1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * kgdbts is a test suite for kgdb for the sole purpose of validating
4 * that key pieces of the kgdb internals are working properly such as
5 * HW/SW breakpoints, single stepping, and NMI.
6 *
7 * Created by: Jason Wessel <jason.wessel@windriver.com>
8 *
9 * Copyright (c) 2008 Wind River Systems, Inc.
10 */
11 /* Information about the kgdb test suite.
12 * -------------------------------------
13 *
14 * The kgdb test suite is designed as a KGDB I/O module which
15 * simulates the communications that a debugger would have with kgdb.
16 * The tests are broken up in to a line by line and referenced here as
17 * a "get" which is kgdb requesting input and "put" which is kgdb
18 * sending a response.
19 *
20 * The kgdb suite can be invoked from the kernel command line
21 * arguments system or executed dynamically at run time. The test
22 * suite uses the variable "kgdbts" to obtain the information about
23 * which tests to run and to configure the verbosity level. The
24 * following are the various characters you can use with the kgdbts=
25 * line:
26 *
27 * When using the "kgdbts=" you only choose one of the following core
28 * test types:
29 * A = Run all the core tests silently
30 * V1 = Run all the core tests with minimal output
31 * V2 = Run all the core tests in debug mode
32 *
33 * You can also specify optional tests:
34 * N## = Go to sleep with interrupts of for ## seconds
35 * to test the HW NMI watchdog
36 * F## = Break at kernel_clone for ## iterations
37 * S## = Break at sys_open for ## iterations
38 * I## = Run the single step test ## iterations
39 *
40 * NOTE: that the kernel_clone and sys_open tests are mutually exclusive.
41 *
42 * To invoke the kgdb test suite from boot you use a kernel start
43 * argument as follows:
44 * kgdbts=V1 kgdbwait
45 * Or if you wanted to perform the NMI test for 6 seconds and kernel_clone
46 * test for 100 forks, you could use:
47 * kgdbts=V1N6F100 kgdbwait
48 *
49 * The test suite can also be invoked at run time with:
50 * echo kgdbts=V1N6F100 > /sys/module/kgdbts/parameters/kgdbts
51 * Or as another example:
52 * echo kgdbts=V2 > /sys/module/kgdbts/parameters/kgdbts
53 *
54 * When developing a new kgdb arch specific implementation or
55 * using these tests for the purpose of regression testing,
56 * several invocations are required.
57 *
58 * 1) Boot with the test suite enabled by using the kernel arguments
59 * "kgdbts=V1F100 kgdbwait"
60 * ## If kgdb arch specific implementation has NMI use
61 * "kgdbts=V1N6F100
62 *
63 * 2) After the system boot run the basic test.
64 * echo kgdbts=V1 > /sys/module/kgdbts/parameters/kgdbts
65 *
66 * 3) Run the concurrency tests. It is best to use n+1
67 * while loops where n is the number of cpus you have
68 * in your system. The example below uses only two
69 * loops.
70 *
71 * ## This tests break points on sys_open
72 * while [ 1 ] ; do find / > /dev/null 2>&1 ; done &
73 * while [ 1 ] ; do find / > /dev/null 2>&1 ; done &
74 * echo kgdbts=V1S10000 > /sys/module/kgdbts/parameters/kgdbts
75 * fg # and hit control-c
76 * fg # and hit control-c
77 * ## This tests break points on kernel_clone
78 * while [ 1 ] ; do date > /dev/null ; done &
79 * while [ 1 ] ; do date > /dev/null ; done &
80 * echo kgdbts=V1F1000 > /sys/module/kgdbts/parameters/kgdbts
81 * fg # and hit control-c
82 *
83 */
84
85 #include <linux/kernel.h>
86 #include <linux/kgdb.h>
87 #include <linux/ctype.h>
88 #include <linux/uaccess.h>
89 #include <linux/syscalls.h>
90 #include <linux/nmi.h>
91 #include <linux/delay.h>
92 #include <linux/kthread.h>
93 #include <linux/module.h>
94 #include <linux/sched/task.h>
95 #include <linux/kallsyms.h>
96
97 #include <asm/sections.h>
98
99 #define v1printk(a...) do { \
100 if (verbose) \
101 printk(KERN_INFO a); \
102 } while (0)
103 #define v2printk(a...) do { \
104 if (verbose > 1) { \
105 printk(KERN_INFO a); \
106 } \
107 touch_nmi_watchdog(); \
108 } while (0)
109 #define eprintk(a...) do { \
110 printk(KERN_ERR a); \
111 WARN_ON(1); \
112 } while (0)
113 #define MAX_CONFIG_LEN 40
114
115 static struct kgdb_io kgdbts_io_ops;
116 static char get_buf[BUFMAX];
117 static int get_buf_cnt;
118 static char put_buf[BUFMAX];
119 static int put_buf_cnt;
120 static char scratch_buf[BUFMAX];
121 static int verbose;
122 static int repeat_test;
123 static int test_complete;
124 static int send_ack;
125 static int final_ack;
126 static int force_hwbrks;
127 static int hwbreaks_ok;
128 static int hw_break_val;
129 static int hw_break_val2;
130 static int cont_instead_of_sstep;
131 static unsigned long cont_thread_id;
132 static unsigned long sstep_thread_id;
133 #if defined(CONFIG_ARM) || defined(CONFIG_MIPS) || defined(CONFIG_SPARC)
134 static int arch_needs_sstep_emulation = 1;
135 #else
136 static int arch_needs_sstep_emulation;
137 #endif
138 static unsigned long cont_addr;
139 static unsigned long sstep_addr;
140 static int restart_from_top_after_write;
141 static int sstep_state;
142
143 /* Storage for the registers, in GDB format. */
144 static unsigned long kgdbts_gdb_regs[(NUMREGBYTES +
145 sizeof(unsigned long) - 1) /
146 sizeof(unsigned long)];
147 static struct pt_regs kgdbts_regs;
148
149 /* -1 = init not run yet, 0 = unconfigured, 1 = configured. */
150 static int configured = -1;
151
152 #ifdef CONFIG_KGDB_TESTS_BOOT_STRING
153 static char config[MAX_CONFIG_LEN] = CONFIG_KGDB_TESTS_BOOT_STRING;
154 #else
155 static char config[MAX_CONFIG_LEN];
156 #endif
157 static struct kparam_string kps = {
158 .string = config,
159 .maxlen = MAX_CONFIG_LEN,
160 };
161
162 static void fill_get_buf(char *buf);
163
164 struct test_struct {
165 char *get;
166 char *put;
167 void (*get_handler)(char *);
168 int (*put_handler)(char *, char *);
169 };
170
171 struct test_state {
172 char *name;
173 struct test_struct *tst;
174 int idx;
175 int (*run_test) (int, int);
176 int (*validate_put) (char *);
177 };
178
179 static struct test_state ts;
180
kgdbts_unreg_thread(void * ptr)181 static int kgdbts_unreg_thread(void *ptr)
182 {
183 /* Wait until the tests are complete and then ungresiter the I/O
184 * driver.
