Merge branch 'linus' into sched/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

4 files changed, 93 insertions, 34 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 99a7e5b388f2..6a936159c6e0 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -216,8 +216,8 @@ static void print_verifier_state(struct bpf_verifier_state *state)
 				reg->map_ptr->key_size,
 				reg->map_ptr->value_size);
 		if (reg->min_value != BPF_REGISTER_MIN_RANGE)
-			verbose(",min_value=%llu",
-				(unsigned long long)reg->min_value);
+			verbose(",min_value=%lld",
+				(long long)reg->min_value);
 		if (reg->max_value != BPF_REGISTER_MAX_RANGE)
 			verbose(",max_value=%llu",
 				(unsigned long long)reg->max_value);
@@ -758,7 +758,7 @@ static int check_mem_access(struct bpf_verifier_env *env, u32 regno, int off,
 			 * index'es we need to make sure that whatever we use
 			 * will have a set floor within our range.
 			 */
-			if ((s64)reg->min_value < 0) {
+			if (reg->min_value < 0) {
 				verbose("R%d min value is negative, either use unsigned index or do a if (index >=0) check.\n",
 					regno);
 				return -EACCES;
@@ -1468,7 +1468,8 @@ static void check_reg_overflow(struct bpf_reg_state *reg)
 {
 	if (reg->max_value > BPF_REGISTER_MAX_RANGE)
 		reg->max_value = BPF_REGISTER_MAX_RANGE;
-	if ((s64)reg->min_value < BPF_REGISTER_MIN_RANGE)
+	if (reg->min_value < BPF_REGISTER_MIN_RANGE ||
+	    reg->min_value > BPF_REGISTER_MAX_RANGE)
 		reg->min_value = BPF_REGISTER_MIN_RANGE;
 }
 
@@ -1476,7 +1477,8 @@ static void adjust_reg_min_max_vals(struct bpf_verifier_env *env,
 				    struct bpf_insn *insn)
 {
 	struct bpf_reg_state *regs = env->cur_state.regs, *dst_reg;
-	u64 min_val = BPF_REGISTER_MIN_RANGE, max_val = BPF_REGISTER_MAX_RANGE;
+	s64 min_val = BPF_REGISTER_MIN_RANGE;
+	u64 max_val = BPF_REGISTER_MAX_RANGE;
 	bool min_set = false, max_set = false;
 	u8 opcode = BPF_OP(insn->code);
 
@@ -1512,22 +1514,43 @@ static void adjust_reg_min_max_vals(struct bpf_verifier_env *env,
 		return;
 	}
 
+	/* If one of our values was at the end of our ranges then we can't just
+	 * do our normal operations to the register, we need to set the values
+	 * to the min/max since they are undefined.
+	 */
+	if (min_val == BPF_REGISTER_MIN_RANGE)
+		dst_reg->min_value = BPF_REGISTER_MIN_RANGE;
+	if (max_val == BPF_REGISTER_MAX_RANGE)
+		dst_reg->max_value = BPF_REGISTER_MAX_RANGE;
+
 	switch (opcode) {
 	case BPF_ADD:
-		dst_reg->min_value += min_val;
-		dst_reg->max_value += max_val;
+		if (dst_reg->min_value != BPF_REGISTER_MIN_RANGE)
+			dst_reg->min_value += min_val;
+		if (dst_reg->max_value != BPF_REGISTER_MAX_RANGE)
+			dst_reg->max_value += max_val;
 		break;
 	case BPF_SUB:
-		dst_reg->min_value -= min_val;
-		dst_reg->max_value -= max_val;
+		if (dst_reg->min_value != BPF_REGISTER_MIN_RANGE)
+			dst_reg->min_value -= min_val;
+		if (dst_reg->max_value != BPF_REGISTER_MAX_RANGE)
+			dst_reg->max_value -= max_val;
 		break;
 	case BPF_MUL:
-		dst_reg->min_value *= min_val;
-		dst_reg->max_value *= max_val;
+		if (dst_reg->min_value != BPF_REGISTER_MIN_RANGE)
+			dst_reg->min_value *= min_val;
+		if (dst_reg->max_value != BPF_REGISTER_MAX_RANGE)
+			dst_reg->max_value *= max_val;
 		break;
 	case BPF_AND:
-		/* & is special since it could end up with 0 bits set. */
-		dst_reg->min_value &= min_val;
+		/* Disallow AND'ing of negative numbers, ain't nobody got time
+		 * for that.  Otherwise the minimum is 0 and the max is the max
+		 * value we could AND against.
+		 */
+		if (min_val < 0)
+			dst_reg->min_value = BPF_REGISTER_MIN_RANGE;
+		else
+			dst_reg->min_value = 0;
 		dst_reg->max_value = max_val;
 		break;
 	case BPF_LSH:
@@ -1537,24 +1560,25 @@ static void adjust_reg_min_max_vals(struct bpf_verifier_env *env,
 		 */
 		if (min_val > ilog2(BPF_REGISTER_MAX_RANGE))
 			dst_reg->min_value = BPF_REGISTER_MIN_RANGE;
-		else
+		else if (dst_reg->min_value != BPF_REGISTER_MIN_RANGE)
 			dst_reg->min_value <<= min_val;
 
