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Diffstat (limited to 'lib/leak-checker.c')
| -rw-r--r-- | lib/leak-checker.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/lib/leak-checker.c b/lib/leak-checker.c new file mode 100644 index 000000000..a25fa71dc --- /dev/null +++ b/lib/leak-checker.c @@ -0,0 +1,244 @@ +/* + * Copyright (c) 2008, 2009 Nicira Networks. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <config.h> +#include "leak-checker.h" +#include <inttypes.h> +#include "backtrace.h" + +#define THIS_MODULE VLM_leak_checker +#include "vlog.h" + +#ifndef HAVE_MALLOC_HOOKS +void +leak_checker_start(const char *file_name UNUSED) +{ + VLOG_WARN("not enabling leak checker because the libc in use does not " + "have the required hooks"); +} + +void +leak_checker_set_limit(off_t max_size UNUSED) +{ +} + +void +leak_checker_claim(const void *p UNUSED) +{ +} + +void +leak_checker_usage(void) +{ + printf(" --check-leaks=FILE (accepted but ignored in this build)\n"); +} +#else /* HAVE_MALLOC_HOOKS */ +#include <errno.h> +#include <fcntl.h> +#include <malloc.h> +#include <sys/stat.h> + +typedef void *malloc_hook_type(size_t, const void *); +typedef void *realloc_hook_type(void *, size_t, const void *); +typedef void free_hook_type(void *, const void *); + +struct hooks { + malloc_hook_type *malloc_hook_func; + realloc_hook_type *realloc_hook_func; + free_hook_type *free_hook_func; +}; + +static malloc_hook_type hook_malloc; +static realloc_hook_type hook_realloc; +static free_hook_type hook_free; + +static struct hooks libc_hooks; +static const struct hooks our_hooks = { hook_malloc, hook_realloc, hook_free }; + +static FILE *file; +static off_t limit = 10 * 1000 * 1000; + +static void +get_hooks(struct hooks *hooks) +{ + hooks->malloc_hook_func = __malloc_hook; + hooks->realloc_hook_func = __realloc_hook; + hooks->free_hook_func = __free_hook; +} + +static void +set_hooks(const struct hooks *hooks) +{ + __malloc_hook = hooks->malloc_hook_func; + __realloc_hook = hooks->realloc_hook_func; + __free_hook = hooks->free_hook_func; +} + +void +leak_checker_start(const char *file_name) +{ + if (!file) { + file = fopen(file_name, "w"); + if (!file) { + VLOG_WARN("failed to create \"%s\": %s", + file_name, strerror(errno)); + return; + } + setvbuf(file, NULL, _IOLBF, 0); + VLOG_WARN("enabled memory leak logging to \"%s\"", file_name); + get_hooks(&libc_hooks); + set_hooks(&our_hooks); + } +} + +void +leak_checker_stop(void) +{ + if (file) { + fclose(file); + file = NULL; + set_hooks(&libc_hooks); + VLOG_WARN("disabled memory leak logging"); + } +} + +void +leak_checker_set_limit(off_t limit_) +{ + limit = limit_; +} + +void +leak_checker_usage(void) +{ + printf(" --check-leaks=FILE log malloc and free calls to FILE\n"); +} + +static void PRINTF_FORMAT(1, 2) +log_callers(const char *format, ...) +{ + struct backtrace backtrace; + va_list args; + int i; + + va_start(args, format); + vfprintf(file, format, args); + va_end(args); + + putc(':', file); + backtrace_capture(&backtrace); + for (i = 0; i < backtrace.n_frames; i++) { + fprintf(file, " 0x%x", backtrace.frames[i]); + } + putc('\n', file); +} + +static void +reset_hooks(void) +{ + static int count; + + if (file) { + if (ferror(file)) { + VLOG_WARN("error writing leak checker log file"); + leak_checker_stop(); + return; + } + + if (count++ >= 100 && limit) { + struct stat s; + count = 0; + if (fstat(fileno(file), &s) < 0) { + VLOG_WARN("cannot fstat leak checker log file: %s", + strerror(errno)); + leak_checker_stop(); + return; + } + if (s.st_size > limit) { + VLOG_WARN("leak checker log file size exceeded limit"); + leak_checker_stop(); + return; + } + } + } + if (file) { + set_hooks(&our_hooks); + } +} + +static void * +hook_malloc(size_t size, const void *caller UNUSED) +{ + void *p; + + set_hooks(&libc_hooks); + p = malloc(size); + get_hooks(&libc_hooks); + + log_callers("malloc(%zu) -> %p", size, p); + + reset_hooks(); + return p; +} + +void +leak_checker_claim(const void *p) +{ + if (!file) { + return; + } + + if (p) { + set_hooks(&libc_hooks); + log_callers("claim(%p)", p); + reset_hooks(); + } +} + +static void +hook_free(void *p, const void *caller UNUSED) +{ + if (!p) { + return; + } + + set_hooks(&libc_hooks); + free(p); + get_hooks(&libc_hooks); + + log_callers("free(%p)", p); + + reset_hooks(); +} + +static void * +hook_realloc(void *p, size_t size, const void *caller UNUSED) +{ + void *q; + + set_hooks(&libc_hooks); + q = realloc(p, size); + get_hooks(&libc_hooks); + + if (p != q) { + log_callers("realloc(%p, %zu) -> %p", p, size, q); + } + + reset_hooks(); + + return q; +} +#endif /* HAVE_MALLOC_HOOKS */ |