| /* |
| * Copyright (C) 2018 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_asm.h> |
| |
| // For arm32 and -mtp=soft, the compiler uses this function to read the thread |
| // pointer for ELF TLS accesses. With -mtp=cp15, the compiler inlines the call |
| // instead. GCC defaults to -mtp=auto, which inlines this function with |
| // -march=armv7-a. Clang does not yet implement -mtp=auto, and instead defaults |
| // to -mtp=soft. |
| // - https://bugs.llvm.org/show_bug.cgi?id=38394. |
| // - https://reviews.llvm.org/D34878?id=114573. |
| // |
| // This function must preserve every register except r0, ip, lr, and cpsr. |
| // |
| // See "Run-time ABI for the ARM Architecture" |
| // http://infocenter.arm.com/help/topic/com.arm.doc.ihi0043d/IHI0043D_rtabi.pdf |
| // |
| ENTRY(__aeabi_read_tp) |
| // __get_tls() |
| mrc p15, 0, r0, c13, c0, 3 |
| bx lr |
| END(__aeabi_read_tp) |