quickjs-tart

quickjs-based runtime for wallet-core logic
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threading_helpers.c (13104B)


      1 /** Mutex usage verification framework. */
      2 
      3 /*
      4  *  Copyright The Mbed TLS Contributors
      5  *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
      6  */
      7 
      8 #include <test/helpers.h>
      9 #include <test/threading_helpers.h>
     10 #include <test/macros.h>
     11 
     12 #include "mbedtls/threading.h"
     13 
     14 #if defined(MBEDTLS_THREADING_C)
     15 
     16 #if defined(MBEDTLS_THREADING_PTHREAD)
     17 
     18 static int threading_thread_create_pthread(mbedtls_test_thread_t *thread, void *(*thread_func)(
     19                                                void *), void *thread_data)
     20 {
     21     if (thread == NULL || thread_func == NULL) {
     22         return MBEDTLS_ERR_THREADING_BAD_INPUT_DATA;
     23     }
     24 
     25     if (pthread_create(&thread->thread, NULL, thread_func, thread_data)) {
     26         return MBEDTLS_ERR_THREADING_THREAD_ERROR;
     27     }
     28 
     29     return 0;
     30 }
     31 
     32 static int threading_thread_join_pthread(mbedtls_test_thread_t *thread)
     33 {
     34     if (thread == NULL) {
     35         return MBEDTLS_ERR_THREADING_BAD_INPUT_DATA;
     36     }
     37 
     38     if (pthread_join(thread->thread, NULL) != 0) {
     39         return MBEDTLS_ERR_THREADING_THREAD_ERROR;
     40     }
     41 
     42     return 0;
     43 }
     44 
     45 int (*mbedtls_test_thread_create)(mbedtls_test_thread_t *thread, void *(*thread_func)(void *),
     46                                   void *thread_data) = threading_thread_create_pthread;
     47 int (*mbedtls_test_thread_join)(mbedtls_test_thread_t *thread) = threading_thread_join_pthread;
     48 
     49 #endif /* MBEDTLS_THREADING_PTHREAD */
     50 
     51 #if defined(MBEDTLS_THREADING_ALT)
     52 
     53 static int threading_thread_create_fail(mbedtls_test_thread_t *thread,
     54                                         void *(*thread_func)(void *),
     55                                         void *thread_data)
     56 {
     57     (void) thread;
     58     (void) thread_func;
     59     (void) thread_data;
     60 
     61     return MBEDTLS_ERR_THREADING_BAD_INPUT_DATA;
     62 }
     63 
     64 static int threading_thread_join_fail(mbedtls_test_thread_t *thread)
     65 {
     66     (void) thread;
     67 
     68     return MBEDTLS_ERR_THREADING_BAD_INPUT_DATA;
     69 }
     70 
     71 int (*mbedtls_test_thread_create)(mbedtls_test_thread_t *thread, void *(*thread_func)(void *),
     72                                   void *thread_data) = threading_thread_create_fail;
     73 int (*mbedtls_test_thread_join)(mbedtls_test_thread_t *thread) = threading_thread_join_fail;
     74 
     75 #endif /* MBEDTLS_THREADING_ALT */
     76 
     77 #if defined(MBEDTLS_TEST_MUTEX_USAGE)
     78 
     79 #include "mbedtls/threading.h"
     80 
     81 /** Mutex usage verification framework.
     82  *
     83  * The mutex usage verification code below aims to detect bad usage of
     84  * Mbed TLS's mutex abstraction layer at runtime. Note that this is solely
     85  * about the use of the mutex itself, not about checking whether the mutex
     86  * correctly protects whatever it is supposed to protect.
     87  *
     88  * The normal usage of a mutex is:
     89  * ```
     90  * digraph mutex_states {
     91  *   "UNINITIALIZED"; // the initial state
     92  *   "IDLE";
     93  *   "FREED";
     94  *   "LOCKED";
     95  *   "UNINITIALIZED" -> "IDLE" [label="init"];
     96  *   "FREED" -> "IDLE" [label="init"];
     97  *   "IDLE" -> "LOCKED" [label="lock"];
     98  *   "LOCKED" -> "IDLE" [label="unlock"];
     99  *   "IDLE" -> "FREED" [label="free"];
    100  * }
    101  * ```
    102  *
    103  * All bad transitions that can be unambiguously detected are reported.
