diff options
Diffstat (limited to 'test/libmallocintercept.c')
| -rw-r--r-- | test/libmallocintercept.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/test/libmallocintercept.c b/test/libmallocintercept.c new file mode 100644 index 0000000..363ea95 --- /dev/null +++ b/test/libmallocintercept.c @@ -0,0 +1,79 @@ +/* + * Copyright (C) 2022 be.storaged GmbH + * + * This file is part of libfaketime + * + * libfaketime is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License v2 as published by the + * Free Software Foundation. + * + * libfaketime is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License v2 along + * with the libfaketime; if not, write to the Free Software Foundation, + * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <pthread.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> +#include <unistd.h> + +static void print_msg(const char *msg) { + write(0, msg, strlen(msg)); +} + +static void* actual_malloc(size_t size) { + /* We would like to use "the real malloc", but cannot. Thus, this + * implements a trivial, allocate-only bump allocator to make things + * work. + */ + static char memory_arena[16 << 20]; + static size_t allocated_index = 0; + + void *result = &memory_arena[allocated_index]; + + allocated_index += size; + /* align to a multiple of 8 bytes */ + allocated_index = (allocated_index + 7) / 8 * 8; + + if (allocated_index >= sizeof(memory_arena)) { + print_msg("libmallocintercept is out of memory!"); + abort(); + } + + return result; +} + +static void poke_faketime(void) { + /* To complicate things for libfaketime, this calls clock_gettime() + * while holding a lock. This should simulate problems that occurred + * with address sanitizer. + */ + static pthread_mutex_t time_mutex = PTHREAD_MUTEX_INITIALIZER; + struct timespec timespec; + + pthread_mutex_lock(&time_mutex); + clock_gettime(CLOCK_REALTIME, ×pec); + pthread_mutex_unlock(&time_mutex); +} + +void *malloc(size_t size) { + print_msg("Called malloc() from libmallocintercept..."); + poke_faketime(); + print_msg("successfully\n"); + return actual_malloc(size); +} + +void free(void *) { + print_msg("Called free() from libmallocintercept..."); + poke_faketime(); + print_msg("successfully\n"); + + /* We cannot actually free memory */ +} + |