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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-03-25 09:51:50 -0400
committerIngo Molnar <mingo@elte.hu>2010-03-26 06:33:55 -0400
commitfaa4602e47690fb11221e00f9b9697c8dc0d4b19 (patch)
treeaf667d1cdff7dc63b6893ee3f27a1f2503229ed1 /arch/x86/kernel/ds_selftest.c
parent7c5ecaf7666617889f337296c610815b519abfa9 (diff)
x86, perf, bts, mm: Delete the never used BTS-ptrace code
Support for the PMU's BTS features has been upstreamed in v2.6.32, but we still have the old and disabled ptrace-BTS, as Linus noticed it not so long ago. It's buggy: TIF_DEBUGCTLMSR is trampling all over that MSR without regard for other uses (perf) and doesn't provide the flexibility needed for perf either. Its users are ptrace-block-step and ptrace-bts, since ptrace-bts was never used and ptrace-block-step can be implemented using a much simpler approach. So axe all 3000 lines of it. That includes the *locked_memory*() APIs in mm/mlock.c as well. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Markus Metzger <markus.t.metzger@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <20100325135413.938004390@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/ds_selftest.c')
-rw-r--r--arch/x86/kernel/ds_selftest.c408
1 files changed, 0 insertions, 408 deletions
diff --git a/arch/x86/kernel/ds_selftest.c b/arch/x86/kernel/ds_selftest.c
deleted file mode 100644
index 6bc7c199ab99..000000000000
--- a/arch/x86/kernel/ds_selftest.c
+++ /dev/null
@@ -1,408 +0,0 @@
1/*
2 * Debug Store support - selftest
3 *
4 *
5 * Copyright (C) 2009 Intel Corporation.
6 * Markus Metzger <markus.t.metzger@intel.com>, 2009
7 */
8
9#include "ds_selftest.h"
10
11#include <linux/kernel.h>
12#include <linux/string.h>
13#include <linux/smp.h>
14#include <linux/cpu.h>
15
16#include <asm/ds.h>
17
18
19#define BUFFER_SIZE 521 /* Intentionally chose an odd size. */
20#define SMALL_BUFFER_SIZE 24 /* A single bts entry. */
21
22struct ds_selftest_bts_conf {
23 struct bts_tracer *tracer;
24 int error;
25 int (*suspend)(struct bts_tracer *);
26 int (*resume)(struct bts_tracer *);
27};
28
29static int ds_selftest_bts_consistency(const struct bts_trace *trace)
30{
31 int error = 0;
32
33 if (!trace) {
34 printk(KERN_CONT "failed to access trace...");
35 /* Bail out. Other tests are pointless. */
36 return -1;
37 }
38
39 if (!trace->read) {
40 printk(KERN_CONT "bts read not available...");
41 error = -1;
42 }
43
44 /* Do some sanity checks on the trace configuration. */
45 if (!trace->ds.n) {
46 printk(KERN_CONT "empty bts buffer...");
47 error = -1;
48 }
49 if (!trace->ds.size) {
50 printk(KERN_CONT "bad bts trace setup...");
51 error = -1;
52 }
53 if (trace->ds.end !=
54 (char *)trace->ds.begin + (trace->ds.n * trace->ds.size)) {
55 printk(KERN_CONT "bad bts buffer setup...");
56 error = -1;
57 }
58 /*
59 * We allow top in [begin; end], since its not clear when the
60 * overflow adjustment happens: after the increment or before the
61 * write.
62 */
63 if ((trace->ds.top < trace->ds.begin) ||
64 (trace->ds.end < trace->ds.top)) {
65 printk(KERN_CONT "bts top out of bounds...");
66 error = -1;
67 }
68
69 return error;
70}
71
72static int ds_selftest_bts_read(struct bts_tracer *tracer,
73 const struct bts_trace *trace,
74 const void *from, const void *to)
75{
76 const unsigned char *at;
77
78 /*
79 * Check a few things which do not belong to this test.
80 * They should be covered by other tests.
