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

Daniel Borkmann says:

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

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

The main changes are:

1) Extend bpftool to build up CFG information of eBPF programs and add an
   option to dump this in DOT format such that this can later be used with
   DOT graphic tools (xdot, graphviz, etc) to visualize it. Part of the
   analysis performed is sub-program detection and basic-block partitioning,
   from Jiong.

2) Multiple enhancements for bpftool's batch mode, more specifically the
   parser now understands comments (#), continuation lines (\), and arguments
   enclosed between quotes. Also, allow to read from stdin via '-' as input
   file, all from Quentin.

3) Improve BPF kselftests by i) unifying the rlimit handling into a helper
   that is then used by all tests, and ii) add support for testing tail calls
   to test_verifier plus add tests covering all corner cases. The latter is
   especially useful for testing JITs, from Daniel.

4) Remove x64 JIT's bpf_flush_icache() since flush_icache_range() is a noop
   on x64, from Daniel.

5) Fix one more occasion in BPF samples where we do not detach the BPF program
   from the cgroup after completion, from Prashant.
====================

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

11 files changed, 154 insertions, 61 deletions

diff --git a/tools/testing/selftests/bpf/bpf_rlimit.h b/tools/testing/selftests/bpf/bpf_rlimit.h
new file mode 100644
index 000000000000..9dac9b30f8ef
--- /dev/null
+++ b/tools/testing/selftests/bpf/bpf_rlimit.h
@@ -0,0 +1,28 @@
+#include <sys/resource.h>
+#include <stdio.h>
+
+static  __attribute__((constructor)) void bpf_rlimit_ctor(void)
+{
+	struct rlimit rlim_old, rlim_new = {
+		.rlim_cur	= RLIM_INFINITY,
+		.rlim_max	= RLIM_INFINITY,
+	};
+
+	getrlimit(RLIMIT_MEMLOCK, &rlim_old);
+	/* For the sake of running the test cases, we temporarily
+	 * set rlimit to infinity in order for kernel to focus on
+	 * errors from actual test cases and not getting noise
+	 * from hitting memlock limits. The limit is on per-process
+	 * basis and not a global one, hence destructor not really
+	 * needed here.
+	 */
+	if (setrlimit(RLIMIT_MEMLOCK, &rlim_new) < 0) {
+		perror("Unable to lift memlock rlimit");
+		/* Trying out lower limit, but expect potential test
+		 * case failures from this!
+		 */
+		rlim_new.rlim_cur = rlim_old.rlim_cur + (1UL << 20);
+		rlim_new.rlim_max = rlim_old.rlim_max + (1UL << 20);
+		setrlimit(RLIMIT_MEMLOCK, &rlim_new);
+	}
+}
diff --git a/tools/testing/selftests/bpf/test_align.c b/tools/testing/selftests/bpf/test_align.c
index ff8bd7e3e50c..6b1b302310fe 100644
--- a/tools/testing/selftests/bpf/test_align.c
+++ b/tools/testing/selftests/bpf/test_align.c
@@ -9,8 +9,6 @@
 #include <stddef.h>
 #include <stdbool.h>
 
-#include <sys/resource.h>
-
 #include <linux/unistd.h>
 #include <linux/filter.h>
 #include <linux/bpf_perf_event.h>
@@ -19,6 +17,7 @@
 #include <bpf/bpf.h>
 
 #include "../../../include/linux/filter.h"
+#include "bpf_rlimit.h"
 
 #ifndef ARRAY_SIZE
 # define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
@@ -702,9 +701,6 @@ static int do_test(unsigned int from, unsigned int to)
 int main(int argc, char **argv)
 {
 	unsigned int from = 0, to = ARRAY_SIZE(tests);
-	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
-
-	setrlimit(RLIMIT_MEMLOCK, &rinf);
 
 	if (argc == 3) {
 		unsigned int l = atoi(argv[argc - 2]);
diff --git a/tools/testing/selftests/bpf/test_dev_cgroup.c b/tools/testing/selftests/bpf/test_dev_cgroup.c
index 3489cc283433..9c8b50bac7e0 100644
--- a/tools/testing/selftests/bpf/test_dev_cgroup.c
+++ b/tools/testing/selftests/bpf/test_dev_cgroup.c
@@ -11,13 +11,13 @@
 #include <errno.h>
 #include <assert.h>
 #include <sys/time.h>
-#include <sys/resource.h>
 
