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Prevent writes to R15 via LDR or LDM from changing the ARM/Thumb state in pre-v5 architectures.

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PR sim/8388
	* armemu.c (WriteR15Load): New function.  Determines if the state
	can be changed upon a write to R15.
	(LoadMult): Use WriteR15Load.
	* armemu.h (WRITEDESTB): Use WriteR15Load.
This commit is contained in:
David McQuillan 2014-03-14 14:03:29 +00:00 committed by Nick Clifton
parent e5b98723a5
commit b9366cf395
3 changed files with 23 additions and 3 deletions
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8
sim/arm/ChangeLog
View File

@ -1,3 +1,11 @@
2014-03-14 David McQuillan <dmcq@tao-group.com>
PR sim/8388
* armemu.c (WriteR15Load): New function. Determines if the state
can be changed upon a write to R15.
(LoadMult): Use WriteR15Load.
* armemu.h (WRITEDESTB): Use WriteR15Load.
2014-03-10 Mike Frysinger <vapier@gentoo.org>
* wrapper.c (sim_do_command): Add const to cmd.

16
sim/arm/armemu.c
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@ -1,7 +1,7 @@
/* armemu.c -- Main instruction emulation: ARM7 Instruction Emulator.
Copyright (C) 1994 Advanced RISC Machines Ltd.
Modifications to add arch. v4 support by <jsmith@cygnus.com>.
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 3 of the License, or
@ -25,6 +25,7 @@ static ARMword GetDPSRegRHS (ARMul_State *, ARMword);
static void WriteR15 (ARMul_State *, ARMword);
static void WriteSR15 (ARMul_State *, ARMword);
static void WriteR15Branch (ARMul_State *, ARMword);
static void WriteR15Load (ARMul_State *, ARMword);
static ARMword GetLSRegRHS (ARMul_State *, ARMword);
static ARMword GetLS7RHS (ARMul_State *, ARMword);
static unsigned LoadWord (ARMul_State *, ARMword, ARMword);
@ -4212,6 +4213,17 @@ WriteR15Branch (ARMul_State * state, ARMword src)
#endif
}
/* Before ARM_v5 LDR and LDM of pc did not change mode. */
static void
WriteR15Load (ARMul_State * state, ARMword src)
{
if (state->is_v5)
WriteR15Branch (state, src);
else
WriteR15 (state, src);
}
/* This routine evaluates most Load and Store register RHS's. It is
intended to be called from the macro LSRegRHS, which filters the
common case of an unshifted register with in line code. */
@ -4724,7 +4736,7 @@ LoadMult (ARMul_State * state, ARMword instr, ARMword address, ARMword WBBase)
if (BIT (15) && !state->Aborted)
/* PC is in the reg list. */
WriteR15Branch (state, PC);
WriteR15Load (state, PC);
/* To write back the final register. */
ARMul_Icycles (state, 1, 0L);

2
sim/arm/armemu.h
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@ -402,7 +402,7 @@ extern ARMword isize;
do \
{ \
if (DESTReg == 15) \
WriteR15Branch (state, d); \
WriteR15Load (state, d); \
else \
DEST = d; \
} \