81 */
82 if (!trace)
83 return -1;
84
85 if (!trace->read)
86 return -1;
87
88 if (to < from)
89 return -1;
90
91 if (from < trace->ds.begin)
92 return -1;
93
94 if (trace->ds.end < to)
95 return -1;
96
97 if (!trace->ds.size)
98 return -1;
99
100 /* Now to the test itself. */
101 for (at = from; (void *)at < to; at += trace->ds.size) {
102 struct bts_struct bts;
103 unsigned long index;
104 int error;
105
106 if (((void *)at - trace->ds.begin) % trace->ds.size) {
107 printk(KERN_CONT
108 "read from non-integer index...");
109 return -1;
110 }
111 index = ((void *)at - trace->ds.begin) / trace->ds.size;
112
113 memset(&bts, 0, sizeof(bts));
114 error = trace->read(tracer, at, &bts);
115 if (error < 0) {
116 printk(KERN_CONT
117 "error reading bts trace at [%lu] (0x%p)...",
118 index, at);
119 return error;
120 }
121
122 switch (bts.qualifier) {
123 case BTS_BRANCH:
124 break;
125 default:
126 printk(KERN_CONT
127 "unexpected bts entry %llu at [%lu] (0x%p)...",
128 bts.qualifier, index, at);
129 return -1;
130 }
131 }
132
133 return 0;
134}
135
136static void ds_selftest_bts_cpu(void *arg)
137{
138 struct ds_selftest_bts_conf *conf = arg;
139 const struct bts_trace *trace;
140 void *top;
141
142 if (IS_ERR(conf->tracer)) {
143 conf->error = PTR_ERR(conf->tracer);
144 conf->tracer = NULL;
145
146 printk(KERN_CONT
147 "initialization failed (err: %d)...", conf->error);
148 return;
149 }
150
151 /* We should meanwhile have enough trace. */
152 conf->error = conf->suspend(conf->tracer);
153 if (conf->error < 0)
154 return;
155
156 /* Let's see if we can access the trace. */
157 trace = ds_read_bts(conf->tracer);
158
159 conf->error = ds_selftest_bts_consistency(trace);
160 if (conf->error < 0)
161 return;
162
163 /* If everything went well, we should have a few trace entries. */
164 if (trace->ds.top == trace->ds.begin) {
165 /*
166 * It is possible but highly unlikely that we got a
167 * buffer overflow and end up at exactly the same
168 * position we started from.
169 * Let's issue a warning, but continue.
170 */
171 printk(KERN_CONT "no trace/overflow...");
172 }
173
174 /* Let's try to read the trace we collected. */
175 conf->error =
176 ds_selftest_bts_read(conf->tracer, trace,
177 trace->ds.begin, trace->ds.top);
178 if (conf->error < 0)
179 return;
180
181 /*
182 * Let's read the trace again.
183 * Since we suspended tracing, we should get the same result.
184 */
185 top = trace->ds.top;
186
187 trace = ds_read_bts(conf->tracer);
188 conf->error = ds_selftest_bts_consistency(trace);
189 if (conf->error < 0)
190 return;
191
192 if (top != trace->ds.top) {
193 printk(KERN_CONT "suspend not working...");
194 conf->error = -1;
195 return;
196 }
197
198 /* Let's collect some more trace - see if resume is working. */
199 conf->error = conf->resume(conf->tracer);
200 if (conf->error < 0)
201 return;
202
203 conf->error = conf->suspend(conf->tracer);
204 if (conf->error < 0)
205 return;
206
207 trace = ds_read_bts(conf->tracer);
208
209 conf->error = ds_selftest_bts_consistency(trace);
210 if (conf->error < 0)
211 return;
212
213 if (trace->ds.top == top) {
214 /*
215 * It is possible but highly unlikely that we got a
216 * buffer overflow and end up at exactly the same
217 * position we started from.
218 * Let's issue a warning and check the full trace.
219 */
220 printk(KERN_CONT
221 "no resume progress/overflow...");
222
223 conf->error =
224 ds_selftest_bts_read(conf->tracer, trace,
225 trace->ds.begin, trace->ds.end);
226 } else if (trace->ds.top < top) {
227 /*
228 * We had a buffer overflow - the entire buffer should
229 * contain trace records.
230 */
231 conf->error =
232 ds_selftest_bts_read(conf->tracer, trace,
233 trace->ds.begin, trace->ds.end);
234 } else {
235 /*
236 * It is quite likely that the buffer did not overflow.
237 * Let's just check the delta trace.
