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

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

38 files changed, 489 insertions, 903 deletions

diff --git a/kernel/acct.c b/kernel/acct.c
index d15c0ee4d955..addf7732fb56 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -102,7 +102,7 @@ static int check_free_space(struct bsd_acct_struct *acct)
 {
 	struct kstatfs sbuf;
 
-	if (time_is_before_jiffies(acct->needcheck))
+	if (time_is_after_jiffies(acct->needcheck))
 		goto out;
 
 	/* May block */
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index e469e05c8e83..3905d4bc5b80 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -114,6 +114,7 @@ static void htab_free_elems(struct bpf_htab *htab)
 		pptr = htab_elem_get_ptr(get_htab_elem(htab, i),
 					 htab->map.key_size);
 		free_percpu(pptr);
+		cond_resched();
 	}
 free_elems:
 	bpf_map_area_free(htab->elems);
@@ -159,6 +160,7 @@ static int prealloc_init(struct bpf_htab *htab)
 			goto free_elems;
 		htab_elem_set_ptr(get_htab_elem(htab, i), htab->map.key_size,
 				  pptr);
+		cond_resched();
 	}
 
 skip_percpu_elems:
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d4593571c404..04b24876cd23 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1059,6 +1059,11 @@ static int check_ptr_alignment(struct bpf_verifier_env *env,
 		break;
 	case PTR_TO_STACK:
 		pointer_desc = "stack ";
+		/* The stack spill tracking logic in check_stack_write()
+		 * and check_stack_read() relies on stack accesses being
+		 * aligned.
+		 */
+		strict = true;
 		break;
 	default:
 		break;
@@ -1067,6 +1072,29 @@ static int check_ptr_alignment(struct bpf_verifier_env *env,
 					   strict);
 }
 
+/* truncate register to smaller size (in bytes)
+ * must be called with size < BPF_REG_SIZE
+ */
+static void coerce_reg_to_size(struct bpf_reg_state *reg, int size)
+{
+	u64 mask;
+
+	/* clear high bits in bit representation */
+	reg->var_off = tnum_cast(reg->var_off, size);
+
+	/* fix arithmetic bounds */
+	mask = ((u64)1 << (size * 8)) - 1;
+	if ((reg->umin_value & ~mask) == (reg->umax_value & ~mask)) {
+		reg->umin_value &= mask;
+		reg->umax_value &= mask;
+	} else {
+		reg->umin_value = 0;
+		reg->umax_value = mask;
+	}
+	reg->smin_value = reg->umin_value;
+	reg->smax_value = reg->umax_value;
+}
+
 /* check whether memory at (regno + off) is accessible for t = (read | write)
  * if t==write, value_regno is a register which value is stored into memory
  * if t==read, value_regno is a register which will receive the value from memory
@@ -1200,9 +1228,7 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn
 	if (!err && size < BPF_REG_SIZE && value_regno >= 0 && t == BPF_READ &&
 	    regs[value_regno].type == SCALAR_VALUE) {
 		/* b/h/w load zero-extends, mark upper bits as known 0 */
-		regs[value_regno].var_off =
-			tnum_cast(regs[value_regno].var_off, size);
-		__update_reg_bounds(&regs[value_regno]);
+		coerce_reg_to_size(&regs[value_regno], size);
 	}
 	return err;
 }
@@ -1282,6 +1308,7 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
 		tnum_strn(tn_buf, sizeof(tn_buf), regs[regno].var_off);
 		verbose(env, "invalid variable stack read R%d var_off=%s\n",
 			regno, tn_buf);
+		return -EACCES;
 	}
 	off = regs[regno].off + regs[regno].var_off.value;
 	if (off >= 0 || off < -MAX_BPF_STACK || off + access_size > 0 ||
@@ -1674,7 +1701,13 @@ static int check_call(struct bpf_verifier_env *env, int func_id, int insn_idx)
 		return -EINVAL;
 	}
 
