1cfeb7489SZachary Loafman /*- 2cfeb7489SZachary Loafman * Copyright (c) 2009 Isilon Inc http://www.isilon.com/ 3cfeb7489SZachary Loafman * 4cfeb7489SZachary Loafman * Redistribution and use in source and binary forms, with or without 5cfeb7489SZachary Loafman * modification, are permitted provided that the following conditions 6cfeb7489SZachary Loafman * are met: 7cfeb7489SZachary Loafman * 1. Redistributions of source code must retain the above copyright 8cfeb7489SZachary Loafman * notice, this list of conditions and the following disclaimer. 9cfeb7489SZachary Loafman * 2. Redistributions in binary form must reproduce the above copyright 10cfeb7489SZachary Loafman * notice, this list of conditions and the following disclaimer in the 11cfeb7489SZachary Loafman * documentation and/or other materials provided with the distribution. 12cfeb7489SZachary Loafman * 13cfeb7489SZachary Loafman * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14cfeb7489SZachary Loafman * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15cfeb7489SZachary Loafman * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16cfeb7489SZachary Loafman * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17cfeb7489SZachary Loafman * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18cfeb7489SZachary Loafman * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19cfeb7489SZachary Loafman * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20cfeb7489SZachary Loafman * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21cfeb7489SZachary Loafman * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22cfeb7489SZachary Loafman * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23cfeb7489SZachary Loafman * SUCH DAMAGE. 24cfeb7489SZachary Loafman */ 25cfeb7489SZachary Loafman /** 26cfeb7489SZachary Loafman * @file 27cfeb7489SZachary Loafman * 28cfeb7489SZachary Loafman * fail(9) Facility. 29cfeb7489SZachary Loafman * 30cfeb7489SZachary Loafman * @ingroup failpoint_private 31cfeb7489SZachary Loafman */ 32cfeb7489SZachary Loafman /** 33cfeb7489SZachary Loafman * @defgroup failpoint fail(9) Facility 34cfeb7489SZachary Loafman * 35cfeb7489SZachary Loafman * Failpoints allow for injecting fake errors into running code on the fly, 36cfeb7489SZachary Loafman * without modifying code or recompiling with flags. Failpoints are always 37cfeb7489SZachary Loafman * present, and are very efficient when disabled. Failpoints are described 38cfeb7489SZachary Loafman * in man fail(9). 39cfeb7489SZachary Loafman */ 40cfeb7489SZachary Loafman /** 41cfeb7489SZachary Loafman * @defgroup failpoint_private Private fail(9) Implementation functions 42cfeb7489SZachary Loafman * 43cfeb7489SZachary Loafman * Private implementations for the actual failpoint code. 44cfeb7489SZachary Loafman * 45cfeb7489SZachary Loafman * @ingroup failpoint 46cfeb7489SZachary Loafman */ 47cfeb7489SZachary Loafman /** 48cfeb7489SZachary Loafman * @addtogroup failpoint_private 49cfeb7489SZachary Loafman * @{ 50cfeb7489SZachary Loafman */ 51cfeb7489SZachary Loafman 52cfeb7489SZachary Loafman #include <sys/cdefs.h> 53cfeb7489SZachary Loafman __FBSDID("$FreeBSD$"); 54cfeb7489SZachary Loafman 550894a9bcSMatthew D Fleming #include <sys/ctype.h> 56cfeb7489SZachary Loafman #include <sys/errno.h> 57cfeb7489SZachary Loafman #include <sys/fail.h> 58cfeb7489SZachary Loafman #include <sys/kernel.h> 59cfeb7489SZachary Loafman #include <sys/libkern.h> 60cfeb7489SZachary Loafman #include <sys/lock.h> 61cfeb7489SZachary Loafman #include <sys/malloc.h> 62cfeb7489SZachary Loafman #include <sys/mutex.h> 63*b5bd50aeSMatthew D Fleming #include <sys/proc.h> 64cfeb7489SZachary Loafman #include <sys/sbuf.h> 65cfeb7489SZachary Loafman 66cfeb7489SZachary Loafman #include <machine/stdarg.h> 67cfeb7489SZachary Loafman 68cfeb7489SZachary Loafman #ifdef ILOG_DEFINE_FOR_FILE 69cfeb7489SZachary Loafman ILOG_DEFINE_FOR_FILE(L_ISI_FAIL_POINT, L_ILOG, fail_point); 