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

Daniel Borkmann says:

====================
pull-request: bpf-next 2018-03-21

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

The main changes are:

1) Add a BPF hook for sendmsg and sendfile by reusing the ULP infrastructure
   and sockmap. Three helpers are added along with this, bpf_msg_apply_bytes(),
   bpf_msg_cork_bytes(), and bpf_msg_pull_data(). The first is used to tell
   for how many bytes the verdict should be applied to, the second to tell
   that x bytes need to be queued first to retrigger the BPF program for a
   verdict, and the third helper is mainly for the sendfile case to pull in
   data for making it private for reading and/or writing, from John.

2) Improve address to symbol resolution of user stack traces in BPF stackmap.
   Currently, the latter stores the address for each entry in the call trace,
   however to map these addresses to user space files, it is necessary to
   maintain the mapping from these virtual addresses to symbols in the binary
   which is not practical for system-wide profiling. Instead, this option for
   the stackmap rather stores the ELF build id and offset for the call trace
   entries, from Song.

3) Add support that allows BPF programs attached to perf events to read the
   address values recorded with the perf events. They are requested through
   PERF_SAMPLE_ADDR via perf_event_open(). Main motivation behind it is to
   support building memory or lock access profiling and tracing tools with
   the help of BPF, from Teng.

4) Several improvements to the tools/bpf/ Makefiles. The 'make bpf' in the
   tools directory does not provide the standard quiet output except for
   bpftool and it also does not respect specifying a build output directory.
   'make bpf_install' command neither respects specified destination nor
   prefix, all from Jiri. In addition, Jakub fixes several other minor issues
   in the Makefiles on top of that, e.g. fixing dependency paths, phony
   targets and more.

5) Various doc updates e.g. add a comment for BPF fs about reserved names
   to make the dentry lookup from there a bit more obvious, and a comment
   to the bpf_devel_QA file in order to explain the diff between native
   and bpf target clang usage with regards to pointer size, from Quentin
   and Daniel.
====================

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

10 files changed, 425 insertions, 8 deletions

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 8567a858b789..f35fb02bdf56 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -13,6 +13,14 @@ endif
 CFLAGS += -Wall -O2 -I$(APIDIR) -I$(LIBDIR) -I$(GENDIR) $(GENFLAGS) -I../../../include
 LDLIBS += -lcap -lelf -lrt -lpthread
 
+TEST_CUSTOM_PROGS = $(OUTPUT)/urandom_read
+all: $(TEST_CUSTOM_PROGS)
+
+$(TEST_CUSTOM_PROGS): urandom_read
+
+urandom_read: urandom_read.c
+	$(CC) -o $(TEST_CUSTOM_PROGS) -static $<
+
 # Order correspond to 'make run_tests' order
 TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \
 	test_align test_verifier_log test_dev_cgroup test_tcpbpf_user
@@ -21,7 +29,8 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test
 	test_pkt_md_access.o test_xdp_redirect.o test_xdp_meta.o sockmap_parse_prog.o     \
 	sockmap_verdict_prog.o dev_cgroup.o sample_ret0.o test_tracepoint.o \
 	test_l4lb_noinline.o test_xdp_noinline.o test_stacktrace_map.o \
-	sample_map_ret0.o test_tcpbpf_kern.o
+	sample_map_ret0.o test_tcpbpf_kern.o test_stacktrace_build_id.o \
+	sockmap_tcp_msg_prog.o
 
 # Order correspond to 'make run_tests' order
 TEST_PROGS := test_kmod.sh \
@@ -74,3 +83,5 @@ $(OUTPUT)/%.o: %.c
 	$(CLANG) $(CLANG_FLAGS) \
 		 -O2 -target bpf -emit-llvm -c $< -o - |      \
 	$(LLC) -march=bpf -mcpu=$(CPU) -filetype=obj -o $@
+
+EXTRA_CLEAN := $(TEST_CUSTOM_PROGS)
diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h
index dde2c11d7771..7cae376d8d0c 100644
--- a/tools/testing/selftests/bpf/bpf_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_helpers.h
@@ -86,6 +86,14 @@ static int (*bpf_perf_prog_read_value)(void *ctx, void *buf,
 	(void *) BPF_FUNC_perf_prog_read_value;
 static int (*bpf_override_return)(void *ctx, unsigned long rc) =
 	(void *) BPF_FUNC_override_return;
+static int (*bpf_msg_redirect_map)(void *ctx, void *map, int key, int flags) =
+	(void *) BPF_FUNC_msg_redirect_map;
+static int (*bpf_msg_apply_bytes)(void *ctx, int len) =
+	(void *) BPF_FUNC_msg_apply_bytes;
+static int (*bpf_msg_cork_bytes)(void *ctx, int len) =
+	(void *) BPF_FUNC_msg_cork_bytes;
+static int (*bpf_msg_pull_data)(void *ctx, int start, int end, int flags) =
+	(void *) BPF_FUNC_msg_pull_data;
 