+	/* With LD_ABS/IND some JITs save/restore skb from r1. */
 	changes_data = bpf_helper_changes_pkt_data(fn->func);
+	if (changes_data && fn->arg1_type != ARG_PTR_TO_CTX) {
+		verbose(env, "kernel subsystem misconfigured func %s#%d: r1 != ctx\n",
+			func_id_name(func_id), func_id);
+		return -EINVAL;
+	}
 
 	memset(&meta, 0, sizeof(meta));
 	meta.pkt_access = fn->pkt_access;
@@ -1766,14 +1799,6 @@ static int check_call(struct bpf_verifier_env *env, int func_id, int insn_idx)
 	return 0;
 }
 
-static void coerce_reg_to_32(struct bpf_reg_state *reg)
-{
-	/* clear high 32 bits */
-	reg->var_off = tnum_cast(reg->var_off, 4);
-	/* Update bounds */
-	__update_reg_bounds(reg);
-}
-
 static bool signed_add_overflows(s64 a, s64 b)
 {
 	/* Do the add in u64, where overflow is well-defined */
@@ -1794,6 +1819,41 @@ static bool signed_sub_overflows(s64 a, s64 b)
 	return res > a;
 }
 
+static bool check_reg_sane_offset(struct bpf_verifier_env *env,
+				  const struct bpf_reg_state *reg,
+				  enum bpf_reg_type type)
+{
+	bool known = tnum_is_const(reg->var_off);
+	s64 val = reg->var_off.value;
+	s64 smin = reg->smin_value;
+
+	if (known && (val >= BPF_MAX_VAR_OFF || val <= -BPF_MAX_VAR_OFF)) {
+		verbose(env, "math between %s pointer and %lld is not allowed\n",
+			reg_type_str[type], val);
+		return false;
+	}
+
+	if (reg->off >= BPF_MAX_VAR_OFF || reg->off <= -BPF_MAX_VAR_OFF) {
+		verbose(env, "%s pointer offset %d is not allowed\n",
+			reg_type_str[type], reg->off);
+		return false;
+	}
+
+	if (smin == S64_MIN) {
+		verbose(env, "math between %s pointer and register with unbounded min value is not allowed\n",
+			reg_type_str[type]);
+		return false;
+	}
+
+	if (smin >= BPF_MAX_VAR_OFF || smin <= -BPF_MAX_VAR_OFF) {
+		verbose(env, "value %lld makes %s pointer be out of bounds\n",
+			smin, reg_type_str[type]);
+		return false;
+	}
+
+	return true;
+}
+
 /* Handles arithmetic on a pointer and a scalar: computes new min/max and var_off.
  * Caller should also handle BPF_MOV case separately.
  * If we return -EACCES, caller may want to try again treating pointer as a
@@ -1830,29 +1890,25 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 
 	if (BPF_CLASS(insn->code) != BPF_ALU64) {
 		/* 32-bit ALU ops on pointers produce (meaningless) scalars */
-		if (!env->allow_ptr_leaks)
-			verbose(env,
-				"R%d 32-bit pointer arithmetic prohibited\n",
-				dst);
+		verbose(env,
+			"R%d 32-bit pointer arithmetic prohibited\n",
+			dst);
 		return -EACCES;
 	}
 
 	if (ptr_reg->type == PTR_TO_MAP_VALUE_OR_NULL) {
-		if (!env->allow_ptr_leaks)
-			verbose(env, "R%d pointer arithmetic on PTR_TO_MAP_VALUE_OR_NULL prohibited, null-check it first\n",
-				dst);
+		verbose(env, "R%d pointer arithmetic on PTR_TO_MAP_VALUE_OR_NULL prohibited, null-check it first\n",
+			dst);
 		return -EACCES;
 	}
 	if (ptr_reg->type == CONST_PTR_TO_MAP) {
-		if (!env->allow_ptr_leaks)
-			verbose(env, "R%d pointer arithmetic on CONST_PTR_TO_MAP prohibited\n",
-				dst);
+		verbose(env, "R%d pointer arithmetic on CONST_PTR_TO_MAP prohibited\n",
+			dst);
 		return -EACCES;
 	}
 	if (ptr_reg->type == PTR_TO_PACKET_END) {
-		if (!env->allow_ptr_leaks)
-			verbose(env, "R%d pointer arithmetic on PTR_TO_PACKET_END prohibited\n",
-				dst);
+		verbose(env, "R%d pointer arithmetic on PTR_TO_PACKET_END prohibited\n",
+			dst);
 		return -EACCES;
 	}
 
