Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Alexei Starovoitov says:

====================
pull-request: bpf 2019-04-25

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) the bpf verifier fix to properly mark registers in all stack frames, from Paul.

2) preempt_enable_no_resched->preempt_enable fix, from Peter.

3) other misc fixes.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 46 insertions, 30 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 6c5a41f7f338..09d5d972c9ff 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4138,15 +4138,35 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
 	return 0;
 }
 
+static void __find_good_pkt_pointers(struct bpf_func_state *state,
+				     struct bpf_reg_state *dst_reg,
+				     enum bpf_reg_type type, u16 new_range)
+{
+	struct bpf_reg_state *reg;
+	int i;
+
+	for (i = 0; i < MAX_BPF_REG; i++) {
+		reg = &state->regs[i];
+		if (reg->type == type && reg->id == dst_reg->id)
+			/* keep the maximum range already checked */
+			reg->range = max(reg->range, new_range);
+	}
+
+	bpf_for_each_spilled_reg(i, state, reg) {
+		if (!reg)
+			continue;
+		if (reg->type == type && reg->id == dst_reg->id)
+			reg->range = max(reg->range, new_range);
+	}
+}
+
 static void find_good_pkt_pointers(struct bpf_verifier_state *vstate,
 				   struct bpf_reg_state *dst_reg,
 				   enum bpf_reg_type type,
 				   bool range_right_open)
 {
-	struct bpf_func_state *state = vstate->frame[vstate->curframe];
-	struct bpf_reg_state *regs = state->regs, *reg;
 	u16 new_range;
-	int i, j;
+	int i;
 
 	if (dst_reg->off < 0 ||
 	    (dst_reg->off == 0 && range_right_open))
@@ -4211,20 +4231,9 @@ static void find_good_pkt_pointers(struct bpf_verifier_state *vstate,
 	 * the range won't allow anything.
 	 * dst_reg->off is known < MAX_PACKET_OFF, therefore it fits in a u16.
 	 */
-	for (i = 0; i < MAX_BPF_REG; i++)
-		if (regs[i].type == type && regs[i].id == dst_reg->id)
-			/* keep the maximum range already checked */
-			regs[i].range = max(regs[i].range, new_range);
-
-	for (j = 0; j <= vstate->curframe; j++) {
-		state = vstate->frame[j];
-		bpf_for_each_spilled_reg(i, state, reg) {
-			if (!reg)
-				continue;
-			if (reg->type == type && reg->id == dst_reg->id)
-				reg->range = max(reg->range, new_range);
-		}
-	}
+	for (i = 0; i <= vstate->curframe; i++)
+		__find_good_pkt_pointers(vstate->frame[i], dst_reg, type,
+					 new_range);
 }
 
 /* compute branch direction of the expression "if (reg opcode val) goto target;"
@@ -4698,6 +4707,22 @@ static void mark_ptr_or_null_reg(struct bpf_func_state *state,
 	}
 }
 
+static void __mark_ptr_or_null_regs(struct bpf_func_state *state, u32 id,
+				    bool is_null)
+{
+	struct bpf_reg_state *reg;
+	int i;
+
+	for (i = 0; i < MAX_BPF_REG; i++)
+		mark_ptr_or_null_reg(state, &state->regs[i], id, is_null);
+
+	bpf_for_each_spilled_reg(i, state, reg) {
+		if (!reg)
+			continue;
+		mark_ptr_or_null_reg(state, reg, id, is_null);
+	}
+}
+
 /* The logic is similar to find_good_pkt_pointers(), both could eventually
  * be folded together at some point.
  */
@@ -4705,10 +4730,10 @@ static void mark_ptr_or_null_regs(struct bpf_verifier_state *vstate, u32 regno,
 				  bool is_null)
 {
 	struct bpf_func_state *state = vstate->frame[vstate->curframe];
-	struct bpf_reg_state *reg, *regs = state->regs;
+	struct bpf_reg_state *regs = state->regs;
 	u32 ref_obj_id = regs[regno].ref_obj_id;
 	u32 id = regs[regno].id;
-	int i, j;
+	int i;
 
 	if (ref_obj_id && ref_obj_id == id && is_null)
 		/* regs[regno] is in the " == NULL" branch.
@@ -4717,17 +4742,8 @@ static void mark_ptr_or_null_regs(struct bpf_verifier_state *vstate, u32 regno,
 		 */
 		WARN_ON_ONCE(release_reference_state(state, id));
 
-	for (i = 0; i < MAX_BPF_REG; i++)
-		mark_ptr_or_null_reg(state, &regs[i], id, is_null);
-
-	for (j = 0; j <= vstate->curframe; j++) {
-		state = vstate->frame[j];
-		bpf_for_each_spilled_reg(i, state, reg) {
-			if (!reg)
-				continue;
-			mark_ptr_or_null_reg(state, reg, id, is_null);
-		}
-	}
+	for (i = 0; i <= vstate->curframe; i++)
+		__mark_ptr_or_null_regs(vstate->frame[i], id, is_null);
 }
 
 static bool try_match_pkt_pointers(const struct bpf_insn *insn,