glibc/sysdeps/arm/setjmp.S

/* setjmp for ARM.
   Copyright (C) 1997-2023 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library.  If not, see
   <https://www.gnu.org/licenses/>.  */

#include <sysdep.h>
#include <pointer_guard.h>
#include <stap-probe.h>
#include <bits/setjmp.h>
#include <rtld-global-offsets.h>
#include <arm-features.h>

ENTRY (__sigsetjmp)
#ifdef PTR_MANGLE
	PTR_MANGLE_LOAD (a3, ip)
#endif
	mov	ip, r0

	/* setjmp probe expects sigsetjmp first argument (4@r0), second
	   argument (-4@r1), and target address (4@r14), respectively.  */
	LIBC_PROBE (setjmp, 3, 4@r0, -4@r1, 4@r14)

	/* Save sp and lr */
#ifdef PTR_MANGLE
	mov	a4, sp
	PTR_MANGLE2 (a4, a4, a3)
	str	a4, [ip], #4
	PTR_MANGLE2 (a4, lr, a3)
	str	a4, [ip], #4
#else
	str	sp, [ip], #4
	str	lr, [ip], #4
#endif
	/* Save registers */
	stmia	ip!, JMP_BUF_REGLIST

#if !defined ARM_ASSUME_NO_IWMMXT || defined __SOFTFP__
# define NEED_HWCAP 1
#endif

#ifdef NEED_HWCAP
	/* Check if we have a VFP unit.  */
# if IS_IN (rtld)
	LDST_PCREL (ldr, a3, a4, \
		    C_SYMBOL_NAME(_rtld_local_ro) \
		    + RTLD_GLOBAL_RO_DL_HWCAP_OFFSET)
# else
#  ifdef SHARED
	LDR_GLOBAL (a3, a4, C_SYMBOL_NAME(_rtld_global_ro), \
		    RTLD_GLOBAL_RO_DL_HWCAP_OFFSET)
#  else
	LDR_GLOBAL (a3, a4, C_SYMBOL_NAME(_dl_hwcap), 0)
#  endif
# endif
#endif

#ifdef __SOFTFP__
	tst	a3, #HWCAP_ARM_VFP
	beq	.Lno_vfp
#endif

	/* Store the VFP registers.
	   Don't use VFP instructions directly because this code
	   is used in non-VFP multilibs.  */
	/* Following instruction is vstmia ip!, {d8-d15}.  */
	stc	p11, cr8, [ip], #64
.Lno_vfp:

#ifndef ARM_ASSUME_NO_IWMMXT
	tst	a3, #HWCAP_ARM_IWMMXT
	beq	.Lno_iwmmxt

	/* Save the call-preserved iWMMXt registers.  */
	/* Following instructions are wstrd wr10, [ip], #8 (etc.)  */
	stcl	p1, cr10, [r12], #8
	stcl	p1, cr11, [r12], #8
	stcl	p1, cr12, [r12], #8
	stcl	p1, cr13, [r12], #8
	stcl	p1, cr14, [r12], #8
	stcl	p1, cr15, [r12], #8
.Lno_iwmmxt:
#endif

	/* Make a tail call to __sigjmp_save; it takes the same args.  */
	B	PLTJMP(C_SYMBOL_NAME(__sigjmp_save))

END (__sigsetjmp)

hidden_def (__sigsetjmp)