185 */
186 while (!final_ack)
187 msleep_interruptible(1500);
188 /* Pause for any other threads to exit after final ack. */
189 msleep_interruptible(1000);
190 if (configured)
191 kgdb_unregister_io_module(&kgdbts_io_ops);
192 configured = 0;
193
194 return 0;
195 }
196
197 /* This is noinline such that it can be used for a single location to
198 * place a breakpoint
199 */
kgdbts_break_test(void)200 static noinline void kgdbts_break_test(void)
201 {
202 v2printk("kgdbts: breakpoint complete\n");
203 }
204
205 /*
206 * This is a cached wrapper for kallsyms_lookup_name().
207 *
208 * The cache is a big win for several tests. For example it more the doubles
209 * the cycles per second during the sys_open test. This is not theoretic,
210 * the performance improvement shows up at human scale, especially when
211 * testing using emulators.
212 *
213 * Obviously neither re-entrant nor thread-safe but that is OK since it
214 * can only be called from the debug trap (and therefore all other CPUs
215 * are halted).
216 */
lookup_addr(char * arg)217 static unsigned long lookup_addr(char *arg)
218 {
219 static char cached_arg[KSYM_NAME_LEN];
220 static unsigned long cached_addr;
221
222 if (strcmp(arg, cached_arg)) {
223 strscpy(cached_arg, arg, KSYM_NAME_LEN);
224 cached_addr = kallsyms_lookup_name(arg);
225 }
226
227 return (unsigned long)dereference_function_descriptor(
228 (void *)cached_addr);
229 }
230
break_helper(char * bp_type,char * arg,unsigned long vaddr)231 static void break_helper(char *bp_type, char *arg, unsigned long vaddr)
232 {
233 unsigned long addr;
234
235 if (arg)
236 addr = lookup_addr(arg);
237 else
238 addr = vaddr;
239
240 sprintf(scratch_buf, "%s,%lx,%i", bp_type, addr,
241 BREAK_INSTR_SIZE);
242 fill_get_buf(scratch_buf);
243 }
244
sw_break(char * arg)245 static void sw_break(char *arg)
246 {
247 break_helper(force_hwbrks ? "Z1" : "Z0", arg, 0);
248 }
249
sw_rem_break(char * arg)250 static void sw_rem_break(char *arg)
251 {
252 break_helper(force_hwbrks ? "z1" : "z0", arg, 0);
253 }
254
hw_break(char * arg)255 static void hw_break(char *arg)
256 {
257 break_helper("Z1", arg, 0);
258 }
259
hw_rem_break(char * arg)260 static void hw_rem_break(char *arg)
261 {
262 break_helper("z1", arg, 0);
263 }
264
hw_write_break(char * arg)265 static void hw_write_break(char *arg)
266 {
267 break_helper("Z2", arg, 0);
268 }
269
hw_rem_write_break(char * arg)270 static void hw_rem_write_break(char *arg)
271 {
272 break_helper("z2", arg, 0);
273 }
274
hw_access_break(char * arg)275 static void hw_access_break(char *arg)
276 {
277 break_helper("Z4", arg, 0);
278 }
279
hw_rem_access_break(char * arg)280 static void hw_rem_access_break(char *arg)
281 {
282 break_helper("z4", arg, 0);
283 }
284
hw_break_val_access(void)285 static void hw_break_val_access(void)
286 {
287 hw_break_val2 = hw_break_val;
288 }
289
hw_break_val_write(void)290 static void hw_break_val_write(void)
291 {
292 hw_break_val++;
293 }
294
get_thread_id_continue(char * put_str,char * arg)295 static int get_thread_id_continue(char *put_str, char *arg)
296 {
297 char *ptr = &put_str[11];
298
299 if (put_str[1] != 'T' || put_str[2] != '0')
300 return 1;
301 kgdb_hex2long(&ptr, &cont_thread_id);
302 return 0;
303 }
304
check_and_rewind_pc(char * put_str,char * arg)305 static int check_and_rewind_pc(char *put_str, char *arg)
306 {
307 unsigned long addr = lookup_addr(arg);
308 unsigned long ip;
309 int offset = 0;
310
311 kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs,
312 NUMREGBYTES);
313 gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs);
314 ip = instruction_pointer(&kgdbts_regs);
315 v2printk("Stopped at IP: %lx\n", ip);
316 #ifdef GDB_ADJUSTS_BREAK_OFFSET
317 /* On some arches, a breakpoint stop requires it to be decremented */
318 if (addr + BREAK_INSTR_SIZE == ip)
319 offset = -BREAK_INSTR_SIZE;
320 #endif
321
322 if (arch_needs_sstep_emulation && sstep_addr &&
323 ip + offset == sstep_addr &&
324 ((!strcmp(arg, "do_sys_openat2") || !strcmp(arg, "kernel_clone")))) {
325 /* This is special case for emulated single step */
326 v2printk("Emul: rewind hit single step bp\n");
327 restart_from_top_after_write = 1;
328 } else if (strcmp(arg, "silent") && ip + offset != addr) {
329 eprintk("kgdbts: BP mismatch %lx expected %lx\n",
