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Diffstat (limited to 'freebsd/sys/sys/fail.h')
| -rw-r--r-- | freebsd/sys/sys/fail.h | 366 |
1 files changed, 366 insertions, 0 deletions
diff --git a/freebsd/sys/sys/fail.h b/freebsd/sys/sys/fail.h new file mode 100644 index 00000000..45499af2 --- /dev/null +++ b/freebsd/sys/sys/fail.h @@ -0,0 +1,366 @@ +/*- + * Copyright (c) 2009 Isilon Inc http://www.isilon.com/ + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ +/** + * @file + * + * Main header for failpoint facility. + */ +#ifndef _SYS_FAIL_H_ +#define _SYS_FAIL_H_ + +#include <rtems/bsd/sys/param.h> +#include <sys/cdefs.h> +#include <sys/linker_set.h> +#include <sys/queue.h> +#include <sys/sysctl.h> +#include <sys/condvar.h> +#include <sys/kernel.h> +#include <rtems/bsd/sys/lock.h> +#include <sys/mutex.h> +#include <sys/systm.h> + +/** + * Failpoint return codes, used internally. + * @ingroup failpoint_private + */ +enum fail_point_return_code { + FAIL_POINT_RC_CONTINUE = 0, /**< Continue with normal execution */ + FAIL_POINT_RC_RETURN, /**< FP evaluated to 'return' */ + FAIL_POINT_RC_QUEUED, /**< sleep_fn will be called */ +}; + +struct fail_point_entry; +struct fail_point_setting; + +/** + * Internal failpoint structure, tracking all the current details of the + * failpoint. This structure is the core component shared between the + * failure-injection code and the user-interface. + * @ingroup failpoint_private + */ +struct fail_point { + const char *fp_name; /* name of fail point */ + const char *fp_location; /* file:line of fail point */ + volatile int fp_ref_cnt; /** + * protects fp_setting: while holding + * a ref, fp_setting points to an + * unfreed fail_point_setting + */ + struct fail_point_setting * volatile fp_setting; + int fp_flags; + + /**< Function to call before sleep or pause */ + void (*fp_pre_sleep_fn)(void *); + /**< Arg for fp_pre_sleep_fn */ + void *fp_pre_sleep_arg; + + /**< Function to call after waking from sleep or pause */ + void (*fp_post_sleep_fn)(void *); + /**< Arg for fp_post_sleep_fn */ + void *fp_post_sleep_arg; +}; + +#define FAIL_POINT_DYNAMIC_NAME 0x01 /**< Must free name on destroy */ +/**< Use timeout path for sleep instead of msleep */ +#define FAIL_POINT_USE_TIMEOUT_PATH 0x02 +/**< If fail point is set to sleep, replace the sleep call with delay */ +#define FAIL_POINT_NONSLEEPABLE 0x04 + +#define FAIL_POINT_CV_DESC "fp cv no iterators" +#define FAIL_POINT_IS_OFF(fp) (__predict_true((fp)->fp_setting == NULL) || \ + __predict_true(fail_point_is_off(fp))) + +__BEGIN_DECLS + +/* Private failpoint eval function -- use fail_point_eval() instead. */ +enum fail_point_return_code fail_point_eval_nontrivial(struct fail_point *, + int *ret); + +/** + * @addtogroup failpoint + * @{ + */ +/* + * Initialize a fail-point. The name is formed in printf-like fashion + * from "fmt" and the subsequent arguments. + * Pair with fail_point_destroy(). + */ +void fail_point_init(struct fail_point *, const char *fmt, ...) + __printflike(2, 3); + +/* Return true iff this fail point is set to off, false otherwise */ +bool fail_point_is_off(struct fail_point *fp); + +/** + * Set the pre-sleep function for a fail point + * If fp_post_sleep_fn is specified, then FAIL_POINT_SLEEP will result in a + * (*fp->fp_pre_sleep_fn)(fp->fp_pre_sleep_arg) call by the thread. + */ +static inline void +fail_point_sleep_set_pre_func(struct fail_point *fp, void (*sleep_fn)(void *)) +{ + fp->fp_pre_sleep_fn = sleep_fn; +} + +static inline void +fail_point_sleep_set_pre_arg(struct fail_point *fp, void *sleep_arg) +{ + fp->fp_pre_sleep_arg = sleep_arg; +} + +/** + * Set the post-sleep function. This will be passed to timeout if we take + * the timeout path. This must be set if you sleep using the timeout path. + */ +static inline void +fail_point_sleep_set_post_func(struct fail_point *fp, void (*sleep_fn)(void *)) +{ + fp->fp_post_sleep_fn = sleep_fn; +} + +static inline