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