@@ -1862,6 +1918,10 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 	dst_reg->type = ptr_reg->type;
 	dst_reg->id = ptr_reg->id;
 
+	if (!check_reg_sane_offset(env, off_reg, ptr_reg->type) ||
+	    !check_reg_sane_offset(env, ptr_reg, ptr_reg->type))
+		return -EINVAL;
+
 	switch (opcode) {
 	case BPF_ADD:
 		/* We can take a fixed offset as long as it doesn't overflow
@@ -1915,9 +1975,8 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 	case BPF_SUB:
 		if (dst_reg == off_reg) {
 			/* scalar -= pointer.  Creates an unknown scalar */
-			if (!env->allow_ptr_leaks)
-				verbose(env, "R%d tried to subtract pointer from scalar\n",
-					dst);
+			verbose(env, "R%d tried to subtract pointer from scalar\n",
+				dst);
 			return -EACCES;
 		}
 		/* We don't allow subtraction from FP, because (according to
@@ -1925,9 +1984,8 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 		 * be able to deal with it.
 		 */
 		if (ptr_reg->type == PTR_TO_STACK) {
-			if (!env->allow_ptr_leaks)
-				verbose(env, "R%d subtraction from stack pointer prohibited\n",
-					dst);
+			verbose(env, "R%d subtraction from stack pointer prohibited\n",
+				dst);
 			return -EACCES;
 		}
 		if (known && (ptr_reg->off - smin_val ==
@@ -1976,28 +2034,30 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 	case BPF_AND:
 	case BPF_OR:
 	case BPF_XOR:
-		/* bitwise ops on pointers are troublesome, prohibit for now.
-		 * (However, in principle we could allow some cases, e.g.
-		 * ptr &= ~3 which would reduce min_value by 3.)
-		 */
-		if (!env->allow_ptr_leaks)
-			verbose(env, "R%d bitwise operator %s on pointer prohibited\n",
-				dst, bpf_alu_string[opcode >> 4]);
+		/* bitwise ops on pointers are troublesome, prohibit. */
+		verbose(env, "R%d bitwise operator %s on pointer prohibited\n",
+			dst, bpf_alu_string[opcode >> 4]);
 		return -EACCES;
 	default:
 		/* other operators (e.g. MUL,LSH) produce non-pointer results */
-		if (!env->allow_ptr_leaks)
-			verbose(env, "R%d pointer arithmetic with %s operator prohibited\n",
-				dst, bpf_alu_string[opcode >> 4]);
+		verbose(env, "R%d pointer arithmetic with %s operator prohibited\n",
+			dst, bpf_alu_string[opcode >> 4]);
 		return -EACCES;
 	}
 
+	if (!check_reg_sane_offset(env, dst_reg, ptr_reg->type))
+		return -EINVAL;
+
 	__update_reg_bounds(dst_reg);
 	__reg_deduce_bounds(dst_reg);
 	__reg_bound_offset(dst_reg);
 	return 0;
 }
 
+/* WARNING: This function does calculations on 64-bit values, but the actual
+ * execution may occur on 32-bit values. Therefore, things like bitshifts
+ * need extra checks in the 32-bit case.
+ */
 static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 				      struct bpf_insn *insn,
 				      struct bpf_reg_state *dst_reg,
@@ -2008,12 +2068,8 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 	bool src_known, dst_known;
 	s64 smin_val, smax_val;
 	u64 umin_val, umax_val;
+	u64 insn_bitness = (BPF_CLASS(insn->code) == BPF_ALU64) ? 64 : 32;
 
-	if (BPF_CLASS(insn->code) != BPF_ALU64) {
-		/* 32-bit ALU ops are (32,32)->64 */
-		coerce_reg_to_32(dst_reg);
-		coerce_reg_to_32(&src_reg);
-	}
 	smin_val = src_reg.smin_value;
 	smax_val = src_reg.smax_value;
 	umin_val = src_reg.umin_value;
@@ -2021,6 +2077,12 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 	src_known = tnum_is_const(src_reg.var_off);
 	dst_known = tnum_is_const(dst_reg->var_off);
 
