Hi,
Add test-case that forces alloc.c functions to fail, and check whether fail
handling is robust.
This is the test-case for "[libbacktrace] Fix segfault upon allocation
failure". Without that patch, this test-case fails like this:
...
allocfail.sh: line 71: 26041 Segmentation fault (core dumped) \
./allocfail $i > /dev/null 2>&1
Unallowed fail found: 13
FAIL allocfail.sh (exit status: 1)
...
This is a seperate patch because the test-case is nontrivial.
Bootstrapped and reg-tested on x86_64.
OK for trunk?
Thanks,
- Tom
[libbacktrace] Add allocfail.sh test-case
2018-11-27 Tom de Vries <tdevr...@suse.de>
* Makefile.am (TESTS): Add allocfail.sh.
(check_PROGRAMS): Add allocfail.
* Makefile.in: Regenerate.
* instrumented_alloc.c: New file. Redefine malloc and realloc.
Include alloc.c.
* allocfail.c: New file.
* allocfail.sh: New file.
---
libbacktrace/Makefile.am | 15 +++++
libbacktrace/Makefile.in | 60 +++++++++++++----
libbacktrace/allocfail.c | 136 ++++++++++++++++++++++++++++++++++++++
libbacktrace/allocfail.sh | 105 +++++++++++++++++++++++++++++
libbacktrace/instrumented_alloc.c | 114 ++++++++++++++++++++++++++++++++
5 files changed, 418 insertions(+), 12 deletions(-)
diff --git a/libbacktrace/Makefile.am b/libbacktrace/Makefile.am
index 13e94f27aef..fdda769f18b 100644
--- a/libbacktrace/Makefile.am
+++ b/libbacktrace/Makefile.am
@@ -94,6 +94,21 @@ unittest_LDADD = libbacktrace.la
check_PROGRAMS += unittest
+libbacktrace_without_alloc = $(libbacktrace_la_OBJECTS) \
+ $(filter-out alloc.lo read.lo mmap.lo mmapio.lo, \
+ $(libbacktrace_la_LIBADD))
+
+instrumented_alloc.lo: alloc.c
+
+allocfail_SOURCES = allocfail.c testlib.c
+allocfail_LDADD = $(libbacktrace_without_alloc) instrumented_alloc.lo read.lo
+
+check_PROGRAMS += allocfail
+
+allocfail.sh: allocfail
+
+TESTS += allocfail.sh
+
btest_SOURCES = btest.c testlib.c
btest_CFLAGS = $(AM_CFLAGS) -g -O
btest_LDADD = libbacktrace.la
diff --git a/libbacktrace/Makefile.in b/libbacktrace/Makefile.in
index 2d62ce20b9a..49f28395686 100644
--- a/libbacktrace/Makefile.in
+++ b/libbacktrace/Makefile.in
@@ -121,11 +121,13 @@ build_triplet = @build@
host_triplet = @host@
target_triplet = @target@
check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3)
-@NATIVE_TRUE@am__append_1 = unittest btest stest ztest edtest
-@HAVE_ZLIB_TRUE@@NATIVE_TRUE@am__append_2 = -lz
-@HAVE_PTHREAD_TRUE@@NATIVE_TRUE@am__append_3 = ttest
-@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@am__append_4 = dtest
-@HAVE_COMPRESSED_DEBUG_TRUE@@NATIVE_TRUE@am__append_5 = ctestg ctesta
+@NATIVE_TRUE@am__append_1 = unittest allocfail btest stest ztest \
+@NATIVE_TRUE@ edtest
+@NATIVE_TRUE@am__append_2 = allocfail.sh
+@HAVE_ZLIB_TRUE@@NATIVE_TRUE@am__append_3 = -lz
+@HAVE_PTHREAD_TRUE@@NATIVE_TRUE@am__append_4 = ttest
+@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@am__append_5 = dtest
+@HAVE_COMPRESSED_DEBUG_TRUE@@NATIVE_TRUE@am__append_6 = ctestg ctesta
subdir = .
ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
am__aclocal_m4_deps = $(top_srcdir)/../config/cet.m4 \
@@ -158,12 +160,18 @@ AM_V_lt = $(am__v_lt_@AM_V@)
am__v_lt_ = $(am__v_lt_@AM_DEFAULT_V@)
am__v_lt_0 = --silent
am__v_lt_1 =
-@NATIVE_TRUE@am__EXEEXT_1 = unittest$(EXEEXT) btest$(EXEEXT) \
-@NATIVE_TRUE@ stest$(EXEEXT) ztest$(EXEEXT) edtest$(EXEEXT)
+@NATIVE_TRUE@am__EXEEXT_1 = unittest$(EXEEXT) allocfail$(EXEEXT) \
+@NATIVE_TRUE@ btest$(EXEEXT) stest$(EXEEXT) ztest$(EXEEXT) \
+@NATIVE_TRUE@ edtest$(EXEEXT)
@HAVE_PTHREAD_TRUE@@NATIVE_TRUE@am__EXEEXT_2 = ttest$(EXEEXT)
@HAVE_COMPRESSED_DEBUG_TRUE@@NATIVE_TRUE@am__EXEEXT_3 = \
@HAVE_COMPRESSED_DEBUG_TRUE@@NATIVE_TRUE@ ctestg$(EXEEXT) \
@HAVE_COMPRESSED_DEBUG_TRUE@@NATIVE_TRUE@ ctesta$(EXEEXT)
+@NATIVE_TRUE@am_allocfail_OBJECTS = allocfail.$(OBJEXT) \
+@NATIVE_TRUE@ testlib.$(OBJEXT)
+allocfail_OBJECTS = $(am_allocfail_OBJECTS)
+@NATIVE_TRUE@allocfail_DEPENDENCIES = $(libbacktrace_without_alloc) \
+@NATIVE_TRUE@ instrumented_alloc.lo read.lo
@NATIVE_TRUE@am_btest_OBJECTS = btest-btest.$(OBJEXT) \
@NATIVE_TRUE@ btest-testlib.$(OBJEXT)
btest_OBJECTS = $(am_btest_OBJECTS)
@@ -248,9 +256,9 @@ am__v_CCLD_ = $(am__v_CCLD_@AM_DEFAULT_V@)
am__v_CCLD_0 = @echo " CCLD " $@;
am__v_CCLD_1 =
SOURCES = $(libbacktrace_la_SOURCES) $(EXTRA_libbacktrace_la_SOURCES) \
- $(btest_SOURCES) $(ctesta_SOURCES) $(ctestg_SOURCES) \
- $(edtest_SOURCES) $(stest_SOURCES) $(ttest_SOURCES) \
- $(unittest_SOURCES) $(ztest_SOURCES)
+ $(allocfail_SOURCES) $(btest_SOURCES) $(ctesta_SOURCES) \
+ $(ctestg_SOURCES) $(edtest_SOURCES) $(stest_SOURCES) \
+ $(ttest_SOURCES) $(unittest_SOURCES) $(ztest_SOURCES)
am__can_run_installinfo = \
case $$AM_UPDATE_INFO_DIR in \
n|no|NO) false;; \
@@ -658,9 +666,15 @@ libbacktrace_la_LIBADD = \
$(ALLOC_FILE)
libbacktrace_la_DEPENDENCIES = $(libbacktrace_la_LIBADD)
-TESTS = $(check_PROGRAMS) $(am__append_4)
+TESTS = $(check_PROGRAMS) $(am__append_2) $(am__append_5)
@NATIVE_TRUE@unittest_SOURCES = unittest.c testlib.c
@NATIVE_TRUE@unittest_LDADD = libbacktrace.la
+@NATIVE_TRUE@libbacktrace_without_alloc = $(libbacktrace_la_OBJECTS) \
+@NATIVE_TRUE@ $(filter-out alloc.lo read.lo mmap.lo mmapio.lo, \
+@NATIVE_TRUE@ $(libbacktrace_la_LIBADD))
+
+@NATIVE_TRUE@allocfail_SOURCES = allocfail.c testlib.c
+@NATIVE_TRUE@allocfail_LDADD = $(libbacktrace_without_alloc)
instrumented_alloc.lo read.lo
@NATIVE_TRUE@btest_SOURCES = btest.c testlib.c
@NATIVE_TRUE@btest_CFLAGS = $(AM_CFLAGS) -g -O
@NATIVE_TRUE@btest_LDADD = libbacktrace.la
@@ -668,7 +682,7 @@ TESTS = $(check_PROGRAMS) $(am__append_4)
@NATIVE_TRUE@stest_LDADD = libbacktrace.la
@NATIVE_TRUE@ztest_SOURCES = ztest.c testlib.c