70cfeb7489SZachary Loafman #endif 71cfeb7489SZachary Loafman 72cfeb7489SZachary Loafman MALLOC_DEFINE(M_FAIL_POINT, "Fail Points", "fail points system"); 73cfeb7489SZachary Loafman #define fp_free(ptr) free(ptr, M_FAIL_POINT) 74cfeb7489SZachary Loafman #define fp_malloc(size, flags) malloc((size), M_FAIL_POINT, (flags)) 75cfeb7489SZachary Loafman 76cfeb7489SZachary Loafman static struct mtx g_fp_mtx; 77cfeb7489SZachary Loafman MTX_SYSINIT(g_fp_mtx, &g_fp_mtx, "fail point mtx", MTX_DEF); 78cfeb7489SZachary Loafman #define FP_LOCK() mtx_lock(&g_fp_mtx) 79cfeb7489SZachary Loafman #define FP_UNLOCK() mtx_unlock(&g_fp_mtx) 80cfeb7489SZachary Loafman 81d26b7945SMatthew D Fleming /** 82d26b7945SMatthew D Fleming * Failpoint types. 83d26b7945SMatthew D Fleming * Don't change these without changing fail_type_strings in fail.c. 84d26b7945SMatthew D Fleming * @ingroup failpoint_private 85d26b7945SMatthew D Fleming */ 86d26b7945SMatthew D Fleming enum fail_point_t { 87d26b7945SMatthew D Fleming FAIL_POINT_OFF, /**< don't fail */ 88d26b7945SMatthew D Fleming FAIL_POINT_PANIC, /**< panic */ 89d26b7945SMatthew D Fleming FAIL_POINT_RETURN, /**< return an errorcode */ 90d26b7945SMatthew D Fleming FAIL_POINT_BREAK, /**< break into the debugger */ 91d26b7945SMatthew D Fleming FAIL_POINT_PRINT, /**< print a message */ 92d26b7945SMatthew D Fleming FAIL_POINT_SLEEP, /**< sleep for some msecs */ 930894a9bcSMatthew D Fleming FAIL_POINT_NUMTYPES 94d26b7945SMatthew D Fleming }; 95d26b7945SMatthew D Fleming 960894a9bcSMatthew D Fleming static struct { 970894a9bcSMatthew D Fleming const char *name; 980894a9bcSMatthew D Fleming int nmlen; 990894a9bcSMatthew D Fleming } fail_type_strings[] = { 1000894a9bcSMatthew D Fleming #define FP_TYPE_NM_LEN(s) { s, sizeof(s) - 1 } 1010894a9bcSMatthew D Fleming [FAIL_POINT_OFF] = FP_TYPE_NM_LEN("off"), 1020894a9bcSMatthew D Fleming [FAIL_POINT_PANIC] = FP_TYPE_NM_LEN("panic"), 1030894a9bcSMatthew D Fleming [FAIL_POINT_RETURN] = FP_TYPE_NM_LEN("return"), 1040894a9bcSMatthew D Fleming [FAIL_POINT_BREAK] = FP_TYPE_NM_LEN("break"), 1050894a9bcSMatthew D Fleming [FAIL_POINT_PRINT] = FP_TYPE_NM_LEN("print"), 1060894a9bcSMatthew D Fleming [FAIL_POINT_SLEEP] = FP_TYPE_NM_LEN("sleep"), 107d26b7945SMatthew D Fleming }; 108d26b7945SMatthew D Fleming 109d26b7945SMatthew D Fleming /** 110d26b7945SMatthew D Fleming * Internal structure tracking a single term of a complete failpoint. 111d26b7945SMatthew D Fleming * @ingroup failpoint_private 112d26b7945SMatthew D Fleming */ 113d26b7945SMatthew D Fleming struct fail_point_entry { 114d26b7945SMatthew D Fleming enum fail_point_t fe_type; /**< type of entry */ 115d26b7945SMatthew D Fleming int fe_arg; /**< argument to type (e.g. return value) */ 116d26b7945SMatthew D Fleming int fe_prob; /**< likelihood of firing in millionths */ 117d26b7945SMatthew D Fleming int fe_count; /**< number of times to fire, 0 means always */ 118*b5bd50aeSMatthew D Fleming pid_t fe_pid; /**< only fail for this process */ 119d26b7945SMatthew D Fleming TAILQ_ENTRY(fail_point_entry) fe_entries; /**< next entry in fail point */ 120d26b7945SMatthew D Fleming }; 121d26b7945SMatthew D Fleming 122cfeb7489SZachary Loafman static inline void 123cfeb7489SZachary Loafman fail_point_sleep(struct fail_point *fp, struct fail_point_entry *ent, 124cfeb7489SZachary Loafman int msecs, enum fail_point_return_code *pret) 125cfeb7489SZachary Loafman { 126cfeb7489SZachary Loafman /* convert from millisecs to ticks, rounding up */ 127cfeb7489SZachary Loafman int timo = ((msecs * hz) + 999) / 1000; 128cfeb7489SZachary Loafman 1290894a9bcSMatthew D Fleming if (timo > 0) { 130cfeb7489SZachary Loafman if (fp->fp_sleep_fn == NULL) { 131cfeb7489SZachary Loafman msleep(fp, &g_fp_mtx, PWAIT, "failpt", timo); 132cfeb7489SZachary Loafman } else { 133cfeb7489SZachary Loafman timeout(fp->fp_sleep_fn, fp->fp_sleep_arg, timo); 134cfeb7489SZachary Loafman *pret = FAIL_POINT_RC_QUEUED; 