tools/perf/builtin-test.c

   1 /*
   2  * builtin-test.c
   3  *
   4  * Builtin regression testing command: ever growing number of sanity tests
   5  */
   6 #include "builtin.h"
   7
   8 #include "util/cache.h"
   9 #include "util/debug.h"
  10 #include "util/parse-options.h"
  11 #include "util/session.h"
  12 #include "util/symbol.h"
  13 #include "util/thread.h"
  14
  15 static long page_size;
  16
  17 static int vmlinux_matches_kallsyms_filter(struct map *map __used, struct symbol *sym)
  18 {
  19         bool *visited = symbol__priv(sym);
  20         *visited = true;
  21         return 0;
  22 }
  23
  24 static int test__vmlinux_matches_kallsyms(void)
  25 {
  26         int err = -1;
  27         struct rb_node *nd;
  28         struct symbol *sym;
  29         struct map *kallsyms_map, *vmlinux_map;
  30         struct machine kallsyms, vmlinux;
  31         enum map_type type = MAP__FUNCTION;
  32         struct ref_reloc_sym ref_reloc_sym = { .name = "_stext", };
  33
  34         /*
  35          * Step 1:
  36          *
  37          * Init the machines that will hold kernel, modules obtained from
  38          * both vmlinux + .ko files and from /proc/kallsyms split by modules.
  39          */
  40         machine__init(&kallsyms, "", HOST_KERNEL_ID);
  41         machine__init(&vmlinux, "", HOST_KERNEL_ID);
  42
  43         /*
  44          * Step 2:
  45          *
  46          * Create the kernel maps for kallsyms and the DSO where we will then
  47          * load /proc/kallsyms. Also create the modules maps from /proc/modules
  48          * and find the .ko files that match them in /lib/modules/`uname -r`/.
  49          */
  50         if (machine__create_kernel_maps(&kallsyms) < 0) {
  51                 pr_debug("machine__create_kernel_maps ");
  52                 return -1;
  53         }
  54
  55         /*
  56          * Step 3:
  57          *
  58          * Load and split /proc/kallsyms into multiple maps, one per module.
  59          */
  60         if (machine__load_kallsyms(&kallsyms, "/proc/kallsyms", type, NULL) <= 0) {
  61                 pr_debug("dso__load_kallsyms ");
  62                 goto out;
  63         }
  64
  65         /*
  66          * Step 4:
  67          *
  68          * kallsyms will be internally on demand sorted by name so that we can
  69          * find the reference relocation * symbol, i.e. the symbol we will use
  70          * to see if the running kernel was relocated by checking if it has the
  71          * same value in the vmlinux file we load.
  72          */
  73         kallsyms_map = machine__kernel_map(&kallsyms, type);
  74
  75         sym = map__find_symbol_by_name(kallsyms_map, ref_reloc_sym.name, NULL);
  76         if (sym == NULL) {
  77                 pr_debug("dso__find_symbol_by_name ");
  78                 goto out;
  79         }
  80
  81         ref_reloc_sym.addr = sym->start;
  82
  83         /*
  84          * Step 5:
  85          *
  86          * Now repeat step 2, this time for the vmlinux file we'll auto-locate.
  87          */
  88         if (machine__create_kernel_maps(&vmlinux) < 0) {
  89                 pr_debug("machine__create_kernel_maps ");
  90                 goto out;
  91         }
  92
  93         vmlinux_map = machine__kernel_map(&vmlinux, type);
  94         map__kmap(vmlinux_map)->ref_reloc_sym = &ref_reloc_sym;
  95
  96         /*
  97          * Step 6:
  98          *
  99          * Locate a vmlinux file in the vmlinux path that has a buildid that
 100          * matches the one of the running kernel.
 101          *
 102          * While doing that look if we find the ref reloc symbol, if we find it
 103          * we'll have its ref_reloc_symbol.unrelocated_addr and then
 104          * maps__reloc_vmlinux will notice and set proper ->[un]map_ip routines
 105          * to fixup the symbols.
 106          */
 107         if (machine__load_vmlinux_path(&vmlinux, type,
 108                                        vmlinux_matches_kallsyms_filter) <= 0) {
 109                 pr_debug("machine__load_vmlinux_path ");
 110                 goto out;
 111         }
 112
 113         err = 0;
 114         /*
 115          * Step 7:
 116          *
 117          * Now look at the symbols in the vmlinux DSO and check if we find all of them
 118          * in the kallsyms dso. For the ones that are in both, check its names and
 119          * end addresses too.
 120          */
 121         for (nd = rb_first(&vmlinux_map->dso->symbols[type]); nd; nd = rb_next(nd)) {
 122                 struct symbol *pair;
 123
 124                 sym  = rb_entry(nd, struct symbol, rb_node);
 125                 pair = machine__find_kernel_symbol(&kallsyms, type, sym->start, NULL, NULL);
 126
 127                 if (pair && pair->start == sym->start) {
 128 next_pair:
 129                         if (strcmp(sym->name, pair->name) == 0) {
 130                                 /*
 131                                  * kallsyms don't have the symbol end, so we
 132                                  * set that by using the next symbol start - 1,
 133                                  * in some cases we get this up to a page
 134                                  * wrong, trace_kmalloc when I was developing
 135                                  * this code was one such example, 2106 bytes
 136                                  * off the real size. More than that and we
 137                                  * _really_ have a problem.