@NATIVE_TRUE@ztest_CFLAGS = -DSRCDIR=\"$(srcdir)\"
-@NATIVE_TRUE@ztest_LDADD = libbacktrace.la $(am__append_2) \
+@NATIVE_TRUE@ztest_LDADD = libbacktrace.la $(am__append_3) \
@NATIVE_TRUE@ $(CLOCK_GETTIME_LINK)
@NATIVE_TRUE@edtest_SOURCES = edtest.c edtest2_build.c testlib.c
@NATIVE_TRUE@edtest_LDADD = libbacktrace.la
@@ -782,6 +796,10 @@ clean-checkPROGRAMS:
echo " rm -f" $$list; \
rm -f $$list
+allocfail$(EXEEXT): $(allocfail_OBJECTS) $(allocfail_DEPENDENCIES)
$(EXTRA_allocfail_DEPENDENCIES)
+ @rm -f allocfail$(EXEEXT)
+ $(AM_V_CCLD)$(LINK) $(allocfail_OBJECTS) $(allocfail_LDADD) $(LIBS)
+
btest$(EXEEXT): $(btest_OBJECTS) $(btest_DEPENDENCIES)
$(EXTRA_btest_DEPENDENCIES)
@rm -f btest$(EXEEXT)
$(AM_V_CCLD)$(btest_LINK) $(btest_OBJECTS) $(btest_LDADD) $(LIBS)
@@ -1105,6 +1123,13 @@ unittest.log: unittest$(EXEEXT)
--log-file $$b.log --trs-file $$b.trs \
$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS)
-- $(LOG_COMPILE) \
"$$tst" $(AM_TESTS_FD_REDIRECT)
+allocfail.log: allocfail$(EXEEXT)
+ @p='allocfail$(EXEEXT)'; \
+ b='allocfail'; \
+ $(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
+ --log-file $$b.log --trs-file $$b.trs \
+ $(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS)
-- $(LOG_COMPILE) \
+ "$$tst" $(AM_TESTS_FD_REDIRECT)
btest.log: btest$(EXEEXT)
@p='btest$(EXEEXT)'; \
b='btest'; \
@@ -1154,6 +1179,13 @@ ctesta.log: ctesta$(EXEEXT)
--log-file $$b.log --trs-file $$b.trs \
$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS)
-- $(LOG_COMPILE) \
"$$tst" $(AM_TESTS_FD_REDIRECT)
+allocfail.sh.log: allocfail.sh
+ @p='allocfail.sh'; \
+ b='allocfail.sh'; \
+ $(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
+ --log-file $$b.log --trs-file $$b.trs \
+ $(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS)
-- $(LOG_COMPILE) \
+ "$$tst" $(AM_TESTS_FD_REDIRECT)
dtest.log: dtest
@p='dtest'; \
b='dtest'; \
@@ -1309,6 +1341,10 @@ uninstall-am:
.PRECIOUS: Makefile
+@NATIVE_TRUE@instrumented_alloc.lo: alloc.c
+
+@native_t...@allocfail.sh: allocfail
+
@NATIVE_TRUE@edtest2_build.c: gen_edtest2_build; @true
@NATIVE_TRUE@gen_edtest2_build: $(srcdir)/edtest2.c
@NATIVE_TRUE@ cat $(srcdir)/edtest2.c > tmp-edtest2_build.c
diff --git a/libbacktrace/allocfail.c b/libbacktrace/allocfail.c
new file mode 100644
index 00000000000..e9149ab977d
--- /dev/null
+++ b/libbacktrace/allocfail.c
@@ -0,0 +1,136 @@
+/* allocfail.c -- Test for libbacktrace library
+ Copyright (C) 2018 Free Software Foundation, Inc.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+ (1) Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+
+ (2) Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in
+ the documentation and/or other materials provided with the
+ distribution.
