libc: Split FORTIFY into its own headers
This patch cleans up our standard headers by moving most of the FORTIFY
cruft out in to its own sandbox. In order to include the *_chk and
*_real declarations, you can either enable FORTIFY, or `#define
__BIONIC_DECLARE_FORTIFY_HELPERS`.
Both sys/select.h and strings.h are explicitly ignored by this patch.
Both of these files have very small __BIONIC_FORTIFY blocks, and don't
define any actual FORTIFY'ed functions (just macros, and 3 *_chk
functions).
This patch also makes the versioner ignore the FORTIFY implementation
headers, since we're guaranteed to pick the FORTIFY'ed headers up when
looking at the regular headers. (...Not to mention that making the
FORTIFY'ed headers freestanding would be annoying to do and maintain for
~no benefit).
We bake the knowledge of where FORTIFY headers live directly into the
versioner. We could go with a more general approach (e.g. adding an -X
IGNORED_FILE flag that tells the versioner to ignore
$HEADER_PATH/$IGNORED_FILE), but we'd then have to repeat that for every
test, every manual invocation of the versioner, etc. for no benefit
that's obvious to me.
Bug: 12231437
Test: m checkbuild on bullhead internal master + CtsBionicTestCases. no
new errors.
Change-Id: Iffc0cc609009b33d989cdaddde0a809282131a5b
diff --git a/libc/include/bits/fortify/fcntl.h b/libc/include/bits/fortify/fcntl.h
new file mode 100644
index 0000000..1d3d7bc
--- /dev/null
+++ b/libc/include/bits/fortify/fcntl.h
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "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
+ * COPYRIGHT OWNER OR CONTRIBUTORS 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.
+ */
+
+#ifndef _FCNTL_H
+#error "Never include this file directly; instead, include <fcntl.h>"
+#endif
+
+int __open_2(const char*, int) __INTRODUCED_IN(17);
+int __openat_2(int, const char*, int) __INTRODUCED_IN(17);
+/*
+ * These are the easiest way to call the real open even in clang FORTIFY.
+ */
+int __open_real(const char*, int, ...) __RENAME(open);
+int __openat_real(int, const char*, int, ...) __RENAME(openat);
+
+#if defined(__BIONIC_FORTIFY)
+#define __open_too_many_args_error "too many arguments"
+#define __open_too_few_args_error "called with O_CREAT, but missing mode"
+#if defined(__clang__)
+
+#if __ANDROID_API__ >= __ANDROID_API_J_MR1__
+__BIONIC_ERROR_FUNCTION_VISIBILITY
+int open(const char* pathname, int flags, mode_t modes, ...) __overloadable
+ __errorattr(__open_too_many_args_error);
+
+__BIONIC_ERROR_FUNCTION_VISIBILITY
+int open(const char* pathname, int flags) __overloadable
+ __enable_if(flags & O_CREAT, __open_too_few_args_error)
+ __errorattr(__open_too_few_args_error);
+
+/*
+ * pass_object_size serves two purposes here, neither of which involve __bos: it
+ * disqualifies this function from having its address taken (so &open works),
+ * and it makes overload resolution prefer open(const char *, int) over
+ * open(const char *, int, ...).
+ */
+__BIONIC_FORTIFY_INLINE
+int open(const char* const __pass_object_size pathname,
+ int flags) __overloadable {
+ return __open_2(pathname, flags);
+}
+
+__BIONIC_FORTIFY_INLINE
+int open(const char* const __pass_object_size pathname, int flags, mode_t modes)
+ __overloadable {
+ return __open_real(pathname, flags, modes);
+}
+
+__BIONIC_ERROR_FUNCTION_VISIBILITY
+int openat(int dirfd, const char* pathname, int flags) __overloadable
+ __enable_if(flags & O_CREAT, __open_too_few_args_error)
+ __errorattr(__open_too_few_args_error);
+
+__BIONIC_ERROR_FUNCTION_VISIBILITY
+int openat(int dirfd, const char* pathname, int flags, mode_t modes, ...)
+ __overloadable
+ __errorattr(__open_too_many_args_error);
+
+__BIONIC_FORTIFY_INLINE
+int openat(int dirfd, const char* const __pass_object_size pathname,
+ int flags) __overloadable {
+ return __openat_2(dirfd, pathname, flags);
+}
+
+__BIONIC_FORTIFY_INLINE
+int openat(int dirfd, const char* const __pass_object_size pathname, int flags,
+ mode_t modes) __overloadable {
+ return __openat_real(dirfd, pathname, flags, modes);
+}
+#endif /* __ANDROID_API__ >= __ANDROID_API_J_MR1__ */
+
+#else /* defined(__clang__) */
+__errordecl(__creat_missing_mode, __open_too_few_args_error);
+__errordecl(__creat_too_many_args, __open_too_many_args_error);
+
+#if __ANDROID_API__ >= __ANDROID_API_J_MR1__
+__BIONIC_FORTIFY_INLINE
+int open(const char* pathname, int flags, ...) {
+ if (__builtin_constant_p(flags)) {
+ if ((flags & O_CREAT) && __builtin_va_arg_pack_len() == 0) {
+ __creat_missing_mode(); /* Compile time error. */
+ }
+ }
+
+ if (__builtin_va_arg_pack_len() > 1) {
+ __creat_too_many_args(); /* Compile time error. */
+ }
+
+ if ((__builtin_va_arg_pack_len() == 0) && !__builtin_constant_p(flags)) {
+ return __open_2(pathname, flags);
+ }
+
+ return __open_real(pathname, flags, __builtin_va_arg_pack());
+}
+
+__BIONIC_FORTIFY_INLINE
+int openat(int dirfd, const char* pathname, int flags, ...) {
+ if (__builtin_constant_p(flags)) {
+ if ((flags & O_CREAT) && __builtin_va_arg_pack_len() == 0) {
+ __creat_missing_mode(); /* Compile time error. */
+ }
+ }
+
+ if (__builtin_va_arg_pack_len() > 1) {
+ __creat_too_many_args(); /* Compile time error. */
+ }
+
+ if ((__builtin_va_arg_pack_len() == 0) && !__builtin_constant_p(flags)) {
+ return __openat_2(dirfd, pathname, flags);
+ }
+
+ return __openat_real(dirfd, pathname, flags, __builtin_va_arg_pack());
+}
+#endif /* __ANDROID_API__ >= __ANDROID_API_J_MR1__ */
+
+#endif /* defined(__clang__) */
+
+#undef __open_too_many_args_error
+#undef __open_too_few_args_error
+#endif /* defined(__BIONIC_FORTIFY) */