void +fail_point_sleep_set_post_arg(struct fail_point *fp, void *sleep_arg) +{ + fp->fp_post_sleep_arg = sleep_arg; +} +/** + * If the FAIL_POINT_USE_TIMEOUT flag is set on a failpoint, then + * FAIL_POINT_SLEEP will result in a call to timeout instead of + * msleep. Note that if you sleep while this flag is set, you must + * set fp_post_sleep_fn or an error will occur upon waking. + */ +static inline void +fail_point_use_timeout_path(struct fail_point *fp, bool use_timeout, + void (*post_sleep_fn)(void *)) +{ + KASSERT(!use_timeout || post_sleep_fn != NULL || + (post_sleep_fn == NULL && fp->fp_post_sleep_fn != NULL), + ("Setting fp to use timeout, but not setting post_sleep_fn\n")); + + if (use_timeout) + fp->fp_flags |= FAIL_POINT_USE_TIMEOUT_PATH; + else + fp->fp_flags &= ~FAIL_POINT_USE_TIMEOUT_PATH; + + if (post_sleep_fn != NULL) + fp->fp_post_sleep_fn = post_sleep_fn; +} + +/** + * Free the resources used by a fail-point. Pair with fail_point_init(). + */ +void fail_point_destroy(struct fail_point *); + +/** + * Evaluate a failpoint. + */ +static inline enum fail_point_return_code +fail_point_eval(struct fail_point *fp, int *ret) +{ + if (__predict_true(fp->fp_setting == NULL)) + return (FAIL_POINT_RC_CONTINUE); + return (fail_point_eval_nontrivial(fp, ret)); +} + +__END_DECLS + +/* Declare a fail_point and its sysctl in a function. */ +#define _FAIL_POINT_NAME(name) _fail_point_##name +#define _FAIL_POINT_LOCATION() "(" __FILE__ ":" __XSTRING(__LINE__) ")" +#ifndef __rtems__ +#define _FAIL_POINT_INIT(parent, name, flags) \ + static struct fail_point _FAIL_POINT_NAME(name) = { \ + .fp_name = #name, \ + .fp_location = _FAIL_POINT_LOCATION(), \ + .fp_ref_cnt = 0, \ + .fp_setting = NULL, \ + .fp_flags = (flags), \ + .fp_pre_sleep_fn = NULL, \ + .fp_pre_sleep_arg = NULL, \ + .fp_post_sleep_fn = NULL, \ + .fp_post_sleep_arg = NULL, \ + }; \ + SYSCTL_OID(parent, OID_AUTO, name, \ + CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE, \ + &_FAIL_POINT_NAME(name), 0, fail_point_sysctl, \ + "A", ""); \ + SYSCTL_OID(parent, OID_AUTO, status_##name, \ + CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, \ + &_FAIL_POINT_NAME(name), 0, \ + fail_point_sysctl_status, "A", ""); +#define _FAIL_POINT_EVAL(name, cond, code...) \ + int RETURN_VALUE; \ + \ + if (__predict_false(cond && \ + fail_point_eval(&_FAIL_POINT_NAME(name), &RETURN_VALUE))) { \ + \ + code; \ + \ + } +#else /* __rtems__ */ +#define _FAIL_POINT_INIT(parent, name, flags) (void)0; +#define _FAIL_POINT_EVAL(name, cond, code...) (void)0; +#endif /* __rtems__ */ + + +/** + * Instantiate a failpoint which returns "RETURN_VALUE" from the function + * when triggered. + * @param parent The parent sysctl under which to locate the fp's sysctl + * @param name The name of the failpoint in the sysctl tree (and printouts) + * @return Instantly returns the RETURN_VALUE specified in the + * failpoint, if triggered. + */ +#define KFAIL_POINT_RETURN(parent, name) \ + KFAIL_POINT_CODE(parent, name, return RETURN_VALUE) + +/** + * Instantiate a failpoint which returns (void) from the function when + * triggered. + * @param parent The parent sysctl under which to locate the sysctl + * @param name The name of the failpoint in the sysctl tree (and printouts) + * @return Instantly returns void, if triggered in the failpoint. + */ +#define KFAIL_POINT_RETURN_VOID(parent, name) \ + KFAIL_POINT_CODE(parent, name, return) + +/** + * Instantiate a failpoint which sets an error when triggered. + * @param parent The parent sysctl under which to locate the sysctl + * @param name The name of the failpoint in the sysctl tree (and + * printouts) + * @param error_var A variable to set to the failpoint's specified + * return-value when triggered + */ +#define KFAIL_POINT_ERROR(parent, name, error_var) \ + KFAIL_POINT_CODE(parent, name, (error_var) = RETURN_VALUE) + +/** + * Instantiate a failpoint which sets an error and then goes to a + * specified