+	if (!src_known &&
+	    opcode != BPF_ADD && opcode != BPF_SUB && opcode != BPF_AND) {
+		__mark_reg_unknown(dst_reg);
+		return 0;
+	}
+
 	switch (opcode) {
 	case BPF_ADD:
 		if (signed_add_overflows(dst_reg->smin_value, smin_val) ||
@@ -2149,9 +2211,9 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 		__update_reg_bounds(dst_reg);
 		break;
 	case BPF_LSH:
-		if (umax_val > 63) {
-			/* Shifts greater than 63 are undefined.  This includes
-			 * shifts by a negative number.
+		if (umax_val >= insn_bitness) {
+			/* Shifts greater than 31 or 63 are undefined.
+			 * This includes shifts by a negative number.
 			 */
 			mark_reg_unknown(env, regs, insn->dst_reg);
 			break;
@@ -2177,27 +2239,29 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 		__update_reg_bounds(dst_reg);
 		break;
 	case BPF_RSH:
-		if (umax_val > 63) {
-			/* Shifts greater than 63 are undefined.  This includes
-			 * shifts by a negative number.
+		if (umax_val >= insn_bitness) {
+			/* Shifts greater than 31 or 63 are undefined.
+			 * This includes shifts by a negative number.
 			 */
 			mark_reg_unknown(env, regs, insn->dst_reg);
 			break;
 		}
-		/* BPF_RSH is an unsigned shift, so make the appropriate casts */
-		if (dst_reg->smin_value < 0) {
-			if (umin_val) {
-				/* Sign bit will be cleared */
-				dst_reg->smin_value = 0;
-			} else {
-				/* Lost sign bit information */
-				dst_reg->smin_value = S64_MIN;
-				dst_reg->smax_value = S64_MAX;
-			}
-		} else {
-			dst_reg->smin_value =
-				(u64)(dst_reg->smin_value) >> umax_val;
-		}
+		/* BPF_RSH is an unsigned shift.  If the value in dst_reg might
+		 * be negative, then either:
+		 * 1) src_reg might be zero, so the sign bit of the result is
+		 *    unknown, so we lose our signed bounds
+		 * 2) it's known negative, thus the unsigned bounds capture the
+		 *    signed bounds
+		 * 3) the signed bounds cross zero, so they tell us nothing
+		 *    about the result
+		 * If the value in dst_reg is known nonnegative, then again the
+		 * unsigned bounts capture the signed bounds.
+		 * Thus, in all cases it suffices to blow away our signed bounds
+		 * and rely on inferring new ones from the unsigned bounds and
+		 * var_off of the result.
+		 */
+		dst_reg->smin_value = S64_MIN;
+		dst_reg->smax_value = S64_MAX;
 		if (src_known)
 			dst_reg->var_off = tnum_rshift(dst_reg->var_off,
 						       umin_val);
@@ -2213,6 +2277,12 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 		break;
 	}
 
+	if (BPF_CLASS(insn->code) != BPF_ALU64) {
+		/* 32-bit ALU ops are (32,32)->32 */
+		coerce_reg_to_size(dst_reg, 4);
+		coerce_reg_to_size(&src_reg, 4);
+	}
+
 	__reg_deduce_bounds(dst_reg);
 	__reg_bound_offset(dst_reg);
 	return 0;
@@ -2227,7 +2297,6 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env,
 	struct bpf_reg_state *regs = cur_regs(env), *dst_reg, *src_reg;
 	struct bpf_reg_state *ptr_reg = NULL, off_reg = {0};
 	u8 opcode = BPF_OP(insn->code);
-	int rc;
 
