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

Daniel Borkmann says:

====================
pull-request: bpf-next 2020-11-14

1) Add BTF generation for kernel modules and extend BTF infra in kernel
   e.g. support for split BTF loading and validation, from Andrii Nakryiko.

2) Support for pointers beyond pkt_end to recognize LLVM generated patterns
   on inlined branch conditions, from Alexei Starovoitov.

3) Implements bpf_local_storage for task_struct for BPF LSM, from KP Singh.

4) Enable FENTRY/FEXIT/RAW_TP tracing program to use the bpf_sk_storage
   infra, from Martin KaFai Lau.

5) Add XDP bulk APIs that introduce a defer/flush mechanism to optimize the
   XDP_REDIRECT path, from Lorenzo Bianconi.

6) Fix a potential (although rather theoretical) deadlock of hashtab in NMI
   context, from Song Liu.

7) Fixes for cross and out-of-tree build of bpftool and runqslower allowing build
   for different target archs on same source tree, from Jean-Philippe Brucker.

8) Fix error path in htab_map_alloc() triggered from syzbot, from Eric Dumazet.

9) Move functionality from test_tcpbpf_user into the test_progs framework so it
   can run in BPF CI, from Alexander Duyck.

10) Lift hashtab key_size limit to be larger than MAX_BPF_STACK, from Florian Lehner.

Note that for the fix from Song we have seen a sparse report on context
imbalance which requires changes in sparse itself for proper annotation
detection where this is currently being discussed on linux-sparse among
developers [0]. Once we have more clarification/guidance after their fix,
Song will follow-up.

  [0] https://lore.kernel.org/linux-sparse/CAHk-=wh4bx8A8dHnX612MsDO13st6uzAz1mJ1PaHHVevJx_ZCw@mail.gmail.com/T/
      https://lore.kernel.org/linux-sparse/20201109221345.uklbp3lzgq6g42zb@ltop.local/T/

* git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (66 commits)
  net: mlx5: Add xdp tx return bulking support
  net: mvpp2: Add xdp tx return bulking support
  net: mvneta: Add xdp tx return bulking support
  net: page_pool: Add bulk support for ptr_ring
  net: xdp: Introduce bulking for xdp tx return path
  bpf: Expose bpf_d_path helper to sleepable LSM hooks
  bpf: Augment the set of sleepable LSM hooks
  bpf: selftest: Use bpf_sk_storage in FENTRY/FEXIT/RAW_TP
  bpf: Allow using bpf_sk_storage in FENTRY/FEXIT/RAW_TP
  bpf: Rename some functions in bpf_sk_storage
  bpf: Folding omem_charge() into sk_storage_charge()
  selftests/bpf: Add asm tests for pkt vs pkt_end comparison.
  selftests/bpf: Add skb_pkt_end test
  bpf: Support for pointers beyond pkt_end.
  tools/bpf: Always run the *-clean recipes
  tools/bpf: Add bootstrap/ to .gitignore
  bpf: Fix NULL dereference in bpf_task_storage
  tools/bpftool: Fix build slowdown
  tools/runqslower: Build bpftool using HOSTCC
  tools/runqslower: Enable out-of-tree build
  ...
====================

Link: https://lore.kernel.org/r/20201114020819.29584-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 138 insertions, 44 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 6200519582a6..fb2943ea715d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2739,7 +2739,9 @@ static int check_packet_access(struct bpf_verifier_env *env, u32 regno, int off,
 			regno);
 		return -EACCES;
 	}
-	err = __check_mem_access(env, regno, off, size, reg->range,
+
+	err = reg->range < 0 ? -EINVAL :
+	      __check_mem_access(env, regno, off, size, reg->range,
 				 zero_size_allowed);
 	if (err) {
 		verbose(env, "R%d offset is outside of the packet\n", regno);
@@ -4469,6 +4471,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
 		    func_id != BPF_FUNC_inode_storage_delete)
 			goto error;
 		break;
+	case BPF_MAP_TYPE_TASK_STORAGE:
+		if (func_id != BPF_FUNC_task_storage_get &&
+		    func_id != BPF_FUNC_task_storage_delete)
+			goto error;
+		break;
 	default:
 		break;
 	}
@@ -4547,6 +4554,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
 		if (map->map_type != BPF_MAP_TYPE_INODE_STORAGE)
 			goto error;
 		break;
+	case BPF_FUNC_task_storage_get:
+	case BPF_FUNC_task_storage_delete:
+		if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE)
+			goto error;
+		break;
 	default:
 		break;
 	}
@@ -4687,6 +4699,32 @@ static void clear_all_pkt_pointers(struct bpf_verifier_env *env)
 		__clear_all_pkt_pointers(env, vstate->frame[i]);
 }
 
