Merge branch 'bpf-kselftest-improvements'

Daniel Borkmann says:

====================
First one unifies the often repeated rlimit handling and the
second one enables and adds run-time tests for BPF tail calls
which provides useful coverage in particular for JITs.
====================

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

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 */