 		if (max_val > ilog2(BPF_REGISTER_MAX_RANGE))
 			dst_reg->max_value = BPF_REGISTER_MAX_RANGE;
-		else
+		else if (dst_reg->max_value != BPF_REGISTER_MAX_RANGE)
 			dst_reg->max_value <<= max_val;
 		break;
 	case BPF_RSH:
-		dst_reg->min_value >>= min_val;
-		dst_reg->max_value >>= max_val;
-		break;
-	case BPF_MOD:
-		/* % is special since it is an unsigned modulus, so the floor
-		 * will always be 0.
+		/* RSH by a negative number is undefined, and the BPF_RSH is an
+		 * unsigned shift, so make the appropriate casts.
 		 */
-		dst_reg->min_value = 0;
-		dst_reg->max_value = max_val - 1;
+		if (min_val < 0 || dst_reg->min_value < 0)
+			dst_reg->min_value = BPF_REGISTER_MIN_RANGE;
+		else
+			dst_reg->min_value =
+				(u64)(dst_reg->min_value) >> min_val;
+		if (dst_reg->max_value != BPF_REGISTER_MAX_RANGE)
+			dst_reg->max_value >>= max_val;
 		break;
 	default:
 		reset_reg_range_values(regs, insn->dst_reg);
diff --git a/kernel/exit.c b/kernel/exit.c
index 9d68c45ebbe3..3076f3089919 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -836,6 +836,7 @@ void __noreturn do_exit(long code)
 	 */
 	perf_event_exit_task(tsk);
 
+	sched_autogroup_exit_task(tsk);
 	cgroup_exit(tsk);
 
 	/*
diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h
index 51c4b24b6328..c2b88490d857 100644
--- a/kernel/locking/lockdep_internals.h
+++ b/kernel/locking/lockdep_internals.h
@@ -46,6 +46,14 @@ enum {
 		(LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)
 
 /*
+ * CONFIG_PROVE_LOCKING_SMALL is defined for sparc. Sparc requires .text,
+ * .data and .bss to fit in required 32MB limit for the kernel. With
+ * PROVE_LOCKING we could go over this limit and cause system boot-up problems.
+ * So, reduce the static allocations for lockdeps related structures so that
+ * everything fits in current required size limit.
+ */
+#ifdef CONFIG_PROVE_LOCKING_SMALL
+/*
  * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
  * we track.
  *
@@ -54,18 +62,24 @@ enum {
  * table (if it's not there yet), and we check it for lock order
  * conflicts and deadlocks.
  */
+#define MAX_LOCKDEP_ENTRIES	16384UL
+#define MAX_LOCKDEP_CHAINS_BITS	15
+#define MAX_STACK_TRACE_ENTRIES	262144UL
+#else
 #define MAX_LOCKDEP_ENTRIES	32768UL
 
 #define MAX_LOCKDEP_CHAINS_BITS	16
-#define MAX_LOCKDEP_CHAINS	(1UL << MAX_LOCKDEP_CHAINS_BITS)
-
-#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
 
 /*
  * Stack-trace: tightly packed array of stack backtrace
  * addresses. Protected by the hash_lock.
  */
 #define MAX_STACK_TRACE_ENTRIES	524288UL
+#endif
+
+#define MAX_LOCKDEP_CHAINS	(1UL << MAX_LOCKDEP_CHAINS_BITS)
+
+#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
 
 extern struct list_head all_lock_classes;
 extern struct lock_chain lock_chains[];
diff --git a/kernel/sched/auto_group.c b/kernel/sched/auto_group.c
index a5d966cb8891..f1c8fd566246 100644
--- a/kernel/sched/auto_group.c
+++ b/kernel/sched/auto_group.c
@@ -111,10 +111,13 @@ bool task_wants_autogroup(struct task_struct *p, struct task_group *tg)
 {
 	if (tg != &root_task_group)
 		return false;
-
 	/*
-	 * We can only assume the task group can't go away on us if
-	 * autogroup_move_group() can see us on ->thread_group list.
+	 * If we race with autogroup_move_group() the caller can use the old
+	 * value of signal->autogroup but in this case sched_move_task() will
+	 * be called again before autogroup_kref_put().
+	 *
+	 * However, there is no way sched_autogroup_exit_task() could tell us
+	 * to avoid autogroup->tg, so we abuse PF_EXITING flag for this case.
 	 */
 	if (p->flags & PF_EXITING)
 		return false;
@@ -122,6 +125,16 @@ bool task_wants_autogroup(struct task_struct *p, struct task_group *tg)
 	return true;
 }
 
+void sched_autogroup_exit_task(struct task_struct *p)
+{
+	/*
+	 * We are going to call exit_notify() and autogroup_move_group() can't
+	 * see this thread after that: we can no longer use signal->autogroup.
+	 * See the PF_EXITING check in task_wants_autogroup().
+	 */
+	sched_move_task(p);
+}
+
 static void
 autogroup_move_group(struct task_struct *p, struct autogroup *ag)
 {
@@ -138,13 +151,20 @@ autogroup_move_group(struct task_struct *p, struct autogroup *ag)
 	}
 
 	p->signal->autogroup = autogroup_kref_get(ag);
-
-	if (!READ_ONCE(sysctl_sched_autogroup_enabled))
-		goto out;
-
+	/*
+	 * We can't avoid sched_move_task() after we changed signal->autogroup,
+	 * this process can already run with task_group() == prev->tg or we can
+	 * race with cgroup code which can read autogroup = prev under rq->lock.
+	 * In the latter case for_each_thread() can not miss a migrating thread,
+	 * cpu_cgroup_attach() must not be possible after cgroup_exit() and it
+	 * can't be removed from thread list, we hold ->siglock.
+	 *
+	 * If an exiting thread was already removed from thread list we rely on
+	 * sched_autogroup_exit_task().
+	 */
 	for_each_thread(p, t)
 		sched_move_task(t);
-out:
+
 	unlock_task_sighand(p, &flags);
 	autogroup_kref_put(prev);
 }