1 // SPDX-License-Identifier: GPL-2.0-only 2 #include <linux/alloc_tag.h> 3 #include <linux/fs.h> 4 #include <linux/gfp.h> 5 #include <linux/module.h> 6 #include <linux/page_ext.h> 7 #include <linux/proc_fs.h> 8 #include <linux/seq_buf.h> 9 #include <linux/seq_file.h> 10 11 static struct codetag_type *alloc_tag_cttype; 12 13 DEFINE_PER_CPU(struct alloc_tag_counters, _shared_alloc_tag); 14 EXPORT_SYMBOL(_shared_alloc_tag); 15 16 DEFINE_STATIC_KEY_MAYBE(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT, 17 mem_alloc_profiling_key); 18 19 struct allocinfo_private { 20 struct codetag_iterator iter; 21 bool print_header; 22 }; 23 24 static void *allocinfo_start(struct seq_file *m, loff_t *pos) 25 { 26 struct allocinfo_private *priv; 27 struct codetag *ct; 28 loff_t node = *pos; 29 30 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 31 m->private = priv; 32 if (!priv) 33 return NULL; 34 35 priv->print_header = (node == 0); 36 codetag_lock_module_list(alloc_tag_cttype, true); 37 priv->iter = codetag_get_ct_iter(alloc_tag_cttype); 38 while ((ct = codetag_next_ct(&priv->iter)) != NULL && node) 39 node--; 40 41 return ct ? priv : NULL; 42 } 43 44 static void *allocinfo_next(struct seq_file *m, void *arg, loff_t *pos) 45 { 46 struct allocinfo_private *priv = (struct allocinfo_private *)arg; 47 struct codetag *ct = codetag_next_ct(&priv->iter); 48 49 (*pos)++; 50 if (!ct) 51 return NULL; 52 53 return priv; 54 } 55 56 static void allocinfo_stop(struct seq_file *m, void *arg) 57 { 58 struct allocinfo_private *priv = (struct allocinfo_private *)m->private; 59 60 if (priv) { 61 codetag_lock_module_list(alloc_tag_cttype, false); 62 kfree(priv); 63 } 64 } 65 66 static void print_allocinfo_header(struct seq_buf *buf) 67 { 68 /* Output format version, so we can change it. */ 69 seq_buf_printf(buf, "allocinfo - version: 1.0\n"); 70 seq_buf_printf(buf, "# <size> <calls> <tag info>\n"); 71 } 72 73 static void alloc_tag_to_text(struct seq_buf *out, struct codetag *ct) 74 { 75 struct alloc_tag *tag = ct_to_alloc_tag(ct); 76 struct alloc_tag_counters counter = alloc_tag_read(tag); 77 s64 bytes = counter.bytes; 78 79 seq_buf_printf(out, "%12lli %8llu ", bytes, counter.calls); 80 codetag_to_text(out, ct); 81 seq_buf_putc(out, ' '); 82 seq_buf_putc(out, '\n'); 83 } 84 85 static int allocinfo_show(struct seq_file *m, void *arg) 86 { 87 struct allocinfo_private *priv = (struct allocinfo_private *)arg; 88 char *bufp; 89 size_t n = seq_get_buf(m, &bufp); 90 struct seq_buf buf; 91 92 seq_buf_init(&buf, bufp, n); 93 if (priv->print_header) { 94 print_allocinfo_header(&buf); 95 priv->print_header = false; 96 } 97 alloc_tag_to_text(&buf, priv->iter.ct); 98 seq_commit(m, seq_buf_used(&buf)); 99 return 0; 100 } 101 102 static const struct seq_operations allocinfo_seq_op = { 103 .start = allocinfo_start, 104 .next = allocinfo_next, 105 .stop = allocinfo_stop, 106 .show = allocinfo_show, 107 }; 108 109 size_t alloc_tag_top_users(struct codetag_bytes *tags, size_t count, bool can_sleep) 110 { 111 struct codetag_iterator iter; 112 struct codetag *ct; 113 struct codetag_bytes n; 114 unsigned int i, nr = 0; 115 116 if (can_sleep) 117 codetag_lock_module_list(alloc_tag_cttype, true); 118 else if (!codetag_trylock_module_list(alloc_tag_cttype)) 119 return 0; 120 121 iter = codetag_get_ct_iter(alloc_tag_cttype); 122 while ((ct = codetag_next_ct(&iter))) { 123 struct alloc_tag_counters counter = alloc_tag_read(ct_to_alloc_tag(ct)); 124 125 n.ct = ct; 126 n.bytes = counter.bytes; 127 128 for (i = 0; i < nr; i++) 129 if (n.bytes > tags[i].bytes) 130 break; 131 132 if (i < count) { 133 nr -= nr == count; 134 memmove(&tags[i + 1], 135 &tags[i], 136 sizeof(tags[0]) * (nr - i)); 137 nr++; 138 tags[i] = n; 139 } 140 } 141 142 codetag_lock_module_list(alloc_tag_cttype, false); 143 144 return nr; 145 } 146 147 static void __init procfs_init(void) 148 { 149 proc_create_seq("allocinfo", 0400, NULL, &allocinfo_seq_op); 150 } 151 152 static bool alloc_tag_module_unload(struct codetag_type *cttype, 153 struct codetag_module *cmod) 154 { 155 struct codetag_iterator iter = codetag_get_ct_iter(cttype); 156 struct alloc_tag_counters counter; 157 bool module_unused = true; 158 struct alloc_tag *tag; 159 struct codetag *ct; 160 161 for (ct = codetag_next_ct(&iter); ct; ct = codetag_next_ct(&iter)) { 162 if (iter.cmod != cmod) 163 continue; 164 165 tag = ct_to_alloc_tag(ct); 166 counter = alloc_tag_read(tag); 167 168 if (WARN(counter.bytes, 169 "%s:%u module %s func:%s has %llu allocated at module unload", 170 ct->filename, ct->lineno, ct->modname, ct->function, counter.bytes)) 171 module_unused = false; 172 } 173 174 return module_unused; 175 } 176 177 #ifdef CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT 178 static bool mem_profiling_support __meminitdata = true; 179 #else 180 static bool mem_profiling_support __meminitdata; 181 #endif 182 183 static int __init setup_early_mem_profiling(char *str) 184 { 185 bool enable; 186 187 if (!str || !str[0]) 188 return -EINVAL; 189 190 if (!strncmp(str, "never", 5)) { 191 enable = false; 192 mem_profiling_support = false; 193 } else { 194 int res; 195 196 res = kstrtobool(str, &enable); 197 if (res) 198 return res; 199 200 mem_profiling_support = true; 201 } 202 203 if (enable != static_key_enabled(&mem_alloc_profiling_key)) { 204 if (enable) 205 static_branch_enable(&mem_alloc_profiling_key); 206 else 207 static_branch_disable(&mem_alloc_profiling_key); 208 } 209 210 return 0; 211 } 212 early_param("sysctl.vm.mem_profiling", setup_early_mem_profiling); 213 214 static __init bool need_page_alloc_tagging(void) 215 { 216 return mem_profiling_support; 217 } 218 219 static __init void init_page_alloc_tagging(void) 220 { 221 } 222 223 struct page_ext_operations page_alloc_tagging_ops = { 224 .size = sizeof(union codetag_ref), 225 .need = need_page_alloc_tagging, 226 .init = init_page_alloc_tagging, 227 }; 228 EXPORT_SYMBOL(page_alloc_tagging_ops); 229 230 static struct ctl_table memory_allocation_profiling_sysctls[] = { 231 { 232 .procname = "mem_profiling", 233 .data = &mem_alloc_profiling_key, 234 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG 235 .mode = 0444, 236 #else 237 .mode = 0644, 238 #endif 239 .proc_handler = proc_do_static_key, 240 }, 241 { } 242 }; 243 244 static int __init alloc_tag_init(void) 245 { 246 const struct codetag_type_desc desc = { 247 .section = "alloc_tags", 248 .tag_size = sizeof(struct alloc_tag), 249 .module_unload = alloc_tag_module_unload, 250 }; 251 252 alloc_tag_cttype = codetag_register_type(&desc); 253 if (IS_ERR(alloc_tag_cttype)) 254 return PTR_ERR(alloc_tag_cttype); 255 256 if (!mem_profiling_support) 257 memory_allocation_profiling_sysctls[0].mode = 0444; 258 register_sysctl_init("vm", memory_allocation_profiling_sysctls); 259 procfs_init(); 260 261 return 0; 262 } 263 module_init(alloc_tag_init); 264