 #include <linux/bpf.h>
 #include <bpf/bpf.h>
 #include <bpf/libbpf.h>
 
 #include "cgroup_helpers.h"
+#include "bpf_rlimit.h"
 
 #define DEV_CGROUP_PROG "./dev_cgroup.o"
 
@@ -25,15 +25,11 @@
 
 int main(int argc, char **argv)
 {
-	struct rlimit limit  = { RLIM_INFINITY, RLIM_INFINITY };
 	struct bpf_object *obj;
 	int error = EXIT_FAILURE;
 	int prog_fd, cgroup_fd;
 	__u32 prog_cnt;
 
-	if (setrlimit(RLIMIT_MEMLOCK, &limit) < 0)
-		perror("Unable to lift memlock rlimit");
-
 	if (bpf_prog_load(DEV_CGROUP_PROG, BPF_PROG_TYPE_CGROUP_DEVICE,
 			  &obj, &prog_fd)) {
 		printf("Failed to load DEV_CGROUP program\n");
diff --git a/tools/testing/selftests/bpf/test_lpm_map.c b/tools/testing/selftests/bpf/test_lpm_map.c
index 2be87e9ee28d..147e34cfceb7 100644
--- a/tools/testing/selftests/bpf/test_lpm_map.c
+++ b/tools/testing/selftests/bpf/test_lpm_map.c
@@ -22,10 +22,11 @@
 #include <unistd.h>
 #include <arpa/inet.h>
 #include <sys/time.h>
-#include <sys/resource.h>
 
 #include <bpf/bpf.h>
+
 #include "bpf_util.h"
+#include "bpf_rlimit.h"
 
 struct tlpm_node {
 	struct tlpm_node *next;
@@ -736,17 +737,11 @@ static void test_lpm_multi_thread(void)
 
 int main(void)
 {
-	struct rlimit limit  = { RLIM_INFINITY, RLIM_INFINITY };
-	int i, ret;
+	int i;
 
 	/* we want predictable, pseudo random tests */
 	srand(0xf00ba1);
 
-	/* allow unlimited locked memory */
-	ret = setrlimit(RLIMIT_MEMLOCK, &limit);
-	if (ret < 0)
-		perror("Unable to lift memlock rlimit");
-
 	test_lpm_basic();
 	test_lpm_order();
 
@@ -755,11 +750,8 @@ int main(void)
 		test_lpm_map(i);
 
 	test_lpm_ipaddr();
-
 	test_lpm_delete();
-
 	test_lpm_get_next_key();
-
 	test_lpm_multi_thread();
 
 	printf("test_lpm: OK\n");
diff --git a/tools/testing/selftests/bpf/test_lru_map.c b/tools/testing/selftests/bpf/test_lru_map.c
index 8c10c9180c1a..781c7de343be 100644
--- a/tools/testing/selftests/bpf/test_lru_map.c
+++ b/tools/testing/selftests/bpf/test_lru_map.c
@@ -16,10 +16,11 @@
 #include <time.h>
 
 #include <sys/wait.h>
-#include <sys/resource.h>
 
 #include <bpf/bpf.h>
+
 #include "bpf_util.h"
+#include "bpf_rlimit.h"
 
 #define LOCAL_FREE_TARGET	(128)
 #define PERCPU_FREE_TARGET	(4)
@@ -613,7 +614,6 @@ static void test_lru_sanity6(int map_type, int map_flags, int tgt_free)
 
 int main(int argc, char **argv)
 {
-	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 	int map_types[] = {BPF_MAP_TYPE_LRU_HASH,
 			     BPF_MAP_TYPE_LRU_PERCPU_HASH};
 	int map_flags[] = {0, BPF_F_NO_COMMON_LRU};
@@ -621,8 +621,6 @@ int main(int argc, char **argv)
 
 	setbuf(stdout, NULL);
 
