From b9366cf3955d81e26537ea1932b183dbdf237361 Mon Sep 17 00:00:00 2001 From: David McQuillan Date: Fri, 14 Mar 2014 14:03:29 +0000 Subject: [PATCH] Prevent writes to R15 via LDR or LDM from changing the ARM/Thumb state in pre-v5 architectures. 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. --- sim/arm/ChangeLog | 8 ++++++++ sim/arm/armemu.c | 16 ++++++++++++++-- sim/arm/armemu.h | 2 +- 3 files changed, 23 insertions(+), 3 deletions(-) diff --git a/sim/arm/ChangeLog b/sim/arm/ChangeLog index 9910633ca71..fe236cbc5ff 100644 --- a/sim/arm/ChangeLog +++ b/sim/arm/ChangeLog @@ -1,3 +1,11 @@ +2014-03-14 David McQuillan + + 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 * wrapper.c (sim_do_command): Add const to cmd. diff --git a/sim/arm/armemu.c b/sim/arm/armemu.c index 20a36bca7b6..64c0146c115 100644 --- a/sim/arm/armemu.c +++ b/sim/arm/armemu.c @@ -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 . - + 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); diff --git a/sim/arm/armemu.h b/sim/arm/armemu.h index 71bee27d5af..d61c85a983d 100644 --- a/sim/arm/armemu.h +++ b/sim/arm/armemu.h @@ -402,7 +402,7 @@ extern ARMword isize; do \ { \ if (DESTReg == 15) \ - WriteR15Branch (state, d); \ + WriteR15Load (state, d); \ else \ DEST = d; \ } \ -- 2.30.2