eb847bc866
The x86_64 build was failing because clone.S had a call to __thread_entry which was being added to a different intermediate .a on the way to making libc.so, and the linker couldn't guarantee statically that such a relocation would be possible. ld: error: out/target/product/generic_x86_64/obj/STATIC_LIBRARIES/libc_common_intermediates/libc_common.a(clone.o): requires dynamic R_X86_64_PC32 reloc against '__thread_entry' which may overflow at runtime; recompile with -fPIC This patch addresses that by ensuring that the caller and callee end up in the same intermediate .a. While I'm here, I've tried to clean up some of the mess that led to this situation too. In particular, this removes libc/private/ from the default include path (except for the DNS code), and splits out the DNS code into its own library (since it's a weird special case of upstream NetBSD code that's diverged so heavily it's unlikely ever to get back in sync). There's more cleanup of the DNS situation possible, but this is definitely a step in the right direction, and it's more than enough to get x86_64 building cleanly. Change-Id: I00425a7245b7a2573df16cc38798187d0729e7c4
111 lines
3.0 KiB
C++
111 lines
3.0 KiB
C++
/*
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* Copyright 2006 The Android Open Source Project
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*/
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#include <stddef.h>
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#include <sys/atomics.h>
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#include <endian.h>
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#include "private/bionic_atomic_inline.h"
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#include "private/bionic_futex.h"
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// This file contains C++ ABI support functions for one time
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// constructors as defined in the "Run-time ABI for the ARM Architecture"
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// section 4.4.2
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//
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// ARM C++ ABI and Itanium/x86 C++ ABI has different definition for
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// one time construction:
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//
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// ARM C++ ABI defines the LSB of guard variable should be tested
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// by compiler-generated code before calling __cxa_guard_acquire et al.
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//
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// The Itanium/x86 C++ ABI defines the low-order _byte_ should be
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// tested instead.
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//
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// Meanwhile, guard variable are 32bit aligned for ARM, and 64bit
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// aligned for x86.
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//
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// Reference documentation:
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//
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// section 3.2.3 of ARM IHI 0041C (for ARM)
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// section 3.3.2 of the Itanium C++ ABI specification v1.83 (for x86).
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//
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// There is no C++ ABI available for other ARCH. But the gcc source
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// shows all other ARCH follow the definition of Itanium/x86 C++ ABI.
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#if defined(__arm__)
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// The ARM C++ ABI mandates that guard variable are
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// 32-bit aligned, 32-bit values. And only its LSB is tested by
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// the compiler-generated code before calling
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// __cxa_guard_acquire.
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//
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typedef union {
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int volatile state;
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int32_t aligner;
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} _guard_t;
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const static int ready = 0x1;
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const static int pending = 0x2;
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const static int waiting = 0x6;
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#else // GCC sources indicates all none-arm follow the same ABI
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// The Itanium/x86 C++ ABI mandates that guard variables
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// are 64-bit aligned, 64-bit values. Also, the least-significant
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// byte is tested by the compiler-generated code before, we calling
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// __cxa_guard_acquire. We can access it through the first
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// 32-bit word in the union below.
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//
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typedef union {
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int volatile state;
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int64_t aligner;
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} _guard_t;
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const static int ready = letoh32(0x1);
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const static int pending = letoh32(0x100);
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const static int waiting = letoh32(0x10000);
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#endif
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extern "C" int __cxa_guard_acquire(_guard_t* gv)
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{
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// 0 -> pending, return 1
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// pending -> waiting, wait and return 0
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// waiting: untouched, wait and return 0
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// ready: untouched, return 0
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retry:
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if (__bionic_cmpxchg(0, pending, &gv->state) == 0) {
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ANDROID_MEMBAR_FULL();
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return 1;
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}
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__bionic_cmpxchg(pending, waiting, &gv->state); // Indicate there is a waiter
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__futex_wait(&gv->state, waiting, NULL);
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if (gv->state != ready) // __cxa_guard_abort was called, let every thread try since there is no return code for this condition
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goto retry;
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ANDROID_MEMBAR_FULL();
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return 0;
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}
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extern "C" void __cxa_guard_release(_guard_t* gv)
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{
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// pending -> ready
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// waiting -> ready, and wake
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ANDROID_MEMBAR_FULL();
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if (__bionic_cmpxchg(pending, ready, &gv->state) == 0) {
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return;
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}
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gv->state = ready;
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__futex_wake(&gv->state, 0x7fffffff);
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}
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extern "C" void __cxa_guard_abort(_guard_t* gv)
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{
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ANDROID_MEMBAR_FULL();
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gv->state= 0;
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__futex_wake(&gv->state, 0x7fffffff);
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}
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