freebsd-src/lib/csu/aarch64/crtn.S
Andrew Turner 522126fea7 csu: Teach csu about PAC and BTI
Add the Branch Target Identification (BTI) note to libc assembly
sources and Pointer Authentication Code (PAC) instructions to _init and
_fini.

_init and _fini may be called indirectly so need a BTI landing pad. As
they are non-leaf functions use the appropriate PAC instruction that
also guards against changing the link register.

As all object files need the note for any binary using these object files
we need to insert it in all asm files.

Reviewed by:	markj
Sponsored by:	Arm Ltd
Differential Revision:	https://reviews.freebsd.org/D42227
2023-10-30 17:55:44 +00:00

47 lines
1.7 KiB
ArmAsm

/*-
* Copyright 2001 David E. O'Brien
* Copyright 2014 The FreeBSD Foundation
* All rights reserved.
*
* Portions of this software were developed by Andrew Turner
* under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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 AUTHOR ``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 AUTHOR 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 <machine/asm.h>
#include <sys/elf_common.h>
.section .init,"ax",@progbits
ldp x29, x30, [sp], #16
PAC_LR_AUTH
ret
.section .fini,"ax",@progbits
ldp x29, x30, [sp], #16
PAC_LR_AUTH
ret
.section .note.GNU-stack,"",%progbits
GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)