330 ip + offset, addr);
331 return 1;
332 }
333 /* Readjust the instruction pointer if needed */
334 ip += offset;
335 cont_addr = ip;
336 #ifdef GDB_ADJUSTS_BREAK_OFFSET
337 instruction_pointer_set(&kgdbts_regs, ip);
338 #endif
339 return 0;
340 }
341
check_single_step(char * put_str,char * arg)342 static int check_single_step(char *put_str, char *arg)
343 {
344 unsigned long addr = lookup_addr(arg);
345 static int matched_id;
346
347 /*
348 * From an arch indepent point of view the instruction pointer
349 * should be on a different instruction
350 */
351 kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs,
352 NUMREGBYTES);
353 gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs);
354 v2printk("Singlestep stopped at IP: %lx\n",
355 instruction_pointer(&kgdbts_regs));
356
357 if (sstep_thread_id != cont_thread_id) {
358 /*
359 * Ensure we stopped in the same thread id as before, else the
360 * debugger should continue until the original thread that was
361 * single stepped is scheduled again, emulating gdb's behavior.
362 */
363 v2printk("ThrID does not match: %lx\n", cont_thread_id);
364 if (arch_needs_sstep_emulation) {
365 if (matched_id &&
366 instruction_pointer(&kgdbts_regs) != addr)
367 goto continue_test;
368 matched_id++;
369 ts.idx -= 2;
370 sstep_state = 0;
371 return 0;
372 }
373 cont_instead_of_sstep = 1;
374 ts.idx -= 4;
375 return 0;
376 }
377 continue_test:
378 matched_id = 0;
379 if (instruction_pointer(&kgdbts_regs) == addr) {
380 eprintk("kgdbts: SingleStep failed at %lx\n",
381 instruction_pointer(&kgdbts_regs));
382 return 1;
383 }
384
385 return 0;
386 }
387
write_regs(char * arg)388 static void write_regs(char *arg)
389 {
390 memset(scratch_buf, 0, sizeof(scratch_buf));
391 scratch_buf[0] = 'G';
392 pt_regs_to_gdb_regs(kgdbts_gdb_regs, &kgdbts_regs);
393 kgdb_mem2hex((char *)kgdbts_gdb_regs, &scratch_buf[1], NUMREGBYTES);
394 fill_get_buf(scratch_buf);
395 }
396
skip_back_repeat_test(char * arg)397 static void skip_back_repeat_test(char *arg)
398 {
399 int go_back = simple_strtol(arg, NULL, 10);
400
401 repeat_test--;
402 if (repeat_test <= 0) {
403 ts.idx++;
404 } else {
405 if (repeat_test % 100 == 0)
406 v1printk("kgdbts:RUN ... %d remaining\n", repeat_test);
407
408 ts.idx -= go_back;
409 }
410 fill_get_buf(ts.tst[ts.idx].get);
411 }
412
got_break(char * put_str,char * arg)413 static int got_break(char *put_str, char *arg)
414 {
415 test_complete = 1;
416 if (!strncmp(put_str+1, arg, 2)) {
417 if (!strncmp(arg, "T0", 2))
418 test_complete = 2;
419 return 0;
420 }
421 return 1;
422 }
423
get_cont_catch(char * arg)424 static void get_cont_catch(char *arg)
425 {
426 /* Always send detach because the test is completed at this point */
427 fill_get_buf("D");
428 }
429
put_cont_catch(char * put_str,char * arg)430 static int put_cont_catch(char *put_str, char *arg)
431 {
432 /* This is at the end of the test and we catch any and all input */
433 v2printk("kgdbts: cleanup task: %lx\n", sstep_thread_id);
434 ts.idx--;
435 return 0;
436 }
437
emul_reset(char * put_str,char * arg)438 static int emul_reset(char *put_str, char *arg)
439 {
440 if (strncmp(put_str, "$OK", 3))
441 return 1;
442 if (restart_from_top_after_write) {
443 restart_from_top_after_write = 0;
444 ts.idx = -1;
445 }
446 return 0;
447 }
448
emul_sstep_get(char * arg)449 static void emul_sstep_get(char *arg)
450 {
451 if (!arch_needs_sstep_emulation) {
452 if (cont_instead_of_sstep) {
453 cont_instead_of_sstep = 0;
454 fill_get_buf("c");
455 } else {
456 fill_get_buf(arg);
457 }
458 return;
459 }
460 switch (sstep_state) {
461 case 0:
462 v2printk("Emulate single step\n");
463 /* Start by looking at the current PC */
464 fill_get_buf("g");
465 break;
466 case 1:
467 /* set breakpoint */
468 break_helper("Z0", NULL, sstep_addr);
469 break;
470 case 2:
471 /* Continue */
472 fill_get_buf("c");
473 break;
474 case 3:
475 /* Clear breakpoint */
476 break_helper("z0", NULL, sstep_addr);
477 break;
478 default:
479 eprintk("kgdbts: ERROR failed sstep get emulation\n");
480 }
481 sstep_state++;
482 }
483
emul_sstep_put(char * put_str,char * arg)484 static int emul_sstep_put(char *put_str, char *arg)
485 {
486 if (!arch_needs_sstep_emulation) {
487 char *ptr = &put_str[11];
