| /* Copyright (c) 2020, Google Inc. |
| * |
| * 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. */ |
| |
| #ifndef OPENSSL_HEADER_CRYPTO_FORK_DETECT_H |
| #define OPENSSL_HEADER_CRYPTO_FORK_DETECT_H |
| |
| #include <openssl/base.h> |
| |
| #if defined(OPENSSL_LINUX) |
| // On linux we use MADVISE instead of pthread_atfork(), due |
| // to concerns about clone() being used for address space |
| // duplication. |
| #define OPENSSL_FORK_DETECTION |
| #define OPENSSL_FORK_DETECTION_MADVISE |
| #elif defined(OPENSSL_MACOS) || defined(OPENSSL_IOS) || \ |
| defined(OPENSSL_OPENBSD) || defined(OPENSSL_FREEBSD) |
| // These platforms may detect address space duplication with pthread_atfork. |
| // iOS doesn't normally allow fork in apps, but it's there. |
| #define OPENSSL_FORK_DETECTION |
| #define OPENSSL_FORK_DETECTION_PTHREAD_ATFORK |
| #elif defined(OPENSSL_WINDOWS) || defined(OPENSSL_TRUSTY) || \ |
| defined(__ZEPHYR__) || defined(CROS_EC) |
| // These platforms do not fork. |
| #define OPENSSL_DOES_NOT_FORK |
| #endif |
| |
| #if defined(__cplusplus) |
| extern "C" { |
| #endif |
| |
| |
| // crypto_get_fork_generation returns the fork generation number for the current |
| // process, or zero if not supported on the platform. The fork generation number |
| // is a non-zero, strictly-monotonic counter with the property that, if queried |
| // in an address space and then again in a subsequently forked copy, the forked |
| // address space will observe a greater value. |
| // |
| // This function may be used to clear cached values across a fork. When |
| // initializing a cache, record the fork generation. Before using the cache, |
| // check if the fork generation has changed. If so, drop the cache and update |
| // the save fork generation. Note this logic transparently handles platforms |
| // which always return zero. |
| // |
| // This is not reliably supported on all platforms which implement |fork|, so it |
| // should only be used as a hardening measure. |
| OPENSSL_EXPORT uint64_t CRYPTO_get_fork_generation(void); |
| |
| // CRYPTO_fork_detect_force_madv_wipeonfork_for_testing is an internal detail |
| // used for testing purposes. |
| OPENSSL_EXPORT void CRYPTO_fork_detect_force_madv_wipeonfork_for_testing( |
| int on); |
| |
| #if defined(__cplusplus) |
| } // extern C |
| #endif |
| |
| #endif // OPENSSL_HEADER_CRYPTO_FORK_DETECT_H |
