check. If we did not take the lock, then we should not be
@@ -2448,8 +2445,7 @@ static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked)
 	if (WARN_ON_ONCE(rt_mutex_owner(&q->pi_state->pi_mutex) == current))
 		return fixup_pi_state_owner(uaddr, q, current);
 
-out:
-	return ret ? ret : locked;
+	return 0;
 }
 
 /**
@@ -3071,6 +3067,11 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
 			 */
 			free_pi_state(q.pi_state);
 			spin_unlock(q.lock_ptr);
+			/*
+			 * Adjust the return value. It's either -EFAULT or
+			 * success (1) but the caller expects 0 for success.
+			 */
+			ret = ret < 0 ? ret : 0;
 		}
 	} else {
 		struct rt_mutex *pi_mutex;
diff --git a/kernel/module.c b/kernel/module.c
index 3b3c4723fe68..7ce940ab20dc 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2107,6 +2107,21 @@ static int verify_export_symbols(struct module *mod)
 	return 0;
 }
 
+static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
+{
+	/*
+	 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
+	 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
+	 * i386 has a similar problem but may not deserve a fix.
+	 *
+	 * If we ever have to ignore many symbols, consider refactoring the code to
+	 * only warn if referenced by a relocation.
+	 */
+	if (emachine == EM_386 || emachine == EM_X86_64)
+		return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
+	return false;
+}
+
 /* Change all symbols so that st_value encodes the pointer directly. */
 static int simplify_symbols(struct module *mod, const struct load_info *info)
 {
@@ -2148,8 +2163,10 @@ static int simplify_symbols(struct module *mod, const struct load_info *info)
 				break;
 			}
 
-			/* Ok if weak.  */
-			if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
+			/* Ok if weak or ignored.  */
+			if (!ksym &&
+			    (ELF_ST_BIND(sym[i].st_info) == STB_WEAK ||
+			     ignore_undef_symbol(info->hdr->e_machine, name)))
 				break;
 
 			pr_warn("%s: Unknown symbol %s (err %li)\n",
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 */