 /* llvm builtin functions that eBPF C program may use to
  * emit BPF_LD_ABS and BPF_LD_IND instructions
@@ -123,6 +131,8 @@ static int (*bpf_skb_under_cgroup)(void *ctx, void *map, int index) =
 	(void *) BPF_FUNC_skb_under_cgroup;
 static int (*bpf_skb_change_head)(void *, int len, int flags) =
 	(void *) BPF_FUNC_skb_change_head;
+static int (*bpf_skb_pull_data)(void *, int len) =
+	(void *) BPF_FUNC_skb_pull_data;
 
 /* Scan the ARCH passed in from ARCH env variable (see Makefile) */
 #if defined(__TARGET_ARCH_x86)
diff --git a/tools/testing/selftests/bpf/sockmap_parse_prog.c b/tools/testing/selftests/bpf/sockmap_parse_prog.c
index a1dec2b6d9c5..0f92858f6226 100644
--- a/tools/testing/selftests/bpf/sockmap_parse_prog.c
+++ b/tools/testing/selftests/bpf/sockmap_parse_prog.c
@@ -20,14 +20,25 @@ int bpf_prog1(struct __sk_buff *skb)
 	__u32 lport = skb->local_port;
 	__u32 rport = skb->remote_port;
 	__u8 *d = data;
+	__u32 len = (__u32) data_end - (__u32) data;
+	int err;
 
-	if (data + 10 > data_end)
-		return skb->len;
+	if (data + 10 > data_end) {
+		err = bpf_skb_pull_data(skb, 10);
+		if (err)
+			return SK_DROP;
+
+		data_end = (void *)(long)skb->data_end;
+		data = (void *)(long)skb->data;
+		if (data + 10 > data_end)
+			return SK_DROP;
+	}
 
 	/* This write/read is a bit pointless but tests the verifier and
 	 * strparser handler for read/write pkt data and access into sk
 	 * fields.
 	 */
+	d = data;
 	d[7] = 1;
 	return skb->len;
 }
diff --git a/tools/testing/selftests/bpf/sockmap_tcp_msg_prog.c b/tools/testing/selftests/bpf/sockmap_tcp_msg_prog.c
new file mode 100644
index 000000000000..12a7b5c82ed6
--- /dev/null
+++ b/tools/testing/selftests/bpf/sockmap_tcp_msg_prog.c
@@ -0,0 +1,33 @@
+#include <linux/bpf.h>
+#include "bpf_helpers.h"
+#include "bpf_util.h"
+#include "bpf_endian.h"
+
+int _version SEC("version") = 1;
+
+#define bpf_printk(fmt, ...)					\
+({								\
+	       char ____fmt[] = fmt;				\
+	       bpf_trace_printk(____fmt, sizeof(____fmt),	\
+				##__VA_ARGS__);			\
+})
+
+SEC("sk_msg1")
+int bpf_prog1(struct sk_msg_md *msg)
+{
+	void *data_end = (void *)(long) msg->data_end;
+	void *data = (void *)(long) msg->data;
+
+	char *d;
+
+	if (data + 8 > data_end)
+		return SK_DROP;
+
+	bpf_printk("data length %i\n", (__u64)msg->data_end - (__u64)msg->data);
+	d = (char *)data;
+	bpf_printk("hello sendmsg hook %i %i\n", d[0], d[1]);
+
+	return SK_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/sockmap_verdict_prog.c b/tools/testing/selftests/bpf/sockmap_verdict_prog.c
index d7bea972cb21..2ce7634a4012 100644
--- a/tools/testing/selftests/bpf/sockmap_verdict_prog.c
+++ b/tools/testing/selftests/bpf/sockmap_verdict_prog.c
@@ -26,6 +26,13 @@ struct bpf_map_def SEC("maps") sock_map_tx = {
 	.max_entries = 20,
 };
 
