glibc/ports/sysdeps/arm/__longjmp.S
Will Newton b7f2d27dbd ARM: Add pointer encryption support.
Add support for pointer encryption in glibc internal structures in C
and assembler code. Pointer encryption is a glibc security feature
described here:

https://sourceware.org/glibc/wiki/PointerEncryption

The ARM implementation uses global variables instead of thread pointer
relative accesses to get the value of the pointer encryption guard
because accessing the thread pointer can be very expensive on older
ARM cores.

ports/ChangeLog.arm:

2013-10-03  Will Newton  <will.newton@linaro.org>

	* sysdeps/arm/__longjmp.S (__longjmp): Demangle fp, sp
	and lr when restoring register values.
	* sysdeps/arm/include/bits/setjmp.h (JMP_BUF_REGLIST): Remove
	sp and lr from list and replace fp with a4.
	* sysdeps/arm/jmpbuf-unwind.h (_jmpbuf_sp): New function.
	(_JMPBUF_UNWINDS_ADJ): Call _jmpbuf_sp.
	* sysdeps/arm/setjmp.S (__sigsetjmp): Mangle fp, sp and lr
	before storing register values.
	* sysdeps/arm/sysdep.h (LDST_GLOBAL): New macro.
	* sysdeps/unix/sysv/linux/arm/sysdep.h (PTR_MANGLE): New macro.
	(PTR_DEMANGLE): Likewise. (PTR_MANGLE2): Likewise.
	(PTR_DEMANGLE2): Likewise.
2013-10-03 11:35:50 +01:00

143 lines
3.2 KiB
ArmAsm

/* longjmp for ARM.
Copyright (C) 1997-2013 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
<http://www.gnu.org/licenses/>. */
/* ??? Needs more rearrangement for the LDM to handle thumb mode. */
#define NO_THUMB
#include <sysdep.h>
#include <bits/setjmp.h>
#include <rtld-global-offsets.h>
#include <arm-features.h>
/* __longjmp(jmpbuf, val) */
ENTRY (__longjmp)
mov ip, r0
movs r0, r1 /* get the return value in place */
moveq r0, #1 /* can't let setjmp() return zero! */
#ifdef CHECK_SP
sfi_breg ip, \
ldr r4, [\B, #32] /* jmpbuf's sp */
cfi_undefined (r4)
#ifdef PTR_DEMANGLE
PTR_DEMANGLE (r4, r4, a3, a4)
#endif
CHECK_SP (r4)
#endif
sfi_sp sfi_breg ip, \
ldmia \B!, JMP_BUF_REGLIST
#ifdef PTR_DEMANGLE
PTR_DEMANGLE (fp, a4, a3, a2)
ldr a4, [ip], #4
PTR_DEMANGLE2 (sp, a4, a3)
ldr a4, [ip], #4
PTR_DEMANGLE2 (lr, a4, a3)
#else
mov fp, a4
ldr sp, [ip], #4
ldr lr, [ip], #4
#endif
cfi_restore (v1)
cfi_restore (v2)
cfi_restore (v3)
cfi_restore (v4)
cfi_restore (v5)
cfi_restore (v6)
cfi_restore (sl)
cfi_restore (fp)
cfi_restore (sp)
cfi_restore (lr)
#if !defined ARM_ASSUME_NO_IWMMXT || defined __SOFTFP__
# define NEED_HWCAP 1
#endif
#ifdef NEED_HWCAP
# ifdef IS_IN_rtld
ldr a2, 1f
ldr a3, .Lrtld_local_ro
0: add a2, pc, a2
add a2, a2, a3
ldr a2, [a2, #RTLD_GLOBAL_RO_DL_HWCAP_OFFSET]
# else
# ifdef PIC
ldr a2, 1f
ldr a3, .Lrtld_global_ro
0: add a2, pc, a2
ldr a2, [a2, a3]
ldr a2, [a2, #RTLD_GLOBAL_RO_DL_HWCAP_OFFSET]
# else
ldr a2, .Lhwcap
ldr a2, [a2, #0]
# endif
# endif
#endif
#ifdef __SOFTFP__
tst a2, #HWCAP_ARM_VFP
beq .Lno_vfp
#endif
/* Restore the VFP registers. */
/* Following instruction is vldmia ip!, {d8-d15}. */
sfi_breg r12, \
ldc p11, cr8, [\B], #64
.Lno_vfp:
#ifndef ARM_ASSUME_NO_IWMMXT
tst a2, #HWCAP_ARM_IWMMXT
beq .Lno_iwmmxt
/* Restore the call-preserved iWMMXt registers. */
/* Following instructions are wldrd wr10, [ip], #8 (etc.) */
sfi_breg r12, \
ldcl p1, cr10, [\B], #8
sfi_breg r12, \
ldcl p1, cr11, [\B], #8
sfi_breg r12, \
ldcl p1, cr12, [\B], #8
sfi_breg r12, \
ldcl p1, cr13, [\B], #8
sfi_breg r12, \
ldcl p1, cr14, [\B], #8
sfi_breg r12, \
ldcl p1, cr15, [\B], #8
.Lno_iwmmxt:
#endif
DO_RET(lr)
#ifdef NEED_HWCAP
# ifdef IS_IN_rtld
1: .long _GLOBAL_OFFSET_TABLE_ - 0b - PC_OFS
.Lrtld_local_ro:
.long C_SYMBOL_NAME(_rtld_local_ro)(GOTOFF)
# else
# ifdef PIC
1: .long _GLOBAL_OFFSET_TABLE_ - 0b - PC_OFS
.Lrtld_global_ro:
.long C_SYMBOL_NAME(_rtld_global_ro)(GOT)
# else
.Lhwcap:
.long C_SYMBOL_NAME(_dl_hwcap)
# endif
# endif
#endif
END (__longjmp)