label in the function when triggered. + * @param parent The parent sysctl under which to locate the sysctl + * @param name The name of the failpoint in the sysctl tree (and + * printouts) + * @param error_var A variable to set to the failpoint's specified + * return-value when triggered + * @param label The location to goto when triggered. + */ +#define KFAIL_POINT_GOTO(parent, name, error_var, label) \ + KFAIL_POINT_CODE(parent, name, (error_var) = RETURN_VALUE; goto label) + +/** + * Instantiate a failpoint which sets its pre- and post-sleep callback + * mechanisms. + * @param parent The parent sysctl under which to locate the sysctl + * @param name The name of the failpoint in the sysctl tree (and + * printouts) + * @param pre_func Function pointer to the pre-sleep function, which will be + * called directly before going to sleep. + * @param pre_arg Argument to the pre-sleep function + * @param post_func Function pointer to the pot-sleep function, which will be + * called directly before going to sleep. + * @param post_arg Argument to the post-sleep function + */ +#define KFAIL_POINT_SLEEP_CALLBACKS(parent, name, pre_func, pre_arg, \ + post_func, post_arg) \ + KFAIL_POINT_CODE_SLEEP_CALLBACKS(parent, name, pre_func, \ + pre_arg, post_func, post_arg, return RETURN_VALUE) + +/** + * Instantiate a failpoint which runs arbitrary code when triggered, and sets + * its pre- and post-sleep callback mechanisms + * @param parent The parent sysctl under which to locate the sysctl + * @param name The name of the failpoint in the sysctl tree (and + * printouts) + * @param pre_func Function pointer to the pre-sleep function, which will be + * called directly before going to sleep. + * @param pre_arg Argument to the pre-sleep function + * @param post_func Function pointer to the pot-sleep function, which will be + * called directly before going to sleep. + * @param post_arg Argument to the post-sleep function + * @param code The arbitrary code to run when triggered. Can reference + * "RETURN_VALUE" if desired to extract the specified + * user return-value when triggered. Note that this is + * implemented with a do-while loop so be careful of + * break and continue statements. + */ +#define KFAIL_POINT_CODE_SLEEP_CALLBACKS(parent, name, pre_func, pre_arg, \ + post_func, post_arg, code...) \ + do { \ + _FAIL_POINT_INIT(parent, name) \ + _FAIL_POINT_NAME(name).fp_pre_sleep_fn = pre_func; \ + _FAIL_POINT_NAME(name).fp_pre_sleep_arg = pre_arg; \ + _FAIL_POINT_NAME(name).fp_post_sleep_fn = post_func; \ + _FAIL_POINT_NAME(name).fp_post_sleep_arg = post_arg; \ + _FAIL_POINT_EVAL(name, true, code) \ + } while (0) + + +/** + * Instantiate a failpoint which runs arbitrary code when triggered. + * @param parent The parent sysctl under which to locate the sysctl + * @param name The name of the failpoint in the sysctl tree + * (and printouts) + * @param code The arbitrary code to run when triggered. Can reference + * "RETURN_VALUE" if desired to extract the specified + * user return-value when triggered. Note that this is + * implemented with a do-while loop so be careful of + * break and continue statements. + */ +#define KFAIL_POINT_CODE(parent, name, code...) \ + do { \ + _FAIL_POINT_INIT(parent, name, 0) \ + _FAIL_POINT_EVAL(name, true, code) \ + } while (0) + +#define KFAIL_POINT_CODE_FLAGS(parent, name, flags, code...) \ + do { \ + _FAIL_POINT_INIT(parent, name, flags) \ + _FAIL_POINT_EVAL(name, true, code) \ + } while (0) + +#define KFAIL_POINT_CODE_COND(parent, name, cond, flags, code...) \ + do { \ + _FAIL_POINT_INIT(parent, name, flags) \ + _FAIL_POINT_EVAL(name, cond, code) \ + } while (0) + +/** + * @} + * (end group failpoint) + */ + +#ifdef _KERNEL +int fail_point_sysctl(SYSCTL_HANDLER_ARGS); +int fail_point_sysctl_status(SYSCTL_HANDLER_ARGS); + +/* The fail point sysctl tree. */ +SYSCTL_DECL(_debug_fail_point); +#define DEBUG_FP _debug_fail_point +#endif + +#endif /* _SYS_FAIL_H_ */ |