Add atexit configuration option to using atexit() in libcrypto at build-time.

This fixes an issue with a mix of atexit() usage in DLL and statically linked
libcrypto that came out in the test suite on NonStop, which has slightly
different DLL unload processing semantics compared to Linux. The change
allows a build configuration to select whether to register OPENSSL_cleanup()
with atexit() or not, so avoid situations where atexit() registration causes
SIGSEGV.

INSTALL.md and CHANGES.md have been modified to include and describe this
option.

Signed-off-by: Randall S. Becker <randall.becker@nexbridge.ca>
Signed-off-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Tom Cosgrove <tom.cosgrove@arm.com>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/23642)

(cherry picked from commit 0e1989d4c7435809b60f614c23ba8c9a7c0373e8)

diff --git a/.github/workflows/run-checker-ci.yml b/.github/workflows/run-checker-ci.yml
index 101c44f1b2ca3ded729e3aee071b74cadf431435..1f033fdba9e724035fbfbb22e41a3a3af5470147 100644 (file)
--- a/.github/workflows/run-checker-ci.yml
+++ b/.github/workflows/run-checker-ci.yml
@@ -17,6 +17,7 @@ jobs:
       fail-fast: false
       matrix:
         opt: [
+          no-atexit,
           no-cmp,
           no-cms,
           no-ct,

diff --git a/CHANGES.md b/CHANGES.md
index 91dd358db8e847d37f17d0ba6f4fbf323d0f9ca2..b42dd83bc0edd6035ec9914aa219491e642ba9c7 100644 (file)
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -30,7 +30,11 @@ breaking changes, and mappings for the large list of deprecated functions.
 
 ### Changes between 3.0.13 and 3.0.14 [xx XXX xxxx]
 
- * none yet
+ * New atexit configuration switch, which controls whether the OPENSSL_cleanup
+   is registered when libcrypto is unloaded. This can be used on platforms
+   where using atexit() from shared libraries causes crashes on exit.
+
+   *Randall S. Becker*
 
 ### Changes between 3.0.12 and 3.0.13 [30 Jan 2024]
 

diff --git a/Configure b/Configure
index 84cc4094644ac75f90a53fc7d81fc2908acdfafd..ab90de6ccc80999ae3c8ff2e7679576820fd886b 100755 (executable)
--- a/Configure
+++ b/Configure
@@ -405,6 +405,7 @@ my @disablables = (
     "asan",
     "asm",
     "async",
+    "atexit",
     "autoalginit",
     "autoerrinit",
     "autoload-config",

diff --git a/INSTALL.md b/INSTALL.md
index fef408e9d1e32b91938d0108ecc9603eff0bac0b..045b13739b34012e83f68d5c01126281b844be9a 100644 (file)
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -546,6 +546,13 @@ be used even with this option.
 
 Do not build support for async operations.
 
+### no-atexit
+
+Do not use `atexit()` in libcrypto builds.
+
+`atexit()` has varied semantics between platforms and can cause SIGSEGV in some
+circumstances. This options disables the atexit registration of OPENSSL_cleanup.
+
 ### no-autoalginit
 
 Don't automatically load all supported ciphers and digests.

diff --git a/NOTES-NONSTOP.md b/NOTES-NONSTOP.md
index 68438b998884e2a068b7f93886867d8ad4c6f38b..ab13de7d3a760af4eccbd7db83a4e1ee440988e1 100644 (file)
--- a/NOTES-NONSTOP.md
+++ b/NOTES-NONSTOP.md
@@ -56,7 +56,10 @@ relating to `atexit()` processing when a shared library is unloaded and when
 the program terminates. This limitation applies to all OpenSSL shared library
 components.
 
-A resolution to this situation is under investigation.
+It is possible to configure the build with `no-atexit` to avoid the SIGSEGV.
+Preferably, you can explicitly call `OPENSSL_cleanup()` from your application.
+It is not mandatory as it just deallocates various global data structures
+OpenSSL allocated.
 
 About Prefix and OpenSSLDir
 ---------------------------

diff --git a/crypto/init.c b/crypto/init.c
index cacf637c89f8e8c264400cc8ae443fb35192f042..994f752b4ea0df9c01523a6701b51e26b3afb377 100644 (file)
--- a/crypto/init.c
+++ b/crypto/init.c
@@ -97,17 +97,19 @@ static int win32atexit(void)
 
 DEFINE_RUN_ONCE_STATIC(ossl_init_register_atexit)
 {
-#ifdef OPENSSL_INIT_DEBUG
+#ifndef OPENSSL_NO_ATEXIT
+# ifdef OPENSSL_INIT_DEBUG
     fprintf(stderr, "OPENSSL_INIT: ossl_init_register_atexit()\n");
-#endif
-#ifndef OPENSSL_SYS_UEFI
-# if defined(_WIN32) && !defined(__BORLANDC__)
+# endif
+# ifndef OPENSSL_SYS_UEFI
+#  if defined(_WIN32) && !defined(__BORLANDC__)
     /* We use _onexit() in preference because it gets called on DLL unload */
     if (_onexit(win32atexit) == NULL)
         return 0;
-# else
+#  else
     if (atexit(OPENSSL_cleanup) != 0)
         return 0;
+#  endif
 # endif
 #endif
 

diff --git a/test/recipes/90-test_shlibload.t b/test/recipes/90-test_shlibload.t
index 8f691dee38e8238c2844a41a5c9fa7ffaaa12847..af6bae20af341483eefd2bf9c1d4981e7f9c601c 100644 (file)
--- a/test/recipes/90-test_shlibload.t
+++ b/test/recipes/90-test_shlibload.t
@@ -23,6 +23,7 @@ plan skip_all => "Test is disabled on AIX" if config('target') =~ m|^aix|;
 plan skip_all => "Test is disabled on NonStop" if config('target') =~ m|^nonstop|;
 plan skip_all => "Test only supported in a dso build" if disabled("dso");
 plan skip_all => "Test is disabled in an address sanitizer build" unless disabled("asan");
+plan skip_all => "Test is disabled if no-atexit is specified" if disabled("atexit");
 
 plan tests => 10;