1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2024 Google */
3
4 #include <test_progs.h>
5 #include <bpf/libbpf.h>
6 #include <bpf/btf.h>
7 #include "kmem_cache_iter.skel.h"
8
9 #define SLAB_NAME_MAX 32
10
11 struct kmem_cache_result {
12 char name[SLAB_NAME_MAX];
13 long obj_size;
14 };
15
subtest_kmem_cache_iter_check_task_struct(struct kmem_cache_iter * skel)16 static void subtest_kmem_cache_iter_check_task_struct(struct kmem_cache_iter *skel)
17 {
18 LIBBPF_OPTS(bpf_test_run_opts, opts,
19 .flags = 0, /* Run it with the current task */
20 );
21 int prog_fd = bpf_program__fd(skel->progs.check_task_struct);
22
23 /* Get task_struct and check it if's from a slab cache */
24 ASSERT_OK(bpf_prog_test_run_opts(prog_fd, &opts), "prog_test_run");
25
26 /* The BPF program should set 'found' variable */
27 ASSERT_EQ(skel->bss->task_struct_found, 1, "task_struct_found");
28 }
29
subtest_kmem_cache_iter_check_slabinfo(struct kmem_cache_iter * skel)30 static void subtest_kmem_cache_iter_check_slabinfo(struct kmem_cache_iter *skel)
31 {
32 FILE *fp;
33 int map_fd;
34 char name[SLAB_NAME_MAX];
35 unsigned long objsize;
36 char rest_of_line[1000];
37 struct kmem_cache_result r;
38 int seen = 0;
39
40 fp = fopen("/proc/slabinfo", "r");
41 if (fp == NULL) {
42 /* CONFIG_SLUB_DEBUG is not enabled */
43 return;
44 }
45
46 map_fd = bpf_map__fd(skel->maps.slab_result);
47
48 /* Ignore first two lines for header */
49 fscanf(fp, "slabinfo - version: %*d.%*d\n");
50 fscanf(fp, "# %*s %*s %*s %*s %*s %*s : %[^\n]\n", rest_of_line);
51
52 /* Compare name and objsize only - others can be changes frequently */
53 while (fscanf(fp, "%s %*u %*u %lu %*u %*u : %[^\n]\n",
54 name, &objsize, rest_of_line) == 3) {
55 int ret = bpf_map_lookup_elem(map_fd, &seen, &r);
56
57 if (!ASSERT_OK(ret, "kmem_cache_lookup"))
58 break;
59
60 ASSERT_STRNEQ(r.name, name, sizeof(r.name) - 1,
61 "kmem_cache_name");
62 ASSERT_EQ(r.obj_size, objsize, "kmem_cache_objsize");
63
64 seen++;
65 }
66
67 ASSERT_EQ(skel->bss->kmem_cache_seen, seen, "kmem_cache_seen_eq");
68
69 fclose(fp);
70 }
71
subtest_kmem_cache_iter_open_coded(struct kmem_cache_iter * skel)72 static void subtest_kmem_cache_iter_open_coded(struct kmem_cache_iter *skel)
73 {
74 LIBBPF_OPTS(bpf_test_run_opts, topts);
75 int err, fd;
76
77 /* No need to attach it, just run it directly */
78 fd = bpf_program__fd(skel->progs.open_coded_iter);
79
80 err = bpf_prog_test_run_opts(fd, &topts);
81 if (!ASSERT_OK(err, "test_run_opts err"))
82 return;
83 if (!ASSERT_OK(topts.retval, "test_run_opts retval"))
84 return;
85
86 /* It should be same as we've seen from the explicit iterator */
87 ASSERT_EQ(skel->bss->open_coded_seen, skel->bss->kmem_cache_seen, "open_code_seen_eq");
88 }
89
test_kmem_cache_iter(void)90 void test_kmem_cache_iter(void)
91 {
92 struct kmem_cache_iter *skel = NULL;
93 char buf[256];
94 int iter_fd;
95
96 skel = kmem_cache_iter__open_and_load();
97 if (!ASSERT_OK_PTR(skel, "kmem_cache_iter__open_and_load"))
98 return;
99
100 if (!ASSERT_OK(kmem_cache_iter__attach(skel), "skel_attach"))
101 goto destroy;
102
103 iter_fd = bpf_iter_create(bpf_link__fd(skel->links.slab_info_collector));
104 if (!ASSERT_GE(iter_fd, 0, "iter_create"))
105 goto destroy;
106
107 while (read(iter_fd, buf, sizeof(buf)) > 0)
108 ; /* Read out all contents */
109
110 /* Next reads should return 0 */
111 ASSERT_EQ(read(iter_fd, buf, sizeof(buf)), 0, "read");
112
113 if (test__start_subtest("check_task_struct"))
114 subtest_kmem_cache_iter_check_task_struct(skel);
115 if (test__start_subtest("check_slabinfo"))
116 subtest_kmem_cache_iter_check_slabinfo(skel);
117 if (test__start_subtest("open_coded_iter"))
118 subtest_kmem_cache_iter_open_coded(skel);
119
120 close(iter_fd);
121
122 destroy:
123 kmem_cache_iter__destroy(skel);
124 }
125