Add a test to catch calls to calloc from libunwind

We'd like to avoid calls to all malloc related functions
so libunwind is still usable from such allocators.

Signed-off-by: Paul Pluzhnikov <ppluzhnikov@google.com>

.gitignore

@@ -35,6 +35,7 @@ tests/[GL]test-init
 tests/[GL]test-resume-sig
 tests/[GL]perf-simple
 tests/Ltest-nomalloc
+tests/Ltest-nocalloc
 tests/Lperf-simple
 tests/check-namespace.sh
 tests/forker

tests/Gtest-nocalloc.c

@@ -0,0 +1,137 @@
+/* libunwind - a platform-independent unwind library
+   Copyright (C) 2011 Google, Inc
+	Contributed by Paul Pluzhnikov <ppluzhnikov@google.com>
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <execinfo.h>  /* for backtrace  */
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <dlfcn.h>
+#include <pthread.h>
+#include <libunwind.h>
+
+#define panic(args...)				\
+	{ fprintf (stderr, args); exit (-1); }
+
+int verbose;
+int num_mallocs;
+int num_callocs;
+int in_unwind;
+
+void *
+calloc(size_t n, size_t s)
+{
+  static void * (*func)();
+
+#ifdef __GLIBC__
+  /* In glibc, dlsym() calls calloc. Calling dlsym(RTLD_NEXT, "calloc") here
+     causes infinite recursion.  Instead, we simply use it by its other
+     name.  */
+  extern void *__libc_calloc();
+  func = &__libc_calloc;
+#else
+  if(!func)
+    func = (void *(*)()) dlsym(RTLD_NEXT, "calloc");
+#endif
+
+  if (in_unwind) {
+    num_callocs++;
+    return NULL;
+  } else {
+    return func(n, s);
+  }
+}
+
+void *
+malloc(size_t s)
+{
+  static void * (*func)();
+
+  if(!func)
+    func = (void *(*)()) dlsym(RTLD_NEXT, "malloc");
+
+  if (in_unwind) {
+    num_mallocs++;
+    return NULL;
+  } else {
+    return func(s);
+  }
+}
+
+static void
+do_backtrace (void)
+{
+  const int num_levels = 100;
+  void *pc[num_levels];
+
+  in_unwind = 1;
+  backtrace(pc, num_levels);
+  in_unwind = 0;
+}
+
+void
+foo3 ()
+{
+  do_backtrace ();
+}
+
+void
+foo2 ()
+{
+  foo3 ();
+}
+
+void
+foo1 (void)
+{
+  foo2 ();
+  return NULL;
+}
+
+int
+main (int argc, char **argv)
+{
+  int i, num_errors;
+
+  /* Create (and leak) 100 TSDs, then call backtrace()
+     and check that it doesn't call malloc()/calloc().  */
+  for (i = 0; i < 100; ++i) {
+    pthread_key_t key;
+    if (pthread_key_create (&key, NULL))
+      panic ("FAILURE: unable to create key %d\n", i);
+  }
+  foo1 ();
+  num_errors = num_mallocs + num_callocs;
+  if (num_errors > 0)
+    {
+      fprintf (stderr,
+	       "FAILURE: detected %d error%s (malloc: %d, calloc: %d)\n",
+	       num_errors, num_errors > 1 ? "s" : "",
+	       num_mallocs, num_callocs);
+      exit (-1);
+    }
+  return 0;
+}

tests/Ltest-nocalloc.c

@@ -0,0 +1,5 @@
+#define UNW_LOCAL_ONLY
+#include <libunwind.h>
+#if !defined(UNW_REMOTE_ONLY)
+#include "Gtest-nocalloc.c"
+#endif

tests/Makefile.am

@@ -1,7 +1,8 @@
 AM_CPPFLAGS = -I$(top_srcdir)/include
 
 EXTRA_DIST =	run-ia64-test-dyn1 run-ptrace-mapper run-ptrace-misc	\
-		run-check-namespace check-namespace.sh.in Gtest-nomalloc.c
+		run-check-namespace check-namespace.sh.in Gtest-nomalloc.c \
+		Gtest-nocalloc.c
 
 MAINTAINERCLEANFILES = Makefile.in
 
@@ -44,7 +45,7 @@ endif #ARCH_IA64
 			Gtest-trace Ltest-trace				 \
 			test-async-sig test-flush-cache test-init-remote \
 			test-mem test-setjmp test-ptrace		 \
-			Ltest-nomalloc rs-race
+			Ltest-nomalloc Ltest-nocalloc rs-race
  noinst_PROGRAMS_cdep = forker mapper test-ptrace-misc test-varargs	\
 			Gperf-simple Lperf-simple			\
 			Gperf-trace Lperf-trace
@@ -102,6 +103,7 @@ Gtest_bt_SOURCES = Gtest-bt.c ident.c
 Ltest_bt_SOURCES = Ltest-bt.c ident.c
 test_ptrace_misc_SOURCES = test-ptrace-misc.c ident.c
 Ltest_nomalloc_SOURCES = Ltest-nomalloc.c
+Ltest_nocalloc_SOURCES = Ltest-nocalloc.c
 Gtest_trace_SOURCES = Gtest-trace.c ident.c
 Ltest_trace_SOURCES = Ltest-trace.c ident.c
 
@@ -148,6 +150,7 @@ Ltest_dyn1_LDADD = $(LIBUNWIND_local)
 Ltest_exc_LDADD = $(LIBUNWIND_local)
 Ltest_init_LDADD = $(LIBUNWIND_local)
 Ltest_nomalloc_LDADD = $(LIBUNWIND_local) @DLLIB@
+Ltest_nocalloc_LDADD = $(LIBUNWIND_local) @DLLIB@ -lpthread
 Ltest_resume_sig_LDADD = $(LIBUNWIND)
 Lperf_simple_LDADD = $(LIBUNWIND_local)
 Ltest_trace_LDADD = $(LIBUNWIND_local)