488 if (put_str[1] != 'T' || put_str[2] != '0')
489 return 1;
490 kgdb_hex2long(&ptr, &sstep_thread_id);
491 return 0;
492 }
493 switch (sstep_state) {
494 case 1:
495 /* validate the "g" packet to get the IP */
496 kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs,
497 NUMREGBYTES);
498 gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs);
499 v2printk("Stopped at IP: %lx\n",
500 instruction_pointer(&kgdbts_regs));
501 /* Want to stop at IP + break instruction size by default */
502 sstep_addr = cont_addr + BREAK_INSTR_SIZE;
503 break;
504 case 2:
505 if (strncmp(put_str, "$OK", 3)) {
506 eprintk("kgdbts: failed sstep break set\n");
507 return 1;
508 }
509 break;
510 case 3:
511 if (strncmp(put_str, "$T0", 3)) {
512 eprintk("kgdbts: failed continue sstep\n");
513 return 1;
514 } else {
515 char *ptr = &put_str[11];
516 kgdb_hex2long(&ptr, &sstep_thread_id);
517 }
518 break;
519 case 4:
520 if (strncmp(put_str, "$OK", 3)) {
521 eprintk("kgdbts: failed sstep break unset\n");
522 return 1;
523 }
524 /* Single step is complete so continue on! */
525 sstep_state = 0;
526 return 0;
527 default:
528 eprintk("kgdbts: ERROR failed sstep put emulation\n");
529 }
530
531 /* Continue on the same test line until emulation is complete */
532 ts.idx--;
533 return 0;
534 }
535
final_ack_set(char * put_str,char * arg)536 static int final_ack_set(char *put_str, char *arg)
537 {
538 if (strncmp(put_str+1, arg, 2))
539 return 1;
540 final_ack = 1;
541 return 0;
542 }
543 /*
544 * Test to plant a breakpoint and detach, which should clear out the
545 * breakpoint and restore the original instruction.
546 */
547 static struct test_struct plant_and_detach_test[] = {
548 { "?", "S0*" }, /* Clear break points */
549 { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
550 { "D", "OK" }, /* Detach */
551 { "", "" },
552 };
553
554 /*
555 * Simple test to write in a software breakpoint, check for the
556 * correct stop location and detach.
557 */
558 static struct test_struct sw_breakpoint_test[] = {
559 { "?", "S0*" }, /* Clear break points */
560 { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
561 { "c", "T0*", }, /* Continue */
562 { "g", "kgdbts_break_test", NULL, check_and_rewind_pc },
563 { "write", "OK", write_regs },
564 { "kgdbts_break_test", "OK", sw_rem_break }, /*remove breakpoint */
565 { "D", "OK" }, /* Detach */
566 { "D", "OK", NULL, got_break }, /* On success we made it here */
567 { "", "" },
568 };
569
570 /*
571 * Test a known bad memory read location to test the fault handler and
572 * read bytes 1-8 at the bad address
573 */
574 static struct test_struct bad_read_test[] = {
575 { "?", "S0*" }, /* Clear break points */
576 { "m0,1", "E*" }, /* read 1 byte at address 1 */
577 { "m0,2", "E*" }, /* read 1 byte at address 2 */
578 { "m0,3", "E*" }, /* read 1 byte at address 3 */
579 { "m0,4", "E*" }, /* read 1 byte at address 4 */
580 { "m0,5", "E*" }, /* read 1 byte at address 5 */
581 { "m0,6", "E*" }, /* read 1 byte at address 6 */
582 { "m0,7", "E*" }, /* read 1 byte at address 7 */
583 { "m0,8", "E*" }, /* read 1 byte at address 8 */
584 { "D", "OK" }, /* Detach which removes all breakpoints and continues */
585 { "", "" },
586 };
587
588 /*
589 * Test for hitting a breakpoint, remove it, single step, plant it
590 * again and detach.
591 */
592 static struct test_struct singlestep_break_test[] = {
593 { "?", "S0*" }, /* Clear break points */
594 { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
595 { "c", "T0*", NULL, get_thread_id_continue }, /* Continue */
596 { "kgdbts_break_test", "OK", sw_rem_break }, /*remove breakpoint */
597 { "g", "kgdbts_break_test", NULL, check_and_rewind_pc },
598 { "write", "OK", write_regs }, /* Write registers */
599 { "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
600 { "g", "kgdbts_break_test", NULL, check_single_step },
601 { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
602 { "c", "T0*", }, /* Continue */
603 { "g", "kgdbts_break_test", NULL, check_and_rewind_pc },
604 { "write", "OK", write_regs }, /* Write registers */
605 { "D", "OK" }, /* Remove all breakpoints and continues */
606 { "", "" },
607 };
608
609 /*
610 * Test for hitting a breakpoint at kernel_clone for what ever the number
611 * of iterations required by the variable repeat_test.
