xref: /linux/drivers/misc/kgdbts.c (revision 492c826b9facefa84995f4dea917e301b5ee0884)
1 /*
2  * kgdbts is a test suite for kgdb for the sole purpose of validating
3  * that key pieces of the kgdb internals are working properly such as
4  * HW/SW breakpoints, single stepping, and NMI.
5  *
6  * Created by: Jason Wessel <jason.wessel@windriver.com>
7  *
8  * Copyright (c) 2008 Wind River Systems, Inc.
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
17  * See the GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22  */
23 /* Information about the kgdb test suite.
24  * -------------------------------------
25  *
26  * The kgdb test suite is designed as a KGDB I/O module which
27  * simulates the communications that a debugger would have with kgdb.
28  * The tests are broken up in to a line by line and referenced here as
29  * a "get" which is kgdb requesting input and "put" which is kgdb
30  * sending a response.
31  *
32  * The kgdb suite can be invoked from the kernel command line
33  * arguments system or executed dynamically at run time.  The test
34  * suite uses the variable "kgdbts" to obtain the information about
35  * which tests to run and to configure the verbosity level.  The
36  * following are the various characters you can use with the kgdbts=
37  * line:
38  *
39  * When using the "kgdbts=" you only choose one of the following core
40  * test types:
41  * A = Run all the core tests silently
42  * V1 = Run all the core tests with minimal output
43  * V2 = Run all the core tests in debug mode
44  *
45  * You can also specify optional tests:
46  * N## = Go to sleep with interrupts of for ## seconds
47  *       to test the HW NMI watchdog
48  * F## = Break at do_fork for ## iterations
49  * S## = Break at sys_open for ## iterations
50  * I## = Run the single step test ## iterations
51  *
52  * NOTE: that the do_fork and sys_open tests are mutually exclusive.
53  *
54  * To invoke the kgdb test suite from boot you use a kernel start
55  * argument as follows:
56  * 	kgdbts=V1 kgdbwait
57  * Or if you wanted to perform the NMI test for 6 seconds and do_fork
58  * test for 100 forks, you could use:
59  * 	kgdbts=V1N6F100 kgdbwait
60  *
61  * The test suite can also be invoked at run time with:
62  *	echo kgdbts=V1N6F100 > /sys/module/kgdbts/parameters/kgdbts
63  * Or as another example:
64  *	echo kgdbts=V2 > /sys/module/kgdbts/parameters/kgdbts
65  *
66  * When developing a new kgdb arch specific implementation or
67  * using these tests for the purpose of regression testing,
68  * several invocations are required.
69  *
70  * 1) Boot with the test suite enabled by using the kernel arguments
71  *       "kgdbts=V1F100 kgdbwait"
72  *    ## If kgdb arch specific implementation has NMI use
73  *       "kgdbts=V1N6F100
74  *
75  * 2) After the system boot run the basic test.
76  * echo kgdbts=V1 > /sys/module/kgdbts/parameters/kgdbts
77  *
78  * 3) Run the concurrency tests.  It is best to use n+1
79  *    while loops where n is the number of cpus you have
80  *    in your system.  The example below uses only two
81  *    loops.
82  *
83  * ## This tests break points on sys_open
84  * while [ 1 ] ; do find / > /dev/null 2>&1 ; done &
85  * while [ 1 ] ; do find / > /dev/null 2>&1 ; done &
86  * echo kgdbts=V1S10000 > /sys/module/kgdbts/parameters/kgdbts
87  * fg # and hit control-c
88  * fg # and hit control-c
89  * ## This tests break points on do_fork
90  * while [ 1 ] ; do date > /dev/null ; done &
91  * while [ 1 ] ; do date > /dev/null ; done &
92  * echo kgdbts=V1F1000 > /sys/module/kgdbts/parameters/kgdbts
93  * fg # and hit control-c
94  *
95  */
96 
97 #include <linux/kernel.h>
98 #include <linux/kgdb.h>
99 #include <linux/ctype.h>
100 #include <linux/uaccess.h>
101 #include <linux/syscalls.h>
102 #include <linux/nmi.h>
103 #include <linux/delay.h>
104 #include <linux/kthread.h>
105 
106 #define v1printk(a...) do { \
107 	if (verbose) \
108 		printk(KERN_INFO a); \
109 	} while (0)
110 #define v2printk(a...) do { \
111 	if (verbose > 1) \
112 		printk(KERN_INFO a); \
113 		touch_nmi_watchdog();	\
114 	} while (0)
115 #define eprintk(a...) do { \
116 		printk(KERN_ERR a); \
117 		WARN_ON(1); \
118 	} while (0)
119 #define MAX_CONFIG_LEN		40
120 