+struct bpf_map_def SEC("maps") sock_map_msg = {
+	.type = BPF_MAP_TYPE_SOCKMAP,
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.max_entries = 20,
+};
+
 struct bpf_map_def SEC("maps") sock_map_break = {
 	.type = BPF_MAP_TYPE_ARRAY,
 	.key_size = sizeof(int),
diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
index 1238733c5b33..6c253343a6f9 100644
--- a/tools/testing/selftests/bpf/test_maps.c
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -464,15 +464,17 @@ static void test_devmap(int task, void *data)
 #include <linux/err.h>
 #define SOCKMAP_PARSE_PROG "./sockmap_parse_prog.o"
 #define SOCKMAP_VERDICT_PROG "./sockmap_verdict_prog.o"
+#define SOCKMAP_TCP_MSG_PROG "./sockmap_tcp_msg_prog.o"
 static void test_sockmap(int tasks, void *data)
 {
-	int one = 1, map_fd_rx = 0, map_fd_tx = 0, map_fd_break, s, sc, rc;
-	struct bpf_map *bpf_map_rx, *bpf_map_tx, *bpf_map_break;
+	struct bpf_map *bpf_map_rx, *bpf_map_tx, *bpf_map_msg, *bpf_map_break;
+	int map_fd_msg = 0, map_fd_rx = 0, map_fd_tx = 0, map_fd_break;
 	int ports[] = {50200, 50201, 50202, 50204};
 	int err, i, fd, udp, sfd[6] = {0xdeadbeef};
 	u8 buf[20] = {0x0, 0x5, 0x3, 0x2, 0x1, 0x0};
-	int parse_prog, verdict_prog;
+	int parse_prog, verdict_prog, msg_prog;
 	struct sockaddr_in addr;
+	int one = 1, s, sc, rc;
 	struct bpf_object *obj;
 	struct timeval to;
 	__u32 key, value;
@@ -584,6 +586,12 @@ static void test_sockmap(int tasks, void *data)
 		goto out_sockmap;
 	}
 
+	err = bpf_prog_attach(-1, fd, BPF_SK_MSG_VERDICT, 0);
+	if (!err) {
+		printf("Failed invalid msg verdict prog attach\n");
+		goto out_sockmap;
+	}
+
 	err = bpf_prog_attach(-1, fd, __MAX_BPF_ATTACH_TYPE, 0);
 	if (!err) {
 		printf("Failed unknown prog attach\n");
@@ -602,6 +610,12 @@ static void test_sockmap(int tasks, void *data)
 		goto out_sockmap;
 	}
 
+	err = bpf_prog_detach(fd, BPF_SK_MSG_VERDICT);
+	if (err) {
+		printf("Failed empty msg verdict prog detach\n");
+		goto out_sockmap;
+	}
+
 	err = bpf_prog_detach(fd, __MAX_BPF_ATTACH_TYPE);
 	if (!err) {
 		printf("Detach invalid prog successful\n");
@@ -616,6 +630,13 @@ static void test_sockmap(int tasks, void *data)
 		goto out_sockmap;
 	}
 
+	err = bpf_prog_load(SOCKMAP_TCP_MSG_PROG,
+			    BPF_PROG_TYPE_SK_MSG, &obj, &msg_prog);
+	if (err) {
+		printf("Failed to load SK_SKB msg prog\n");
+		goto out_sockmap;
+	}
+
 	err = bpf_prog_load(SOCKMAP_VERDICT_PROG,
 			    BPF_PROG_TYPE_SK_SKB, &obj, &verdict_prog);
 	if (err) {
@@ -631,7 +652,7 @@ static void test_sockmap(int tasks, void *data)
 
 	map_fd_rx = bpf_map__fd(bpf_map_rx);
 	if (map_fd_rx < 0) {
-		printf("Failed to get map fd\n");
+		printf("Failed to get map rx fd\n");
 		goto out_sockmap;
 	}
 