+enum {
+	AT_PKT_END = -1,
+	BEYOND_PKT_END = -2,
+};
+
+static void mark_pkt_end(struct bpf_verifier_state *vstate, int regn, bool range_open)
+{
+	struct bpf_func_state *state = vstate->frame[vstate->curframe];
+	struct bpf_reg_state *reg = &state->regs[regn];
+
+	if (reg->type != PTR_TO_PACKET)
+		/* PTR_TO_PACKET_META is not supported yet */
+		return;
+
+	/* The 'reg' is pkt > pkt_end or pkt >= pkt_end.
+	 * How far beyond pkt_end it goes is unknown.
+	 * if (!range_open) it's the case of pkt >= pkt_end
+	 * if (range_open) it's the case of pkt > pkt_end
+	 * hence this pointer is at least 1 byte bigger than pkt_end
+	 */
+	if (range_open)
+		reg->range = BEYOND_PKT_END;
+	else
+		reg->range = AT_PKT_END;
+}
+
 static void release_reg_references(struct bpf_verifier_env *env,
 				   struct bpf_func_state *state,
 				   int ref_obj_id)
@@ -5176,11 +5214,14 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
 				PTR_TO_BTF_ID : PTR_TO_BTF_ID_OR_NULL;
 			regs[BPF_REG_0].btf_id = meta.ret_btf_id;
 		}
-	} else if (fn->ret_type == RET_PTR_TO_BTF_ID_OR_NULL) {
+	} else if (fn->ret_type == RET_PTR_TO_BTF_ID_OR_NULL ||
+		   fn->ret_type == RET_PTR_TO_BTF_ID) {
 		int ret_btf_id;
 
 		mark_reg_known_zero(env, regs, BPF_REG_0);
-		regs[BPF_REG_0].type = PTR_TO_BTF_ID_OR_NULL;
+		regs[BPF_REG_0].type = fn->ret_type == RET_PTR_TO_BTF_ID ?
+						     PTR_TO_BTF_ID :
+						     PTR_TO_BTF_ID_OR_NULL;
 		ret_btf_id = *fn->ret_btf_id;
 		if (ret_btf_id == 0) {
 			verbose(env, "invalid return type %d of func %s#%d\n",
@@ -6695,7 +6736,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
 
 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)
+				     enum bpf_reg_type type, int new_range)
 {
 	struct bpf_reg_state *reg;
 	int i;
@@ -6720,8 +6761,7 @@ static void find_good_pkt_pointers(struct bpf_verifier_state *vstate,
 				   enum bpf_reg_type type,
 				   bool range_right_open)
 {
-	u16 new_range;
-	int i;
+	int new_range, i;
 
 	if (dst_reg->off < 0 ||
 	    (dst_reg->off == 0 && range_right_open))
@@ -6972,6 +7012,67 @@ static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode,
 	return is_branch64_taken(reg, val, opcode);
 }
 