121 static struct kgdb_io kgdbts_io_ops;
122 static char get_buf[BUFMAX];
123 static int get_buf_cnt;
124 static char put_buf[BUFMAX];
125 static int put_buf_cnt;
126 static char scratch_buf[BUFMAX];
127 static int verbose;
128 static int repeat_test;
129 static int test_complete;
130 static int send_ack;
131 static int final_ack;
132 static int force_hwbrks;
133 static int hwbreaks_ok;
134 static int hw_break_val;
135 static int hw_break_val2;
136 #if defined(CONFIG_ARM) || defined(CONFIG_MIPS) || defined(CONFIG_SPARC)
137 static int arch_needs_sstep_emulation = 1;
138 #else
139 static int arch_needs_sstep_emulation;
140 #endif
141 static unsigned long sstep_addr;
142 static int sstep_state;
143 
144 /* Storage for the registers, in GDB format. */
145 static unsigned long kgdbts_gdb_regs[(NUMREGBYTES +
146 					sizeof(unsigned long) - 1) /
147 					sizeof(unsigned long)];
148 static struct pt_regs kgdbts_regs;
149 
150 /* -1 = init not run yet, 0 = unconfigured, 1 = configured. */
151 static int configured		= -1;
152 
153 #ifdef CONFIG_KGDB_TESTS_BOOT_STRING
154 static char config[MAX_CONFIG_LEN] = CONFIG_KGDB_TESTS_BOOT_STRING;
155 #else
156 static char config[MAX_CONFIG_LEN];
157 #endif
158 static struct kparam_string kps = {
159 	.string			= config,
160 	.maxlen			= MAX_CONFIG_LEN,
161 };
162 
163 static void fill_get_buf(char *buf);
164 
165 struct test_struct {
166 	char *get;
167 	char *put;
168 	void (*get_handler)(char *);
169 	int (*put_handler)(char *, char *);
170 };
171 
172 struct test_state {
173 	char *name;
174 	struct test_struct *tst;
175 	int idx;
176 	int (*run_test) (int, int);
177 	int (*validate_put) (char *);
178 };
179 
180 static struct test_state ts;
181 
182 static int kgdbts_unreg_thread(void *ptr)
183 {
184 	/* Wait until the tests are complete and then ungresiter the I/O
185 	 * driver.
186 	 */
187 	while (!final_ack)
188 		msleep_interruptible(1500);
189 
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  */
200 static noinline void kgdbts_break_test(void)
201 {
202 	v2printk("kgdbts: breakpoint complete\n");
203 }
204 
205 /* Lookup symbol info in the kernel */
206 static unsigned long lookup_addr(char *arg)
207 {
208 	unsigned long addr = 0;
209 
210 	if (!strcmp(arg, "kgdbts_break_test"))
211 		addr = (unsigned long)kgdbts_break_test;
212 	else if (!strcmp(arg, "sys_open"))
213 		addr = (unsigned long)sys_open;
214 	else if (!strcmp(arg, "do_fork"))
215 		addr = (unsigned long)do_fork;
216 	else if (!strcmp(arg, "hw_break_val"))
217 		addr = (unsigned long)&hw_break_val;
218 	return addr;
219 }
220 
221 static void break_helper(char *bp_type, char *arg, unsigned long vaddr)
222 {
223 	unsigned long addr;
224 
225 	if (arg)
226 		addr = lookup_addr(arg);
227 	else
228 		addr = vaddr;
229 
230 	sprintf(scratch_buf, "%s,%lx,%i", bp_type, addr,
231 		BREAK_INSTR_SIZE);
232 	fill_get_buf(scratch_buf);
233 }
234 
235 static void sw_break(char *arg)
236 {
237 	break_helper(force_hwbrks ? "Z1" : "Z0", arg, 0);
238 }
239 
240 static void sw_rem_break(char *arg)
241 {
242 	break_helper(force_hwbrks ? "z1" : "z0", arg, 0);
243 }
244 
245 static void hw_break(char *arg)
246 {
247 	break_helper("Z1", arg, 0);
248 }
249 
250 static void hw_rem_break(char *arg)
251 {
252 	break_helper("z1", arg, 0);
253 }
254 
255 static void hw_write_break(char *arg)
256 {
257 	break_helper("Z2", arg, 0);
258 }
259 
260 static void hw_rem_write_break(char *arg)
261 {
262 	break_helper("z2", arg, 0);
263 }
264 
265 static void hw_access_break(char *arg)
266 {
267 	break_helper("Z4", arg, 0);
268 }
269 
270 static void hw_rem_access_break(char *arg)
271 {
272 	break_helper("z4", arg, 0);
273 }
274 
275 static void hw_break_val_access(void)
276 {
277 	hw_break_val2 = hw_break_val;
278 }
279 
280 static void hw_break_val_write(void)
281 {
282 	hw_break_val++;
283 }
284 
285 static int check_and_rewind_pc(char *put_str, char *arg)
286 {
287 	unsigned long addr = lookup_addr(arg);
288 	unsigned long ip;
289 	int offset = 0;
290 
291 	kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs,
292 		 NUMREGBYTES);
293 	gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs);
294 	ip = instruction_pointer(&kgdbts_regs);
295 	v2printk("Stopped at IP: %lx\n", ip);
296 #ifdef GDB_ADJUSTS_BREAK_OFFSET