@@ -647,6 +668,18 @@ static void test_sockmap(int tasks, void *data)
 		goto out_sockmap;
 	}
 
+	bpf_map_msg = bpf_object__find_map_by_name(obj, "sock_map_msg");
+	if (IS_ERR(bpf_map_msg)) {
+		printf("Failed to load map msg from msg_verdict prog\n");
+		goto out_sockmap;
+	}
+
+	map_fd_msg = bpf_map__fd(bpf_map_msg);
+	if (map_fd_msg < 0) {
+		printf("Failed to get map msg fd\n");
+		goto out_sockmap;
+	}
+
 	bpf_map_break = bpf_object__find_map_by_name(obj, "sock_map_break");
 	if (IS_ERR(bpf_map_break)) {
 		printf("Failed to load map tx from verdict prog\n");
@@ -680,6 +713,12 @@ static void test_sockmap(int tasks, void *data)
 		goto out_sockmap;
 	}
 
+	err = bpf_prog_attach(msg_prog, map_fd_msg, BPF_SK_MSG_VERDICT, 0);
+	if (err) {
+		printf("Failed msg verdict bpf prog attach\n");
+		goto out_sockmap;
+	}
+
 	err = bpf_prog_attach(verdict_prog, map_fd_rx,
 			      __MAX_BPF_ATTACH_TYPE, 0);
 	if (!err) {
@@ -719,6 +758,14 @@ static void test_sockmap(int tasks, void *data)
 		}
 	}
 
+	/* Put sfd[2] (sending fd below) into msg map to test sendmsg bpf */
+	i = 0;
+	err = bpf_map_update_elem(map_fd_msg, &i, &sfd[2], BPF_ANY);
+	if (err) {
+		printf("Failed map_fd_msg update sockmap %i\n", err);
+		goto out_sockmap;
+	}
+
 	/* Test map send/recv */
 	for (i = 0; i < 2; i++) {
 		buf[0] = i;
diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index 27ad5404389e..e9df48b306df 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -841,7 +841,8 @@ static void test_tp_attach_query(void)
 static int compare_map_keys(int map1_fd, int map2_fd)
 {
 	__u32 key, next_key;
-	char val_buf[PERF_MAX_STACK_DEPTH * sizeof(__u64)];
+	char val_buf[PERF_MAX_STACK_DEPTH *
+		     sizeof(struct bpf_stack_build_id)];
 	int err;
 
 	err = bpf_map_get_next_key(map1_fd, NULL, &key);
@@ -964,6 +965,166 @@ out:
 	return;
 }
 