-	assert(!setrlimit(RLIMIT_MEMLOCK, &r));
-
 	nr_cpus = bpf_num_possible_cpus();
 	assert(nr_cpus != -1);
 	printf("nr_cpus:%d\n\n", nr_cpus);
diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
index 9e03a4c356a4..1238733c5b33 100644
--- a/tools/testing/selftests/bpf/test_maps.c
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -17,13 +17,14 @@
 #include <stdlib.h>
 
 #include <sys/wait.h>
-#include <sys/resource.h>
 
 #include <linux/bpf.h>
 
 #include <bpf/bpf.h>
 #include <bpf/libbpf.h>
+
 #include "bpf_util.h"
+#include "bpf_rlimit.h"
 
 static int map_flags;
 
@@ -1126,10 +1127,6 @@ static void run_all_tests(void)
 
 int main(void)
 {
-	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
-
-	setrlimit(RLIMIT_MEMLOCK, &rinf);
-
 	map_flags = 0;
 	run_all_tests();
 
diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index b549308abd19..27ad5404389e 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -26,7 +26,6 @@ typedef __u16 __sum16;
 
 #include <sys/ioctl.h>
 #include <sys/wait.h>
-#include <sys/resource.h>
 #include <sys/types.h>
 #include <fcntl.h>
 
@@ -34,9 +33,11 @@ typedef __u16 __sum16;
 #include <linux/err.h>
 #include <bpf/bpf.h>
 #include <bpf/libbpf.h>
+
 #include "test_iptunnel_common.h"
 #include "bpf_util.h"
 #include "bpf_endian.h"
+#include "bpf_rlimit.h"
 
 static int error_cnt, pass_cnt;
 
@@ -965,10 +966,6 @@ out:
 
 int main(void)
 {
-	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
-
-	setrlimit(RLIMIT_MEMLOCK, &rinf);
-
 	test_pkt_access();
 	test_xdp();
 	test_l4lb_all();
diff --git a/tools/testing/selftests/bpf/test_tag.c b/tools/testing/selftests/bpf/test_tag.c
index 8b201895c569..6272c784ca2a 100644
--- a/tools/testing/selftests/bpf/test_tag.c
+++ b/tools/testing/selftests/bpf/test_tag.c
@@ -12,7 +12,6 @@
 #include <assert.h>
 
 #include <sys/socket.h>
-#include <sys/resource.h>
 
 #include <linux/filter.h>
 #include <linux/bpf.h>
@@ -21,6 +20,7 @@
 #include <bpf/bpf.h>
 
 #include "../../../include/linux/filter.h"
+#include "bpf_rlimit.h"
 
 static struct bpf_insn prog[BPF_MAXINSNS];
 
@@ -184,11 +184,9 @@ static void do_test(uint32_t *tests, int start_insns, int fd_map,
 
 int main(void)
 {
-	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
 	uint32_t tests = 0;
 	int i, fd_map;
 
-	setrlimit(RLIMIT_MEMLOCK, &rinf);
 	fd_map = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(int),
 				sizeof(int), 1, BPF_F_NO_PREALLOC);
 	assert(fd_map > 0);
diff --git a/tools/testing/selftests/bpf/test_tcpbpf_user.c b/tools/testing/selftests/bpf/test_tcpbpf_user.c
index 5d73db416460..84ab5163c828 100644
--- a/tools/testing/selftests/bpf/test_tcpbpf_user.c
+++ b/tools/testing/selftests/bpf/test_tcpbpf_user.c
@@ -12,13 +12,13 @@
 #include <linux/bpf.h>
 #include <sys/ioctl.h>
 #include <sys/time.h>
-#include <sys/resource.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <bpf/bpf.h>
 #include <bpf/libbpf.h>
 #include "bpf_util.h"
+#include "bpf_rlimit.h"
 #include <linux/perf_event.h>
 #include "test_tcpbpf.h"
 