 	dst_reg = &regs[insn->dst_reg];
 	src_reg = NULL;
@@ -2238,43 +2307,29 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env,
 		if (src_reg->type != SCALAR_VALUE) {
 			if (dst_reg->type != SCALAR_VALUE) {
 				/* Combining two pointers by any ALU op yields
-				 * an arbitrary scalar.
+				 * an arbitrary scalar. Disallow all math except
+				 * pointer subtraction
 				 */
-				if (!env->allow_ptr_leaks) {
-					verbose(env, "R%d pointer %s pointer prohibited\n",
-						insn->dst_reg,
-						bpf_alu_string[opcode >> 4]);
-					return -EACCES;
+				if (opcode == BPF_SUB){
+					mark_reg_unknown(env, regs, insn->dst_reg);
+					return 0;
 				}
-				mark_reg_unknown(env, regs, insn->dst_reg);
-				return 0;
+				verbose(env, "R%d pointer %s pointer prohibited\n",
+					insn->dst_reg,
+					bpf_alu_string[opcode >> 4]);
+				return -EACCES;
 			} else {
 				/* scalar += pointer
 				 * This is legal, but we have to reverse our
 				 * src/dest handling in computing the range
 				 */
-				rc = adjust_ptr_min_max_vals(env, insn,
-							     src_reg, dst_reg);
-				if (rc == -EACCES && env->allow_ptr_leaks) {
-					/* scalar += unknown scalar */
-					__mark_reg_unknown(&off_reg);
-					return adjust_scalar_min_max_vals(
-							env, insn,
-							dst_reg, off_reg);
-				}
-				return rc;
+				return adjust_ptr_min_max_vals(env, insn,
+							       src_reg, dst_reg);
 			}
 		} else if (ptr_reg) {
 			/* pointer += scalar */
-			rc = adjust_ptr_min_max_vals(env, insn,
-						     dst_reg, src_reg);
-			if (rc == -EACCES && env->allow_ptr_leaks) {
-				/* unknown scalar += scalar */
-				__mark_reg_unknown(dst_reg);
-				return adjust_scalar_min_max_vals(
-						env, insn, dst_reg, *src_reg);
-			}
-			return rc;
+			return adjust_ptr_min_max_vals(env, insn,
+						       dst_reg, src_reg);
 		}
 	} else {
 		/* Pretend the src is a reg with a known value, since we only
@@ -2283,17 +2338,9 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env,
 		off_reg.type = SCALAR_VALUE;
 		__mark_reg_known(&off_reg, insn->imm);
 		src_reg = &off_reg;
-		if (ptr_reg) { /* pointer += K */
-			rc = adjust_ptr_min_max_vals(env, insn,
-						     ptr_reg, src_reg);
-			if (rc == -EACCES && env->allow_ptr_leaks) {
-				/* unknown scalar += K */
-				__mark_reg_unknown(dst_reg);
-				return adjust_scalar_min_max_vals(
-						env, insn, dst_reg, off_reg);
-			}
-			return rc;
-		}
+		if (ptr_reg) /* pointer += K */
+			return adjust_ptr_min_max_vals(env, insn,
+						       ptr_reg, src_reg);
 	}
 
 	/* Got here implies adding two SCALAR_VALUEs */
@@ -2390,17 +2437,20 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
 					return -EACCES;
 				}
 				mark_reg_unknown(env, regs, insn->dst_reg);
-				/* high 32 bits are known zero. */
-				regs[insn->dst_reg].var_off = tnum_cast(
-						regs[insn->dst_reg].var_off, 4);
-				__update_reg_bounds(&regs[insn->dst_reg]);
+				coerce_reg_to_size(&regs[insn->dst_reg], 4);
 			}
 		} else {
 			/* case: R = imm
 			 * remember the value we stored into this reg
 			 */
 			regs[insn->dst_reg].type = SCALAR_VALUE;
-			__mark_reg_known(regs + insn->dst_reg, insn->imm);
+			if (BPF_CLASS(insn->code) == BPF_ALU64) {
+				__mark_reg_known(regs + insn->dst_reg,
+						 insn->imm);
+			} else {
+				__mark_reg_known(regs + insn->dst_reg,
+						 (u32)insn->imm);
+			}
 		}
 
 	} else if (opcode > BPF_END) {
@@ -3431,15 +3481,14 @@ static bool regsafe(struct bpf_reg_state *rold, struct bpf_reg_state *rcur,
 			return range_within(rold, rcur) &&
 			       tnum_in(rold->var_off, rcur->var_off);
 		} else {
-			/* if we knew anything about the old value, we're not
-			 * equal, because we can't know anything about the
-			 * scalar value of the pointer in the new value.
+			/* We're trying to use a pointer in place of a scalar.
+			 * Even if the scalar was unbounded, this could lead to
+			 * pointer leaks because scalars are allowed to leak
+			 * while pointers are not. We could make this safe in
+			 * special cases if root is calling us, but it's
+			 * probably not worth the hassle.
 			 */
-			return rold->umin_value == 0 &&
-			       rold->umax_value == U64_MAX &&
-			       rold->smin_value == S64_MIN &&
-			       rold->smax_value == S64_MAX &&
-			       tnum_is_unknown(rold->var_off);
+			return false;
 		}
 	case PTR_TO_MAP_VALUE:
 		/* If the new min/max/var_off satisfy the old ones and
diff --git a/kernel/cgroup/debug.c b/kernel/cgroup/debug.c
index 5f780d8f6a9d..9caeda610249 100644
--- a/kernel/cgroup/debug.c
+++ b/kernel/cgroup/debug.c
@@ -50,7 +50,7 @@ static int current_css_set_read(struct seq_file *seq, void *v)
 
