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/*
* Copyright (C) 2019 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.
*/
#include "private/bionic_call_ifunc_resolver.h"
#include <sys/auxv.h>
#include <sys/ifunc.h>
#include "private/bionic_auxv.h"
// This code is called in the linker before it has been relocated, so minimize calls into other
// parts of Bionic. In particular, we won't ever have two ifunc resolvers called concurrently, so
// initializing the ifunc resolver argument doesn't need to be thread-safe.
ElfW(Addr) __bionic_call_ifunc_resolver(ElfW(Addr) resolver_addr) {
#if defined(__aarch64__)
typedef ElfW(Addr) (*ifunc_resolver_t)(uint64_t, __ifunc_arg_t*);
static __ifunc_arg_t arg;
static bool initialized = false;
if (!initialized) {
initialized = true;
arg._size = sizeof(__ifunc_arg_t);
arg._hwcap = getauxval(AT_HWCAP);
arg._hwcap2 = getauxval(AT_HWCAP2);
}
return reinterpret_cast<ifunc_resolver_t>(resolver_addr)(arg._hwcap | _IFUNC_ARG_HWCAP, &arg);
#elif defined(__arm__)
typedef ElfW(Addr) (*ifunc_resolver_t)(unsigned long);
static unsigned long hwcap;
static bool initialized = false;
if (!initialized) {
initialized = true;
hwcap = getauxval(AT_HWCAP);
}
return reinterpret_cast<ifunc_resolver_t>(resolver_addr)(hwcap);
#else
typedef ElfW(Addr) (*ifunc_resolver_t)(void);
return reinterpret_cast<ifunc_resolver_t>(resolver_addr)();
#endif
}
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