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

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

4 files changed, 72 insertions, 27 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 2ce967a63ede..1904e814f282 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -156,7 +156,29 @@ struct bpf_verifier_stack_elem {
 #define BPF_COMPLEXITY_LIMIT_INSNS	131072
 #define BPF_COMPLEXITY_LIMIT_STACK	1024
 
-#define BPF_MAP_PTR_POISON ((void *)0xeB9F + POISON_POINTER_DELTA)
+#define BPF_MAP_PTR_UNPRIV	1UL
+#define BPF_MAP_PTR_POISON	((void *)((0xeB9FUL << 1) +	\
+					  POISON_POINTER_DELTA))
+#define BPF_MAP_PTR(X)		((struct bpf_map *)((X) & ~BPF_MAP_PTR_UNPRIV))
+
+static bool bpf_map_ptr_poisoned(const struct bpf_insn_aux_data *aux)
+{
+	return BPF_MAP_PTR(aux->map_state) == BPF_MAP_PTR_POISON;
+}
+
+static bool bpf_map_ptr_unpriv(const struct bpf_insn_aux_data *aux)
+{
+	return aux->map_state & BPF_MAP_PTR_UNPRIV;
+}
+
+static void bpf_map_ptr_store(struct bpf_insn_aux_data *aux,
+			      const struct bpf_map *map, bool unpriv)
+{
+	BUILD_BUG_ON((unsigned long)BPF_MAP_PTR_POISON & BPF_MAP_PTR_UNPRIV);
+	unpriv |= bpf_map_ptr_unpriv(aux);
+	aux->map_state = (unsigned long)map |
+			 (unpriv ? BPF_MAP_PTR_UNPRIV : 0UL);
+}
 
 struct bpf_call_arg_meta {
 	struct bpf_map *map_ptr;
@@ -2358,6 +2380,29 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
 	return 0;
 }
 
+static int
+record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
+		int func_id, int insn_idx)
+{
+	struct bpf_insn_aux_data *aux = &env->insn_aux_data[insn_idx];
+
+	if (func_id != BPF_FUNC_tail_call &&
+	    func_id != BPF_FUNC_map_lookup_elem)
+		return 0;
+	if (meta->map_ptr == NULL) {
+		verbose(env, "kernel subsystem misconfigured verifier\n");
+		return -EINVAL;
+	}
+
+	if (!BPF_MAP_PTR(aux->map_state))
+		bpf_map_ptr_store(aux, meta->map_ptr,
+				  meta->map_ptr->unpriv_array);
+	else if (BPF_MAP_PTR(aux->map_state) != meta->map_ptr)
+		bpf_map_ptr_store(aux, BPF_MAP_PTR_POISON,
+				  meta->map_ptr->unpriv_array);
+	return 0;
+}
+
 static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn_idx)
 {
 	const struct bpf_func_proto *fn = NULL;
@@ -2412,13 +2457,6 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
 	err = check_func_arg(env, BPF_REG_2, fn->arg2_type, &meta);
 	if (err)
 		return err;
-	if (func_id == BPF_FUNC_tail_call) {
-		if (meta.map_ptr == NULL) {
-			verbose(env, "verifier bug\n");
-			return -EINVAL;
-		}
-		env->insn_aux_data[insn_idx].map_ptr = meta.map_ptr;
-	}
 	err = check_func_arg(env, BPF_REG_3, fn->arg3_type, &meta);
 	if (err)
 		return err;
@@ -2429,6 +2467,10 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
 	if (err)
 		return err;
 
+	err = record_func_map(env, &meta, func_id, insn_idx);
+	if (err)
+		return err;
+
 	/* Mark slots with STACK_MISC in case of raw mode, stack offset
 	 * is inferred from register state.
 	 */
@@ -2453,8 +2495,6 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
 	} else if (fn->ret_type == RET_VOID) {
 		regs[BPF_REG_0].type = NOT_INIT;
 	} else if (fn->ret_type == RET_PTR_TO_MAP_VALUE_OR_NULL) {
-		struct bpf_insn_aux_data *insn_aux;
-
 		regs[BPF_REG_0].type = PTR_TO_MAP_VALUE_OR_NULL;
 		/* There is no offset yet applied, variable or fixed */
 		mark_reg_known_zero(env, regs, BPF_REG_0);
@@ -2470,11 +2510,6 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
 		}
 		regs[BPF_REG_0].map_ptr = meta.map_ptr;
 		regs[BPF_REG_0].id = ++env->id_gen;
-		insn_aux = &env->insn_aux_data[insn_idx];
-		if (!insn_aux->map_ptr)
-			insn_aux->map_ptr = meta.map_ptr;
-		else if (insn_aux->map_ptr != meta.map_ptr)
-			insn_aux->map_ptr = BPF_MAP_PTR_POISON;
 	} else {
 		verbose(env, "unknown return type %d of func %s#%d\n",
 			fn->ret_type, func_id_name(func_id), func_id);
@@ -5470,6 +5505,7 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env)
 	struct bpf_insn *insn = prog->insnsi;
 	const struct bpf_func_proto *fn;
 	const int insn_cnt = prog->len;
+	struct bpf_insn_aux_data *aux;
 	struct bpf_insn insn_buf[16];
 	struct bpf_prog *new_prog;
 	struct bpf_map *map_ptr;
@@ -5544,19 +5580,22 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env)
 			insn->imm = 0;
 			insn->code = BPF_JMP | BPF_TAIL_CALL;
 