135cfeb7489SZachary Loafman } 136cfeb7489SZachary Loafman } 137cfeb7489SZachary Loafman } 138cfeb7489SZachary Loafman 139cfeb7489SZachary Loafman 140cfeb7489SZachary Loafman /** 141cfeb7489SZachary Loafman * Defines stating the equivalent of probablilty one (100%) 142cfeb7489SZachary Loafman */ 143cfeb7489SZachary Loafman enum { 144cfeb7489SZachary Loafman PROB_MAX = 1000000, /* probability between zero and this number */ 145cfeb7489SZachary Loafman PROB_DIGITS = 6, /* number of zero's in above number */ 146cfeb7489SZachary Loafman }; 147cfeb7489SZachary Loafman 148cfeb7489SZachary Loafman static char *parse_fail_point(struct fail_point_entries *, char *); 149cfeb7489SZachary Loafman static char *parse_term(struct fail_point_entries *, char *); 150cfeb7489SZachary Loafman static char *parse_number(int *out_units, int *out_decimal, char *); 151cfeb7489SZachary Loafman static char *parse_type(struct fail_point_entry *, char *); 152cfeb7489SZachary Loafman static void free_entry(struct fail_point_entries *, struct fail_point_entry *); 153cfeb7489SZachary Loafman static void clear_entries(struct fail_point_entries *); 154cfeb7489SZachary Loafman 155cfeb7489SZachary Loafman /** 156cfeb7489SZachary Loafman * Initialize a fail_point. The name is formed in a printf-like fashion 157cfeb7489SZachary Loafman * from "fmt" and subsequent arguments. This function is generally used 158cfeb7489SZachary Loafman * for custom failpoints located at odd places in the sysctl tree, and is 159cfeb7489SZachary Loafman * not explicitly needed for standard in-line-declared failpoints. 160cfeb7489SZachary Loafman * 161cfeb7489SZachary Loafman * @ingroup failpoint 162cfeb7489SZachary Loafman */ 163cfeb7489SZachary Loafman void 164cfeb7489SZachary Loafman fail_point_init(struct fail_point *fp, const char *fmt, ...) 165cfeb7489SZachary Loafman { 166cfeb7489SZachary Loafman va_list ap; 167cfeb7489SZachary Loafman char *name; 168cfeb7489SZachary Loafman int n; 169cfeb7489SZachary Loafman 170cfeb7489SZachary Loafman TAILQ_INIT(&fp->fp_entries); 171cfeb7489SZachary Loafman fp->fp_flags = 0; 172cfeb7489SZachary Loafman 173cfeb7489SZachary Loafman /* Figure out the size of the name. */ 174cfeb7489SZachary Loafman va_start(ap, fmt); 175cfeb7489SZachary Loafman n = vsnprintf(NULL, 0, fmt, ap); 176cfeb7489SZachary Loafman va_end(ap); 177cfeb7489SZachary Loafman 178cfeb7489SZachary Loafman /* Allocate the name and fill it in. */ 179cfeb7489SZachary Loafman name = fp_malloc(n + 1, M_WAITOK); 180cfeb7489SZachary Loafman if (name != NULL) { 181cfeb7489SZachary Loafman va_start(ap, fmt); 182cfeb7489SZachary Loafman vsnprintf(name, n + 1, fmt, ap); 183cfeb7489SZachary Loafman va_end(ap); 184cfeb7489SZachary Loafman } 185cfeb7489SZachary Loafman fp->fp_name = name; 1864b7c6844SMatthew D Fleming fp->fp_location = ""; 187cfeb7489SZachary Loafman fp->fp_flags |= FAIL_POINT_DYNAMIC_NAME; 188cfeb7489SZachary Loafman fp->fp_sleep_fn = NULL; 189cfeb7489SZachary Loafman fp->fp_sleep_arg = NULL; 190cfeb7489SZachary Loafman } 191cfeb7489SZachary Loafman 192cfeb7489SZachary Loafman /** 193cfeb7489SZachary Loafman * Free the resources held by a fail_point. 194cfeb7489SZachary Loafman * 195cfeb7489SZachary Loafman * @ingroup failpoint 196cfeb7489SZachary Loafman */ 197cfeb7489SZachary Loafman void 198cfeb7489SZachary Loafman fail_point_destroy(struct fail_point *fp) 199cfeb7489SZachary Loafman { 200cfeb7489SZachary Loafman 2010894a9bcSMatthew D Fleming if ((fp->fp_flags & FAIL_POINT_DYNAMIC_NAME) != 0) { 2020894a9bcSMatthew D Fleming fp_free(__DECONST(void *, fp->fp_name)); 203cfeb7489SZachary Loafman fp->fp_name = NULL; 204cfeb7489SZachary Loafman } 205cfeb7489SZachary Loafman fp->fp_flags = 0; 2060894a9bcSMatthew D Fleming clear_entries(&fp->fp_entries); 207cfeb7489SZachary Loafman } 208cfeb7489SZachary Loafman 209cfeb7489SZachary Loafman /** 210cfeb7489SZachary Loafman * This does the real work of evaluating a fail point. If the fail point tells 211cfeb7489SZachary Loafman * us to return a value, this function returns 1 and fills in 'return_value' 212cfeb7489SZachary Loafman * (return_value is allowed to be null). If the fail point tells us to panic, 213cfeb7489SZachary Loafman * we never return. Otherwise we just return 0 after doing some work, which 214cfeb7489SZachary Loafman * means "keep going". 