platform_bionic/libc/arch-arm64/bionic/__bionic_clone.S
Tamas Petz f5bdee7fdf libc: Add Armv8.3-A PAuth and Armv8.5-A BTI compatibility to *.S
The most notable change is in sigsetjmp/siglongjmp. The former
stores LR signed with the current SP into jmp_buf. Calling siglongjmp
reads a signed LR and the corresponding SP from jmp_buf. This way not
only the checksum provides some means of integrity protection but
Pointer Authentication too.

Test: Tested on FVP with BTI enabled.

Change-Id: I9d720239775f8d2829a677901f546c4b14b5cbe5
2020-09-04 11:29:12 +02:00

61 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_PRIVATE(__bionic_clone)
# Push '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, #0
# Setting x30 to 0 will make the unwinder stop at __start_thread.
mov x30, #0
# 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)
NOTE_GNU_PROPERTY()