612 */
613 static struct test_struct do_kernel_clone_test[] = {
614 { "?", "S0*" }, /* Clear break points */
615 { "kernel_clone", "OK", sw_break, }, /* set sw breakpoint */
616 { "c", "T0*", NULL, get_thread_id_continue }, /* Continue */
617 { "kernel_clone", "OK", sw_rem_break }, /*remove breakpoint */
618 { "g", "kernel_clone", NULL, check_and_rewind_pc }, /* check location */
619 { "write", "OK", write_regs, emul_reset }, /* Write registers */
620 { "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
621 { "g", "kernel_clone", NULL, check_single_step },
622 { "kernel_clone", "OK", sw_break, }, /* set sw breakpoint */
623 { "7", "T0*", skip_back_repeat_test }, /* Loop based on repeat_test */
624 { "D", "OK", NULL, final_ack_set }, /* detach and unregister I/O */
625 { "", "", get_cont_catch, put_cont_catch },
626 };
627
628 /* Test for hitting a breakpoint at sys_open for what ever the number
629 * of iterations required by the variable repeat_test.
630 */
631 static struct test_struct sys_open_test[] = {
632 { "?", "S0*" }, /* Clear break points */
633 { "do_sys_openat2", "OK", sw_break, }, /* set sw breakpoint */
634 { "c", "T0*", NULL, get_thread_id_continue }, /* Continue */
635 { "do_sys_openat2", "OK", sw_rem_break }, /*remove breakpoint */
636 { "g", "do_sys_openat2", NULL, check_and_rewind_pc }, /* check location */
637 { "write", "OK", write_regs, emul_reset }, /* Write registers */
638 { "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
639 { "g", "do_sys_openat2", NULL, check_single_step },
640 { "do_sys_openat2", "OK", sw_break, }, /* set sw breakpoint */
641 { "7", "T0*", skip_back_repeat_test }, /* Loop based on repeat_test */
642 { "D", "OK", NULL, final_ack_set }, /* detach and unregister I/O */
643 { "", "", get_cont_catch, put_cont_catch },
644 };
645
646 /*
647 * Test for hitting a simple hw breakpoint
648 */
649 static struct test_struct hw_breakpoint_test[] = {
650 { "?", "S0*" }, /* Clear break points */
651 { "kgdbts_break_test", "OK", hw_break, }, /* set hw breakpoint */
652 { "c", "T0*", }, /* Continue */
653 { "g", "kgdbts_break_test", NULL, check_and_rewind_pc },
654 { "write", "OK", write_regs },
655 { "kgdbts_break_test", "OK", hw_rem_break }, /*remove breakpoint */
656 { "D", "OK" }, /* Detach */
657 { "D", "OK", NULL, got_break }, /* On success we made it here */
658 { "", "" },
659 };
660
661 /*
662 * Test for hitting a hw write breakpoint
663 */
664 static struct test_struct hw_write_break_test[] = {
665 { "?", "S0*" }, /* Clear break points */
666 { "hw_break_val", "OK", hw_write_break, }, /* set hw breakpoint */
667 { "c", "T0*", NULL, got_break }, /* Continue */
668 { "g", "silent", NULL, check_and_rewind_pc },
669 { "write", "OK", write_regs },
670 { "hw_break_val", "OK", hw_rem_write_break }, /*remove breakpoint */
671 { "D", "OK" }, /* Detach */
672 { "D", "OK", NULL, got_break }, /* On success we made it here */
673 { "", "" },
674 };
675
676 /*
677 * Test for hitting a hw access breakpoint
678 */
679 static struct test_struct hw_access_break_test[] = {
680 { "?", "S0*" }, /* Clear break points */
681 { "hw_break_val", "OK", hw_access_break, }, /* set hw breakpoint */
682 { "c", "T0*", NULL, got_break }, /* Continue */
683 { "g", "silent", NULL, check_and_rewind_pc },
684 { "write", "OK", write_regs },
685 { "hw_break_val", "OK", hw_rem_access_break }, /*remove breakpoint */
686 { "D", "OK" }, /* Detach */
687 { "D", "OK", NULL, got_break }, /* On success we made it here */
688 { "", "" },
689 };
690
691 /*
692 * Test for hitting a hw access breakpoint
693 */
694 static struct test_struct nmi_sleep_test[] = {
695 { "?", "S0*" }, /* Clear break points */
696 { "c", "T0*", NULL, got_break }, /* Continue */
697 { "D", "OK" }, /* Detach */
698 { "D", "OK", NULL, got_break }, /* On success we made it here */
699 { "", "" },
700 };
701
fill_get_buf(char * buf)702 static void fill_get_buf(char *buf)
703 {
704 unsigned char checksum = 0;
705 int count = 0;
706 char ch;
707
708 strcpy(get_buf, "$");
709 strcat(get_buf, buf);
710 while ((ch = buf[count])) {
711 checksum += ch;
712 count++;
713 }
714 strcat(get_buf, "#");
715 get_buf[count + 2] = hex_asc_hi(checksum);
716 get_buf[count + 3] = hex_asc_lo(checksum);
717 get_buf[count + 4] = '\0';
718 v2printk("get%i: %s\n", ts.idx, get_buf);
719 }
720
validate_simple_test(char * put_str)721 static int validate_simple_test(char *put_str)
722 {
723 char *chk_str;
724
725 if (ts.tst[ts.idx].put_handler)
726 return ts.tst[ts.idx].put_handler(put_str,
727 ts.tst[ts.idx].put);
728
729 chk_str = ts.tst[ts.idx].put;
730 if (*put_str == '$')
731 put_str++;
732
733 while (*chk_str != '\0' && *put_str != '\0') {
734 /* If someone does a * to match the rest of the string, allow
735 * it, or stop if the received string is complete.
