platform_bionic/libc/arch-arm64/bionic/syscall.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

51 lines
1.8 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>
ENTRY(syscall)
/* Move syscall No. from x0 to x8 */
mov x8, x0
/* Move syscall parameters from x1 thru x6 to x0 thru x5 */
mov x0, x1
mov x1, x2
mov x2, x3
mov x3, x4
mov x4, x5
mov x5, x6
svc #0
/* check if syscall returned successfully */
cmn x0, #(MAX_ERRNO + 1)
cneg x0, x0, hi
b.hi __set_errno_internal
ret
END(syscall)
NOTE_GNU_PROPERTY()