297 	/* On some arches, a breakpoint stop requires it to be decremented */
298 	if (addr + BREAK_INSTR_SIZE == ip)
299 		offset = -BREAK_INSTR_SIZE;
300 #endif
301 	if (strcmp(arg, "silent") && ip + offset != addr) {
302 		eprintk("kgdbts: BP mismatch %lx expected %lx\n",
303 			   ip + offset, addr);
304 		return 1;
305 	}
306 	/* Readjust the instruction pointer if needed */
307 	instruction_pointer_set(&kgdbts_regs, ip + offset);
308 	return 0;
309 }
310 
311 static int check_single_step(char *put_str, char *arg)
312 {
313 	unsigned long addr = lookup_addr(arg);
314 	/*
315 	 * From an arch indepent point of view the instruction pointer
316 	 * should be on a different instruction
317 	 */
318 	kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs,
319 		 NUMREGBYTES);
320 	gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs);
321 	v2printk("Singlestep stopped at IP: %lx\n",
322 		   instruction_pointer(&kgdbts_regs));
323 	if (instruction_pointer(&kgdbts_regs) == addr) {
324 		eprintk("kgdbts: SingleStep failed at %lx\n",
325 			   instruction_pointer(&kgdbts_regs));
326 		return 1;
327 	}
328 
329 	return 0;
330 }
331 
332 static void write_regs(char *arg)
333 {
334 	memset(scratch_buf, 0, sizeof(scratch_buf));
335 	scratch_buf[0] = 'G';
336 	pt_regs_to_gdb_regs(kgdbts_gdb_regs, &kgdbts_regs);
337 	kgdb_mem2hex((char *)kgdbts_gdb_regs, &scratch_buf[1], NUMREGBYTES);
338 	fill_get_buf(scratch_buf);
339 }
340 
341 static void skip_back_repeat_test(char *arg)
342 {
343 	int go_back = simple_strtol(arg, NULL, 10);
344 
345 	repeat_test--;
346 	if (repeat_test <= 0)
347 		ts.idx++;
348 	else
349 		ts.idx -= go_back;
350 	fill_get_buf(ts.tst[ts.idx].get);
351 }
352 
353 static int got_break(char *put_str, char *arg)
354 {
355 	test_complete = 1;
356 	if (!strncmp(put_str+1, arg, 2)) {
357 		if (!strncmp(arg, "T0", 2))
358 			test_complete = 2;
359 		return 0;
360 	}
361 	return 1;
362 }
363 
364 static void emul_sstep_get(char *arg)
365 {
366 	if (!arch_needs_sstep_emulation) {
367 		fill_get_buf(arg);
368 		return;
369 	}
370 	switch (sstep_state) {
371 	case 0:
372 		v2printk("Emulate single step\n");
373 		/* Start by looking at the current PC */
374 		fill_get_buf("g");
375 		break;
376 	case 1:
377 		/* set breakpoint */
378 		break_helper("Z0", NULL, sstep_addr);
379 		break;
380 	case 2:
381 		/* Continue */
382 		fill_get_buf("c");
383 		break;
384 	case 3:
385 		/* Clear breakpoint */
386 		break_helper("z0", NULL, sstep_addr);
387 		break;
388 	default:
389 		eprintk("kgdbts: ERROR failed sstep get emulation\n");
390 	}
391 	sstep_state++;
392 }
393 
394 static int emul_sstep_put(char *put_str, char *arg)
395 {
396 	if (!arch_needs_sstep_emulation) {
397 		if (!strncmp(put_str+1, arg, 2))
398 			return 0;
399 		return 1;
400 	}
401 	switch (sstep_state) {
402 	case 1:
403 		/* validate the "g" packet to get the IP */
404 		kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs,
405 			 NUMREGBYTES);
406 		gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs);
407 		v2printk("Stopped at IP: %lx\n",
408 			 instruction_pointer(&kgdbts_regs));
409 		/* Want to stop at IP + break instruction size by default */
410 		sstep_addr = instruction_pointer(&kgdbts_regs) +
411 			BREAK_INSTR_SIZE;
412 		break;
413 	case 2:
414 		if (strncmp(put_str, "$OK", 3)) {
415 			eprintk("kgdbts: failed sstep break set\n");
416 			return 1;
417 		}
418 		break;
419 	case 3:
420 		if (strncmp(put_str, "$T0", 3)) {
421 			eprintk("kgdbts: failed continue sstep\n");
422 			return 1;
423 		}
424 		break;
425 	case 4:
426 		if (strncmp(put_str, "$OK", 3)) {
427 			eprintk("kgdbts: failed sstep break unset\n");
428 			return 1;
429 		}
430 		/* Single step is complete so continue on! */
431 		sstep_state = 0;
432 		return 0;
433 	default:
434 		eprintk("kgdbts: ERROR failed sstep put emulation\n");
435 	}
436 
437 	/* Continue on the same test line until emulation is complete */
438 	ts.idx--;
439 	return 0;
440 }
441 
442 static int final_ack_set(char *put_str, char *arg)
443 {
444 	if (strncmp(put_str+1, arg, 2))
445 		return 1;
446 	final_ack = 1;
447 	return 0;
448 }
449 /*
450  * Test to plant a breakpoint and detach, which should clear out the
451  * breakpoint and restore the original instruction.
