Add "random malloc failure" tooling

Still needs to be documented, somehow/somewhere.

The env var OPENSSL_MALLOC_FAILURES controls how often malloc/realloc
should fail.  It's a set of fields separated by semicolons.  Each field
is a count and optional percentage (separated by @) which defaults to 100.
If count is zero then it lasts "forever."  For example: 100;@25 means the
first 100 allocations pass, then the rest have a 25% chance of failing
until the program exits or crashes.

If env var OPENSSL_MALLOC_FD parses as a positive integer, a record
of all malloc "shouldfail" tests is written to that file descriptor.
If a malloc will fail, and OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE is not set
(platform specific), then a backtrace will be written to the descriptor
when a malloc fails.  This can be useful because a malloc may fail but
not be checked, and problems will only occur later.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1252)

1 files changed, 1 insertions, 0 deletions

diff --git a/crypto/include/internal/cryptlib_int.h b/crypto/include/internal/cryptlib_int.h
index 8e2a7199a1..60241d15dc 100644
--- a/crypto/include/internal/cryptlib_int.h
+++ b/crypto/include/internal/cryptlib_int.h
@@ -29,3 +29,4 @@ int ossl_init_thread_start(uint64_t opts);
 # define OPENSSL_INIT_THREAD_ASYNC           0x01
 # define OPENSSL_INIT_THREAD_ERR_STATE       0x02
 
+void ossl_malloc_setup_failures(void);