/*--------------------------------------------------------------------*/
/*--- The core dispatch loop, for jumping to a code address. ---*/
/*--- dispatch-arm-linux.S ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Valgrind, a dynamic binary instrumentation
framework.
Copyright (C) 2008-2017 Evan Geller
gaze@bea.ms
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307, USA.
The GNU General Public License is contained in the file COPYING.
*/
#include "pub_core_basics_asm.h"
#if defined(VGP_arm_linux)
.fpu vfp
#include "pub_core_dispatch_asm.h"
#include "pub_core_transtab_asm.h"
#include "libvex_guest_offsets.h" /* for OFFSET_arm_R* */
/*------------------------------------------------------------*/
/*--- ---*/
/*--- The dispatch loop. VG_(disp_run_translations) is ---*/
/*--- used to run all translations, ---*/
/*--- including no-redir ones. ---*/
/*--- ---*/
/*------------------------------------------------------------*/
/*----------------------------------------------------*/
/*--- Entry and preamble (set everything up) ---*/
/*----------------------------------------------------*/
/* signature:
void VG_(disp_run_translations)( UWord* two_words,
void* guest_state,
Addr host_addr );
*/
.text
.global VG_(disp_run_translations)
VG_(disp_run_translations):
/* r0 holds two_words
r1 holds guest_state
r2 holds host_addr
*/
/* The number of regs in this list needs to be even, in
order to keep the stack 8-aligned. */
push {r0, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, lr}
/* set FPSCR to vex-required default value */
mov r4, #0
fmxr fpscr, r4
/* Set up the guest state pointer */
mov r8, r1
/* and jump into the code cache. Chained translations in
the code cache run, until for whatever reason, they can't
continue. When that happens, the translation in question
will jump (or call) to one of the continuation points
VG_(cp_...) below. */
bx r2
/* NOTREACHED */
/*----------------------------------------------------*/
/*--- Postamble and exit. ---*/
/*----------------------------------------------------*/
postamble:
/* At this point, r1 and r2 contain two
words to be returned to the caller. r1
holds a TRC value, and r2 optionally may
hold another word (for CHAIN_ME exits, the
address of the place to patch.) */
/* We're leaving. Check that nobody messed with
FPSCR in ways we don't expect. */
fmrx r4, fpscr
bic r4, #0xF8000000 /* mask out NZCV and QC */
bic r4, #0x0000009F /* mask out IDC,IXC,UFC,OFC,DZC,IOC */
cmp r4, #0
beq remove_frame /* we're OK */
/* otherwise we have an invariant violation */
movw r1, #VG_TRC_INVARIANT_FAILED
movw r2, #0
/* fall through */
remove_frame:
/* Restore int regs, including importantly r0 (two_words) */
pop {r0, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, lr}
/* Stash return values */
str r1, [r0, #0]
str r2, [r0, #4]
bx lr
/*----------------------------------------------------*/
/*--- Continuation points ---*/
/*----------------------------------------------------*/
/* ------ Chain me to slow entry point ------ */
.global VG_(disp_cp_chain_me_to_slowEP)
VG_(disp_cp_chain_me_to_slowEP):
/* We got called. The return address indicates
where the patching needs to happen. Collect
the return address and, exit back to C land,
handing the caller the pair (Chain_me_S, RA) */
mov r1, #VG_TRC_CHAIN_ME_TO_SLOW_EP
mov r2, lr
/* 4 = movw r12, lo16(disp_cp_chain_me_to_slowEP)
4 = movt r12, hi16(disp_cp_chain_me_to_slowEP)
4 = blx r12 */
sub r2, r2, #4+4+4
b postamble
/* ------ Chain me to fast entry point ------ */
.global VG_(disp_cp_chain_me_to_fastEP)
VG_(disp_cp_chain_me_to_fastEP):
/* We got called. The return address indicates
where the patching needs to happen. Collect
the return address and, exit back to C land,
handing the caller the pair (Chain_me_F, RA) */
mov r1, #VG_TRC_CHAIN_ME_TO_FAST_EP
mov r2, lr
/* 4 = movw r12, lo16(disp_cp_chain_me_to_fastEP)
4 = movt r12, hi16(disp_cp_chain_me_to_fastEP)
4 = blx r12 */
sub r2, r2, #4+4+4
b postamble
/* ------ Indirect but boring jump ------ */
.global VG_(disp_cp_xindir)
VG_(disp_cp_xindir):
/* Where are we going? */
ldr r0, [r8, #OFFSET_arm_R15T]
/* stats only */
movw r1, #:lower16:vgPlain_stats__n_xindirs_32
movt r1, #:upper16:vgPlain_stats__n_xindirs_32
ldr r2, [r1, #0]
add r2, r2, #1
str r2, [r1, #0]
/* try a fast lookup in the translation cache */
// r0 = next guest, r1,r2,r3,r4 scratch
movw r1, #VG_TT_FAST_MASK // r1 = VG_TT_FAST_MASK
movw r4, #:lower16:VG_(tt_fast)
and r2, r1, r0, LSR #1 // r2 = entry #
movt r4, #:upper16:VG_(tt_fast) // r4 = &VG_(tt_fast)
add r1, r4, r2, LSL #3 // r1 = &tt_fast[entry#]
ldrd r4, r5, [r1, #0] // r4 = .guest, r5 = .host
cmp r4, r0
// jump to host if lookup succeeded
bxeq r5
/* otherwise the fast lookup failed */
/* RM ME -- stats only */
movw r1, #:lower16:vgPlain_stats__n_xindir_misses_32
movt r1, #:upper16:vgPlain_stats__n_xindir_misses_32
ldr r2, [r1, #0]
add r2, r2, #1
str r2, [r1, #0]
mov r1, #VG_TRC_INNER_FASTMISS
mov r2, #0
b postamble
/* ------ Assisted jump ------ */
.global VG_(disp_cp_xassisted)
VG_(disp_cp_xassisted):
/* r8 contains the TRC */
mov r1, r8
mov r2, #0
b postamble
/* ------ Event check failed ------ */
.global VG_(disp_cp_evcheck_fail)
VG_(disp_cp_evcheck_fail):
mov r1, #VG_TRC_INNER_COUNTERZERO
mov r2, #0
b postamble
.size VG_(disp_run_translations), .-VG_(disp_run_translations)
#endif // defined(VGP_arm_linux)
/* Let the linker know we don't need an executable stack */
MARK_STACK_NO_EXEC
/*--------------------------------------------------------------------*/
/*--- end dispatch-arm-linux.S ---*/
/*--------------------------------------------------------------------*/