+static int extract_build_id(char *build_id, size_t size)
+{
+	FILE *fp;
+	char *line = NULL;
+	size_t len = 0;
+
+	fp = popen("readelf -n ./urandom_read | grep 'Build ID'", "r");
+	if (fp == NULL)
+		return -1;
+
+	if (getline(&line, &len, fp) == -1)
+		goto err;
+	fclose(fp);
+
+	if (len > size)
+		len = size;
+	memcpy(build_id, line, len);
+	build_id[len] = '\0';
+	return 0;
+err:
+	fclose(fp);
+	return -1;
+}
+
+static void test_stacktrace_build_id(void)
+{
+	int control_map_fd, stackid_hmap_fd, stackmap_fd;
+	const char *file = "./test_stacktrace_build_id.o";
+	int bytes, efd, err, pmu_fd, prog_fd;
+	struct perf_event_attr attr = {};
+	__u32 key, previous_key, val, duration = 0;
+	struct bpf_object *obj;
+	char buf[256];
+	int i, j;
+	struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH];
+	int build_id_matches = 0;
+
+	err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd);
+	if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno))
+		goto out;
+
+	/* Get the ID for the sched/sched_switch tracepoint */
+	snprintf(buf, sizeof(buf),
+		 "/sys/kernel/debug/tracing/events/random/urandom_read/id");
+	efd = open(buf, O_RDONLY, 0);
+	if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno))
+		goto close_prog;
+
+	bytes = read(efd, buf, sizeof(buf));
+	close(efd);
+	if (CHECK(bytes <= 0 || bytes >= sizeof(buf),
+		  "read", "bytes %d errno %d\n", bytes, errno))
+		goto close_prog;
+
+	/* Open the perf event and attach bpf progrram */
+	attr.config = strtol(buf, NULL, 0);
+	attr.type = PERF_TYPE_TRACEPOINT;
+	attr.sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_CALLCHAIN;
+	attr.sample_period = 1;
+	attr.wakeup_events = 1;
+	pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
+			 0 /* cpu 0 */, -1 /* group id */,
+			 0 /* flags */);
+	if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n",
+		  pmu_fd, errno))
+		goto close_prog;
+
+	err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
+	if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n",
+		  err, errno))
+		goto close_pmu;
+
+	err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
+	if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n",
+		  err, errno))
+		goto disable_pmu;
+
+	/* find map fds */
+	control_map_fd = bpf_find_map(__func__, obj, "control_map");
+	if (CHECK(control_map_fd < 0, "bpf_find_map control_map",
+		  "err %d errno %d\n", err, errno))
+		goto disable_pmu;
+
+	stackid_hmap_fd = bpf_find_map(__func__, obj, "stackid_hmap");
+	if (CHECK(stackid_hmap_fd < 0, "bpf_find_map stackid_hmap",
+		  "err %d errno %d\n", err, errno))
+		goto disable_pmu;
+
+	stackmap_fd = bpf_find_map(__func__, obj, "stackmap");
+	if (CHECK(stackmap_fd < 0, "bpf_find_map stackmap", "err %d errno %d\n",
+		  err, errno))
+		goto disable_pmu;
+
+	assert(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null")
+	       == 0);
+	assert(system("./urandom_read if=/dev/urandom of=/dev/zero count=4 2> /dev/null") == 0);
+	/* disable stack trace collection */
+	key = 0;
+	val = 1;
+	bpf_map_update_elem(control_map_fd, &key, &val, 0);
+
+	/* for every element in stackid_hmap, we can find a corresponding one
+	 * in stackmap, and vise versa.
+	 */
+	err = compare_map_keys(stackid_hmap_fd, stackmap_fd);
+	if (CHECK(err, "compare_map_keys stackid_hmap vs. stackmap",
+		  "err %d errno %d\n", err, errno))
+		goto disable_pmu;
+
+	err = compare_map_keys(stackmap_fd, stackid_hmap_fd);
+	if (CHECK(err, "compare_map_keys stackmap vs. stackid_hmap",
+		  "err %d errno %d\n", err, errno))
+		goto disable_pmu;
+
+	err = extract_build_id(buf, 256);
+
+	if (CHECK(err, "get build_id with readelf",
+		  "err %d errno %d\n", err, errno))
+		goto disable_pmu;
+
+	err = bpf_map_get_next_key(stackmap_fd, NULL, &key);
+	if (CHECK(err, "get_next_key from stackmap",
+		  "err %d, errno %d\n", err, errno))
+		goto disable_pmu;
+
+	do {
+		char build_id[64];
+
+		err = bpf_map_lookup_elem(stackmap_fd, &key, id_offs);
+		if (CHECK(err, "lookup_elem from stackmap",
+			  "err %d, errno %d\n", err, errno))
+			goto disable_pmu;
+		for (i = 0; i < PERF_MAX_STACK_DEPTH; ++i)
+			if (id_offs[i].status == BPF_STACK_BUILD_ID_VALID &&
+			    id_offs[i].offset != 0) {
+				for (j = 0; j < 20; ++j)
+					sprintf(build_id + 2 * j, "%02x",
+						id_offs[i].build_id[j] & 0xff);
+				if (strstr(buf, build_id) != NULL)
+					build_id_matches = 1;
+			}
+		previous_key = key;
+	} while (bpf_map_get_next_key(stackmap_fd, &previous_key, &key) == 0);
+
+	CHECK(build_id_matches < 1, "build id match",
+	      "Didn't find expected build ID from the map");
+
+disable_pmu:
+	ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
+
+close_pmu:
+	close(pmu_fd);
+
+close_prog:
+	bpf_object__close(obj);
+
+out:
+	return;
+}
+
 int main(void)
 {
 	test_pkt_access();
@@ -976,6 +1137,7 @@ int main(void)
 	test_obj_name();
 	test_tp_attach_query();
 	test_stacktrace_map();
+	test_stacktrace_build_id();
 