@@ -44,7 +44,6 @@ static int bpf_find_map(const char *test, struct bpf_object *obj,
 
 int main(int argc, char **argv)
 {
-	struct rlimit limit  = { RLIM_INFINITY, RLIM_INFINITY };
 	const char *file = "test_tcpbpf_kern.o";
 	struct tcpbpf_globals g = {0};
 	int cg_fd, prog_fd, map_fd;
@@ -57,9 +56,6 @@ int main(int argc, char **argv)
 	int pid;
 	int rv;
 
-	if (setrlimit(RLIMIT_MEMLOCK, &limit) < 0)
-		perror("Unable to lift memlock rlimit");
-
 	if (argc > 1 && strcmp(argv[1], "-d") == 0)
 		debug_flag = true;
 
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 2164d218322e..9eb05f3135ac 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -24,7 +24,6 @@
 #include <limits.h>
 
 #include <sys/capability.h>
-#include <sys/resource.h>
 
 #include <linux/unistd.h>
 #include <linux/filter.h>
@@ -41,7 +40,7 @@
 #  define CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 1
 # endif
 #endif
-
+#include "bpf_rlimit.h"
 #include "../../../include/linux/filter.h"
 
 #ifndef ARRAY_SIZE
@@ -2590,17 +2589,74 @@ static struct bpf_test tests[] = {
 		.result = ACCEPT,
 	},
 	{
+		"runtime/jit: tail_call within bounds, prog once",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_3, 0),
+			BPF_LD_MAP_FD(BPF_REG_2, 0),
+			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_prog = { 1 },
+		.result = ACCEPT,
+		.retval = 42,
+	},
+	{
+		"runtime/jit: tail_call within bounds, prog loop",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_3, 1),
+			BPF_LD_MAP_FD(BPF_REG_2, 0),
+			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_prog = { 1 },
+		.result = ACCEPT,
+		.retval = 41,
+	},
+	{
+		"runtime/jit: tail_call within bounds, no prog",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_3, 2),
+			BPF_LD_MAP_FD(BPF_REG_2, 0),
+			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_prog = { 1 },
+		.result = ACCEPT,
+		.retval = 1,
+	},
+	{
+		"runtime/jit: tail_call out of bounds",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_3, 256),
+			BPF_LD_MAP_FD(BPF_REG_2, 0),
+			BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				     BPF_FUNC_tail_call),
+			BPF_MOV64_IMM(BPF_REG_0, 2),
+			BPF_EXIT_INSN(),
+		},
+		.fixup_prog = { 1 },
+		.result = ACCEPT,
+		.retval = 2,
+	},
+	{
 		"runtime/jit: pass negative index to tail_call",
 		.insns = {
 			BPF_MOV64_IMM(BPF_REG_3, -1),
 			BPF_LD_MAP_FD(BPF_REG_2, 0),
 			BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
 				     BPF_FUNC_tail_call),
-			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_MOV64_IMM(BPF_REG_0, 2),
 			BPF_EXIT_INSN(),
 		},
 		.fixup_prog = { 1 },
 		.result = ACCEPT,
+		.retval = 2,
 	},
 	{
 		"runtime/jit: pass > 32bit index to tail_call",
@@ -2609,11 +2665,12 @@ static struct bpf_test tests[] = {
 			BPF_LD_MAP_FD(BPF_REG_2, 0),
 			BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
 				     BPF_FUNC_tail_call),
-			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_MOV64_IMM(BPF_REG_0, 2),
 			BPF_EXIT_INSN(),
 		},
 		.fixup_prog = { 2 },
 		.result = ACCEPT,
+		.retval = 42,
 	},
 	{
 		"stack pointer arithmetic",
@@ -11279,16 +11336,61 @@ static int create_map(uint32_t size_value, uint32_t max_elem)
 	return fd;
 }
 
