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Re: [Qemu-devel] [PATCH] target-arm: Handle 'smc' as an undefined instru
From: |
Adam Lackorzynski |
Subject: |
Re: [Qemu-devel] [PATCH] target-arm: Handle 'smc' as an undefined instruction |
Date: |
Fri, 3 Sep 2010 01:11:24 +0200 |
User-agent: |
Mutt/1.5.20 (2009-06-14) |
On Thu Sep 02, 2010 at 23:14:23 +0100, Peter Maydell wrote:
> On Thu, Sep 02, 2010 at 11:40:50PM +0200, Adam Lackorzynski wrote:
> > + case 7:
> > + /* SMC? */
> > + if ((insn & 0xfffffff0) == 0xe1600070) {
> > + goto illegal_op;
> > + }
> > + /* bkpt */
>
> This doesn't look right to me. SMC in the ARM encoding is a standard
> conditionalised instruction, so you shouldn't be mandating that the
> cond field is 0xe.
True.
> I think the correct way to distinguish BKPT from SMC is to look at
> bits [22..21] of the instruction: 01 for BKPT, 11 for SMC and
> other combinations are UNDEFINED. This is in 'op1' at this point
> in the code...
target-arm: Handle 'smc' as an undefined instruction
Refine check on bkpt so that smc is handled as an undefined instruction.
Signed-off-by: Adam Lackorzynski <address@hidden>
---
target-arm/translate.c | 6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/target-arm/translate.c b/target-arm/translate.c
index 6fcdd7e..fac4f5d 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -6346,7 +6346,11 @@ static void disas_arm_insn(CPUState * env, DisasContext
*s)
dead_tmp(tmp2);
store_reg(s, rd, tmp);
break;
- case 7: /* bkpt */
+ case 7:
+ if (op1 != 1) {
+ goto illegal_op;
+ }
+ /* bkpt */
gen_set_condexec(s);
gen_set_pc_im(s->pc - 4);
gen_exception(EXCP_BKPT);
--
1.7.1
Thanks,
Adam
--
Adam address@hidden
Lackorzynski http://os.inf.tu-dresden.de/~adam/