 	printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, error_cnt);
 	return error_cnt ? EXIT_FAILURE : EXIT_SUCCESS;
diff --git a/tools/testing/selftests/bpf/test_stacktrace_build_id.c b/tools/testing/selftests/bpf/test_stacktrace_build_id.c
new file mode 100644
index 000000000000..b755bd783ce5
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_stacktrace_build_id.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018 Facebook
+
+#include <linux/bpf.h>
+#include "bpf_helpers.h"
+
+#ifndef PERF_MAX_STACK_DEPTH
+#define PERF_MAX_STACK_DEPTH         127
+#endif
+
+struct bpf_map_def SEC("maps") control_map = {
+	.type = BPF_MAP_TYPE_ARRAY,
+	.key_size = sizeof(__u32),
+	.value_size = sizeof(__u32),
+	.max_entries = 1,
+};
+
+struct bpf_map_def SEC("maps") stackid_hmap = {
+	.type = BPF_MAP_TYPE_HASH,
+	.key_size = sizeof(__u32),
+	.value_size = sizeof(__u32),
+	.max_entries = 10000,
+};
+
+struct bpf_map_def SEC("maps") stackmap = {
+	.type = BPF_MAP_TYPE_STACK_TRACE,
+	.key_size = sizeof(__u32),
+	.value_size = sizeof(struct bpf_stack_build_id)
+		* PERF_MAX_STACK_DEPTH,
+	.max_entries = 128,
+	.map_flags = BPF_F_STACK_BUILD_ID,
+};
+
+/* taken from /sys/kernel/debug/tracing/events/random/urandom_read/format */
+struct random_urandom_args {
+	unsigned long long pad;
+	int got_bits;
+	int pool_left;
+	int input_left;
+};
+
+SEC("tracepoint/random/urandom_read")
+int oncpu(struct random_urandom_args *args)
+{
+	__u32 key = 0, val = 0, *value_p;
+
+	value_p = bpf_map_lookup_elem(&control_map, &key);
+	if (value_p && *value_p)
+		return 0; /* skip if non-zero *value_p */
+
+	/* The size of stackmap and stackid_hmap should be the same */
+	key = bpf_get_stackid(args, &stackmap, BPF_F_USER_STACK);
+	if ((int)key >= 0)
+		bpf_map_update_elem(&stackid_hmap, &key, &val, 0);
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+__u32 _version SEC("version") = 1; /* ignored by tracepoints, required by libbpf.a */
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 86d7ff491b6f..3e7718b1a9ae 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -1597,6 +1597,60 @@ static struct bpf_test tests[] = {
 		.prog_type = BPF_PROG_TYPE_SK_SKB,
 	},
 	{
+		"direct packet read for SK_MSG",
+		.insns = {
+			BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct sk_msg_md, data)),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct sk_msg_md, 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, 1),
+			BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_2, 0),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_SK_MSG,
+	},
+	{
+		"direct packet write for SK_MSG",
+		.insns = {
+			BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct sk_msg_md, data)),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct sk_msg_md, 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, 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_SK_MSG,
+	},
+	{
+		"overlapping checks for direct packet access SK_MSG",
+		.insns = {
+			BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct sk_msg_md, data)),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct sk_msg_md, 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, 4),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 6),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 1),
+			BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_2, 6),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_SK_MSG,
+	},
+	{
 		"check skb->mark is not writeable by sockets",
 		.insns = {
 			BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_1,
diff --git a/tools/testing/selftests/bpf/urandom_read.c b/tools/testing/selftests/bpf/urandom_read.c
new file mode 100644
index 000000000000..4acfdebf36fa
--- /dev/null
+++ b/tools/testing/selftests/bpf/urandom_read.c
@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdlib.h>
+
+#define BUF_SIZE 256
+int main(void)
+{
+	int fd = open("/dev/urandom", O_RDONLY);
+	int i;
+	char buf[BUF_SIZE];
+
+	if (fd < 0)
+		return 1;
+	for (i = 0; i < 4; ++i)
+		read(fd, buf, BUF_SIZE);
+
+	close(fd);
+	return 0;
+}