Merge branch 'misc-BPF-improvements'

Daniel Borkmann says:

====================
This set adds various patches I still had in my queue, first two
are test cases to provide coverage for the recent two fixes that
went to bpf tree, then a small improvement on the error message
for gpl helpers. Next, we expose prog and map id into fdinfo in
order to allow for inspection of these objections currently used
in applications. Patch after that removes a retpoline call for
map lookup/update/delete helpers. A new helper is added in the
subsequent patch to lookup the skb's socket's cgroup v2 id which
can be used in an efficient way for e.g. lookups on egress side.
Next one is a fix to fully clear state info in tunnel/xfrm helpers.
Given this is full cap_sys_admin from init ns and has same priv
requirements like tracing, bpf-next should be okay. A small bug
fix for bpf_asm follows, and next a fix for context access in
tracing which was recently reported. Lastly, a small update in
the maintainer's file to add patchwork url and missing files.

Thanks!

v2 -> v3:
  - Noticed a merge artefact inside uapi header comment, sigh,
    fixed now.
v1 -> v2:
  - minor fix in getting context access work on 32 bit for tracing
  - add paragraph to uapi helper doc to better describe kernel
    build deps for cggroup helper
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

4 files changed, 189 insertions, 30 deletions

diff --git a/tools/bpf/bpf_exp.l b/tools/bpf/bpf_exp.l
index bd83149e7be0..4da8d053d68f 100644
--- a/tools/bpf/bpf_exp.l
+++ b/tools/bpf/bpf_exp.l
@@ -175,7 +175,7 @@ extern void yyerror(const char *str);
 			yylval.number = strtol(yytext, NULL, 10);
 			return number;
 		}
-([0][0-9]+)	{
+([0][0-7]+)	{
 			yylval.number = strtol(yytext + 1, NULL, 8);
 			return number;
 		}
diff --git a/tools/include/linux/filter.h b/tools/include/linux/filter.h
index c5e512da8d8a..af55acf73e75 100644
--- a/tools/include/linux/filter.h
+++ b/tools/include/linux/filter.h
@@ -263,6 +263,16 @@
 #define BPF_LD_MAP_FD(DST, MAP_FD)				\
 	BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 
+/* Relative call */
+
+#define BPF_CALL_REL(TGT)					\
+	((struct bpf_insn) {					\
+		.code  = BPF_JMP | BPF_CALL,			\
+		.dst_reg = 0,					\
+		.src_reg = BPF_PSEUDO_CALL,			\
+		.off   = 0,					\
+		.imm   = TGT })
+
 /* Program exit */
 
 #define BPF_EXIT_INSN()						\
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 64ac0f7a689e..f0b6608b1f1c 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -2054,6 +2054,22 @@ union bpf_attr {
  *
  *	Return
  *		0
+ *
+ * uint64_t bpf_skb_cgroup_id(struct sk_buff *skb)
+ * 	Description
+ * 		Return the cgroup v2 id of the socket associated with the *skb*.
+ * 		This is roughly similar to the **bpf_get_cgroup_classid**\ ()
+ * 		helper for cgroup v1 by providing a tag resp. identifier that
+ * 		can be matched on or used for map lookups e.g. to implement
+ * 		policy. The cgroup v2 id of a given path in the hierarchy is
+ * 		exposed in user space through the f_handle API in order to get
+ * 		to the same 64-bit id.
+ *
+ * 		This helper can be used on TC egress path, but not on ingress,
+ * 		and is available only if the kernel was compiled with the
+ * 		**CONFIG_SOCK_CGROUP_DATA** configuration option.
+ * 	Return
+ * 		The id is returned or 0 in case the id could not be retrieved.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -2134,7 +2150,8 @@ union bpf_attr {
 	FN(lwt_seg6_adjust_srh),	\
 	FN(lwt_seg6_action),		\
 	FN(rc_repeat),			\
-	FN(rc_keydown),
+	FN(rc_keydown),			\
+	FN(skb_cgroup_id),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -2251,7 +2268,7 @@ struct bpf_tunnel_key {
 	};
 	__u8 tunnel_tos;
 	__u8 tunnel_ttl;
-	__u16 tunnel_ext;
+	__u16 tunnel_ext;	/* Padding, future use. */
 	__u32 tunnel_label;
 };
 
