platform_bionic/libc/arch-arm64/bionic/__bionic_clone.S
Elliott Hughes 011e111d29 Ensure __set_errno is still visible on LP32.
The use of the .hidden directive to avoid going via the PLT for
__set_errno had the side-effect of actually making __set_errno
hidden (which is odd because assembler directives don't usually
affect symbols defined in a different file --- you can't even
create a weak reference to a symbol that's defined in a different
file).

This change switches the system call stubs over to a new always-hidden
__set_errno_internal and has a visible __set_errno on LP32 just for
binary compatibility with old NDK apps.

(cherry-pick of 7efad83d430f4d824f2aaa75edea5106f6ff8aae.)

Bug: 17423135
Change-Id: I6b6d7a05dda85f923d22e5ffd169a91e23499b7b
2014-09-08 16:46:50 -07:00

60 lines
2.3 KiB
ArmAsm

/*
* Copyright (C) 2013 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>
// pid_t __bionic_clone(int flags, void* child_stack, pid_t* parent_tid, void* tls, pid_t* child_tid, int (*fn)(void*), void* arg);
ENTRY(__bionic_clone)
# Copy 'fn' and 'arg' onto the child stack.
stp x5, x6, [x1, #-16]
# Make the system call.
mov x8, __NR_clone
svc #0
# Are we the child?
cbz x0, .L_bc_child
# Set errno if something went wrong.
cmn x0, #(MAX_ERRNO + 1)
cneg x0, x0, hi
b.hi __set_errno_internal
ret
.L_bc_child:
# We're in the child now. Set the end of the frame record chain...
mov x29, xzr
# Setting x30 to 0 will make the unwinder stop at __start_thread
mov x30, xzr
# ...and call __start_thread with the 'fn' and 'arg' we stored on the child stack.
ldp x0, x1, [sp, #-16]
b __start_thread
END(__bionic_clone)
.hidden __bionic_clone