736 */
737 if (*put_str == '#' || *chk_str == '*')
738 return 0;
739 if (*put_str != *chk_str)
740 return 1;
741
742 chk_str++;
743 put_str++;
744 }
745 if (*chk_str == '\0' && (*put_str == '\0' || *put_str == '#'))
746 return 0;
747
748 return 1;
749 }
750
run_simple_test(int is_get_char,int chr)751 static int run_simple_test(int is_get_char, int chr)
752 {
753 int ret = 0;
754 if (is_get_char) {
755 /* Send an ACK on the get if a prior put completed and set the
756 * send ack variable
757 */
758 if (send_ack) {
759 send_ack = 0;
760 return '+';
761 }
762 /* On the first get char, fill the transmit buffer and then
763 * take from the get_string.
764 */
765 if (get_buf_cnt == 0) {
766 if (ts.tst[ts.idx].get_handler)
767 ts.tst[ts.idx].get_handler(ts.tst[ts.idx].get);
768 else
769 fill_get_buf(ts.tst[ts.idx].get);
770 }
771
772 if (get_buf[get_buf_cnt] == '\0') {
773 eprintk("kgdbts: ERROR GET: EOB on '%s' at %i\n",
774 ts.name, ts.idx);
775 get_buf_cnt = 0;
776 fill_get_buf("D");
777 }
778 ret = get_buf[get_buf_cnt];
779 get_buf_cnt++;
780 return ret;
781 }
782
783 /* This callback is a put char which is when kgdb sends data to
784 * this I/O module.
785 */
786 if (ts.tst[ts.idx].get[0] == '\0' && ts.tst[ts.idx].put[0] == '\0' &&
787 !ts.tst[ts.idx].get_handler) {
788 eprintk("kgdbts: ERROR: beyond end of test on"
789 " '%s' line %i\n", ts.name, ts.idx);
790 return 0;
791 }
792
793 if (put_buf_cnt >= BUFMAX) {
794 eprintk("kgdbts: ERROR: put buffer overflow on"
795 " '%s' line %i\n", ts.name, ts.idx);
796 put_buf_cnt = 0;
797 return 0;
798 }
799 /* Ignore everything until the first valid packet start '$' */
800 if (put_buf_cnt == 0 && chr != '$')
801 return 0;
802
803 put_buf[put_buf_cnt] = chr;
804 put_buf_cnt++;
805
806 /* End of packet == #XX so look for the '#' */
807 if (put_buf_cnt > 3 && put_buf[put_buf_cnt - 3] == '#') {
808 if (put_buf_cnt >= BUFMAX) {
809 eprintk("kgdbts: ERROR: put buffer overflow on"
810 " '%s' line %i\n", ts.name, ts.idx);
811 put_buf_cnt = 0;
812 return 0;
813 }
814 put_buf[put_buf_cnt] = '\0';
815 v2printk("put%i: %s\n", ts.idx, put_buf);
816 /* Trigger check here */
817 if (ts.validate_put && ts.validate_put(put_buf)) {
818 eprintk("kgdbts: ERROR PUT: end of test "
819 "buffer on '%s' line %i expected %s got %s\n",
820 ts.name, ts.idx, ts.tst[ts.idx].put, put_buf);
821 }
822 ts.idx++;
823 put_buf_cnt = 0;
824 get_buf_cnt = 0;
825 send_ack = 1;
826 }
827 return 0;
828 }
829
init_simple_test(void)830 static void init_simple_test(void)
831 {
832 memset(&ts, 0, sizeof(ts));
833 ts.run_test = run_simple_test;
834 ts.validate_put = validate_simple_test;
835 }
836
run_plant_and_detach_test(int is_early)837 static void run_plant_and_detach_test(int is_early)
838 {
839 char before[BREAK_INSTR_SIZE];
840 char after[BREAK_INSTR_SIZE];
841
842 copy_from_kernel_nofault(before, (char *)kgdbts_break_test,
843 BREAK_INSTR_SIZE);
844 init_simple_test();
845 ts.tst = plant_and_detach_test;
846 ts.name = "plant_and_detach_test";
847 /* Activate test with initial breakpoint */
848 if (!is_early)
849 kgdb_breakpoint();
850 copy_from_kernel_nofault(after, (char *)kgdbts_break_test,
851 BREAK_INSTR_SIZE);
852 if (memcmp(before, after, BREAK_INSTR_SIZE)) {
853 printk(KERN_CRIT "kgdbts: ERROR kgdb corrupted memory\n");
854 panic("kgdb memory corruption");
855 }
856
857 /* complete the detach test */
858 if (!is_early)
859 kgdbts_break_test();
860 }
861
run_breakpoint_test(int is_hw_breakpoint)862 static void run_breakpoint_test(int is_hw_breakpoint)
863 {
864 test_complete = 0;
865 init_simple_test();
866 if (is_hw_breakpoint) {
867 ts.tst = hw_breakpoint_test;
868 ts.name = "hw_breakpoint_test";
869 } else {
870 ts.tst = sw_breakpoint_test;
871 ts.name = "sw_breakpoint_test";
872 }
873 /* Activate test with initial breakpoint */
874 kgdb_breakpoint();
875 /* run code with the break point in it */
876 kgdbts_break_test();
877 kgdb_breakpoint();
878
879 if (test_complete)
880 return;
881
882 eprintk("kgdbts: ERROR %s test failed\n", ts.name);
883 if (is_hw_breakpoint)
884 hwbreaks_ok = 0;
885 }
886
run_hw_break_test(int is_write_test)887 static void run_hw_break_test(int is_write_test)
888 {
889 test_complete = 0;
890 init_simple_test();
891 if (is_write_test) {