 	spin_lock_irq(&css_set_lock);
 	rcu_read_lock();
-	cset = rcu_dereference(current->cgroups);
+	cset = task_css_set(current);
 	refcnt = refcount_read(&cset->refcount);
 	seq_printf(seq, "css_set %pK %d", cset, refcnt);
 	if (refcnt > cset->nr_tasks)
@@ -96,7 +96,7 @@ static int current_css_set_cg_links_read(struct seq_file *seq, void *v)
 
 	spin_lock_irq(&css_set_lock);
 	rcu_read_lock();
-	cset = rcu_dereference(current->cgroups);
+	cset = task_css_set(current);
 	list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {
 		struct cgroup *c = link->cgrp;
 
diff --git a/kernel/cgroup/stat.c b/kernel/cgroup/stat.c
index 133b465691d6..1e111dd455c4 100644
--- a/kernel/cgroup/stat.c
+++ b/kernel/cgroup/stat.c
@@ -296,8 +296,12 @@ int cgroup_stat_init(struct cgroup *cgrp)
 	}
 
 	/* ->updated_children list is self terminated */
-	for_each_possible_cpu(cpu)
-		cgroup_cpu_stat(cgrp, cpu)->updated_children = cgrp;
+	for_each_possible_cpu(cpu) {
+		struct cgroup_cpu_stat *cstat = cgroup_cpu_stat(cgrp, cpu);
+
+		cstat->updated_children = cgrp;
+		u64_stats_init(&cstat->sync);
+	}
 
 	prev_cputime_init(&cgrp->stat.prev_cputime);
 
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 04892a82f6ac..53f7dc65f9a3 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -80,19 +80,19 @@ static struct lockdep_map cpuhp_state_down_map =
 	STATIC_LOCKDEP_MAP_INIT("cpuhp_state-down", &cpuhp_state_down_map);
 
 
-static void inline cpuhp_lock_acquire(bool bringup)
+static inline void cpuhp_lock_acquire(bool bringup)
 {
 	lock_map_acquire(bringup ? &cpuhp_state_up_map : &cpuhp_state_down_map);
 }
 
-static void inline cpuhp_lock_release(bool bringup)
+static inline void cpuhp_lock_release(bool bringup)
 {
 	lock_map_release(bringup ? &cpuhp_state_up_map : &cpuhp_state_down_map);
 }
 #else
 
-static void inline cpuhp_lock_acquire(bool bringup) { }
-static void inline cpuhp_lock_release(bool bringup) { }
+static inline void cpuhp_lock_acquire(bool bringup) { }
+static inline void cpuhp_lock_release(bool bringup) { }
 
 #endif
 
@@ -780,8 +780,8 @@ static int takedown_cpu(unsigned int cpu)
 	BUG_ON(cpu_online(cpu));
 
