perf test: Look forward for symbol aliases
[linux-2.6.git] / 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, *first_pair;
123                 bool backwards = true;
124
125                 sym  = rb_entry(nd, struct symbol, rb_node);
126
127                 if (sym->start == sym->end)
128                         continue;
129
130                 first_pair = machine__find_kernel_symbol(&kallsyms, type, sym->start, NULL, NULL);
131                 pair = first_pair;
132
133                 if (pair && pair->start == sym->start) {
134 next_pair:
135                         if (strcmp(sym->name, pair->name) == 0) {
136                                 /*
137                                  * kallsyms don't have the symbol end, so we
138                                  * set that by using the next symbol start - 1,
139                                  * in some cases we get this up to a page
140                                  * wrong, trace_kmalloc when I was developing
141                                  * this code was one such example, 2106 bytes
142                                  * off the real size. More than that and we
143                                  * _really_ have a problem.
144                                  */
145                                 s64 skew = sym->end - pair->end;
146                                 if (llabs(skew) < page_size)
147                                         continue;
148
149                                 pr_debug("%#Lx: diff end addr for %s v: %#Lx k: %#Lx\n",
150                                          sym->start, sym->name, sym->end, pair->end);
151                         } else {
152                                 struct rb_node *nnd;
153 detour:
154                                 nnd = backwards ? rb_prev(&pair->rb_node) :
155                                                   rb_next(&pair->rb_node);
156                                 if (nnd) {
157                                         struct symbol *next = rb_entry(nnd, struct symbol, rb_node);
158
159                                         if (next->start == sym->start) {
160                                                 pair = next;
161                                                 goto next_pair;
162                                         }
163                                 }
164
165                                 if (backwards) {
166                                         backwards = false;
167                                         pair = first_pair;
168                                         goto detour;
169                                 }
170
171                                 pr_debug("%#Lx: diff name v: %s k: %s\n",
172                                          sym->start, sym->name, pair->name);
173                         }
174                 } else
175                         pr_debug("%#Lx: %s not on kallsyms\n", sym->start, sym->name);
176
177                 err = -1;
178         }
179
180         if (!verbose)
181                 goto out;
182
183         pr_info("Maps only in vmlinux:\n");
184
185         for (nd = rb_first(&vmlinux.kmaps.maps[type]); nd; nd = rb_next(nd)) {
186                 struct map *pos = rb_entry(nd, struct map, rb_node), *pair;
187                 /*
188                  * If it is the kernel, kallsyms is always "[kernel.kallsyms]", while
189                  * the kernel will have the path for the vmlinux file being used,
190                  * so use the short name, less descriptive but the same ("[kernel]" in
191                  * both cases.
192                  */
193                 pair = map_groups__find_by_name(&kallsyms.kmaps, type,
194                                                 (pos->dso->kernel ?
195                                                         pos->dso->short_name :
196                                                         pos->dso->name));
197                 if (pair)
198                         pair->priv = 1;
199                 else
200                         map__fprintf(pos, stderr);
201         }
202
203         pr_info("Maps in vmlinux with a different name in kallsyms:\n");
204
205         for (nd = rb_first(&vmlinux.kmaps.maps[type]); nd; nd = rb_next(nd)) {
206                 struct map *pos = rb_entry(nd, struct map, rb_node), *pair;
207
208                 pair = map_groups__find(&kallsyms.kmaps, type, pos->start);
209                 if (pair == NULL || pair->priv)
210                         continue;
211
212                 if (pair->start == pos->start) {
213                         pair->priv = 1;
214                         pr_info(" %Lx-%Lx %Lx %s in kallsyms as",
215                                 pos->start, pos->end, pos->pgoff, pos->dso->name);
216                         if (pos->pgoff != pair->pgoff || pos->end != pair->end)
217                                 pr_info(": \n*%Lx-%Lx %Lx",
218                                         pair->start, pair->end, pair->pgoff);
219                         pr_info(" %s\n", pair->dso->name);
220                         pair->priv = 1;
221                 }
222         }
223
224         pr_info("Maps only in kallsyms:\n");
225
226         for (nd = rb_first(&kallsyms.kmaps.maps[type]);
227              nd; nd = rb_next(nd)) {
228                 struct map *pos = rb_entry(nd, struct map, rb_node);
229
230                 if (!pos->priv)
231                         map__fprintf(pos, stderr);
232         }
233 out:
234         return err;
235 }
236
237 static struct test {
238         const char *desc;
239         int (*func)(void);
240 } tests[] = {
241         {
242                 .desc = "vmlinux symtab matches kallsyms",
243                 .func = test__vmlinux_matches_kallsyms,
244         },
245         {
246                 .func = NULL,
247         },
248 };
249
250 static int __cmd_test(void)
251 {
252         int i = 0;
253
254         page_size = sysconf(_SC_PAGE_SIZE);
255
256         while (tests[i].func) {
257                 int err;
258                 pr_info("%2d: %s:", i + 1, tests[i].desc);
259                 pr_debug("\n--- start ---\n");
260                 err = tests[i].func();
261                 pr_debug("---- end ----\n%s:", tests[i].desc);
262                 pr_info(" %s\n", err ? "FAILED!\n" : "Ok");
263                 ++i;
264         }
265
266         return 0;
267 }
268
269 static const char * const test_usage[] = {
270         "perf test [<options>]",
271         NULL,
272 };
273
274 static const struct option test_options[] = {
275         OPT_INTEGER('v', "verbose", &verbose,
276                     "be more verbose (show symbol address, etc)"),
277         OPT_END()
278 };
279
280 int cmd_test(int argc, const char **argv, const char *prefix __used)
281 {
282         argc = parse_options(argc, argv, test_options, test_usage, 0);
283         if (argc)
284                 usage_with_options(test_usage, test_options);
285
286         symbol_conf.priv_size = sizeof(int);
287         symbol_conf.sort_by_name = true;
288         symbol_conf.try_vmlinux_path = true;
289
290         if (symbol__init() < 0)
291                 return -1;
292
293         setup_pager();
294
295         return __cmd_test();
296 }