+			aux = &env->insn_aux_data[i + delta];
+			if (!bpf_map_ptr_unpriv(aux))
+				continue;
+
 			/* instead of changing every JIT dealing with tail_call
 			 * emit two extra insns:
 			 * if (index >= max_entries) goto out;
 			 * index &= array->index_mask;
 			 * to avoid out-of-bounds cpu speculation
 			 */
-			map_ptr = env->insn_aux_data[i + delta].map_ptr;
-			if (map_ptr == BPF_MAP_PTR_POISON) {
+			if (bpf_map_ptr_poisoned(aux)) {
 				verbose(env, "tail_call abusing map_ptr\n");
 				return -EINVAL;
 			}
-			if (!map_ptr->unpriv_array)
-				continue;
+
+			map_ptr = BPF_MAP_PTR(aux->map_state);
 			insn_buf[0] = BPF_JMP_IMM(BPF_JGE, BPF_REG_3,
 						  map_ptr->max_entries, 2);
 			insn_buf[1] = BPF_ALU32_IMM(BPF_AND, BPF_REG_3,
@@ -5580,9 +5619,12 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env)
 		 */
 		if (prog->jit_requested && BITS_PER_LONG == 64 &&
 		    insn->imm == BPF_FUNC_map_lookup_elem) {
-			map_ptr = env->insn_aux_data[i + delta].map_ptr;
-			if (map_ptr == BPF_MAP_PTR_POISON ||
-			    !map_ptr->ops->map_gen_lookup)
+			aux = &env->insn_aux_data[i + delta];
+			if (bpf_map_ptr_poisoned(aux))
+				goto patch_call_imm;
+
+			map_ptr = BPF_MAP_PTR(aux->map_state);
+			if (!map_ptr->ops->map_gen_lookup)
 				goto patch_call_imm;
 
 			cnt = map_ptr->ops->map_gen_lookup(map_ptr, insn_buf);
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 2017a39ab490..481951bf091d 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -193,7 +193,7 @@ EXPORT_SYMBOL_GPL(kthread_parkme);
 
 void kthread_park_complete(struct task_struct *k)
 {
-	complete(&to_kthread(k)->parked);
+	complete_all(&to_kthread(k)->parked);
 }
 
 static int kthread(void *_create)
@@ -459,6 +459,7 @@ void kthread_unpark(struct task_struct *k)
 	if (test_bit(KTHREAD_IS_PER_CPU, &kthread->flags))
 		__kthread_bind(k, kthread->cpu, TASK_PARKED);
 
+	reinit_completion(&kthread->parked);
 	clear_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
 	wake_up_state(k, TASK_PARKED);
 }
@@ -483,9 +484,6 @@ int kthread_park(struct task_struct *k)
 	if (WARN_ON(k->flags & PF_EXITING))
 		return -ENOSYS;
 
-	if (WARN_ON_ONCE(test_bit(KTHREAD_SHOULD_PARK, &kthread->flags)))
-		return -EBUSY;
-
 	set_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
 	if (k != current) {
 		wake_up_process(k);
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 64cc564f5255..61a1125c1ae4 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1708,7 +1708,7 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att
 	rcu_read_unlock();
 
 	if (rq && sched_debug_enabled) {
-		pr_info("span: %*pbl (max cpu_capacity = %lu)\n",
+		pr_info("root domain span: %*pbl (max cpu_capacity = %lu)\n",
 			cpumask_pr_args(cpu_map), rq->rd->max_cpu_capacity);
 	}
 
diff --git a/kernel/sys.c b/kernel/sys.c
index b0eee418ee0d..d1b2b8d934bb 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -71,6 +71,9 @@
 #include <asm/io.h>
 #include <asm/unistd.h>
 
+/* Hardening for Spectre-v1 */
+#include <linux/nospec.h>
+
 #include "uid16.h"
 
 #ifndef SET_UNALIGN_CTL
@@ -1453,6 +1456,7 @@ SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
 	if (resource >= RLIM_NLIMITS)
 		return -EINVAL;
 
+	resource = array_index_nospec(resource, RLIM_NLIMITS);
 	task_lock(current->group_leader);
 	x = current->signal->rlim[resource];
 	task_unlock(current->group_leader);
@@ -1472,6 +1476,7 @@ COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
 	if (resource >= RLIM_NLIMITS)
 		return -EINVAL;
 
+	resource = array_index_nospec(resource, RLIM_NLIMITS);
 	task_lock(current->group_leader);
 	r = current->signal->rlim[resource];
 	task_unlock(current->group_leader);