@@ -2262,6 +2279,7 @@ struct bpf_xfrm_state {
 	__u32 reqid;
 	__u32 spi;	/* Stored in network byte order */
 	__u16 family;
+	__u16 ext;	/* Padding, future use. */
 	union {
 		__u32 remote_ipv4;	/* Stored in network byte order */
 		__u32 remote_ipv6[4];	/* Stored in network byte order */
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 4b4f015be217..7cb1d74057ce 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -50,7 +50,7 @@
 
 #define MAX_INSNS	BPF_MAXINSNS
 #define MAX_FIXUPS	8
-#define MAX_NR_MAPS	4
+#define MAX_NR_MAPS	7
 #define POINTER_VALUE	0xcafe4all
 #define TEST_DATA_LEN	64
 
@@ -66,7 +66,9 @@ struct bpf_test {
 	int fixup_map1[MAX_FIXUPS];
 	int fixup_map2[MAX_FIXUPS];
 	int fixup_map3[MAX_FIXUPS];
-	int fixup_prog[MAX_FIXUPS];
+	int fixup_map4[MAX_FIXUPS];
+	int fixup_prog1[MAX_FIXUPS];
+	int fixup_prog2[MAX_FIXUPS];
 	int fixup_map_in_map[MAX_FIXUPS];
 	const char *errstr;
 	const char *errstr_unpriv;
@@ -2769,7 +2771,7 @@ static struct bpf_test tests[] = {
 			BPF_MOV64_IMM(BPF_REG_0, 0),
 			BPF_EXIT_INSN(),
 		},
-		.fixup_prog = { 1 },
+		.fixup_prog1 = { 1 },
 		.errstr_unpriv = "R3 leaks addr into helper",
 		.result_unpriv = REJECT,
 		.result = ACCEPT,
@@ -2856,7 +2858,7 @@ static struct bpf_test tests[] = {
 			BPF_MOV64_IMM(BPF_REG_0, 1),
 			BPF_EXIT_INSN(),
 		},
-		.fixup_prog = { 1 },
+		.fixup_prog1 = { 1 },
 		.result = ACCEPT,
 		.retval = 42,
 	},
@@ -2870,7 +2872,7 @@ static struct bpf_test tests[] = {
 			BPF_MOV64_IMM(BPF_REG_0, 1),
 			BPF_EXIT_INSN(),
 		},
-		.fixup_prog = { 1 },
+		.fixup_prog1 = { 1 },
 		.result = ACCEPT,
 		.retval = 41,
 	},
@@ -2884,7 +2886,7 @@ static struct bpf_test tests[] = {
 			BPF_MOV64_IMM(BPF_REG_0, 1),
 			BPF_EXIT_INSN(),
 		},
-		.fixup_prog = { 1 },
+		.fixup_prog1 = { 1 },
 		.result = ACCEPT,
 		.retval = 1,
 	},
@@ -2898,7 +2900,7 @@ static struct bpf_test tests[] = {
 			BPF_MOV64_IMM(BPF_REG_0, 2),
 			BPF_EXIT_INSN(),
 		},
-		.fixup_prog = { 1 },
+		.fixup_prog1 = { 1 },
 		.result = ACCEPT,
 		.retval = 2,
 	},
@@ -2912,7 +2914,7 @@ static struct bpf_test tests[] = {
 			BPF_MOV64_IMM(BPF_REG_0, 2),
 			BPF_EXIT_INSN(),
 		},
-		.fixup_prog = { 1 },
+		.fixup_prog1 = { 1 },
 		.result = ACCEPT,
 		.retval = 2,
 	},
@@ -2926,7 +2928,7 @@ static struct bpf_test tests[] = {
 			BPF_MOV64_IMM(BPF_REG_0, 2),
 			BPF_EXIT_INSN(),
 		},
-		.fixup_prog = { 2 },
+		.fixup_prog1 = { 2 },
 		.result = ACCEPT,
 		.retval = 42,
 	},
@@ -11682,6 +11684,112 @@ static struct bpf_test tests[] = {
 		.prog_type = BPF_PROG_TYPE_XDP,
 	},
 	{
+		"calls: two calls returning different map pointers for lookup (hash, array)",
+		.insns = {
+			/* main prog */
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
+			BPF_CALL_REL(11),
+			BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+			BPF_CALL_REL(12),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+			BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+			BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+			BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				     BPF_FUNC_map_lookup_elem),
+			BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
+			BPF_ST_MEM(BPF_DW, BPF_REG_0, 0,
+				   offsetof(struct test_val, foo)),
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_EXIT_INSN(),
+			/* subprog 1 */