238 */
239 conf->error =
240 ds_selftest_bts_read(conf->tracer, trace, top,
241 trace->ds.top);
242 }
243 if (conf->error < 0)
244 return;
245
246 conf->error = 0;
247}
248
249static int ds_suspend_bts_wrap(struct bts_tracer *tracer)
250{
251 ds_suspend_bts(tracer);
252 return 0;
253}
254
255static int ds_resume_bts_wrap(struct bts_tracer *tracer)
256{
257 ds_resume_bts(tracer);
258 return 0;
259}
260
261static void ds_release_bts_noirq_wrap(void *tracer)
262{
263 (void)ds_release_bts_noirq(tracer);
264}
265
266static int ds_selftest_bts_bad_release_noirq(int cpu,
267 struct bts_tracer *tracer)
268{
269 int error = -EPERM;
270
271 /* Try to release the tracer on the wrong cpu. */
272 get_cpu();
273 if (cpu != smp_processor_id()) {
274 error = ds_release_bts_noirq(tracer);
275 if (error != -EPERM)
276 printk(KERN_CONT "release on wrong cpu...");
277 }
278 put_cpu();
279
280 return error ? 0 : -1;
281}
282
283static int ds_selftest_bts_bad_request_cpu(int cpu, void *buffer)
284{
285 struct bts_tracer *tracer;
286 int error;
287
288 /* Try to request cpu tracing while task tracing is active. */
289 tracer = ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE, NULL,
290 (size_t)-1, BTS_KERNEL);
291 error = PTR_ERR(tracer);
292 if (!IS_ERR(tracer)) {
293 ds_release_bts(tracer);
294 error = 0;
295 }
296
297 if (error != -EPERM)
298 printk(KERN_CONT "cpu/task tracing overlap...");
299
300 return error ? 0 : -1;
301}
302
303static int ds_selftest_bts_bad_request_task(void *buffer)
304{
305 struct bts_tracer *tracer;
306 int error;
307
308 /* Try to request cpu tracing while task tracing is active. */
309 tracer = ds_request_bts_task(current, buffer, BUFFER_SIZE, NULL,
310 (size_t)-1, BTS_KERNEL);
311 error = PTR_ERR(tracer);
312 if (!IS_ERR(tracer)) {
313 error = 0;
314 ds_release_bts(tracer);
315 }
316
317 if (error != -EPERM)
318 printk(KERN_CONT "task/cpu tracing overlap...");
319
320 return error ? 0 : -1;
321}
322
323int ds_selftest_bts(void)
324{
325 struct ds_selftest_bts_conf conf;
326 unsigned char buffer[BUFFER_SIZE], *small_buffer;
327 unsigned long irq;
328 int cpu;
329
330 printk(KERN_INFO "[ds] bts selftest...");
331 conf.error = 0;
332
333 small_buffer = (unsigned char *)ALIGN((unsigned long)buffer, 8) + 8;
334
335 get_online_cpus();
336 for_each_online_cpu(cpu) {
337 conf.suspend = ds_suspend_bts_wrap;
338 conf.resume = ds_resume_bts_wrap;
339 conf.tracer =
340 ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE,
341 NULL, (size_t)-1, BTS_KERNEL);
342 ds_selftest_bts_cpu(&conf);
343 if (conf.error >= 0)
344 conf.error = ds_selftest_bts_bad_request_task(buffer);
345 ds_release_bts(conf.tracer);
346 if (conf.error < 0)
347 goto out;
348
349 conf.suspend = ds_suspend_bts_noirq;
350 conf.resume = ds_resume_bts_noirq;
351 conf.tracer =
352 ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE,
353 NULL, (size_t)-1, BTS_KERNEL);
354 smp_call_function_single(cpu, ds_selftest_bts_cpu, &conf, 1);
355 if (conf.error >= 0) {
356 conf.error =
357 ds_selftest_bts_bad_release_noirq(cpu,
358 conf.tracer);
359 /* We must not release the tracer twice. */
360 if (conf.error < 0)
361 conf.tracer = NULL;
362 }
363 if (conf.error >= 0)
364 conf.error = ds_selftest_bts_bad_request_task(buffer);
365 smp_call_function_single(cpu, ds_release_bts_noirq_wrap,
366 conf.tracer, 1);
367 if (conf.error < 0)
368 goto out;
369 }
370
371 conf.suspend = ds_suspend_bts_wrap;
372 conf.resume = ds_resume_bts_wrap;
373 conf.tracer =
374 ds_request_bts_task(current, buffer, BUFFER_SIZE,
375 NULL, (size_t)-1, BTS_KERNEL);
376 ds_selftest_bts_cpu(&conf);
377 if (conf.error >= 0)
378 conf.error = ds_selftest_bts_bad_request_cpu(0, buffer);
379 ds_release_bts(conf.tracer);
380 if (conf.error < 0)
381 goto out;
382
383 conf.suspend = ds_suspend_bts_noirq;
384 conf.resume = ds_resume_bts_noirq;
385 conf.tracer =
386 ds_request_bts_task(current, small_buffer, SMALL_BUFFER_SIZE,
387 NULL, (size_t)-1, BTS_KERNEL);
388 local_irq_save(irq);
389 ds_selftest_bts_cpu(&conf);
390 if (conf.error >= 0)
391 conf.error = ds_selftest_bts_bad_request_cpu(0, buffer);
392 ds_release_bts_noirq(conf.tracer);
393 local_irq_restore(irq);
394 if (conf.error < 0)
395 goto out;
396
397 conf.error = 0;
398 out:
399 put_online_cpus();
400 printk(KERN_CONT "%s.\n", (conf.error ? "failed" : "passed"));
401
402 return conf.error;
403}
404
405int ds_selftest_pebs(void)
406{
407 return 0;
408}
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