+
+ (3) The name of the author may not be used to
+ endorse or promote products derived from this software without
+ specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE. */
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "filenames.h"
+
+#include "backtrace.h"
+#include "backtrace-supported.h"
+
+#include "testlib.h"
+
+extern uint64_t get_nr_allocs (void);
+extern void set_fail_at_alloc (uint64_t);
+extern int at_fail_alloc_p (void);
+
+static int test1 (void) __attribute__ ((noinline, unused));
+static int f2 (int) __attribute__ ((noinline));
+static int f3 (int, int) __attribute__ ((noinline));
+
+static unsigned callback_errors = 0;
+
+static void
+error_callback_full (void *vdata ATTRIBUTE_UNUSED,
+ const char *msg ATTRIBUTE_UNUSED,
+ int errnum ATTRIBUTE_UNUSED)
+{
+ if (at_fail_alloc_p ())
+ {
+ set_fail_at_alloc (0);
+ return;
+ }
+
+ callback_errors++;
+}
+
+static int
+callback_full (void *vdata ATTRIBUTE_UNUSED, uintptr_t pc ATTRIBUTE_UNUSED,
+ const char *filename ATTRIBUTE_UNUSED,
+ int lineno ATTRIBUTE_UNUSED,
+ const char *function ATTRIBUTE_UNUSED)
+{
+
+ return 0;
+}
+
+static int
+test1 (void)
+{
+ return f2 (__LINE__) + 1;
+}
+
+static int
+f2 (int f1line)
+{
+ return f3 (f1line, __LINE__) + 2;
+}
+
+static int
+f3 (int f1line ATTRIBUTE_UNUSED, int f2line ATTRIBUTE_UNUSED)
+{
+ int i;
+
+ i = backtrace_full (state, 0, callback_full, error_callback_full, NULL);
+
+ if (i != 0)
+ {
+ fprintf (stderr, "test1: unexpected return value %d\n", i);
+ ++failures;
+ }
+
+ if (callback_errors)
+ ++failures;
+
+ return failures;
+}
+
+/* Run all the tests. */
+
+int
+main (int argc, char **argv)
+{
+ uint64_t fail_at = 0;
+
+ if (argc == 2)
+ {
+ fail_at = atoi (argv[1]);
+ set_fail_at_alloc (fail_at);
+ }
+
+ state = backtrace_create_state (argv[0], BACKTRACE_SUPPORTS_THREADS,
+ error_callback_full, NULL);
+ if (state == NULL)
+ exit (failures ? EXIT_FAILURE : EXIT_SUCCESS);
+
+#if BACKTRACE_SUPPORTED
+ test1 ();
+#endif
+
+ if (argc == 1)
+ fprintf (stderr, "%lu\n", get_nr_allocs ());
+
+ exit (failures ? EXIT_FAILURE : EXIT_SUCCESS);
+}
diff --git a/libbacktrace/allocfail.sh b/libbacktrace/allocfail.sh
new file mode 100755
index 00000000000..91bc7a3e73d
--- /dev/null
+++ b/libbacktrace/allocfail.sh
@@ -0,0 +1,105 @@
+#!/bin/sh
+
+# allocfail.sh -- Test for libbacktrace library.
+# Copyright (C) 2018 Free Software Foundation, Inc.
+
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+
+# (1) Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+
+# (2) Redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in
+# the documentation and/or other materials provided with the
+# distribution.
+
+# (3) The name of the author may not be used to
+# endorse or promote products derived from this software without
+# specific prior written permission.
+
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+# INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+# STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+# IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+set -e
+set -o pipefail
+
+if [ ! -f ./allocfail ]; then
+ # Hard failure.
+ exit 99
+fi
+
+allocs=$(./allocfail 2>&1)
+if [ "$allocs" = "" ]; then
+ # Hard failure.
+ exit 99
+fi
+
+# This generates the following output:
+# ...
+# $ allocfail.sh
+# allocs: 80495
+# Status changed to 0 at 1
+# Status changed to 1 at 3
+# Status changed to 0 at 11
+# Status changed to 1 at 12
+# Status changed to 0 at 845
+# ...
+#
+# We have status 0 for an allocation failure at:
+# - 1 because backtrace_create_state handles failure robustly
+# - 2 because the fail switches backtrace_full to !can_alloc mode.
+# - 11 because failure of elf_open_debugfile_by_buildid does not generate an
+# error callback beyond the one for the allocation failure itself.
+
+echo "allocs: $allocs"
+
+step=1
+i=1
+passes=0
+prev_status=-1
+while [ $i -le $allocs ]; do
+ if ./allocfail $i >/dev/null 2>&1; status=$?; then
+ true
+ fi
+ if [ $status -gt 1 ]; then
+ echo "Unallowed fail found: $i"
+ # Failure.
+ exit 1
+ fi
+
+ # The test-case would run too long if we would excercise all allocs.
+ # So, run with step 1 initially, and increase the step once we have 10
+ # subsequent passes, and drop back to step 1 once we encounter another
+ # failure. This takes ~2.6 seconds on an i7-6600U CPU @ 2.60GHz.
+ if [ $status -eq 0 ]; then
+ passes=$(($passes + 1))
+ if [ $passes -ge 10 ]; then
+ step=$((step * 10))
+ passes=0
+ fi
+ elif [ $status -eq 1 ]; then
+ passes=0
+ step=1
+ fi
+
+ if [ $status -ne $prev_status ]; then
+ echo "Status changed to $status at $i"
+ fi
+ prev_status=$status
+
+ i=$(($i + $step))
+done
+
+# Success.
+exit 0
diff --git a/libbacktrace/instrumented_alloc.c
b/libbacktrace/instrumented_alloc.c
new file mode 100644
index 00000000000..ba42ea65a04
--- /dev/null
+++ b/libbacktrace/instrumented_alloc.c
@@ -0,0 +1,114 @@
+/* instrumented_alloc.c -- Memory allocation instrumented to fail when
+ requested, for testing purposes.
+ Copyright (C) 2018 Free Software Foundation, Inc.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+ (1) Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+
+ (2) Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in
+ the documentation and/or other materials provided with the
+ distribution.
+
+ (3) The name of the author may not be used to
+ endorse or promote products derived from this software without
+ specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE. */
+
+/* Include all the header files of alloc here, to make sure they're not
+ processed when including alloc.c below, such that the redefinitions of
malloc
+ and realloc are only effective in alloc.c itself. This does not work for
+ config.h, because it's not wrapped in "#ifndef CONFIG_H\n#define CONFIG_H"
+ and "#endif" but that does not seem to be harmful. */
+
+#include "config.h"
+
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <inttypes.h>
+
+#include "backtrace.h"
+#include "internal.h"
+
+extern void *instrumented_malloc (size_t size);
+extern void *instrumented_realloc (void *ptr, size_t size);
+
+#define malloc instrumented_malloc
+#define realloc instrumented_realloc
+#include "alloc.c"
+#undef malloc
+#undef realloc
+
+static uint64_t nr_allocs = 0;
+static uint64_t fail_at_alloc = 0;
+
+extern int at_fail_alloc_p (void);
+extern uint64_t get_nr_allocs (void);
+extern void set_fail_at_alloc (uint64_t);
+
+void *
+instrumented_malloc (size_t size)
+{
+ void *res;
+
+ if (at_fail_alloc_p ())
+ return NULL;
+
+ res = malloc (size);
+ if (res != NULL)
+ nr_allocs++;
+
+ return res;
+}
+
+void *
+instrumented_realloc (void *ptr, size_t size)
+{
+ void *res;
+
+ if (size != 0)
+ {
+ if (at_fail_alloc_p ())
+ return NULL;
+ }
+
+ res = realloc (ptr, size);
+ if (res != NULL)
+ nr_allocs++;
+
+ return res;
+}
+
+int
+at_fail_alloc_p (void)
+{
+ return fail_at_alloc == nr_allocs + 1;
+}
+
+uint64_t
+get_nr_allocs (void)
+{
+ return nr_allocs;
+}
+
+void
+set_fail_at_alloc (uint64_t nr)
+{
+ fail_at_alloc = nr;
+}