    104  * An attempt to use an uninitialized mutex cannot be detected in general
    105  * since the memory content may happen to denote a valid state. For the same
    106  * reason, a double init cannot be detected.
    107  * All-bits-zero is the state of a freed mutex, which is distinct from an
    108  * initialized mutex, so attempting to use zero-initialized memory as a mutex
    109  * without calling the init function is detected.
    110  *
    111  * The framework attempts to detect missing calls to init and free by counting
    112  * calls to init and free. If there are more calls to init than free, this
    113  * means that a mutex is not being freed somewhere, which is a memory leak
    114  * on platforms where a mutex consumes resources other than the
    115  * mbedtls_threading_mutex_t object itself. If there are more calls to free
    116  * than init, this indicates a missing init, which is likely to be detected
    117  * by an attempt to lock the mutex as well. A limitation of this framework is
    118  * that it cannot detect scenarios where there is exactly the same number of
    119  * calls to init and free but the calls don't match. A bug like this is
    120  * unlikely to happen uniformly throughout the whole test suite though.
    121  *
    122  * If an error is detected, this framework will report what happened and the
    123  * test case will be marked as failed. Unfortunately, the error report cannot
    124  * indicate the exact location of the problematic call. To locate the error,
    125  * use a debugger and set a breakpoint on mbedtls_test_mutex_usage_error().
    126  */
    127 enum value_of_mutex_state_field {
    128     /* Potential values for the state field of mbedtls_threading_mutex_t.
    129      * Note that MUTEX_FREED must be 0 and MUTEX_IDLE must be 1 for
    130      * compatibility with threading_mutex_init_pthread() and
    131      * threading_mutex_free_pthread(). MUTEX_LOCKED could be any nonzero
    132      * value. */
    133     MUTEX_FREED = 0, //! < Set by mbedtls_test_wrap_mutex_free
    134     MUTEX_IDLE = 1, //! < Set by mbedtls_test_wrap_mutex_init and by mbedtls_test_wrap_mutex_unlock
    135     MUTEX_LOCKED = 2, //! < Set by mbedtls_test_wrap_mutex_lock
    136 };
    137 
    138 typedef struct {
    139     void (*init)(mbedtls_threading_mutex_t *);
    140     void (*free)(mbedtls_threading_mutex_t *);
    141     int (*lock)(mbedtls_threading_mutex_t *);
    142     int (*unlock)(mbedtls_threading_mutex_t *);
    143 } mutex_functions_t;
    144 static mutex_functions_t mutex_functions;
    145 
    146 /**
    147  *  The mutex used to guard live_mutexes below and access to the status variable
    148  *  in every mbedtls_threading_mutex_t.
    149  *  Note that we are not reporting any errors when locking and unlocking this
    150  *  mutex. This is for a couple of reasons:
    151  *
    152  *  1. We have no real way of reporting any errors with this mutex - we cannot
    153  *  report it back to the caller, as the failure was not that of the mutex
    154  *  passed in. We could fail the test, but again this would indicate a problem
    155  *  with the test code that did not exist.
    156  *
    157  *  2. Any failure to lock is unlikely to be intermittent, and will thus not
    158  *  give false test results - the overall result would be to turn off the
    159  *  testing. This is not a situation that is likely to happen with normal
    160  *  testing and we still have TSan to fall back on should this happen.
    161  */
    162 mbedtls_threading_mutex_t mbedtls_test_mutex_mutex;
    163 
    164 /**
    165  *  The total number of calls to mbedtls_mutex_init(), minus the total number
    166  *  of calls to mbedtls_mutex_free().
    167  *
    168  *  Do not read or write without holding mbedtls_test_mutex_mutex (above). Reset
    169  *  to 0 after each test case.