215cfeb7489SZachary Loafman */ 216cfeb7489SZachary Loafman enum fail_point_return_code 217cfeb7489SZachary Loafman fail_point_eval_nontrivial(struct fail_point *fp, int *return_value) 218cfeb7489SZachary Loafman { 219cfeb7489SZachary Loafman enum fail_point_return_code ret = FAIL_POINT_RC_CONTINUE; 220cfeb7489SZachary Loafman struct fail_point_entry *ent, *next; 221cfeb7489SZachary Loafman int msecs; 222cfeb7489SZachary Loafman 223cfeb7489SZachary Loafman FP_LOCK(); 224cfeb7489SZachary Loafman 2250894a9bcSMatthew D Fleming TAILQ_FOREACH_SAFE(ent, &fp->fp_entries, fe_entries, next) { 226cfeb7489SZachary Loafman int cont = 0; /* don't continue by default */ 227cfeb7489SZachary Loafman 228cfeb7489SZachary Loafman if (ent->fe_prob < PROB_MAX && 2290894a9bcSMatthew D Fleming ent->fe_prob < random() % PROB_MAX) 2300894a9bcSMatthew D Fleming continue; 231*b5bd50aeSMatthew D Fleming if (ent->fe_pid != NO_PID && ent->fe_pid != curproc->p_pid) 232*b5bd50aeSMatthew D Fleming continue; 233cfeb7489SZachary Loafman 234cfeb7489SZachary Loafman switch (ent->fe_type) { 235cfeb7489SZachary Loafman case FAIL_POINT_PANIC: 236cfeb7489SZachary Loafman panic("fail point %s panicking", fp->fp_name); 237cfeb7489SZachary Loafman /* NOTREACHED */ 238cfeb7489SZachary Loafman 239cfeb7489SZachary Loafman case FAIL_POINT_RETURN: 2400894a9bcSMatthew D Fleming if (return_value != NULL) 241cfeb7489SZachary Loafman *return_value = ent->fe_arg; 242cfeb7489SZachary Loafman ret = FAIL_POINT_RC_RETURN; 243cfeb7489SZachary Loafman break; 244cfeb7489SZachary Loafman 245cfeb7489SZachary Loafman case FAIL_POINT_BREAK: 2460894a9bcSMatthew D Fleming printf("fail point %s breaking to debugger\n", 2470894a9bcSMatthew D Fleming fp->fp_name); 248cfeb7489SZachary Loafman breakpoint(); 249cfeb7489SZachary Loafman break; 250cfeb7489SZachary Loafman 251cfeb7489SZachary Loafman case FAIL_POINT_PRINT: 252cfeb7489SZachary Loafman printf("fail point %s executing\n", fp->fp_name); 253cfeb7489SZachary Loafman cont = ent->fe_arg; 254cfeb7489SZachary Loafman break; 255cfeb7489SZachary Loafman 256cfeb7489SZachary Loafman case FAIL_POINT_SLEEP: 257cfeb7489SZachary Loafman /* 258cfeb7489SZachary Loafman * Free the entry now if necessary, since 259cfeb7489SZachary Loafman * we're about to drop the mutex and sleep. 260cfeb7489SZachary Loafman */ 261cfeb7489SZachary Loafman msecs = ent->fe_arg; 262cfeb7489SZachary Loafman if (ent->fe_count > 0 && --ent->fe_count == 0) { 263cfeb7489SZachary Loafman free_entry(&fp->fp_entries, ent); 264cfeb7489SZachary Loafman ent = NULL; 265cfeb7489SZachary Loafman } 266cfeb7489SZachary Loafman 267cfeb7489SZachary Loafman if (msecs) 268cfeb7489SZachary Loafman fail_point_sleep(fp, ent, msecs, &ret); 269cfeb7489SZachary Loafman break; 270cfeb7489SZachary Loafman 271cfeb7489SZachary Loafman default: 272cfeb7489SZachary Loafman break; 273cfeb7489SZachary Loafman } 274cfeb7489SZachary Loafman 2750894a9bcSMatthew D Fleming if (ent != NULL && ent->fe_count > 0 && --ent->fe_count == 0) 276cfeb7489SZachary Loafman free_entry(&fp->fp_entries, ent); 2770894a9bcSMatthew D Fleming if (cont == 0) 278cfeb7489SZachary Loafman break; 279cfeb7489SZachary Loafman } 280cfeb7489SZachary Loafman 281cfeb7489SZachary Loafman /* Get rid of "off"s at the end. */ 282cfeb7489SZachary Loafman while ((ent = TAILQ_LAST(&fp->fp_entries, fail_point_entries)) && 283cfeb7489SZachary Loafman ent->fe_type == FAIL_POINT_OFF) 284cfeb7489SZachary Loafman free_entry(&fp->fp_entries, ent); 285cfeb7489SZachary Loafman 286cfeb7489SZachary Loafman