892 ts.tst = hw_write_break_test;
893 ts.name = "hw_write_break_test";
894 } else {
895 ts.tst = hw_access_break_test;
896 ts.name = "hw_access_break_test";
897 }
898 /* Activate test with initial breakpoint */
899 kgdb_breakpoint();
900 hw_break_val_access();
901 if (is_write_test) {
902 if (test_complete == 2) {
903 eprintk("kgdbts: ERROR %s broke on access\n",
904 ts.name);
905 hwbreaks_ok = 0;
906 }
907 hw_break_val_write();
908 }
909 kgdb_breakpoint();
910
911 if (test_complete == 1)
912 return;
913
914 eprintk("kgdbts: ERROR %s test failed\n", ts.name);
915 hwbreaks_ok = 0;
916 }
917
run_nmi_sleep_test(int nmi_sleep)918 static void run_nmi_sleep_test(int nmi_sleep)
919 {
920 unsigned long flags;
921
922 init_simple_test();
923 ts.tst = nmi_sleep_test;
924 ts.name = "nmi_sleep_test";
925 /* Activate test with initial breakpoint */
926 kgdb_breakpoint();
927 local_irq_save(flags);
928 mdelay(nmi_sleep*1000);
929 touch_nmi_watchdog();
930 local_irq_restore(flags);
931 if (test_complete != 2)
932 eprintk("kgdbts: ERROR nmi_test did not hit nmi\n");
933 kgdb_breakpoint();
934 if (test_complete == 1)
935 return;
936
937 eprintk("kgdbts: ERROR %s test failed\n", ts.name);
938 }
939
run_bad_read_test(void)940 static void run_bad_read_test(void)
941 {
942 init_simple_test();
943 ts.tst = bad_read_test;
944 ts.name = "bad_read_test";
945 /* Activate test with initial breakpoint */
946 kgdb_breakpoint();
947 }
948
run_kernel_clone_test(void)949 static void run_kernel_clone_test(void)
950 {
951 init_simple_test();
952 ts.tst = do_kernel_clone_test;
953 ts.name = "do_kernel_clone_test";
954 /* Activate test with initial breakpoint */
955 kgdb_breakpoint();
956 }
957
run_sys_open_test(void)958 static void run_sys_open_test(void)
959 {
960 init_simple_test();
961 ts.tst = sys_open_test;
962 ts.name = "sys_open_test";
963 /* Activate test with initial breakpoint */
964 kgdb_breakpoint();
965 }
966
run_singlestep_break_test(void)967 static void run_singlestep_break_test(void)
968 {
969 init_simple_test();
970 ts.tst = singlestep_break_test;
971 ts.name = "singlestep_breakpoint_test";
972 /* Activate test with initial breakpoint */
973 kgdb_breakpoint();
974 kgdbts_break_test();
975 kgdbts_break_test();
976 }
977
kgdbts_run_tests(void)978 static void kgdbts_run_tests(void)
979 {
980 char *ptr;
981 int clone_test = 0;
982 int do_sys_open_test = 0;
983 int sstep_test = 1000;
984 int nmi_sleep = 0;
985 int i;
986
987 verbose = 0;
988 if (strstr(config, "V1"))
989 verbose = 1;
990 if (strstr(config, "V2"))
991 verbose = 2;
992
993 ptr = strchr(config, 'F');
994 if (ptr)
995 clone_test = simple_strtol(ptr + 1, NULL, 10);
996 ptr = strchr(config, 'S');
997 if (ptr)
998 do_sys_open_test = simple_strtol(ptr + 1, NULL, 10);
999 ptr = strchr(config, 'N');
1000 if (ptr)
1001 nmi_sleep = simple_strtol(ptr+1, NULL, 10);
1002 ptr = strchr(config, 'I');
1003 if (ptr)
1004 sstep_test = simple_strtol(ptr+1, NULL, 10);
1005
1006 /* All HW break point tests */
1007 if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT) {
1008 hwbreaks_ok = 1;
1009 v1printk("kgdbts:RUN hw breakpoint test\n");
1010 run_breakpoint_test(1);
1011 v1printk("kgdbts:RUN hw write breakpoint test\n");
1012 run_hw_break_test(1);
1013 v1printk("kgdbts:RUN access write breakpoint test\n");
1014 run_hw_break_test(0);
1015 }
1016
1017 /* required internal KGDB tests */
1018 v1printk("kgdbts:RUN plant and detach test\n");
1019 run_plant_and_detach_test(0);
1020 v1printk("kgdbts:RUN sw breakpoint test\n");
1021 run_breakpoint_test(0);
1022 v1printk("kgdbts:RUN bad memory access test\n");
1023 run_bad_read_test();
1024 v1printk("kgdbts:RUN singlestep test %i iterations\n", sstep_test);
1025 for (i = 0; i < sstep_test; i++) {
1026 run_singlestep_break_test();
1027 if (i % 100 == 0)
1028 v1printk("kgdbts:RUN singlestep [%i/%i]\n",
1029 i, sstep_test);
1030 }
1031
1032 /* ===Optional tests=== */
1033
1034 if (nmi_sleep) {
1035 v1printk("kgdbts:RUN NMI sleep %i seconds test\n", nmi_sleep);
1036 run_nmi_sleep_test(nmi_sleep);
1037 }
1038
1039 /* If the kernel_clone test is run it will be the last test that is
1040 * executed because a kernel thread will be spawned at the very
1041 * end to unregister the debug hooks.
