From 41a0ee10717a5afaa2bfdd0225245feecc09eea9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Sur=C3=BD?= <ondrej@isc.org>
Date: Thu, 21 Dec 2023 11:12:54 +0100
Subject: [PATCH] Add workaround for jemalloc linking order

Because we don't use jemalloc functions directly, but only via the
libisc library, the dynamic linker might pull the jemalloc library
too late when memory has been already allocated via standard libc
allocator.

Add a workaround round isc_mem_create() that makes the dynamic linker
to pull jemalloc earlier than libc.
---
 Makefile.top              | 12 ++++++++++--
 lib/isc/include/isc/mem.h | 19 +++++++++++++++++++
 lib/isc/mem.c             |  2 ++
 tests/libtest/dns.c       |  7 ++-----
 4 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/Makefile.top b/Makefile.top
index d01317dadb..da95a2d47a 100644
--- a/Makefile.top
+++ b/Makefile.top
@@ -23,12 +23,20 @@ AM_LDFLAGS +=					\
 	-Wl,-flat_namespace
 endif HOST_MACOS
 
-LIBISC_CFLAGS =						\
+if HAVE_JEMALLOC
+LIBISC_CFLAGS = $(JEMALLOC_CFLAGS)
+LIBISC_LIBS = $(JEMALLOC_LIBS)
+else
+LIBISC_CFLAGS =
+LIBISC_LIBS =
+endif
+
+LIBISC_CFLAGS +=						\
 	-I$(top_srcdir)/include				\
 	-I$(top_srcdir)/lib/isc/include			\
 	-I$(top_builddir)/lib/isc/include
 
-LIBISC_LIBS = $(top_builddir)/lib/isc/libisc.la
+LIBISC_LIBS += $(top_builddir)/lib/isc/libisc.la
 if HAVE_DTRACE
 LIBISC_DTRACE = $(top_builddir)/lib/isc/probes.lo
 endif
diff --git a/lib/isc/include/isc/mem.h b/lib/isc/include/isc/mem.h
index 6c099d8742..b7143bdbdd 100644
--- a/lib/isc/include/isc/mem.h
+++ b/lib/isc/include/isc/mem.h
@@ -23,6 +23,7 @@
 #include <isc/mutex.h>
 #include <isc/overflow.h>
 #include <isc/types.h>
+#include <isc/urcu.h>
 
 ISC_LANG_BEGINDECLS
 
@@ -183,7 +184,25 @@ extern unsigned int isc_mem_defaultflags;
 	} while (0)
 
 /*@{*/
+/*
+ * This is a little hack to help with dynamic link order,
+ * see https://github.com/jemalloc/jemalloc/issues/2566
+ * for more information.
+ */
+#if HAVE_JEMALLOC
+#include <jemalloc/jemalloc.h>
+
+extern volatile void *isc__mem_malloc;
+
+#define isc_mem_create(cp)                                        \
+	{                                                         \
+		isc__mem_create((cp)_ISC_MEM_FILELINE);           \
+		isc__mem_malloc = mallocx;                        \
+		ISC_INSIST(CMM_ACCESS_ONCE(isc__mem_malloc) != NULL); \
+	}
+#else
 #define isc_mem_create(cp) isc__mem_create((cp)_ISC_MEM_FILELINE)
+#endif
 void
 isc__mem_create(isc_mem_t **_ISC_MEM_FLARG);
 
diff --git a/lib/isc/mem.c b/lib/isc/mem.c
index e43ae4fc03..c23a39075e 100644
--- a/lib/isc/mem.c
+++ b/lib/isc/mem.c
@@ -69,6 +69,8 @@ unsigned int isc_mem_defaultflags = ISC_MEMFLAG_DEFAULT;
 
 #define ISC_MEM_ILLEGAL_ARENA (UINT_MAX)
 
+volatile void *isc__mem_malloc = mallocx;
+
 /*
  * Constants.
  */
diff --git a/tests/libtest/dns.c b/tests/libtest/dns.c
index 73fb630807..29ac69e5fa 100644
--- a/tests/libtest/dns.c
+++ b/tests/libtest/dns.c
@@ -24,9 +24,6 @@
 #include <time.h>
 #include <unistd.h>
 
-#define UNIT_TESTING
-#include <cmocka.h>
-
 #include <isc/buffer.h>
 #include <isc/file.h>
 #include <isc/hash.h>
@@ -264,7 +261,7 @@ dns_test_tohex(const unsigned char *data, size_t len, char *buf,
 	memset(buf, 0, buflen);
 	isc_buffer_init(&target, buf, buflen);
 	result = isc_hex_totext((isc_region_t *)&source, 1, " ", &target);
-	assert_int_equal(result, ISC_R_SUCCESS);
+	INSIST(result == ISC_R_SUCCESS);
 
 	return (buf);
 }
@@ -428,7 +425,7 @@ dns_test_namefromstring(const char *namestr, dns_fixedname_t *fname) {
 
 	isc_buffer_putmem(b, (const unsigned char *)namestr, length);
 	result = dns_name_fromtext(name, b, NULL, 0, NULL);
-	assert_int_equal(result, ISC_R_SUCCESS);
+	INSIST(result == ISC_R_SUCCESS);
 
 	isc_buffer_free(&b);
 }