+			BPF_LD_MAP_FD(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+			/* subprog 2 */
+			BPF_LD_MAP_FD(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.fixup_map2 = { 13 },
+		.fixup_map4 = { 16 },
+		.result = ACCEPT,
+		.retval = 1,
+	},
+	{
+		"calls: two calls returning different map pointers for lookup (hash, map in map)",
+		.insns = {
+			/* main prog */
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
+			BPF_CALL_REL(11),
+			BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+			BPF_CALL_REL(12),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+			BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+			BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+			BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				     BPF_FUNC_map_lookup_elem),
+			BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
+			BPF_ST_MEM(BPF_DW, BPF_REG_0, 0,
+				   offsetof(struct test_val, foo)),
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_EXIT_INSN(),
+			/* subprog 1 */
+			BPF_LD_MAP_FD(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+			/* subprog 2 */
+			BPF_LD_MAP_FD(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.fixup_map_in_map = { 16 },
+		.fixup_map4 = { 13 },
+		.result = REJECT,
+		.errstr = "R0 invalid mem access 'map_ptr'",
+	},
+	{
+		"cond: two branches returning different map pointers for lookup (tail, tail)",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+				    offsetof(struct __sk_buff, mark)),
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 0, 3),
+			BPF_LD_MAP_FD(BPF_REG_2, 0),
+			BPF_JMP_IMM(BPF_JA, 0, 0, 2),
+			BPF_LD_MAP_FD(BPF_REG_2, 0),
+			BPF_MOV64_IMM(BPF_REG_3, 7),
+			BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				     BPF_FUNC_tail_call),
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_EXIT_INSN(),
+		},
+		.fixup_prog1 = { 5 },
+		.fixup_prog2 = { 2 },
+		.result_unpriv = REJECT,
+		.errstr_unpriv = "tail_call abusing map_ptr",
+		.result = ACCEPT,
+		.retval = 42,
+	},
+	{
+		"cond: two branches returning same map pointers for lookup (tail, tail)",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+				    offsetof(struct __sk_buff, mark)),
+			BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 3),
+			BPF_LD_MAP_FD(BPF_REG_2, 0),
+			BPF_JMP_IMM(BPF_JA, 0, 0, 2),
+			BPF_LD_MAP_FD(BPF_REG_2, 0),
+			BPF_MOV64_IMM(BPF_REG_3, 7),
+			BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				     BPF_FUNC_tail_call),
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_EXIT_INSN(),
+		},
+		.fixup_prog2 = { 2, 5 },
+		.result_unpriv = ACCEPT,
+		.result = ACCEPT,
+		.retval = 42,
+	},
+	{
 		"search pruning: all branches should be verified (nop operation)",
 		.insns = {
 			BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
@@ -12162,12 +12270,13 @@ static int probe_filter_length(const struct bpf_insn *fp)
 	return len + 1;
 }
 
-static int create_map(uint32_t size_value, uint32_t max_elem)
+static int create_map(uint32_t type, uint32_t size_key,
+		      uint32_t size_value, uint32_t max_elem)
 {
 	int fd;
 
-	fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(long long),
-			    size_value, max_elem, BPF_F_NO_PREALLOC);
+	fd = bpf_create_map(type, size_key, size_value, max_elem,
+			    type == BPF_MAP_TYPE_HASH ? BPF_F_NO_PREALLOC : 0);
 	if (fd < 0)
 		printf("Failed to create hash map '%s'!\n", strerror(errno));
 