+static int flip_opcode(u32 opcode)
+{
+	/* How can we transform "a <op> b" into "b <op> a"? */
+	static const u8 opcode_flip[16] = {
+		/* these stay the same */
+		[BPF_JEQ  >> 4] = BPF_JEQ,
+		[BPF_JNE  >> 4] = BPF_JNE,
+		[BPF_JSET >> 4] = BPF_JSET,
+		/* these swap "lesser" and "greater" (L and G in the opcodes) */
+		[BPF_JGE  >> 4] = BPF_JLE,
+		[BPF_JGT  >> 4] = BPF_JLT,
+		[BPF_JLE  >> 4] = BPF_JGE,
+		[BPF_JLT  >> 4] = BPF_JGT,
+		[BPF_JSGE >> 4] = BPF_JSLE,
+		[BPF_JSGT >> 4] = BPF_JSLT,
+		[BPF_JSLE >> 4] = BPF_JSGE,
+		[BPF_JSLT >> 4] = BPF_JSGT
+	};
+	return opcode_flip[opcode >> 4];
+}
+
+static int is_pkt_ptr_branch_taken(struct bpf_reg_state *dst_reg,
+				   struct bpf_reg_state *src_reg,
+				   u8 opcode)
+{
+	struct bpf_reg_state *pkt;
+
+	if (src_reg->type == PTR_TO_PACKET_END) {
+		pkt = dst_reg;
+	} else if (dst_reg->type == PTR_TO_PACKET_END) {
+		pkt = src_reg;
+		opcode = flip_opcode(opcode);
+	} else {
+		return -1;
+	}
+
+	if (pkt->range >= 0)
+		return -1;
+
+	switch (opcode) {
+	case BPF_JLE:
+		/* pkt <= pkt_end */
+		fallthrough;
+	case BPF_JGT:
+		/* pkt > pkt_end */
+		if (pkt->range == BEYOND_PKT_END)
+			/* pkt has at last one extra byte beyond pkt_end */
+			return opcode == BPF_JGT;
+		break;
+	case BPF_JLT:
+		/* pkt < pkt_end */
+		fallthrough;
+	case BPF_JGE:
+		/* pkt >= pkt_end */
+		if (pkt->range == BEYOND_PKT_END || pkt->range == AT_PKT_END)
+			return opcode == BPF_JGE;
+		break;
+	}
+	return -1;
+}
+
 /* Adjusts the register min/max values in the case that the dst_reg is the
  * variable register that we are working on, and src_reg is a constant or we're
  * simply doing a BPF_K check.
@@ -7135,23 +7236,7 @@ static void reg_set_min_max_inv(struct bpf_reg_state *true_reg,
 				u64 val, u32 val32,
 				u8 opcode, bool is_jmp32)
 {
-	/* How can we transform "a <op> b" into "b <op> a"? */
-	static const u8 opcode_flip[16] = {
-		/* these stay the same */
-		[BPF_JEQ  >> 4] = BPF_JEQ,
-		[BPF_JNE  >> 4] = BPF_JNE,
-		[BPF_JSET >> 4] = BPF_JSET,
-		/* these swap "lesser" and "greater" (L and G in the opcodes) */
-		[BPF_JGE  >> 4] = BPF_JLE,
-		[BPF_JGT  >> 4] = BPF_JLT,
-		[BPF_JLE  >> 4] = BPF_JGE,
-		[BPF_JLT  >> 4] = BPF_JGT,
-		[BPF_JSGE >> 4] = BPF_JSLE,
-		[BPF_JSGT >> 4] = BPF_JSLT,
-		[BPF_JSLE >> 4] = BPF_JSGE,
-		[BPF_JSLT >> 4] = BPF_JSGT
-	};
-	opcode = opcode_flip[opcode >> 4];
+	opcode = flip_opcode(opcode);
 	/* This uses zero as "not present in table"; luckily the zero opcode,
 	 * BPF_JA, can't get here.
 	 */
@@ -7333,6 +7418,7 @@ static bool try_match_pkt_pointers(const struct bpf_insn *insn,
 			/* pkt_data' > pkt_end, pkt_meta' > pkt_data */
 			find_good_pkt_pointers(this_branch, dst_reg,
 					       dst_reg->type, false);
+			mark_pkt_end(other_branch, insn->dst_reg, true);
 		} else if ((dst_reg->type == PTR_TO_PACKET_END &&
 			    src_reg->type == PTR_TO_PACKET) ||
 			   (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) &&
@@ -7340,6 +7426,7 @@ static bool try_match_pkt_pointers(const struct bpf_insn *insn,
 			/* pkt_end > pkt_data', pkt_data > pkt_meta' */
 			find_good_pkt_pointers(other_branch, src_reg,
 					       src_reg->type, true);
+			mark_pkt_end(this_branch, insn->src_reg, false);
 		} else {
 			return false;
 		}
@@ -7352,6 +7439,7 @@ static bool try_match_pkt_pointers(const struct bpf_insn *insn,
 			/* pkt_data' < pkt_end, pkt_meta' < pkt_data */
 			find_good_pkt_pointers(other_branch, dst_reg,
 					       dst_reg->type, true);
+			mark_pkt_end(this_branch, insn->dst_reg, false);
 		} else if ((dst_reg->type == PTR_TO_PACKET_END &&
 			    src_reg->type == PTR_TO_PACKET) ||
 			   (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) &&
@@ -7359,6 +7447,7 @@ static bool try_match_pkt_pointers(const struct bpf_insn *insn,
 			/* pkt_end < pkt_data', pkt_data > pkt_meta' */
 			find_good_pkt_pointers(this_branch, src_reg,
 					       src_reg->type, false);
+			mark_pkt_end(other_branch, insn->src_reg, true);
 		} else {
 			return false;
 		}
@@ -7371,6 +7460,7 @@ static bool try_match_pkt_pointers(const struct bpf_insn *insn,
 			/* pkt_data' >= pkt_end, pkt_meta' >= pkt_data */
 			find_good_pkt_pointers(this_branch, dst_reg,
 					       dst_reg->type, true);
+			mark_pkt_end(other_branch, insn->dst_reg, false);
 		} else if ((dst_reg->type == PTR_TO_PACKET_END &&
 			    src_reg->type == PTR_TO_PACKET) ||
 			   (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) &&
@@ -7378,6 +7468,7 @@ static bool try_match_pkt_pointers(const struct bpf_insn *insn,
 			/* pkt_end >= pkt_data', pkt_data >= pkt_meta' */
 			find_good_pkt_pointers(other_branch, src_reg,
 					       src_reg->type, false);
+			mark_pkt_end(this_branch, insn->src_reg, true);
 		} else {
 			return false;
 		}
@@ -7390,6 +7481,7 @@ static bool try_match_pkt_pointers(const struct bpf_insn *insn,
 			/* pkt_data' <= pkt_end, pkt_meta' <= pkt_data */
 			find_good_pkt_pointers(other_branch, dst_reg,
 					       dst_reg->type, false);
+			mark_pkt_end(this_branch, insn->dst_reg, true);
 		} else if ((dst_reg->type == PTR_TO_PACKET_END &&
 			    src_reg->type == PTR_TO_PACKET) ||
 			   (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) &&
@@ -7397,6 +7489,7 @@ static bool try_match_pkt_pointers(const struct bpf_insn *insn,
 			/* pkt_end <= pkt_data', pkt_data <= pkt_meta' */
 			find_good_pkt_pointers(this_branch, src_reg,
 					       src_reg->type, true);
+			mark_pkt_end(other_branch, insn->src_reg, false);
 		} else {
 			return false;
 		}
@@ -7496,6 +7589,10 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
 				       src_reg->var_off.value,
 				       opcode,
 				       is_jmp32);
+	} else if (reg_is_pkt_pointer_any(dst_reg) &&
+		   reg_is_pkt_pointer_any(src_reg) &&
+		   !is_jmp32) {
+		pred = is_pkt_ptr_branch_taken(dst_reg, src_reg, opcode);
 	}
 