    170  */
    171 static int live_mutexes;
    172 
    173 static void mbedtls_test_mutex_usage_error(mbedtls_threading_mutex_t *mutex,
    174                                            const char *msg)
    175 {
    176     (void) mutex;
    177 
    178     mbedtls_test_set_mutex_usage_error(msg);
    179     mbedtls_fprintf(stdout, "[mutex: %s] ", msg);
    180     /* Don't mark the test as failed yet. This way, if the test fails later
    181      * for a functional reason, the test framework will report the message
    182      * and location for this functional reason. If the test passes,
    183      * mbedtls_test_mutex_usage_check() will mark it as failed. */
    184 }
    185 
    186 static int mbedtls_test_mutex_can_test(mbedtls_threading_mutex_t *mutex)
    187 {
    188     /* If we attempt to run tests on this mutex then we are going to run into a
    189      * couple of problems:
    190      * 1. If any test on this mutex fails, we are going to deadlock when
    191      * reporting that failure, as we already hold the mutex at that point.
    192      * 2. Given the 'global' position of the initialization and free of this
    193      * mutex, it will be shown as leaked on the first test run. */
    194     if (mutex == mbedtls_test_get_info_mutex()) {
    195         return 0;
    196     }
    197 
    198     return 1;
    199 }
    200 
    201 static void mbedtls_test_wrap_mutex_init(mbedtls_threading_mutex_t *mutex)
    202 {
    203     mutex_functions.init(mutex);
    204 
    205     if (mbedtls_test_mutex_can_test(mutex)) {
    206         if (mutex_functions.lock(&mbedtls_test_mutex_mutex) == 0) {
    207             mutex->state = MUTEX_IDLE;
    208             ++live_mutexes;
    209 
    210             mutex_functions.unlock(&mbedtls_test_mutex_mutex);
    211         }
    212     }
    213 }
    214 
    215 static void mbedtls_test_wrap_mutex_free(mbedtls_threading_mutex_t *mutex)
    216 {
    217     if (mbedtls_test_mutex_can_test(mutex)) {
    218         if (mutex_functions.lock(&mbedtls_test_mutex_mutex) == 0) {
    219 
    220             switch (mutex->state) {
    221                 case MUTEX_FREED:
    222                     mbedtls_test_mutex_usage_error(mutex, "free without init or double free");
    223                     break;
    224                 case MUTEX_IDLE:
    225                     mutex->state = MUTEX_FREED;
    226                     --live_mutexes;
    227                     break;
    228                 case MUTEX_LOCKED:
    229                     mbedtls_test_mutex_usage_error(mutex, "free without unlock");
    230                     break;
    231                 default:
    232                     mbedtls_test_mutex_usage_error(mutex, "corrupted state");
    233                     break;
    234             }
    235 
    236             mutex_functions.unlock(&mbedtls_test_mutex_mutex);
    237         }
    238     }
    239 
    240     mutex_functions.free(mutex);
    241 }
    242 
    243 static int mbedtls_test_wrap_mutex_lock(mbedtls_threading_mutex_t *mutex)
    244 {
    245     /* Lock the passed in mutex first, so that the only way to change the state
    246      * is to hold the passed in and internal mutex - otherwise we create a race
    247      * condition. */
    248     int ret = mutex_functions.lock(mutex);
    249 
    250     if (mbedtls_test_mutex_can_test(mutex)) {
    251         if (mutex_functions.lock(&mbedtls_test_mutex_mutex) == 0) {
    252             switch (mutex->state) {
    253                 case MUTEX_FREED:
    254                     mbedtls_test_mutex_usage_error(mutex, "lock without init");
    255                     break;
    256                 case MUTEX_IDLE:
    257                     if (ret == 0) {
    258                         mutex->state = MUTEX_LOCKED;
    259                     }
    260                     break;
    261                 case MUTEX_LOCKED:
    262                     mbedtls_test_mutex_usage_error(mutex, "double lock");