FP_UNLOCK(); 287cfeb7489SZachary Loafman 2880894a9bcSMatthew D Fleming return (ret); 289cfeb7489SZachary Loafman } 290cfeb7489SZachary Loafman 291cfeb7489SZachary Loafman /** 292cfeb7489SZachary Loafman * Translate internal fail_point structure into human-readable text. 293cfeb7489SZachary Loafman */ 294cfeb7489SZachary Loafman static void 295cfeb7489SZachary Loafman fail_point_get(struct fail_point *fp, struct sbuf *sb) 296cfeb7489SZachary Loafman { 297cfeb7489SZachary Loafman struct fail_point_entry *ent; 298cfeb7489SZachary Loafman 299cfeb7489SZachary Loafman FP_LOCK(); 300cfeb7489SZachary Loafman 301cfeb7489SZachary Loafman TAILQ_FOREACH(ent, &fp->fp_entries, fe_entries) { 302cfeb7489SZachary Loafman if (ent->fe_prob < PROB_MAX) { 303cfeb7489SZachary Loafman int decimal = ent->fe_prob % (PROB_MAX / 100); 304cfeb7489SZachary Loafman int units = ent->fe_prob / (PROB_MAX / 100); 305cfeb7489SZachary Loafman sbuf_printf(sb, "%d", units); 306cfeb7489SZachary Loafman if (decimal) { 307cfeb7489SZachary Loafman int digits = PROB_DIGITS - 2; 308cfeb7489SZachary Loafman while (!(decimal % 10)) { 309cfeb7489SZachary Loafman digits--; 310cfeb7489SZachary Loafman decimal /= 10; 311cfeb7489SZachary Loafman } 312cfeb7489SZachary Loafman sbuf_printf(sb, ".%0*d", digits, decimal); 313cfeb7489SZachary Loafman } 314cfeb7489SZachary Loafman sbuf_printf(sb, "%%"); 315cfeb7489SZachary Loafman } 316cfeb7489SZachary Loafman if (ent->fe_count > 0) 317cfeb7489SZachary Loafman sbuf_printf(sb, "%d*", ent->fe_count); 3180894a9bcSMatthew D Fleming sbuf_printf(sb, "%s", fail_type_strings[ent->fe_type].name); 319cfeb7489SZachary Loafman if (ent->fe_arg) 320cfeb7489SZachary Loafman sbuf_printf(sb, "(%d)", ent->fe_arg); 321*b5bd50aeSMatthew D Fleming if (ent->fe_pid != NO_PID) 322*b5bd50aeSMatthew D Fleming sbuf_printf(sb, "[pid %d]", ent->fe_pid); 323cfeb7489SZachary Loafman if (TAILQ_NEXT(ent, fe_entries)) 324cfeb7489SZachary Loafman sbuf_printf(sb, "->"); 325cfeb7489SZachary Loafman } 326cfeb7489SZachary Loafman if (TAILQ_EMPTY(&fp->fp_entries)) 327cfeb7489SZachary Loafman sbuf_printf(sb, "off"); 328cfeb7489SZachary Loafman 329cfeb7489SZachary Loafman FP_UNLOCK(); 330cfeb7489SZachary Loafman } 331cfeb7489SZachary Loafman 332cfeb7489SZachary Loafman /** 333cfeb7489SZachary Loafman * Set an internal fail_point structure from a human-readable failpoint string 334cfeb7489SZachary Loafman * in a lock-safe manner. 335cfeb7489SZachary Loafman */ 336cfeb7489SZachary Loafman static int 337cfeb7489SZachary Loafman fail_point_set(struct fail_point *fp, char *buf) 338cfeb7489SZachary Loafman { 339cfeb7489SZachary Loafman int error = 0; 340cfeb7489SZachary Loafman struct fail_point_entry *ent, *ent_next; 341cfeb7489SZachary Loafman struct fail_point_entries new_entries; 342cfeb7489SZachary Loafman 343cfeb7489SZachary Loafman /* Parse new entries. */ 344cfeb7489SZachary Loafman TAILQ_INIT(&new_entries); 345cfeb7489SZachary Loafman if (!parse_fail_point(&new_entries, buf)) { 346cfeb7489SZachary Loafman clear_entries(&new_entries); 347cfeb7489SZachary Loafman error = EINVAL; 348cfeb7489SZachary Loafman goto end; 349cfeb7489SZachary Loafman } 350cfeb7489SZachary Loafman 351cfeb7489SZachary Loafman FP_LOCK(); 352cfeb7489SZachary Loafman 353cfeb7489SZachary Loafman /* Move new entries in. */ 354cfeb7489SZachary Loafman TAILQ_SWAP(&fp->fp_entries, &new_entries, fail_point_entry, fe_entries); 355cfeb7489SZachary Loafman clear_entries(&new_entries); 356cfeb7489SZachary Loafman 357cfeb7489SZachary Loafman /* Get rid of useless zero probability entries. */ 358cfeb7489SZachary Loafman TAILQ_FOREACH_SAFE(ent, &fp->fp_entries, fe_entries, ent_next) { 359cfeb7489SZachary Loafman if (ent->fe_prob == 0) 360cfeb7489SZachary Loafman free_entry(&fp->fp_entries, ent); 361cfeb7489SZachary Loafman } 362cfeb7489SZachary Loafman 363cfeb7489SZachary Loafman /* Get rid of "off"s at the end. */ 364cfeb7489SZachary Loafman while ((ent = TAILQ_LAST(&fp->fp_entries, fail_point_entries)) && 365cfeb7489SZachary Loafman ent->fe_type == FAIL_POINT_OFF) 366cfeb7489SZachary Loafman free_entry(&fp->fp_entries, ent); 367cfeb7489SZachary Loafman 368cfeb7489SZachary Loafman FP_UNLOCK(); 369cfeb7489SZachary Loafman 370cfeb7489SZachary Loafman end: 371cfeb7489SZachary Loafman #ifdef IWARNING 372cfeb7489SZachary Loafman if (error) 3734b7c6844SMatthew D Fleming IWARNING("Failed to set %s %s to %s", 374cfeb7489SZachary Loafman fp->fp_name, fp->fp_location, buf); 375cfeb7489SZachary Loafman else 3764b7c6844SMatthew D Fleming INOTICE("Set %s %s to %s", 377cfeb7489SZachary Loafman fp->fp_name, fp->fp_location, buf); 378cfeb7489SZachary Loafman #endif /* IWARNING */ 379cfeb7489SZachary Loafman 3800894a9bcSMatthew D Fleming return (error); 381cfeb7489SZachary Loafman } 382cfeb7489SZachary Loafman 383cfeb7489SZachary Loafman #define MAX_FAIL_POINT_BUF 1023 384cfeb7489SZachary Loafman 385cfeb7489SZachary Loafman /** 386cfeb7489SZachary Loafman * Handle kernel failpoint set/get. 387cfeb7489SZachary Loafman */ 388cfeb7489SZachary Loafman int 389cfeb7489SZachary Loafman fail_point_sysctl(SYSCTL_HANDLER_ARGS) 390cfeb7489SZachary Loafman { 391cfeb7489SZachary Loafman struct fail_point *fp = arg1; 392cfeb7489SZachary Loafman char *buf = NULL; 393cfeb7489SZachary Loafman struct sbuf sb; 394cfeb7489SZachary Loafman int error; 395cfeb7489SZachary Loafman 396cfeb7489SZachary Loafman /* Retrieving */ 397cfeb7489SZachary Loafman sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND); 398cfeb7489SZachary Loafman fail_point_get(fp, &sb); 399cfeb7489SZachary Loafman sbuf_trim(&sb); 400cfeb7489SZachary Loafman sbuf_finish(&sb); 401cfeb7489SZachary Loafman error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb)); 402cfeb7489SZachary Loafman sbuf_delete(&sb); 403cfeb7489SZachary Loafman 404cfeb7489SZachary Loafman /* Setting */ 405cfeb7489SZachary Loafman if (!error && req->newptr) { 406cfeb7489SZachary Loafman if (req->newlen > MAX_FAIL_POINT_BUF) { 407cfeb7489SZachary Loafman error = EINVAL; 408cfeb7489SZachary Loafman goto out; 409cfeb7489SZachary Loafman } 410cfeb7489SZachary Loafman 411cfeb7489SZachary Loafman buf = fp_malloc(req->newlen + 1, M_WAITOK); 412cfeb7489SZachary Loafman 413cfeb7489SZachary Loafman error = SYSCTL_IN(req, buf, req->newlen); 414cfeb7489SZachary Loafman if (error) 415cfeb7489SZachary Loafman goto out; 416cfeb7489SZachary Loafman buf[req->newlen] = '\0'; 417cfeb7489SZachary Loafman 418cfeb7489SZachary Loafman error = fail_point_set(fp, buf); 419cfeb7489SZachary Loafman } 420cfeb7489SZachary Loafman 421cfeb7489SZachary Loafman out: 422cfeb7489SZachary Loafman fp_free(buf); 4230894a9bcSMatthew D Fleming return (error); 424cfeb7489SZachary Loafman } 425cfeb7489SZachary Loafman 426cfeb7489SZachary Loafman /** 427cfeb7489SZachary Loafman * Internal helper function to translate a human-readable failpoint string 428cfeb7489SZachary Loafman * into a internally-parsable fail_point structure. 429cfeb7489SZachary Loafman */ 430cfeb7489SZachary Loafman static char * 431cfeb7489SZachary Loafman parse_fail_point(struct fail_point_entries *ents, char *p) 432cfeb7489SZachary Loafman { 433cfeb7489SZachary Loafman /* <fail_point> :: 434cfeb7489SZachary Loafman * <term> ( "->" <term> )* 435cfeb7489SZachary Loafman */ 4360894a9bcSMatthew D Fleming p = parse_term(ents, p); 4370894a9bcSMatthew D Fleming if (p == NULL) 4380894a9bcSMatthew D Fleming return (NULL); 4390894a9bcSMatthew D Fleming while (*p != '\0') { 4400894a9bcSMatthew D Fleming if (p[0] != '-' || p[1] != '>') 4410894a9bcSMatthew D Fleming return (NULL); 4420894a9bcSMatthew D Fleming p = parse_term(ents, p + 2); 4430894a9bcSMatthew D Fleming if (p == NULL) 4440894a9bcSMatthew D Fleming return (NULL); 4450894a9bcSMatthew D Fleming } 4460894a9bcSMatthew D Fleming return (p); 447cfeb7489SZachary Loafman } 448cfeb7489SZachary Loafman 449cfeb7489SZachary Loafman /** 450cfeb7489SZachary Loafman * Internal helper function to parse an individual term from a failpoint. 