+static int create_prog_dummy1(void)
+{
+	struct bpf_insn prog[] = {
+		BPF_MOV64_IMM(BPF_REG_0, 42),
+		BPF_EXIT_INSN(),
+	};
+
+	return bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER, prog,
+				ARRAY_SIZE(prog), "GPL", 0, NULL, 0);
+}
+
+static int create_prog_dummy2(int mfd, int idx)
+{
+	struct bpf_insn prog[] = {
+		BPF_MOV64_IMM(BPF_REG_3, idx),
+		BPF_LD_MAP_FD(BPF_REG_2, mfd),
+		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+			     BPF_FUNC_tail_call),
+		BPF_MOV64_IMM(BPF_REG_0, 41),
+		BPF_EXIT_INSN(),
+	};
+
+	return bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER, prog,
+				ARRAY_SIZE(prog), "GPL", 0, NULL, 0);
+}
+
 static int create_prog_array(void)
 {
-	int fd;
+	int p1key = 0, p2key = 1;
+	int mfd, p1fd, p2fd;
 
-	fd = bpf_create_map(BPF_MAP_TYPE_PROG_ARRAY, sizeof(int),
-			    sizeof(int), 4, 0);
-	if (fd < 0)
+	mfd = bpf_create_map(BPF_MAP_TYPE_PROG_ARRAY, sizeof(int),
+			     sizeof(int), 4, 0);
+	if (mfd < 0) {
 		printf("Failed to create prog array '%s'!\n", strerror(errno));
+		return -1;
+	}
 
-	return fd;
+	p1fd = create_prog_dummy1();
+	p2fd = create_prog_dummy2(mfd, p2key);
+	if (p1fd < 0 || p2fd < 0)
+		goto out;
+	if (bpf_map_update_elem(mfd, &p1key, &p1fd, BPF_ANY) < 0)
+		goto out;
+	if (bpf_map_update_elem(mfd, &p2key, &p2fd, BPF_ANY) < 0)
+		goto out;
+	close(p2fd);
+	close(p1fd);
+
+	return mfd;
+out:
+	close(p2fd);
+	close(p1fd);
+	close(mfd);
+	return -1;
 }
 
 static int create_map_in_map(void)
@@ -11543,8 +11645,6 @@ static int do_test(bool unpriv, unsigned int from, unsigned int to)
 
 int main(int argc, char **argv)
 {
-	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
-	struct rlimit rlim = { 1 << 20, 1 << 20 };
 	unsigned int from = 0, to = ARRAY_SIZE(tests);
 	bool unpriv = !is_admin();
 
@@ -11572,6 +11672,5 @@ int main(int argc, char **argv)
 		return EXIT_FAILURE;
 	}
 
-	setrlimit(RLIMIT_MEMLOCK, unpriv ? &rlim : &rinf);
 	return do_test(unpriv, from, to);
 }
diff --git a/tools/testing/selftests/bpf/test_verifier_log.c b/tools/testing/selftests/bpf/test_verifier_log.c
index e9626cf5607a..8d6918c3b4a2 100644
--- a/tools/testing/selftests/bpf/test_verifier_log.c
+++ b/tools/testing/selftests/bpf/test_verifier_log.c
@@ -4,7 +4,6 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/time.h>
-#include <sys/resource.h>
 
 #include <linux/bpf.h>
 #include <linux/filter.h>
@@ -12,6 +11,8 @@
 
 #include <bpf/bpf.h>
 
+#include "bpf_rlimit.h"
+
 #define LOG_SIZE (1 << 20)
 
 #define err(str...)	printf("ERROR: " str)
@@ -133,16 +134,11 @@ static void test_log_bad(char *log, size_t log_len, int log_level)
 
 int main(int argc, char **argv)
 {
-	struct rlimit limit  = { RLIM_INFINITY, RLIM_INFINITY };
 	char full_log[LOG_SIZE];
 	char log[LOG_SIZE];
 	size_t want_len;
 	int i;
 
-	/* allow unlimited locked memory to have more consistent error code */
-	if (setrlimit(RLIMIT_MEMLOCK, &limit) < 0)
-		perror("Unable to lift memlock rlimit");
-
 	memset(log, 1, LOG_SIZE);
 
 	/* Test incorrect attr */