diff options
Diffstat (limited to 'crypto/mem.c')
| -rw-r--r-- | crypto/mem.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/crypto/mem.c b/crypto/mem.c index ddcc1113d5..1498672800 100644 --- a/crypto/mem.c +++ b/crypto/mem.c @@ -137,9 +137,23 @@ int CRYPTO_mem_ctrl(int mode) if (mh_mode & CRYPTO_MEM_CHECK_ON) { mh_mode&= ~CRYPTO_MEM_CHECK_ENABLE; - if (disabling_thread != CRYPTO_thread_id()) + if (disabling_thread != CRYPTO_thread_id()) /* otherwise we already have the MALLOC2 lock */ { + /* Long-time lock CRYPTO_LOCK_MALLOC2 must not be claimed while + * we're holding CRYPTO_LOCK_MALLOC, or we'll deadlock if + * somebody else holds CRYPTO_LOCK_MALLOC2 (and cannot release it + * because we block entry to this function). + * Give them a chance, first, and then claim the locks in + * appropriate order (long-time lock first). + */ + CRYPTO_w_unlock(CRYPTO_LOCK_MALLOC); + /* Note that after we have waited for CRYPTO_LOCK_MALLOC2 + * and CRYPTO_LOCK_MALLOC, we'll still be in the right + * "case" and "if" branch because MemCheck_start and + * MemCheck_stop may never be used while there are multiple + * OpenSSL threads. */ CRYPTO_w_lock(CRYPTO_LOCK_MALLOC2); + CRYPTO_w_lock(CRYPTO_LOCK_MALLOC); disabling_thread=CRYPTO_thread_id(); } } |