452  */
453 static struct test_struct plant_and_detach_test[] = {
454 	{ "?", "S0*" }, /* Clear break points */
455 	{ "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
456 	{ "D", "OK" }, /* Detach */
457 	{ "", "" },
458 };
459 
460 /*
461  * Simple test to write in a software breakpoint, check for the
462  * correct stop location and detach.
463  */
464 static struct test_struct sw_breakpoint_test[] = {
465 	{ "?", "S0*" }, /* Clear break points */
466 	{ "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
467 	{ "c", "T0*", }, /* Continue */
468 	{ "g", "kgdbts_break_test", NULL, check_and_rewind_pc },
469 	{ "write", "OK", write_regs },
470 	{ "kgdbts_break_test", "OK", sw_rem_break }, /*remove breakpoint */
471 	{ "D", "OK" }, /* Detach */
472 	{ "D", "OK", NULL,  got_break }, /* On success we made it here */
473 	{ "", "" },
474 };
475 
476 /*
477  * Test a known bad memory read location to test the fault handler and
478  * read bytes 1-8 at the bad address
479  */
480 static struct test_struct bad_read_test[] = {
481 	{ "?", "S0*" }, /* Clear break points */
482 	{ "m0,1", "E*" }, /* read 1 byte at address 1 */
483 	{ "m0,2", "E*" }, /* read 1 byte at address 2 */
484 	{ "m0,3", "E*" }, /* read 1 byte at address 3 */
485 	{ "m0,4", "E*" }, /* read 1 byte at address 4 */
486 	{ "m0,5", "E*" }, /* read 1 byte at address 5 */
487 	{ "m0,6", "E*" }, /* read 1 byte at address 6 */
488 	{ "m0,7", "E*" }, /* read 1 byte at address 7 */
489 	{ "m0,8", "E*" }, /* read 1 byte at address 8 */
490 	{ "D", "OK" }, /* Detach which removes all breakpoints and continues */
491 	{ "", "" },
492 };
493 
494 /*
495  * Test for hitting a breakpoint, remove it, single step, plant it
496  * again and detach.
497  */
498 static struct test_struct singlestep_break_test[] = {
499 	{ "?", "S0*" }, /* Clear break points */
500 	{ "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
501 	{ "c", "T0*", }, /* Continue */
502 	{ "g", "kgdbts_break_test", NULL, check_and_rewind_pc },
503 	{ "write", "OK", write_regs }, /* Write registers */
504 	{ "kgdbts_break_test", "OK", sw_rem_break }, /*remove breakpoint */
505 	{ "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
506 	{ "g", "kgdbts_break_test", NULL, check_single_step },
507 	{ "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
508 	{ "c", "T0*", }, /* Continue */
509 	{ "g", "kgdbts_break_test", NULL, check_and_rewind_pc },
510 	{ "write", "OK", write_regs }, /* Write registers */
511 	{ "D", "OK" }, /* Remove all breakpoints and continues */
512 	{ "", "" },
513 };
514 
515 /*
516  * Test for hitting a breakpoint at do_fork for what ever the number
517  * of iterations required by the variable repeat_test.
518  */
519 static struct test_struct do_fork_test[] = {
520 	{ "?", "S0*" }, /* Clear break points */
521 	{ "do_fork", "OK", sw_break, }, /* set sw breakpoint */
522 	{ "c", "T0*", }, /* Continue */
523 	{ "g", "do_fork", NULL, check_and_rewind_pc }, /* check location */
524 	{ "write", "OK", write_regs }, /* Write registers */
525 	{ "do_fork", "OK", sw_rem_break }, /*remove breakpoint */
526 	{ "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
527 	{ "g", "do_fork", NULL, check_single_step },
528 	{ "do_fork", "OK", sw_break, }, /* set sw breakpoint */
529 	{ "7", "T0*", skip_back_repeat_test }, /* Loop based on repeat_test */
530 	{ "D", "OK", NULL, final_ack_set }, /* detach and unregister I/O */
531 	{ "", "" },
532 };
533 
534 /* Test for hitting a breakpoint at sys_open for what ever the number
535  * of iterations required by the variable repeat_test.
