Merge branch 'bpf-misc-helper-verifier-improvements'

Daniel Borkmann says:

====================
Misc BPF helper/verifier improvements

Miscellanous improvements I still had in my queue, it adds a new
bpf_skb_adjust_room() helper for cls_bpf, exports to fdinfo whether
tail call array owner is JITed, so iproute2 error reporting can be
improved on that regard, a small cleanup and extension to trace
printk, two verifier patches, one to make the code around narrower
ctx access a bit more straight forward and one to allow for imm += x
operations, that we've seen LLVM generating and the verifier currently
rejecting. We've included the patch 6 given it's rather small and
we ran into it from LLVM side, it would be great if it could be
queued for stable as well after the merge window. Last but not least,
test cases are added also related to imm alu improvement.

Thanks a lot!
====================

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

2 files changed, 180 insertions, 1 deletions

diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 284b3661f1df..ce2988be4f0e 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -531,6 +531,14 @@ union bpf_attr {
  *     @optval: pointer to option value
  *     @optlen: length of optval in byes
  *     Return: 0 or negative error
+ *
+ * int bpf_skb_adjust_room(skb, len_diff, mode, flags)
+ *     Grow or shrink room in sk_buff.
+ *     @skb: pointer to skb
+ *     @len_diff: (signed) amount of room to grow/shrink
+ *     @mode: operation mode (enum bpf_adj_room_mode)
+ *     @flags: reserved for future use
+ *     Return: 0 on success or negative error code
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -582,7 +590,8 @@ union bpf_attr {
 	FN(get_socket_cookie),		\
 	FN(get_socket_uid),		\
 	FN(set_hash),			\
-	FN(setsockopt),
+	FN(setsockopt),			\
+	FN(skb_adjust_room),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -632,6 +641,11 @@ enum bpf_func_id {
 /* BPF_FUNC_perf_event_output for sk_buff input context. */
 #define BPF_F_CTXLEN_MASK		(0xfffffULL << 32)
 
+/* Mode for BPF_FUNC_skb_adjust_room helper. */
+enum bpf_adj_room_mode {
+	BPF_ADJ_ROOM_NET_OPTS,
+};
+
 /* user accessible mirror of in-kernel sk_buff.
  * new fields can only be added to the end of this structure
  */
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 26f1eefdc782..404aec520812 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -2658,6 +2658,171 @@ static struct bpf_test tests[] = {
 		.flags = F_LOAD_WITH_STRICT_ALIGNMENT,
 	},
 	{
+		"direct packet access: test18 (imm += pkt_ptr, 1)",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct __sk_buff, data)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct __sk_buff, data_end)),
+			BPF_MOV64_IMM(BPF_REG_0, 8),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_2),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),
+			BPF_STX_MEM(BPF_B, BPF_REG_2, BPF_REG_2, 0),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	},
+	{
+		"direct packet access: test19 (imm += pkt_ptr, 2)",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct __sk_buff, data)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct __sk_buff, data_end)),
+			BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 3),
+			BPF_MOV64_IMM(BPF_REG_4, 4),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_4, BPF_REG_2),
+			BPF_STX_MEM(BPF_B, BPF_REG_4, BPF_REG_4, 0),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	},
+	{
+		"direct packet access: test20 (x += pkt_ptr, 1)",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct __sk_buff, data)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct __sk_buff, data_end)),
+			BPF_MOV64_IMM(BPF_REG_0, 0xffffffff),
+			BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
+			BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 0xffff),
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_0),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_4, BPF_REG_2),
+			BPF_MOV64_REG(BPF_REG_5, BPF_REG_4),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 0xffff - 1),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_4, BPF_REG_3, 1),
+			BPF_STX_MEM(BPF_DW, BPF_REG_5, BPF_REG_4, 0),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.result = ACCEPT,
+	},
+	{
+		"direct packet access: test21 (x += pkt_ptr, 2)",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct __sk_buff, data)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct __sk_buff, data_end)),
+			BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 9),
+			BPF_MOV64_IMM(BPF_REG_4, 0xffffffff),
+			BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_4, -8),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_4, BPF_REG_10, -8),
+			BPF_ALU64_IMM(BPF_AND, BPF_REG_4, 0xffff),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_4, BPF_REG_2),
+			BPF_MOV64_REG(BPF_REG_5, BPF_REG_4),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 0xffff - 1),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_4, BPF_REG_3, 1),
+			BPF_STX_MEM(BPF_DW, BPF_REG_5, BPF_REG_4, 0),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.result = ACCEPT,
+	},
+	{
+		"direct packet access: test22 (x += pkt_ptr, 3)",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct __sk_buff, data)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct __sk_buff, data_end)),
+			BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
+			BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -8),
+			BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_3, -16),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_10, -16),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 11),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_10, -8),
+			BPF_MOV64_IMM(BPF_REG_4, 0xffffffff),
+			BPF_STX_XADD(BPF_DW, BPF_REG_10, BPF_REG_4, -8),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_4, BPF_REG_10, -8),
+			BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 48),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_4, BPF_REG_2),
+			BPF_MOV64_REG(BPF_REG_0, BPF_REG_4),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 2),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 2),
+			BPF_MOV64_IMM(BPF_REG_2, 1),
+			BPF_STX_MEM(BPF_H, BPF_REG_4, BPF_REG_2, 0),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.result = ACCEPT,
+	},
+	{
+		"direct packet access: test23 (x += pkt_ptr, 4)",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct __sk_buff, data)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct __sk_buff, data_end)),
+			BPF_MOV64_IMM(BPF_REG_0, 0xffffffff),
+			BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
+			BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 0xffff),
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_0),
+			BPF_MOV64_IMM(BPF_REG_0, 31),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_4),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_2),
+			BPF_MOV64_REG(BPF_REG_5, BPF_REG_0),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 0xffff - 1),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),
+			BPF_STX_MEM(BPF_DW, BPF_REG_5, BPF_REG_0, 0),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.result = REJECT,
+		.errstr = "cannot add integer value with 47 upper zero bits to ptr_to_packet",
+	},
+	{
+		"direct packet access: test24 (x += pkt_ptr, 5)",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct __sk_buff, data)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct __sk_buff, data_end)),
+			BPF_MOV64_IMM(BPF_REG_0, 0xffffffff),
+			BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
+			BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 0xff),
+			BPF_MOV64_REG(BPF_REG_4, BPF_REG_0),
+			BPF_MOV64_IMM(BPF_REG_0, 64),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_4),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_2),
+			BPF_MOV64_REG(BPF_REG_5, BPF_REG_0),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 0xffff - 1),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),
+			BPF_STX_MEM(BPF_DW, BPF_REG_5, BPF_REG_0, 0),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.result = ACCEPT,
+	},
+	{
 		"helper access to packet: test1, valid packet_ptr range",
 		.insns = {
 			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,