Deprecate most of debug-memory

Fixes #8322

The leak-checking (and backtrace option, on some platforms) provided
by crypto-mdebug and crypto-mdebug-backtrace have been mostly neutered;
only the "make malloc fail" capability remains.  OpenSSL recommends using
the compiler's leak-detection instead.

The OPENSSL_DEBUG_MEMORY environment variable is no longer used.
CRYPTO_mem_ctrl(), CRYPTO_set_mem_debug(), CRYPTO_mem_leaks(),
CRYPTO_mem_leaks_fp() and CRYPTO_mem_leaks_cb() return a failure code.
CRYPTO_mem_debug_{malloc,realloc,free}() have been removed.  All of the
above are now deprecated.

Merge (now really small) mem_dbg.c into mem.c

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10572)

1 files changed, 2 insertions, 7 deletions

diff --git a/crypto/ex_data.c b/crypto/ex_data.c
index 58614b68a3..3cffef897b 100644
--- a/crypto/ex_data.c
+++ b/crypto/ex_data.c
@@ -38,13 +38,8 @@ static EX_CALLBACKS *get_and_lock(OPENSSL_CTX *ctx, int class_index)
     global = openssl_ctx_get_ex_data_global(ctx);
     if (global == NULL || global->ex_data_lock == NULL) {
         /*
-         * This can happen in normal operation when using CRYPTO_mem_leaks().
-         * The CRYPTO_mem_leaks() function calls OPENSSL_cleanup() which cleans
-         * up the locks. Subsequently the BIO that CRYPTO_mem_leaks() uses gets
-         * freed, which also attempts to free the ex_data. However
-         * CRYPTO_mem_leaks() ensures that the ex_data is freed early (i.e.
-         * before OPENSSL_cleanup() is called), so if we get here we can safely
-         * ignore this operation. We just treat it as an error.
+         * If we get here, someone (who?) cleaned up the lock, so just
+         * treat it as an error.
          */
          return NULL;
     }