536  */
537 static struct test_struct sys_open_test[] = {
538 	{ "?", "S0*" }, /* Clear break points */
539 	{ "sys_open", "OK", sw_break, }, /* set sw breakpoint */
540 	{ "c", "T0*", }, /* Continue */
541 	{ "g", "sys_open", NULL, check_and_rewind_pc }, /* check location */
542 	{ "write", "OK", write_regs }, /* Write registers */
543 	{ "sys_open", "OK", sw_rem_break }, /*remove breakpoint */
544 	{ "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
545 	{ "g", "sys_open", NULL, check_single_step },
546 	{ "sys_open", "OK", sw_break, }, /* set sw breakpoint */
547 	{ "7", "T0*", skip_back_repeat_test }, /* Loop based on repeat_test */
548 	{ "D", "OK", NULL, final_ack_set }, /* detach and unregister I/O */
549 	{ "", "" },
550 };
551 
552 /*
553  * Test for hitting a simple hw breakpoint
554  */
555 static struct test_struct hw_breakpoint_test[] = {
556 	{ "?", "S0*" }, /* Clear break points */
557 	{ "kgdbts_break_test", "OK", hw_break, }, /* set hw breakpoint */
558 	{ "c", "T0*", }, /* Continue */
559 	{ "g", "kgdbts_break_test", NULL, check_and_rewind_pc },
560 	{ "write", "OK", write_regs },
561 	{ "kgdbts_break_test", "OK", hw_rem_break }, /*remove breakpoint */
562 	{ "D", "OK" }, /* Detach */
563 	{ "D", "OK", NULL,  got_break }, /* On success we made it here */
564 	{ "", "" },
565 };
566 
567 /*
568  * Test for hitting a hw write breakpoint
569  */
570 static struct test_struct hw_write_break_test[] = {
571 	{ "?", "S0*" }, /* Clear break points */
572 	{ "hw_break_val", "OK", hw_write_break, }, /* set hw breakpoint */
573 	{ "c", "T0*", NULL, got_break }, /* Continue */
574 	{ "g", "silent", NULL, check_and_rewind_pc },
575 	{ "write", "OK", write_regs },
576 	{ "hw_break_val", "OK", hw_rem_write_break }, /*remove breakpoint */
577 	{ "D", "OK" }, /* Detach */
578 	{ "D", "OK", NULL,  got_break }, /* On success we made it here */
579 	{ "", "" },
580 };
581 
582 /*
583  * Test for hitting a hw access breakpoint
584  */
585 static struct test_struct hw_access_break_test[] = {
586 	{ "?", "S0*" }, /* Clear break points */
587 	{ "hw_break_val", "OK", hw_access_break, }, /* set hw breakpoint */
588 	{ "c", "T0*", NULL, got_break }, /* Continue */
589 	{ "g", "silent", NULL, check_and_rewind_pc },
590 	{ "write", "OK", write_regs },
591 	{ "hw_break_val", "OK", hw_rem_access_break }, /*remove breakpoint */
592 	{ "D", "OK" }, /* Detach */
593 	{ "D", "OK", NULL,  got_break }, /* On success we made it here */
594 	{ "", "" },
595 };
596 
597 /*
598  * Test for hitting a hw access breakpoint
599  */
600 static struct test_struct nmi_sleep_test[] = {
601 	{ "?", "S0*" }, /* Clear break points */
602 	{ "c", "T0*", NULL, got_break }, /* Continue */
603 	{ "D", "OK" }, /* Detach */
604 	{ "D", "OK", NULL,  got_break }, /* On success we made it here */
605 	{ "", "" },
606 };
607 
608 static void fill_get_buf(char *buf)
609 {
610 	unsigned char checksum = 0;
611 	int count = 0;
612 	char ch;
613 
614 	strcpy(get_buf, "$");
615 	strcat(get_buf, buf);
616 	while ((ch = buf[count])) {
617 		checksum += ch;
618 		count++;
619 	}
620 	strcat(get_buf, "#");
621 	get_buf[count + 2] = hex_asc_hi(checksum);
622 	get_buf[count + 3] = hex_asc_lo(checksum);
623 	get_buf[count + 4] = '\0';
624 	v2printk("get%i: %s\n", ts.idx, get_buf);
625 }
626 
627 static int validate_simple_test(char *put_str)
628 {
629 	char *chk_str;
630 
631 	if (ts.tst[ts.idx].put_handler)
632 		return ts.tst[ts.idx].put_handler(put_str,
633 			ts.tst[ts.idx].put);
634 
635 	chk_str = ts.tst[ts.idx].put;
636 	if (*put_str == '$')
637 		put_str++;
638 
639 	while (*chk_str != '\0' && *put_str != '\0') {
640 		/* If someone does a * to match the rest of the string, allow
641 		 * it, or stop if the received string is complete.
642 		 */
643 		if (*put_str == '#' || *chk_str == '*')
644 			return 0;
645 		if (*put_str != *chk_str)
646 			return 1;
647 
648 		chk_str++;
649 		put_str++;
650 	}
651 	if (*chk_str == '\0' && (*put_str == '\0' || *put_str == '#'))
652 		return 0;
653 
654 	return 1;
655 }
656 
657 static int run_simple_test(int is_get_char, int chr)
658 {
659 	int ret = 0;
660 	if (is_get_char) {
661 		/* Send an ACK on the get if a prior put completed and set the
662 		 * send ack variable
663 		 */
664 		if (send_ack) {
665 			send_ack = 0;
666 			return '+';
667 		}
668 		/* On the first get char, fill the transmit buffer and then
669 		 * take from the get_string.
670 		 */
671 		if (get_buf_cnt == 0) {
672 			if (ts.tst[ts.idx].get_handler)
673 				ts.tst[ts.idx].get_handler(ts.tst[ts.idx].get);
674 			else
675 				fill_get_buf(ts.tst[ts.idx].get);
676 		}
677 
678 		if (get_buf[get_buf_cnt] == '\0') {
679 			eprintk("kgdbts: ERROR GET: EOB on '%s' at %i\n",
680 			   ts.name, ts.idx);
681 			get_buf_cnt = 0;
682 			fill_get_buf("D");
683 		}
684 		ret = get_buf[get_buf_cnt];
685 		get_buf_cnt++;
686 		return ret;
687 	}
688 
689 	/* This callback is a put char which is when kgdb sends data to
690 	 * this I/O module.