451cfeb7489SZachary Loafman */ 452cfeb7489SZachary Loafman static char * 453cfeb7489SZachary Loafman parse_term(struct fail_point_entries *ents, char *p) 454cfeb7489SZachary Loafman { 455cfeb7489SZachary Loafman struct fail_point_entry *ent; 456cfeb7489SZachary Loafman 457cfeb7489SZachary Loafman ent = fp_malloc(sizeof *ent, M_WAITOK | M_ZERO); 458cfeb7489SZachary Loafman ent->fe_prob = PROB_MAX; 459*b5bd50aeSMatthew D Fleming ent->fe_pid = NO_PID; 460cfeb7489SZachary Loafman TAILQ_INSERT_TAIL(ents, ent, fe_entries); 461cfeb7489SZachary Loafman 462cfeb7489SZachary Loafman /* 463cfeb7489SZachary Loafman * <term> :: 464cfeb7489SZachary Loafman * ( (<float> "%") | (<integer> "*" ) )* 465cfeb7489SZachary Loafman * <type> 466cfeb7489SZachary Loafman * [ "(" <integer> ")" ] 467*b5bd50aeSMatthew D Fleming * [ "[pid " <integer> "]" ] 468cfeb7489SZachary Loafman */ 469cfeb7489SZachary Loafman 470cfeb7489SZachary Loafman /* ( (<float> "%") | (<integer> "*" ) )* */ 4710894a9bcSMatthew D Fleming while (isdigit(*p) || *p == '.') { 472cfeb7489SZachary Loafman int units, decimal; 473cfeb7489SZachary Loafman 4740894a9bcSMatthew D Fleming p = parse_number(&units, &decimal, p); 4750894a9bcSMatthew D Fleming if (p == NULL) 4760894a9bcSMatthew D Fleming return (NULL); 477cfeb7489SZachary Loafman 478cfeb7489SZachary Loafman if (*p == '%') { 479cfeb7489SZachary Loafman if (units > 100) /* prevent overflow early */ 480cfeb7489SZachary Loafman units = 100; 481cfeb7489SZachary Loafman ent->fe_prob = units * (PROB_MAX / 100) + decimal; 482cfeb7489SZachary Loafman if (ent->fe_prob > PROB_MAX) 483cfeb7489SZachary Loafman ent->fe_prob = PROB_MAX; 484cfeb7489SZachary Loafman } else if (*p == '*') { 485cfeb7489SZachary Loafman if (!units || decimal) 4860894a9bcSMatthew D Fleming return (NULL); 487c2ede4b3SMartin Blapp ent->fe_count = units; 4880894a9bcSMatthew D Fleming } else 4890894a9bcSMatthew D Fleming return (NULL); 490cfeb7489SZachary Loafman p++; 491cfeb7489SZachary Loafman } 492cfeb7489SZachary Loafman 493cfeb7489SZachary Loafman /* <type> */ 4940894a9bcSMatthew D Fleming p = parse_type(ent, p); 4950894a9bcSMatthew D Fleming if (p == NULL) 4960894a9bcSMatthew D Fleming return (NULL); 497cfeb7489SZachary Loafman if (*p == '\0') 4980894a9bcSMatthew D Fleming return (p); 499cfeb7489SZachary Loafman 500cfeb7489SZachary Loafman /* [ "(" <integer> ")" ] */ 501cfeb7489SZachary Loafman if (*p != '(') 502cfeb7489SZachary Loafman return p; 503cfeb7489SZachary Loafman p++; 5040894a9bcSMatthew D Fleming if (!isdigit(*p) && *p != '-') 5050894a9bcSMatthew D Fleming return (NULL); 506cfeb7489SZachary Loafman ent->fe_arg = strtol(p, &p, 0); 507cfeb7489SZachary Loafman if (*p++ != ')') 5080894a9bcSMatthew D Fleming return (NULL); 509cfeb7489SZachary Loafman 510*b5bd50aeSMatthew D Fleming /* [ "[pid " <integer> "]" ] */ 511*b5bd50aeSMatthew D Fleming #define PID_STRING "[pid " 512*b5bd50aeSMatthew D Fleming if (strncmp(p, PID_STRING, sizeof(PID_STRING) - 1) != 0) 513*b5bd50aeSMatthew D Fleming return (p); 514*b5bd50aeSMatthew D Fleming p += sizeof(PID_STRING) - 1; 515*b5bd50aeSMatthew D Fleming if (!isdigit(*p)) 516*b5bd50aeSMatthew D Fleming return (NULL); 517*b5bd50aeSMatthew D Fleming ent->fe_pid = strtol(p, &p, 0); 518*b5bd50aeSMatthew D Fleming if (*p++ != ']') 519*b5bd50aeSMatthew D Fleming return (NULL); 520*b5bd50aeSMatthew D Fleming 5210894a9bcSMatthew D Fleming return (p); 522cfeb7489SZachary Loafman } 523cfeb7489SZachary Loafman 524cfeb7489SZachary Loafman /** 525cfeb7489SZachary Loafman * Internal helper function to parse a numeric for a failpoint term. 526cfeb7489SZachary Loafman */ 527cfeb7489SZachary Loafman static char * 528cfeb7489SZachary Loafman parse_number(int *out_units, int *out_decimal, char *p) 529cfeb7489SZachary Loafman { 530cfeb7489SZachary Loafman char *old_p; 531cfeb7489SZachary Loafman 532cfeb7489SZachary Loafman /* 533cfeb7489SZachary Loafman * <number> :: 534cfeb7489SZachary Loafman * <integer> [ "." <integer> ] | 535cfeb7489SZachary Loafman * "." <integer> 536cfeb7489SZachary Loafman */ 537cfeb7489SZachary Loafman 538cfeb7489SZachary Loafman /* whole part */ 539cfeb7489SZachary Loafman old_p = p; 540c2ede4b3SMartin Blapp *out_units = strtol(p, &p, 10); 541cfeb7489SZachary Loafman if (p == old_p && *p != '.') 