@@ -12200,13 +12309,13 @@ static int create_prog_dummy2(int mfd, int idx)
 				ARRAY_SIZE(prog), "GPL", 0, NULL, 0);
 }
 
-static int create_prog_array(void)
+static int create_prog_array(uint32_t max_elem, int p1key)
 {
-	int p1key = 0, p2key = 1;
+	int p2key = 1;
 	int mfd, p1fd, p2fd;
 
 	mfd = bpf_create_map(BPF_MAP_TYPE_PROG_ARRAY, sizeof(int),
-			     sizeof(int), 4, 0);
+			     sizeof(int), max_elem, 0);
 	if (mfd < 0) {
 		printf("Failed to create prog array '%s'!\n", strerror(errno));
 		return -1;
@@ -12261,7 +12370,9 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog,
 	int *fixup_map1 = test->fixup_map1;
 	int *fixup_map2 = test->fixup_map2;
 	int *fixup_map3 = test->fixup_map3;
-	int *fixup_prog = test->fixup_prog;
+	int *fixup_map4 = test->fixup_map4;
+	int *fixup_prog1 = test->fixup_prog1;
+	int *fixup_prog2 = test->fixup_prog2;
 	int *fixup_map_in_map = test->fixup_map_in_map;
 
 	if (test->fill_helper)
@@ -12272,7 +12383,8 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog,
 	 * that really matters is value size in this case.
 	 */
 	if (*fixup_map1) {
-		map_fds[0] = create_map(sizeof(long long), 1);
+		map_fds[0] = create_map(BPF_MAP_TYPE_HASH, sizeof(long long),
+					sizeof(long long), 1);
 		do {
 			prog[*fixup_map1].imm = map_fds[0];
 			fixup_map1++;
@@ -12280,7 +12392,8 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog,
 	}
 
 	if (*fixup_map2) {
-		map_fds[1] = create_map(sizeof(struct test_val), 1);
+		map_fds[1] = create_map(BPF_MAP_TYPE_HASH, sizeof(long long),
+					sizeof(struct test_val), 1);
 		do {
 			prog[*fixup_map2].imm = map_fds[1];
 			fixup_map2++;
@@ -12288,25 +12401,43 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog,
 	}
 
 	if (*fixup_map3) {
-		map_fds[1] = create_map(sizeof(struct other_val), 1);
+		map_fds[2] = create_map(BPF_MAP_TYPE_HASH, sizeof(long long),
+					sizeof(struct other_val), 1);
 		do {
-			prog[*fixup_map3].imm = map_fds[1];
+			prog[*fixup_map3].imm = map_fds[2];
 			fixup_map3++;
 		} while (*fixup_map3);
 	}
 
-	if (*fixup_prog) {
-		map_fds[2] = create_prog_array();
+	if (*fixup_map4) {
+		map_fds[3] = create_map(BPF_MAP_TYPE_ARRAY, sizeof(int),
+					sizeof(struct test_val), 1);
+		do {
+			prog[*fixup_map4].imm = map_fds[3];
+			fixup_map4++;
+		} while (*fixup_map4);
+	}
+
+	if (*fixup_prog1) {
+		map_fds[4] = create_prog_array(4, 0);
+		do {
+			prog[*fixup_prog1].imm = map_fds[4];
+			fixup_prog1++;
+		} while (*fixup_prog1);
+	}
+
+	if (*fixup_prog2) {
+		map_fds[5] = create_prog_array(8, 7);
 		do {
-			prog[*fixup_prog].imm = map_fds[2];
-			fixup_prog++;
-		} while (*fixup_prog);
+			prog[*fixup_prog2].imm = map_fds[5];
+			fixup_prog2++;
+		} while (*fixup_prog2);
 	}
 
 	if (*fixup_map_in_map) {
-		map_fds[3] = create_map_in_map();
+		map_fds[6] = create_map_in_map();
 		do {
-			prog[*fixup_map_in_map].imm = map_fds[3];
+			prog[*fixup_map_in_map].imm = map_fds[6];
 			fixup_map_in_map++;
 		} while (*fixup_map_in_map);
 	}