691 	 */
692 	if (ts.tst[ts.idx].get[0] == '\0' &&
693 		ts.tst[ts.idx].put[0] == '\0') {
694 		eprintk("kgdbts: ERROR: beyond end of test on"
695 			   " '%s' line %i\n", ts.name, ts.idx);
696 		return 0;
697 	}
698 
699 	if (put_buf_cnt >= BUFMAX) {
700 		eprintk("kgdbts: ERROR: put buffer overflow on"
701 			   " '%s' line %i\n", ts.name, ts.idx);
702 		put_buf_cnt = 0;
703 		return 0;
704 	}
705 	/* Ignore everything until the first valid packet start '$' */
706 	if (put_buf_cnt == 0 && chr != '$')
707 		return 0;
708 
709 	put_buf[put_buf_cnt] = chr;
710 	put_buf_cnt++;
711 
712 	/* End of packet == #XX so look for the '#' */
713 	if (put_buf_cnt > 3 && put_buf[put_buf_cnt - 3] == '#') {
714 		if (put_buf_cnt >= BUFMAX) {
715 			eprintk("kgdbts: ERROR: put buffer overflow on"
716 				" '%s' line %i\n", ts.name, ts.idx);
717 			put_buf_cnt = 0;
718 			return 0;
719 		}
720 		put_buf[put_buf_cnt] = '\0';
721 		v2printk("put%i: %s\n", ts.idx, put_buf);
722 		/* Trigger check here */
723 		if (ts.validate_put && ts.validate_put(put_buf)) {
724 			eprintk("kgdbts: ERROR PUT: end of test "
725 			   "buffer on '%s' line %i expected %s got %s\n",
726 			   ts.name, ts.idx, ts.tst[ts.idx].put, put_buf);
727 		}
728 		ts.idx++;
729 		put_buf_cnt = 0;
730 		get_buf_cnt = 0;
731 		send_ack = 1;
732 	}
733 	return 0;
734 }
735 
736 static void init_simple_test(void)
737 {
738 	memset(&ts, 0, sizeof(ts));
739 	ts.run_test = run_simple_test;
740 	ts.validate_put = validate_simple_test;
741 }
742 
743 static void run_plant_and_detach_test(int is_early)
744 {
745 	char before[BREAK_INSTR_SIZE];
746 	char after[BREAK_INSTR_SIZE];
747 
748 	probe_kernel_read(before, (char *)kgdbts_break_test,
749 	  BREAK_INSTR_SIZE);
750 	init_simple_test();
751 	ts.tst = plant_and_detach_test;
752 	ts.name = "plant_and_detach_test";
753 	/* Activate test with initial breakpoint */
754 	if (!is_early)
755 		kgdb_breakpoint();
756 	probe_kernel_read(after, (char *)kgdbts_break_test,
757 	  BREAK_INSTR_SIZE);
758 	if (memcmp(before, after, BREAK_INSTR_SIZE)) {
759 		printk(KERN_CRIT "kgdbts: ERROR kgdb corrupted memory\n");
760 		panic("kgdb memory corruption");
761 	}
762 
763 	/* complete the detach test */
764 	if (!is_early)
765 		kgdbts_break_test();
766 }
767 
768 static void run_breakpoint_test(int is_hw_breakpoint)
769 {
770 	test_complete = 0;
771 	init_simple_test();
772 	if (is_hw_breakpoint) {
773 		ts.tst = hw_breakpoint_test;
774 		ts.name = "hw_breakpoint_test";
775 	} else {
776 		ts.tst = sw_breakpoint_test;
777 		ts.name = "sw_breakpoint_test";
778 	}
779 	/* Activate test with initial breakpoint */
780 	kgdb_breakpoint();
781 	/* run code with the break point in it */
782 	kgdbts_break_test();
783 	kgdb_breakpoint();
784 
785 	if (test_complete)
786 		return;
787 
788 	eprintk("kgdbts: ERROR %s test failed\n", ts.name);
789 	if (is_hw_breakpoint)
790 		hwbreaks_ok = 0;
791 }
792 
793 static void run_hw_break_test(int is_write_test)
794 {
795 	test_complete = 0;
796 	init_simple_test();
797 	if (is_write_test) {
798 		ts.tst = hw_write_break_test;
799 		ts.name = "hw_write_break_test";
800 	} else {
801 		ts.tst = hw_access_break_test;
802 		ts.name = "hw_access_break_test";
803 	}
804 	/* Activate test with initial breakpoint */
805 	kgdb_breakpoint();
806 	hw_break_val_access();
807 	if (is_write_test) {
808 		if (test_complete == 2) {
809 			eprintk("kgdbts: ERROR %s broke on access\n",
810 				ts.name);
811 			hwbreaks_ok = 0;
812 		}
813 		hw_break_val_write();
814 	}
815 	kgdb_breakpoint();
816 
817 	if (test_complete == 1)
818 		return;
819 
820 	eprintk("kgdbts: ERROR %s test failed\n", ts.name);
821 	hwbreaks_ok = 0;
822 }
823 
824 static void run_nmi_sleep_test(int nmi_sleep)
825 {
826 	unsigned long flags;
827 
828 	init_simple_test();
