drivers/misc/kgdbts.c

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

DEFINITIONS