1042 */
1043 if (clone_test) {
1044 repeat_test = clone_test;
1045 printk(KERN_INFO "kgdbts:RUN kernel_clone for %i breakpoints\n",
1046 repeat_test);
1047 kthread_run(kgdbts_unreg_thread, NULL, "kgdbts_unreg");
1048 run_kernel_clone_test();
1049 return;
1050 }
1051
1052 /* If the sys_open test is run it will be the last test that is
1053 * executed because a kernel thread will be spawned at the very
1054 * end to unregister the debug hooks.
1055 */
1056 if (do_sys_open_test) {
1057 repeat_test = do_sys_open_test;
1058 printk(KERN_INFO "kgdbts:RUN sys_open for %i breakpoints\n",
1059 repeat_test);
1060 kthread_run(kgdbts_unreg_thread, NULL, "kgdbts_unreg");
1061 run_sys_open_test();
1062 return;
1063 }
1064 /* Shutdown and unregister */
1065 kgdb_unregister_io_module(&kgdbts_io_ops);
1066 configured = 0;
1067 }
1068
kgdbts_option_setup(char * opt)1069 static int kgdbts_option_setup(char *opt)
1070 {
1071 if (strlen(opt) >= MAX_CONFIG_LEN) {
1072 printk(KERN_ERR "kgdbts: config string too long\n");
1073 return 1;
1074 }
1075 strcpy(config, opt);
1076 return 1;
1077 }
1078
1079 __setup("kgdbts=", kgdbts_option_setup);
1080
configure_kgdbts(void)1081 static int configure_kgdbts(void)
1082 {
1083 int err = 0;
1084
1085 if (!strlen(config) || isspace(config[0]))
1086 goto noconfig;
1087
1088 final_ack = 0;
1089 run_plant_and_detach_test(1);
1090
1091 err = kgdb_register_io_module(&kgdbts_io_ops);
1092 if (err) {
1093 configured = 0;
1094 return err;
1095 }
1096 configured = 1;
1097 kgdbts_run_tests();
1098
1099 return err;
1100
1101 noconfig:
1102 config[0] = 0;
1103 configured = 0;
1104
1105 return err;
1106 }
1107
init_kgdbts(void)1108 static int __init init_kgdbts(void)
1109 {
1110 /* Already configured? */
1111 if (configured == 1)
1112 return 0;
1113
1114 return configure_kgdbts();
1115 }
1116 device_initcall(init_kgdbts);
1117
kgdbts_get_char(void)1118 static int kgdbts_get_char(void)
1119 {
1120 int val = 0;
1121
1122 if (ts.run_test)
1123 val = ts.run_test(1, 0);
1124
1125 return val;
1126 }
1127
kgdbts_put_char(u8 chr)1128 static void kgdbts_put_char(u8 chr)
1129 {
1130 if (ts.run_test)
1131 ts.run_test(0, chr);
1132 }
1133
param_set_kgdbts_var(const char * kmessage,const struct kernel_param * kp)1134 static int param_set_kgdbts_var(const char *kmessage,
1135 const struct kernel_param *kp)
1136 {
1137 size_t len = strlen(kmessage);
1138
1139 if (len >= MAX_CONFIG_LEN) {
1140 printk(KERN_ERR "kgdbts: config string too long\n");
1141 return -ENOSPC;
1142 }
1143
1144 /* Only copy in the string if the init function has not run yet */
1145 if (configured < 0) {
1146 strcpy(config, kmessage);
1147 return 0;
1148 }
1149
1150 if (configured == 1) {
1151 printk(KERN_ERR "kgdbts: ERROR: Already configured and running.\n");
1152 return -EBUSY;
1153 }
1154
1155 strcpy(config, kmessage);
1156 /* Chop out \n char as a result of echo */
1157 if (len && config[len - 1] == '\n')
1158 config[len - 1] = '\0';
1159
1160 /* Go and configure with the new params. */
1161 return configure_kgdbts();
1162 }
1163
kgdbts_pre_exp_handler(void)1164 static void kgdbts_pre_exp_handler(void)
1165 {
1166 /* Increment the module count when the debugger is active */
1167 if (!kgdb_connected)
1168 try_module_get(THIS_MODULE);
1169 }
1170
kgdbts_post_exp_handler(void)1171 static void kgdbts_post_exp_handler(void)
1172 {
1173 /* decrement the module count when the debugger detaches */
1174 if (!kgdb_connected)
1175 module_put(THIS_MODULE);
1176 }
1177
1178 static struct kgdb_io kgdbts_io_ops = {
1179 .name = "kgdbts",
1180 .read_char = kgdbts_get_char,
1181 .write_char = kgdbts_put_char,
1182 .pre_exception = kgdbts_pre_exp_handler,
1183 .post_exception = kgdbts_post_exp_handler,
1184 };
1185
1186 /*
1187 * not really modular, but the easiest way to keep compat with existing
1188 * bootargs behaviour is to continue using module_param here.
1189 */
1190 module_param_call(kgdbts, param_set_kgdbts_var, param_get_string, &kps, 0644);
1191 MODULE_PARM_DESC(kgdbts, "<A|V1|V2>[F#|S#][N#]");
1192