Add interrupter library to simulate EINTR

To check for robustness against EINTR from syscalls, add an
interrupter library that can be preloaded with LD_PRELOAD.

Change-Id: I0a6cd8702ec5bc6b2927a5e223ee3cdc033860a2

3 files changed, 153 insertions, 0 deletions

diff --git a/cmds/interrupter/Android.mk b/cmds/interrupter/Android.mk
new file mode 100644
index 0000000..e324627
--- /dev/null
+++ b/cmds/interrupter/Android.mk
@@ -0,0 +1,21 @@
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    interrupter.c
+LOCAL_MODULE := interrupter
+LOCAL_MODULE_TAGS := eng tests
+LOCAL_LDFLAGS := -ldl
+
+include $(BUILD_SHARED_LIBRARY)
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    interrupter.c
+LOCAL_MODULE := interrupter
+LOCAL_MODULE_TAGS := eng tests
+LOCAL_LDFLAGS := -ldl
+
+include $(BUILD_HOST_SHARED_LIBRARY)
\ No newline at end of file
diff --git a/cmds/interrupter/interrupter.c b/cmds/interrupter/interrupter.c
new file mode 100644
index 0000000..ae55515
--- /dev/null
+++ b/cmds/interrupter/interrupter.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2012, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+/**
+ * The probability of a syscall failing from 0.0 to 1.0
+ */
+#define PROBABILITY 0.9
+
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+
+/* for various intercepted calls */
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+/* For builds on glibc */
+#define __USE_GNU
+#include <dlfcn.h>
+
+#include "interrupter.h"
+
+static int probability = PROBABILITY * RAND_MAX;
+
+static int maybe_interrupt() {
+    if (rand() < probability) {
+        return 1;
+    }
+    return 0;
+}
+
+DEFINE_INTERCEPT(read, ssize_t, int, void*, size_t);
+DEFINE_INTERCEPT(write, ssize_t, int, const void*, size_t);
+DEFINE_INTERCEPT(accept, int, int, struct sockaddr*, socklen_t*);
+DEFINE_INTERCEPT(creat, int, const char*, mode_t);
diff --git a/cmds/interrupter/interrupter.h b/cmds/interrupter/interrupter.h
new file mode 100644
index 0000000..9ad0277
--- /dev/null
+++ b/cmds/interrupter/interrupter.h
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2012, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define CONCATENATE(arg1, arg2)   CONCATENATE1(arg1, arg2)
+#define CONCATENATE1(arg1, arg2)  CONCATENATE2(arg1, arg2)
+#define CONCATENATE2(arg1, arg2)  arg1##arg2
+
+#define INTERRUPTER(sym) \
+    if (real_##sym == NULL) \
+        __init_##sym(); \
+    if (maybe_interrupt()) { \
+        errno = EINTR; \
+        return -1; \
+    }
+
+#define CALL_FUNCTION_1(sym, ret, type1) \
+ret (*real_##sym)(type1) = NULL; \
+ret sym(type1 arg1) { \
+    INTERRUPTER(sym) \
+    return real_##sym(arg1); \
+}
+
+#define CALL_FUNCTION_2(sym, ret, type1, type2) \
+ret (*real_##sym)(type1, type2) = NULL; \
+ret sym(type1 arg1, type2 arg2) { \
+    INTERRUPTER(sym) \
+    return real_##sym(arg1, arg2); \
+}
+
+#define CALL_FUNCTION_3(sym, ret, type1, type2, type3) \
+ret (*real_##sym)(type1, type2, type3) = NULL; \
+ret sym(type1 arg1, type2 arg2, type3 arg3) { \
+    INTERRUPTER(sym) \
+    return real_##sym(arg1, arg2, arg3); \
+}
+
+#define CALL_FUNCTION_4(sym, ret, type1, type2, type3, type4) \
+ret (*real_##sym)(type1, type2, type3, type4) = NULL; \
+ret sym(type1 arg1, type2 arg2, type3 arg3, type4 arg4) { \
+    INTERRUPTER(sym) \
+    return real_##sym(arg1, arg2, arg3, arg4); \
+}
+
+#define CALL_FUNCTION_5(sym, ret, type1, type2, type3, type4, type5) \
+ret (*real_##sym)(type1, type2, type3, type4, type5) = NULL; \
+ret sym(type1 arg1, type2 arg2, type3 arg3, type4 arg4, type5 arg5) { \
+    INTERRUPTER(sym) \
+    return real_##sym(arg1, arg2, arg3, arg4, arg5); \
+}
+
+#define DEFINE_INTERCEPT_N(N, sym, ret, ...) \
+static void __init_##sym(void); \
+CONCATENATE(CALL_FUNCTION_, N)(sym, ret, __VA_ARGS__) \
+static void __init_##sym(void) { \
+    real_##sym = dlsym(RTLD_NEXT, #sym); \
+    if (real_##sym == NULL) { \
+        fprintf(stderr, "Error hooking " #sym ": %s\n", dlerror()); \
+    } \
+}
+
+#define INTERCEPT_NARG(...) INTERCEPT_NARG_N(__VA_ARGS__, INTERCEPT_RSEQ_N())
+#define INTERCEPT_NARG_N(...) INTERCEPT_ARG_N(__VA_ARGS__)
+#define INTERCEPT_ARG_N(_1, _2, _3, _4, _5, _6, _7, _8, N, ...) N
+#define INTERCEPT_RSEQ_N() 8, 7, 6, 5, 4, 3, 2, 1, 0
+
+#define DEFINE_INTERCEPT(sym, ret, ...) DEFINE_INTERCEPT_N(INTERCEPT_NARG(__VA_ARGS__), sym, ret, __VA_ARGS__)