829 	ts.tst = nmi_sleep_test;
830 	ts.name = "nmi_sleep_test";
831 	/* Activate test with initial breakpoint */
832 	kgdb_breakpoint();
833 	local_irq_save(flags);
834 	mdelay(nmi_sleep*1000);
835 	touch_nmi_watchdog();
836 	local_irq_restore(flags);
837 	if (test_complete != 2)
838 		eprintk("kgdbts: ERROR nmi_test did not hit nmi\n");
839 	kgdb_breakpoint();
840 	if (test_complete == 1)
841 		return;
842 
843 	eprintk("kgdbts: ERROR %s test failed\n", ts.name);
844 }
845 
846 static void run_bad_read_test(void)
847 {
848 	init_simple_test();
849 	ts.tst = bad_read_test;
850 	ts.name = "bad_read_test";
851 	/* Activate test with initial breakpoint */
852 	kgdb_breakpoint();
853 }
854 
855 static void run_do_fork_test(void)
856 {
857 	init_simple_test();
858 	ts.tst = do_fork_test;
859 	ts.name = "do_fork_test";
860 	/* Activate test with initial breakpoint */
861 	kgdb_breakpoint();
862 }
863 
864 static void run_sys_open_test(void)
865 {
866 	init_simple_test();
867 	ts.tst = sys_open_test;
868 	ts.name = "sys_open_test";
869 	/* Activate test with initial breakpoint */
870 	kgdb_breakpoint();
871 }
872 
873 static void run_singlestep_break_test(void)
874 {
875 	init_simple_test();
876 	ts.tst = singlestep_break_test;
877 	ts.name = "singlestep_breakpoint_test";
878 	/* Activate test with initial breakpoint */
879 	kgdb_breakpoint();
880 	kgdbts_break_test();
881 	kgdbts_break_test();
882 }
883 
884 static void kgdbts_run_tests(void)
885 {
886 	char *ptr;
887 	int fork_test = 0;
888 	int do_sys_open_test = 0;
889 	int sstep_test = 1000;
890 	int nmi_sleep = 0;
891 	int i;
892 
893 	ptr = strchr(config, 'F');
894 	if (ptr)
895 		fork_test = simple_strtol(ptr + 1, NULL, 10);
896 	ptr = strchr(config, 'S');
897 	if (ptr)
898 		do_sys_open_test = simple_strtol(ptr + 1, NULL, 10);
899 	ptr = strchr(config, 'N');
900 	if (ptr)
901 		nmi_sleep = simple_strtol(ptr+1, NULL, 10);
902 	ptr = strchr(config, 'I');
903 	if (ptr)
904 		sstep_test = simple_strtol(ptr+1, NULL, 10);
905 
906 	/* required internal KGDB tests */
907 	v1printk("kgdbts:RUN plant and detach test\n");
908 	run_plant_and_detach_test(0);
909 	v1printk("kgdbts:RUN sw breakpoint test\n");
910 	run_breakpoint_test(0);
911 	v1printk("kgdbts:RUN bad memory access test\n");
912 	run_bad_read_test();
913 	v1printk("kgdbts:RUN singlestep test %i iterations\n", sstep_test);
914 	for (i = 0; i < sstep_test; i++) {
915 		run_singlestep_break_test();
916 		if (i % 100 == 0)
917 			v1printk("kgdbts:RUN singlestep [%i/%i]\n",
918 				 i, sstep_test);
919 	}
920 
921 	/* ===Optional tests=== */
922 
923 	/* All HW break point tests */
924 	if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT) {
925 		hwbreaks_ok = 1;
926 		v1printk("kgdbts:RUN hw breakpoint test\n");
927 		run_breakpoint_test(1);
928 		v1printk("kgdbts:RUN hw write breakpoint test\n");
929 		run_hw_break_test(1);
930 		v1printk("kgdbts:RUN access write breakpoint test\n");
931 		run_hw_break_test(0);
932 	}
933 
934 	if (nmi_sleep) {
935 		v1printk("kgdbts:RUN NMI sleep %i seconds test\n", nmi_sleep);
936 		run_nmi_sleep_test(nmi_sleep);
937 	}
938 
939 #ifdef CONFIG_DEBUG_RODATA
940 	/* Until there is an api to write to read-only text segments, use
941 	 * HW breakpoints for the remainder of any tests, else print a
942 	 * failure message if hw breakpoints do not work.
943 	 */
944 	if (!(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT && hwbreaks_ok)) {
945 		eprintk("kgdbts: HW breakpoints do not work,"
946 			"skipping remaining tests\n");
947 		return;
948 	}
949 	force_hwbrks = 1;
950 #endif /* CONFIG_DEBUG_RODATA */
951 
952 	/* If the do_fork test is run it will be the last test that is
953 	 * executed because a kernel thread will be spawned at the very
954 	 * end to unregister the debug hooks.