 	/*
-	 * The CPUHP_AP_SCHED_MIGRATE_DYING callback will have removed all
-	 * runnable tasks from the cpu, there's only the idle task left now
+	 * The teardown callback for CPUHP_AP_SCHED_STARTING will have removed
+	 * all runnable tasks from the CPU, there's only the idle task left now
 	 * that the migration thread is done doing the stop_machine thing.
 	 *
 	 * Wait for the stop thread to go away.
@@ -1277,9 +1277,9 @@ static struct cpuhp_step cpuhp_bp_states[] = {
 	 * before blk_mq_queue_reinit_notify() from notify_dead(),
 	 * otherwise a RCU stall occurs.
 	 */
-	[CPUHP_TIMERS_DEAD] = {
+	[CPUHP_TIMERS_PREPARE] = {
 		.name			= "timers:dead",
-		.startup.single		= NULL,
+		.startup.single		= timers_prepare_cpu,
 		.teardown.single	= timers_dead_cpu,
 	},
 	/* Kicks the plugged cpu into life */
@@ -1289,11 +1289,6 @@ static struct cpuhp_step cpuhp_bp_states[] = {
 		.teardown.single	= NULL,
 		.cant_stop		= true,
 	},
-	[CPUHP_AP_SMPCFD_DYING] = {
-		.name			= "smpcfd:dying",
-		.startup.single		= NULL,
-		.teardown.single	= smpcfd_dying_cpu,
-	},
 	/*
 	 * Handled on controll processor until the plugged processor manages
 	 * this itself.
@@ -1335,6 +1330,11 @@ static struct cpuhp_step cpuhp_ap_states[] = {
 		.startup.single		= NULL,
 		.teardown.single	= rcutree_dying_cpu,
 	},
+	[CPUHP_AP_SMPCFD_DYING] = {
+		.name			= "smpcfd:dying",
+		.startup.single		= NULL,
+		.teardown.single	= smpcfd_dying_cpu,
+	},
 	/* Entry state on starting. Interrupts enabled from here on. Transient
 	 * state for synchronsization */
 	[CPUHP_AP_ONLINE] = {
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index e74be38245ad..ed5d34925ad0 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -350,7 +350,7 @@ poll_again:
 			}
 			kdb_printf("\n");
 			for (i = 0; i < count; i++) {
-				if (kallsyms_symbol_next(p_tmp, i) < 0)
+				if (WARN_ON(!kallsyms_symbol_next(p_tmp, i)))
 					break;
 				kdb_printf("%s ", p_tmp);
 				*(p_tmp + len) = '\0';
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 16beab4767e1..4df5b695bf0d 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6639,6 +6639,7 @@ static void perf_event_namespaces_output(struct perf_event *event,
 	struct perf_namespaces_event *namespaces_event = data;
 	struct perf_output_handle handle;
 	struct perf_sample_data sample;
+	u16 header_size = namespaces_event->event_id.header.size;
 	int ret;
 
 	if (!perf_event_namespaces_match(event))
@@ -6649,7 +6650,7 @@ static void perf_event_namespaces_output(struct perf_event *event,
 	ret = perf_output_begin(&handle, event,
 				namespaces_event->event_id.header.size);
 	if (ret)
-		return;
+		goto out;
 
 	namespaces_event->event_id.pid = perf_event_pid(event,
 							namespaces_event->task);
@@ -6661,6 +6662,8 @@ static void perf_event_namespaces_output(struct perf_event *event,
 	perf_event__output_id_sample(event, &handle, &sample);
 
 	perf_output_end(&handle);
+out:
+	namespaces_event->event_id.header.size = header_size;
 }
 
 static void perf_fill_ns_link_info(struct perf_ns_link_info *ns_link_info,
@@ -7987,11 +7990,11 @@ static void bpf_overflow_handler(struct perf_event *event,
 {
 	struct bpf_perf_event_data_kern ctx = {
 		.data = data,
-		.regs = regs,
 		.event = event,
 	};
 	int ret = 0;
 
+	ctx.regs = perf_arch_bpf_user_pt_regs(regs);
 	preempt_disable();
 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1))
 		goto out;
diff --git a/kernel/exit.c b/kernel/exit.c
index 6b4298a41167..995453d9fb55 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1755,3 +1755,12 @@ Efault:
 	return -EFAULT;
 }
 #endif
+
+__weak void abort(void)
+{
+	BUG();
+
+	/* if that doesn't kill us, halt */
+	panic("Oops failed to kill thread");
+}
+EXPORT_SYMBOL(abort);
diff --git a/kernel/fork.c b/kernel/fork.c
index 432eadf6b58c..2295fc69717f 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -721,8 +721,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
 			goto out;
 	}
 	/* a new mm has just been created */
-	arch_dup_mmap(oldmm, mm);
-	retval = 0;
+	retval = arch_dup_mmap(oldmm, mm);
 out:
 	up_write(&mm->mmap_sem);