    263                     break;
    264                 default:
    265                     mbedtls_test_mutex_usage_error(mutex, "corrupted state");
    266                     break;
    267             }
    268 
    269             mutex_functions.unlock(&mbedtls_test_mutex_mutex);
    270         }
    271     }
    272 
    273     return ret;
    274 }
    275 
    276 static int mbedtls_test_wrap_mutex_unlock(mbedtls_threading_mutex_t *mutex)
    277 {
    278     /* Lock the internal mutex first and change state, so that the only way to
    279      * change the state is to hold the passed in and internal mutex - otherwise
    280      * we create a race condition. */
    281     if (mbedtls_test_mutex_can_test(mutex)) {
    282         if (mutex_functions.lock(&mbedtls_test_mutex_mutex) == 0) {
    283             switch (mutex->state) {
    284                 case MUTEX_FREED:
    285                     mbedtls_test_mutex_usage_error(mutex, "unlock without init");
    286                     break;
    287                 case MUTEX_IDLE:
    288                     mbedtls_test_mutex_usage_error(mutex, "unlock without lock");
    289                     break;
    290                 case MUTEX_LOCKED:
    291                     mutex->state = MUTEX_IDLE;
    292                     break;
    293                 default:
    294                     mbedtls_test_mutex_usage_error(mutex, "corrupted state");
    295                     break;
    296             }
    297             mutex_functions.unlock(&mbedtls_test_mutex_mutex);
    298         }
    299     }
    300 
    301     return mutex_functions.unlock(mutex);
    302 }
    303 
    304 void mbedtls_test_mutex_usage_init(void)
    305 {
    306     mutex_functions.init = mbedtls_mutex_init;
    307     mutex_functions.free = mbedtls_mutex_free;
    308     mutex_functions.lock = mbedtls_mutex_lock;
    309     mutex_functions.unlock = mbedtls_mutex_unlock;
    310     mbedtls_mutex_init = &mbedtls_test_wrap_mutex_init;
    311     mbedtls_mutex_free = &mbedtls_test_wrap_mutex_free;
    312     mbedtls_mutex_lock = &mbedtls_test_wrap_mutex_lock;
    313     mbedtls_mutex_unlock = &mbedtls_test_wrap_mutex_unlock;
    314 
    315     mutex_functions.init(&mbedtls_test_mutex_mutex);
    316 }
    317 
    318 void mbedtls_test_mutex_usage_check(void)
    319 {
    320     if (mutex_functions.lock(&mbedtls_test_mutex_mutex) == 0) {
    321         if (live_mutexes != 0) {
    322             /* A positive number (more init than free) means that a mutex resource
    323              * is leaking (on platforms where a mutex consumes more than the
    324              * mbedtls_threading_mutex_t object itself). The (hopefully) rare
    325              * case of a negative number means a missing init somewhere. */
    326             mbedtls_fprintf(stdout, "[mutex: %d leaked] ", live_mutexes);
    327             live_mutexes = 0;
    328             mbedtls_test_set_mutex_usage_error("missing free");
    329         }
    330         if (mbedtls_test_get_mutex_usage_error() != NULL &&
    331             mbedtls_test_get_result() != MBEDTLS_TEST_RESULT_FAILED) {
    332             /* Functionally, the test passed. But there was a mutex usage error,
    333              * so mark the test as failed after all. */
    334             mbedtls_test_fail("Mutex usage error", __LINE__, __FILE__);
    335         }
    336         mbedtls_test_set_mutex_usage_error(NULL);
    337 
    338         mutex_functions.unlock(&mbedtls_test_mutex_mutex);
    339     }
    340 }
    341 
    342 void mbedtls_test_mutex_usage_end(void)
    343 {
    344     mbedtls_mutex_init = mutex_functions.init;
    345     mbedtls_mutex_free = mutex_functions.free;
    346     mbedtls_mutex_lock = mutex_functions.lock;
    347     mbedtls_mutex_unlock = mutex_functions.unlock;
    348 
    349     mutex_functions.free(&mbedtls_test_mutex_mutex);
    350 }
    351 
    352 #endif /* MBEDTLS_TEST_MUTEX_USAGE */
    353 
    354 #endif /* MBEDTLS_THREADING_C */