 	if (pred >= 0) {
@@ -7504,7 +7601,8 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
 		 */
 		if (!__is_pointer_value(false, dst_reg))
 			err = mark_chain_precision(env, insn->dst_reg);
-		if (BPF_SRC(insn->code) == BPF_X && !err)
+		if (BPF_SRC(insn->code) == BPF_X && !err &&
+		    !__is_pointer_value(false, src_reg))
 			err = mark_chain_precision(env, insn->src_reg);
 		if (err)
 			return err;
@@ -9719,11 +9817,21 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
 		verbose(env, "trace type programs with run-time allocated hash maps are unsafe. Switch to preallocated hash maps.\n");
 	}
 
-	if ((is_tracing_prog_type(prog_type) ||
-	     prog_type == BPF_PROG_TYPE_SOCKET_FILTER) &&
-	    map_value_has_spin_lock(map)) {
-		verbose(env, "tracing progs cannot use bpf_spin_lock yet\n");
-		return -EINVAL;
+	if (map_value_has_spin_lock(map)) {
+		if (prog_type == BPF_PROG_TYPE_SOCKET_FILTER) {
+			verbose(env, "socket filter progs cannot use bpf_spin_lock yet\n");
+			return -EINVAL;
+		}
+
+		if (is_tracing_prog_type(prog_type)) {
+			verbose(env, "tracing progs cannot use bpf_spin_lock yet\n");
+			return -EINVAL;
+		}
+
+		if (prog->aux->sleepable) {
+			verbose(env, "sleepable progs cannot use bpf_spin_lock yet\n");
+			return -EINVAL;
+		}
 	}
 
 	if ((bpf_prog_is_dev_bound(prog->aux) || bpf_map_is_dev_bound(map)) &&
@@ -11454,20 +11562,6 @@ static int check_attach_modify_return(unsigned long addr, const char *func_name)
 	return -EINVAL;
 }
 
-/* non exhaustive list of sleepable bpf_lsm_*() functions */
-BTF_SET_START(btf_sleepable_lsm_hooks)
-#ifdef CONFIG_BPF_LSM
-BTF_ID(func, bpf_lsm_bprm_committed_creds)
-#else
-BTF_ID_UNUSED
-#endif
-BTF_SET_END(btf_sleepable_lsm_hooks)
-
-static int check_sleepable_lsm_hook(u32 btf_id)
-{
-	return btf_id_set_contains(&btf_sleepable_lsm_hooks, btf_id);
-}
-
 /* list of non-sleepable functions that are otherwise on
  * ALLOW_ERROR_INJECTION list
  */
@@ -11689,7 +11783,7 @@ int bpf_check_attach_target(struct bpf_verifier_log *log,
 				/* LSM progs check that they are attached to bpf_lsm_*() funcs.
 				 * Only some of them are sleepable.
 				 */
-				if (check_sleepable_lsm_hook(btf_id))
+				if (bpf_lsm_is_sleepable_hook(btf_id))
 					ret = 0;
 				break;
 			default: