platform_bionic/libc/private/bionic_macros.h
Tom Cherry 4362f897f7 Only use uids and gids for which we've allocated AIDs
Currently, getpwnam, getpwent, etc return successfully for any uid
from AID_APP_START (10000) to AID_USER_OFFSET (100000) for each user.
This is not correct however, as only specific ranges above
AID_APP_START are reserved as valid ranges.  This change corrects this.

This is particularly important as the newly added AID_OVERFLOWUID is
65534, which is above AID_APP_START but not in any reserved range,
collided with the faulty returned values.

Bug: 69119022
Bug: 69128408
Test: pwd/grp bionic unit tests
Change-Id: I3dae97a90597915fa30a88fe27cda88b107e9c35
2017-11-15 10:31:49 -08:00

97 lines
3.6 KiB
C++

/*
* Copyright (C) 2010 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.
*/
#ifndef _BIONIC_MACROS_H_
#define _BIONIC_MACROS_H_
#include <stdint.h>
// Frameworks OpenGL code currently leaks this header and allows
// collisions with other declarations, e.g., from libnativehelper.
// TODO: Remove once cleaned up. b/18334516
#if !defined(DISALLOW_COPY_AND_ASSIGN)
// DISALLOW_COPY_AND_ASSIGN disallows the copy and operator= functions.
// It goes in the private: declarations in a class.
#define DISALLOW_COPY_AND_ASSIGN(TypeName) \
TypeName(const TypeName&) = delete; \
void operator=(const TypeName&) = delete
#endif // !defined(DISALLOW_COPY_AND_ASSIGN)
// A macro to disallow all the implicit constructors, namely the
// default constructor, copy constructor and operator= functions.
//
// This should be used in the private: declarations for a class
// that wants to prevent anyone from instantiating it. This is
// especially useful for classes containing only static methods.
#define DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \
TypeName() = delete; \
DISALLOW_COPY_AND_ASSIGN(TypeName)
#define BIONIC_ROUND_UP_POWER_OF_2(value) \
((sizeof(value) == 8) \
? (1UL << (64 - __builtin_clzl(static_cast<unsigned long>(value)))) \
: (1UL << (32 - __builtin_clz(static_cast<unsigned int>(value)))))
static constexpr uintptr_t align_down(uintptr_t p, size_t align) {
return p & ~(align - 1);
}
static constexpr uintptr_t align_up(uintptr_t p, size_t align) {
return (p + align - 1) & ~(align - 1);
}
template <typename T>
static inline T* align_down(T* p, size_t align) {
return reinterpret_cast<T*>(align_down(reinterpret_cast<uintptr_t>(p), align));
}
template <typename T>
static inline T* align_up(T* p, size_t align) {
return reinterpret_cast<T*>(align_up(reinterpret_cast<uintptr_t>(p), align));
}
#if defined(__arm__)
// Do not emit anything for arm, clang does not allow emiting an arm unwind
// directive.
// #define BIONIC_STOP_UNWIND asm volatile(".cantunwind")
#define BIONIC_STOP_UNWIND
#elif defined(__aarch64__)
#define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined x30")
#elif defined(__i386__)
#define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined \%eip")
#elif defined(__x86_64__)
#define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined \%rip")
#elif defined (__mips__)
#define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined $ra")
#endif
// The arraysize(arr) macro returns the # of elements in an array arr.
// The expression is a compile-time constant, and therefore can be
// used in defining new arrays, for example. If you use arraysize on
// a pointer by mistake, you will get a compile-time error.
//
// One caveat is that arraysize() doesn't accept any array of an
// anonymous type or a type defined inside a function.
//
// This template function declaration is used in defining arraysize.
// Note that the function doesn't need an implementation, as we only
// use its type.
template <typename T, size_t N>
char (&ArraySizeHelper(T (&array)[N]))[N]; // NOLINT(readability/casting)
#define arraysize(array) (sizeof(ArraySizeHelper(array)))
#endif // _BIONIC_MACROS_H_