5420894a9bcSMatthew D Fleming return (NULL); 543cfeb7489SZachary Loafman 544cfeb7489SZachary Loafman /* fractional part */ 545cfeb7489SZachary Loafman *out_decimal = 0; 546cfeb7489SZachary Loafman if (*p == '.') { 547cfeb7489SZachary Loafman int digits = 0; 548cfeb7489SZachary Loafman p++; 5490894a9bcSMatthew D Fleming while (isdigit(*p)) { 550cfeb7489SZachary Loafman int digit = *p - '0'; 551cfeb7489SZachary Loafman if (digits < PROB_DIGITS - 2) 552cfeb7489SZachary Loafman *out_decimal = *out_decimal * 10 + digit; 553cfeb7489SZachary Loafman else if (digits == PROB_DIGITS - 2 && digit >= 5) 554cfeb7489SZachary Loafman (*out_decimal)++; 555cfeb7489SZachary Loafman digits++; 556cfeb7489SZachary Loafman p++; 557cfeb7489SZachary Loafman } 558cfeb7489SZachary Loafman if (!digits) /* need at least one digit after '.' */ 5590894a9bcSMatthew D Fleming return (NULL); 560cfeb7489SZachary Loafman while (digits++ < PROB_DIGITS - 2) /* add implicit zeros */ 561cfeb7489SZachary Loafman *out_decimal *= 10; 562cfeb7489SZachary Loafman } 563cfeb7489SZachary Loafman 5640894a9bcSMatthew D Fleming return (p); /* success */ 565cfeb7489SZachary Loafman } 566cfeb7489SZachary Loafman 567cfeb7489SZachary Loafman /** 568cfeb7489SZachary Loafman * Internal helper function to parse an individual type for a failpoint term. 569cfeb7489SZachary Loafman */ 570cfeb7489SZachary Loafman static char * 571cfeb7489SZachary Loafman parse_type(struct fail_point_entry *ent, char *beg) 572cfeb7489SZachary Loafman { 573cfeb7489SZachary Loafman enum fail_point_t type; 5740894a9bcSMatthew D Fleming int len; 5750894a9bcSMatthew D Fleming 5760894a9bcSMatthew D Fleming for (type = FAIL_POINT_OFF; type < FAIL_POINT_NUMTYPES; type++) { 5770894a9bcSMatthew D Fleming len = fail_type_strings[type].nmlen; 5780894a9bcSMatthew D Fleming if (strncmp(fail_type_strings[type].name, beg, len) == 0) { 579cfeb7489SZachary Loafman ent->fe_type = type; 5800894a9bcSMatthew D Fleming return (beg + len); 581cfeb7489SZachary Loafman } 582cfeb7489SZachary Loafman } 5830894a9bcSMatthew D Fleming return (NULL); 584cfeb7489SZachary Loafman } 585cfeb7489SZachary Loafman 586cfeb7489SZachary Loafman /** 587cfeb7489SZachary Loafman * Internal helper function to free an individual failpoint term. 588cfeb7489SZachary Loafman */ 589cfeb7489SZachary Loafman static void 590cfeb7489SZachary Loafman free_entry(struct fail_point_entries *ents, struct fail_point_entry *ent) 591cfeb7489SZachary Loafman { 592cfeb7489SZachary Loafman TAILQ_REMOVE(ents, ent, fe_entries); 593cfeb7489SZachary Loafman fp_free(ent); 594cfeb7489SZachary Loafman } 595cfeb7489SZachary Loafman 596cfeb7489SZachary Loafman /** 597cfeb7489SZachary Loafman * Internal helper function to clear out all failpoint terms for a single 598cfeb7489SZachary Loafman * failpoint. 599cfeb7489SZachary Loafman */ 600cfeb7489SZachary Loafman static void 601cfeb7489SZachary Loafman clear_entries(struct fail_point_entries *ents) 602cfeb7489SZachary Loafman { 603cfeb7489SZachary Loafman struct fail_point_entry *ent, *ent_next; 6040894a9bcSMatthew D Fleming 605cfeb7489SZachary Loafman TAILQ_FOREACH_SAFE(ent, ents, fe_entries, ent_next) 606cfeb7489SZachary Loafman fp_free(ent); 607cfeb7489SZachary Loafman TAILQ_INIT(ents); 608cfeb7489SZachary Loafman } 609cfeb7489SZachary Loafman 610cfeb7489SZachary Loafman /* The fail point sysctl tree. */ 611cfeb7489SZachary Loafman SYSCTL_NODE(_debug, OID_AUTO, fail_point, CTLFLAG_RW, 0, "fail points"); 612