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 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 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_STREQ(r.name, name, "kmem_cache_name"); 61 ASSERT_EQ(r.obj_size, objsize, "kmem_cache_objsize"); 62 63 seen++; 64 } 65 66 ASSERT_EQ(skel->bss->kmem_cache_seen, seen, "kmem_cache_seen_eq"); 67 68 fclose(fp); 69 } 70 71 static void subtest_kmem_cache_iter_open_coded(struct kmem_cache_iter *skel) 72 { 73 LIBBPF_OPTS(bpf_test_run_opts, topts); 74 int err, fd; 75 76 /* No need to attach it, just run it directly */ 77 fd = bpf_program__fd(skel->progs.open_coded_iter); 78 79 err = bpf_prog_test_run_opts(fd, &topts); 80 if (!ASSERT_OK(err, "test_run_opts err")) 81 return; 82 if (!ASSERT_OK(topts.retval, "test_run_opts retval")) 83 return; 84 85 /* It should be same as we've seen from the explicit iterator */ 86 ASSERT_EQ(skel->bss->open_coded_seen, skel->bss->kmem_cache_seen, "open_code_seen_eq"); 87 } 88 89 void test_kmem_cache_iter(void) 90 { 91 struct kmem_cache_iter *skel = NULL; 92 char buf[256]; 93 int iter_fd; 94 95 skel = kmem_cache_iter__open_and_load(); 96 if (!ASSERT_OK_PTR(skel, "kmem_cache_iter__open_and_load")) 97 return; 98 99 if (!ASSERT_OK(kmem_cache_iter__attach(skel), "skel_attach")) 100 goto destroy; 101 102 iter_fd = bpf_iter_create(bpf_link__fd(skel->links.slab_info_collector)); 103 if (!ASSERT_GE(iter_fd, 0, "iter_create")) 104 goto destroy; 105 106 memset(buf, 0, sizeof(buf)); 107 while (read(iter_fd, buf, sizeof(buf) > 0)) { 108 /* Read out all contents */ 109 printf("%s", buf); 110 } 111 112 /* Next reads should return 0 */ 113 ASSERT_EQ(read(iter_fd, buf, sizeof(buf)), 0, "read"); 114 115 if (test__start_subtest("check_task_struct")) 116 subtest_kmem_cache_iter_check_task_struct(skel); 117 if (test__start_subtest("check_slabinfo")) 118 subtest_kmem_cache_iter_check_slabinfo(skel); 119 if (test__start_subtest("open_coded_iter")) 120 subtest_kmem_cache_iter_open_coded(skel); 121 122 close(iter_fd); 123 124 destroy: 125 kmem_cache_iter__destroy(skel); 126 } 127