 138                                  */
 139                                 s64 skew = sym->end - pair->end;
 140                                 if (llabs(skew) < page_size)
 141                                         continue;
 142
 143                                 pr_debug("%#Lx: diff end addr for %s v: %#Lx k: %#Lx\n",
 144                                          sym->start, sym->name, sym->end, pair->end);
 145                         } else {
 146                                 struct rb_node *nnd = rb_prev(&pair->rb_node);
 147
 148                                 if (nnd) {
 149                                         struct symbol *next = rb_entry(nnd, struct symbol, rb_node);
 150
 151                                         if (next->start == sym->start) {
 152                                                 pair = next;
 153                                                 goto next_pair;
 154                                         }
 155                                 }
 156                                 pr_debug("%#Lx: diff name v: %s k: %s\n",
 157                                          sym->start, sym->name, pair->name);
 158                         }
 159                 } else
 160                         pr_debug("%#Lx: %s not on kallsyms\n", sym->start, sym->name);
 161
 162                 err = -1;
 163         }
 164
 165         if (!verbose)
 166                 goto out;
 167
 168         pr_info("Maps only in vmlinux:\n");
 169
 170         for (nd = rb_first(&vmlinux.kmaps.maps[type]); nd; nd = rb_next(nd)) {
 171                 struct map *pos = rb_entry(nd, struct map, rb_node), *pair;
 172                 /*
 173                  * If it is the kernel, kallsyms is always "[kernel.kallsyms]", while
 174                  * the kernel will have the path for the vmlinux file being used,
 175                  * so use the short name, less descriptive but the same ("[kernel]" in
 176                  * both cases.
 177                  */
 178                 pair = map_groups__find_by_name(&kallsyms.kmaps, type,
 179                                                 (pos->dso->kernel ?
 180                                                         pos->dso->short_name :
 181                                                         pos->dso->name));
 182                 if (pair)
 183                         pair->priv = 1;
 184                 else
 185                         map__fprintf(pos, stderr);
 186         }
 187
 188         pr_info("Maps in vmlinux with a different name in kallsyms:\n");
 189
 190         for (nd = rb_first(&vmlinux.kmaps.maps[type]); nd; nd = rb_next(nd)) {
 191                 struct map *pos = rb_entry(nd, struct map, rb_node), *pair;
 192
 193                 pair = map_groups__find(&kallsyms.kmaps, type, pos->start);
 194                 if (pair == NULL || pair->priv)
 195                         continue;
 196
 197                 if (pair->start == pos->start) {
 198                         pair->priv = 1;
 199                         pr_info(" %Lx-%Lx %Lx %s in kallsyms as",
 200                                 pos->start, pos->end, pos->pgoff, pos->dso->name);
 201                         if (pos->pgoff != pair->pgoff || pos->end != pair->end)
 202                                 pr_info(": \n*%Lx-%Lx %Lx",
 203                                         pair->start, pair->end, pair->pgoff);
 204                         pr_info(" %s\n", pair->dso->name);
 205                         pair->priv = 1;
 206                 }
 207         }
 208
 209         pr_info("Maps only in kallsyms:\n");
 210
 211         for (nd = rb_first(&kallsyms.kmaps.maps[type]);
 212              nd; nd = rb_next(nd)) {
 213                 struct map *pos = rb_entry(nd, struct map, rb_node);
 214
 215                 if (!pos->priv)
 216                         map__fprintf(pos, stderr);
 217         }
 218 out:
 219         return err;
 220 }
 221
 222 static struct test {
 223         const char *desc;
 224         int (*func)(void);
 225 } tests[] = {
 226         {
 227                 .desc = "vmlinux symtab matches kallsyms",
 228                 .func = test__vmlinux_matches_kallsyms,
 229         },
 230         {
 231                 .func = NULL,
 232         },
 233 };
 234
 235 static int __cmd_test(void)
 236 {
 237         int i = 0;
 238
 239         page_size = sysconf(_SC_PAGE_SIZE);
 240
 241         while (tests[i].func) {
 242                 int err;
 243                 pr_info("%2d: %s:", i + 1, tests[i].desc);
 244                 pr_debug("\n--- start ---\n");
 245                 err = tests[i].func();
 246                 pr_debug("---- end ----\n%s:", tests[i].desc);
 247                 pr_info(" %s\n", err ? "FAILED!\n" : "Ok");
 248                 ++i;
 249         }
 250
 251         return 0;
 252 }
 253
 254 static const char * const test_usage[] = {
 255         "perf test [<options>]",
 256         NULL,
 257 };
 258
 259 static const struct option test_options[] = {
 260         OPT_INTEGER('v', "verbose", &verbose,
 261                     "be more verbose (show symbol address, etc)"),
 262         OPT_END()
 263 };
 264
 265 int cmd_test(int argc, const char **argv, const char *prefix __used)
 266 {
 267         argc = parse_options(argc, argv, test_options, test_usage, 0);
 268         if (argc)
 269                 usage_with_options(test_usage, test_options);
 270
 271         symbol_conf.priv_size = sizeof(int);
 272         symbol_conf.sort_by_name = true;
 273         symbol_conf.try_vmlinux_path = true;
 274
 275         if (symbol__init() < 0)
 276                 return -1;
 277
 278         setup_pager();
 279
 280         return __cmd_test();
 281 }