955 	 */
956 	if (fork_test) {
957 		repeat_test = fork_test;
958 		printk(KERN_INFO "kgdbts:RUN do_fork for %i breakpoints\n",
959 			repeat_test);
960 		kthread_run(kgdbts_unreg_thread, NULL, "kgdbts_unreg");
961 		run_do_fork_test();
962 		return;
963 	}
964 
965 	/* If the sys_open test is run it will be the last test that is
966 	 * executed because a kernel thread will be spawned at the very
967 	 * end to unregister the debug hooks.
968 	 */
969 	if (do_sys_open_test) {
970 		repeat_test = do_sys_open_test;
971 		printk(KERN_INFO "kgdbts:RUN sys_open for %i breakpoints\n",
972 			repeat_test);
973 		kthread_run(kgdbts_unreg_thread, NULL, "kgdbts_unreg");
974 		run_sys_open_test();
975 		return;
976 	}
977 	/* Shutdown and unregister */
978 	kgdb_unregister_io_module(&kgdbts_io_ops);
979 	configured = 0;
980 }
981 
982 static int kgdbts_option_setup(char *opt)
983 {
984 	if (strlen(opt) >= MAX_CONFIG_LEN) {
985 		printk(KERN_ERR "kgdbts: config string too long\n");
986 		return -ENOSPC;
987 	}
988 	strcpy(config, opt);
989 
990 	verbose = 0;
991 	if (strstr(config, "V1"))
992 		verbose = 1;
993 	if (strstr(config, "V2"))
994 		verbose = 2;
995 
996 	return 0;
997 }
998 
999 __setup("kgdbts=", kgdbts_option_setup);
1000 
1001 static int configure_kgdbts(void)
1002 {
1003 	int err = 0;
1004 
1005 	if (!strlen(config) || isspace(config[0]))
1006 		goto noconfig;
1007 	err = kgdbts_option_setup(config);
1008 	if (err)
1009 		goto noconfig;
1010 
1011 	final_ack = 0;
1012 	run_plant_and_detach_test(1);
1013 
1014 	err = kgdb_register_io_module(&kgdbts_io_ops);
1015 	if (err) {
1016 		configured = 0;
1017 		return err;
1018 	}
1019 	configured = 1;
1020 	kgdbts_run_tests();
1021 
1022 	return err;
1023 
1024 noconfig:
1025 	config[0] = 0;
1026 	configured = 0;
1027 
1028 	return err;
1029 }
1030 
1031 static int __init init_kgdbts(void)
1032 {
1033 	/* Already configured? */
1034 	if (configured == 1)
1035 		return 0;
1036 
1037 	return configure_kgdbts();
1038 }
1039 
1040 static int kgdbts_get_char(void)
1041 {
1042 	int val = 0;
1043 
1044 	if (ts.run_test)
1045 		val = ts.run_test(1, 0);
1046 
1047 	return val;
1048 }
1049 
1050 static void kgdbts_put_char(u8 chr)
1051 {
1052 	if (ts.run_test)
1053 		ts.run_test(0, chr);
1054 }
1055 
1056 static int param_set_kgdbts_var(const char *kmessage, struct kernel_param *kp)
1057 {
1058 	int len = strlen(kmessage);
1059 
1060 	if (len >= MAX_CONFIG_LEN) {
1061 		printk(KERN_ERR "kgdbts: config string too long\n");
1062 		return -ENOSPC;
1063 	}
1064 
1065 	/* Only copy in the string if the init function has not run yet */
1066 	if (configured < 0) {
1067 		strcpy(config, kmessage);
1068 		return 0;
1069 	}
1070 
1071 	if (configured == 1) {
1072 		printk(KERN_ERR "kgdbts: ERROR: Already configured and running.\n");
1073 		return -EBUSY;
1074 	}
1075 
1076 	strcpy(config, kmessage);
1077 	/* Chop out \n char as a result of echo */
1078 	if (config[len - 1] == '\n')
1079 		config[len - 1] = '\0';
1080 
1081 	/* Go and configure with the new params. */
1082 	return configure_kgdbts();
1083 }
1084 
1085 static void kgdbts_pre_exp_handler(void)
1086 {
1087 	/* Increment the module count when the debugger is active */
1088 	if (!kgdb_connected)
1089 		try_module_get(THIS_MODULE);
1090 }
1091 
1092 static void kgdbts_post_exp_handler(void)
1093 {
1094 	/* decrement the module count when the debugger detaches */
1095 	if (!kgdb_connected)
1096 		module_put(THIS_MODULE);
1097 }
1098 
1099 static struct kgdb_io kgdbts_io_ops = {
1100 	.name			= "kgdbts",
1101 	.read_char		= kgdbts_get_char,
1102 	.write_char		= kgdbts_put_char,
1103 	.pre_exception		= kgdbts_pre_exp_handler,
1104 	.post_exception		= kgdbts_post_exp_handler,
1105 };
1106 
1107 module_init(init_kgdbts);
1108 module_param_call(kgdbts, param_set_kgdbts_var, param_get_string, &kps, 0644);
1109 MODULE_PARM_DESC(kgdbts, "<A|V1|V2>[F#|S#][N#]");
1110 MODULE_DESCRIPTION("KGDB Test Suite");
1111 MODULE_LICENSE("GPL");
1112 MODULE_AUTHOR("Wind River Systems, Inc.");
1113 
1114