7:57 a.m.
MALLOC_CHECK_ and MALLOC_PERTURB_ environment variables have been
replaced in glibc 2.34 by GLIBC_TUNABLES settings[1][2]. In addition
the new glibc requires that you preload a new library called
libc_malloc_debug.so.0 to get these features.
These features never worked in non-glibc (but the environment
variables are ignored).
Only define MALLOC_* environment variables when we detect glibc < 2.34,
using the ordinary glibc macros[3].
For glibc >= 2.34, use the new library and GLIBC_TUNABLES. Note this
relies on LD_PRELOAD warning but otherwise not breaking if a preload
library does not exist.
[1] https://www.gnu.org/software/libc/manual/html_node/Memory-Allocation-Tuna...
[2] https://sourceware.org/pipermail/libc-alpha/2021-August/129718.html
[3] https://sourceforge.net/p/predef/wiki/Libraries/
Thanks: Eric Blake
---
configure.ac | 24 ++++++++++++++++++++++++
tests/Makefile.am | 23 +++++++++++++++++------
2 files changed, 41 insertions(+), 6 deletions(-)
diff --git a/configure.ac b/configure.ac
index 9eb9b174..bdb56b37 100644
--- a/configure.ac
+++ b/configure.ac
@@ -569,6 +569,30 @@ AS_IF([test "x$is_windows" = "xyes"],[
AC_SEARCH_LIBS([getaddrinfo], [network socket])
+dnl Does this libc have MALLOC_CHECK_ and MALLOC_PERTURB_ (both glibc)
+dnl and does the feature require libc_malloc_debug.so (glibc >= 2.34)?
+AC_MSG_CHECKING([if this is glibc])
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+#include <limits.h>
+#ifndef __GLIBC__
+#error "not glibc"
+#endif
+ ]])], [is_glibc=yes], [is_glibc=no]
+)
+AC_MSG_RESULT([$is_glibc])
+AM_CONDITIONAL([HAVE_GLIBC], [test "x$is_glibc" = "xyes"])
+
+AC_MSG_CHECKING([if this is glibc >= 2.34])
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+#include <limits.h>
+#if !defined(__GLIBC__) || __GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__
< 34)
+#error "not glibc 2.34"
+#endif
+ ]])], [is_glibc_234=yes], [is_glibc_234=no]
+)
+AC_MSG_RESULT([$is_glibc_234])
+AM_CONDITIONAL([HAVE_GLIBC_234], [test "x$is_glibc_234" = "xyes"])
+
dnl Check for SELinux socket labelling (optional).
PKG_CHECK_MODULES([LIBSELINUX], [libselinux], [
AC_SUBST([LIBSELINUX_CFLAGS])
diff --git a/tests/Makefile.am b/tests/Makefile.am
index a6e27d95..5919187b 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -61,21 +61,32 @@ EXTRA_DIST = README.tests
EXTRA_PROGRAMS =
# Use the 'direct' backend, and ensure maximum libguestfs debugging.
-#
# Enable libnbd debugging.
-#
-# Enable malloc-check as a cheap way to find some use-after-free and
-# uninitialized read problems when using glibc, and doesn't affect
-# normal operation or other libc.
TESTS_ENVIRONMENT = \
SRCDIR=$(srcdir) \
LIBGUESTFS_ATTACH_METHOD=appliance \
LIBGUESTFS_DEBUG=1 \
LIBGUESTFS_TRACE=1 \
LIBNBD_DEBUG=1 \
+ $(NULL)
+
+# Enable malloc-check as a cheap way to find some use-after-free and
+# uninitialized read problems when using glibc, and doesn't affect
+# normal operation or other libc.
+random = $(shell bash -c 'echo $$(( 1 + (RANDOM & 255) ))')
+if HAVE_GLIBC_234
+TESTS_ENVIRONMENT += \
+ LD_PRELOAD="$${LD_PRELOAD:+"$$LD_PRELOAD:"}$(libdir)/libc_malloc_debug.so.0"
\
+ GLIBC_TUNABLES=glibc.malloc.check=1:glibc.malloc.perturb=$(random) \
+ $(NULL)
+else
+if HAVE_GLIBC
+TESTS_ENVIRONMENT += \
MALLOC_CHECK_=1 \
- MALLOC_PERTURB_=$(shell bash -c 'echo $$(( 1 + (RANDOM & 255) ))') \
+ MALLOC_PERTURB_=$(random) \
$(NULL)
+endif
+endif
if !IS_WINDOWS
# Ensure we're testing the local copy by running everything through
--
2.32.0