glibc/sysdeps/arm/setjmp.S
Will Newton 80a56cc3ee ARM: Add SystemTap probes to longjmp and setjmp.
Now the ARM port implements pointer encryption for jmpbufs, gdb needs
a SystemTap probe point in longjmp to determine the target PC of
a call to longjmp. This patch implements the probe point in longjmp
and a similar probe point in setjmp.

In order to have all the appropriate registers available to pass to the
probe this reorders the layout of jmpbuf, putting the sp and lr registers
at the start rather than the end, allowing them to be read and
written sequentially.

Tested on armv7, no new failures in the glibc testsuite and confirmed
that this fixes the gdb.base/longjmp.exp failures in the gdb testsuite.

ChangeLog:

2014-02-25  Will Newton  <will.newton@linaro.org>

	* sysdeps/arm/__longjmp.S: Include stap-probe.h.
	(__longjmp): Restore sp and lr before restoring callee
	saved registers.  Add longjmp and longjmp_target
	SystemTap probe point.
	* sysdeps/arm/bits/setjmp.h (__jmp_buf): Update comment.
	* sysdeps/arm/include/bits/setjmp.h (__JMP_BUF_SP):
	Define to zero to match jmpbuf layout.
	* sysdeps/arm/setjmp.S: Include stap-probe.h.
	(__sigsetjmp): Save sp and lr before saving callee
	saved registers.  Add setjmp SystemTap probe point.
2014-02-25 10:07:04 +00:00

133 lines
3.1 KiB
ArmAsm

/* setjmp for ARM.
Copyright (C) 1997-2014 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/>. */
#include <sysdep.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 */
sfi_breg ip, \
stmia \B!, 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. */
# ifdef IS_IN_rtld
ldr a3, 1f
ldr a4, .Lrtld_local_ro
0: add a3, pc, a3
add a3, a3, a4
ldr a3, [a3, #RTLD_GLOBAL_RO_DL_HWCAP_OFFSET]
# else
# ifdef PIC
ldr a3, 1f
ldr a4, .Lrtld_global_ro
0: add a3, pc, a3
ldr a3, [a3, a4]
ldr a3, [a3, #RTLD_GLOBAL_RO_DL_HWCAP_OFFSET]
# else
ldr a3, .Lhwcap
ldr a3, [a3, #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}. */
sfi_breg ip, \
stc p11, cr8, [\B], #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.) */
sfi_breg r12, \
stcl p1, cr10, [\B], #8
sfi_breg r12, \
stcl p1, cr11, [\B], #8
sfi_breg r12, \
stcl p1, cr12, [\B], #8
sfi_breg r12, \
stcl p1, cr13, [\B], #8
sfi_breg r12, \
stcl p1, cr14, [\B], #8
sfi_breg r12, \
stcl p1, cr15, [\B], #8
.Lno_iwmmxt:
#endif
/* Make a tail call to __sigjmp_save; it takes the same args. */
B PLTJMP(C_SYMBOL_NAME(__sigjmp_save))
#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 (__sigsetjmp)
hidden_def (__sigsetjmp)