From: Otto Moerbeek <otto.moerbeek@open-xchange.com>
Date: Fri, 7 Mar 2025 14:20:45 +0000 (+0100)
Subject: rec: comment on an issue encountered runnig asan on trixie
X-Git-Tag: dnsdist-2.0.0-alpha1~32^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d775afbd8bf10833cba257038b60525f48cefd02;p=thirdparty%2Fpdns.git

rec: comment on an issue encountered runnig asan on trixie
---

diff --git a/meson/sanitizers/meson.build b/meson/sanitizers/meson.build
index d708ba79fe..afeb398c5a 100644
--- a/meson/sanitizers/meson.build
+++ b/meson/sanitizers/meson.build
@@ -2,6 +2,11 @@ opt_sanitize = get_option('b_sanitize')
 
 if opt_sanitize == 'address' or opt_sanitize == 'address,undefined'
   subdir('address-sanitizer-fiber-switching')
+  conf.set(
+    'HAVE_LEAK_SANITIZER_INTERFACE',
+    cxx.has_header('sanitizer/lsan_interface.h'),
+    description: 'Have leak sanitizer inteface',
+  )
 endif
 
 if opt_sanitize != 'none'
diff --git a/pdns/recursordist/mtasker_context.cc b/pdns/recursordist/mtasker_context.cc
index 1bd3fd8ae1..06766b16ba 100644
--- a/pdns/recursordist/mtasker_context.cc
+++ b/pdns/recursordist/mtasker_context.cc
@@ -118,6 +118,10 @@ extern "C"
   threadWrapper(intptr_t const xargs)
   {
 #else
+  // If you see asan trouble in this function, run with
+  // ASAN_OPTIONS=detect_stack_use_after_return=0 or completely disable it by comping with
+  // -fsanitize-address-use-after-return=never.  On debian clang versions up and including 14 do
+  // not seem to trigger a problem here, but starting from version 15 they do.
   threadWrapper(transfer_t const theThread)
   {
 #endif