[PATCH] m68k: fix 'bkpt' instruction in softmmu mode

[PATCH] m68k: fix 'bkpt' instruction in softmmu mode

[Laurent Vivier]

In linux-user mode, 'bkpt' generates an EXP_DEBUG exception to allow
QEMU gdb server to intercept and manage the operation with an external
debugger.

In softmmu mode, the instruction must generate an illegal instruction
exception as it is on real hardware to be managed by the kernel.

Buglink: https://gitlab.com/qemu-project/qemu/-/issues/146
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 target/m68k/translate.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index 18418312b14b..31178c3b1d17 100644
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -2774,7 +2774,11 @@ DISAS_INSN(swap)
 
 DISAS_INSN(bkpt)
 {
+#if defined(CONFIG_SOFTMMU)
+    gen_exception(s, s->base.pc_next, EXCP_ILLEGAL);
+#else
     gen_exception(s, s->base.pc_next, EXCP_DEBUG);
+#endif
 }
 
 DISAS_INSN(pea)
-- 
2.38.1

Re: [PATCH] m68k: fix 'bkpt' instruction in softmmu mode

[Richard Henderson]

On 1/26/23 02:52, Laurent Vivier wrote:
> In linux-user mode, 'bkpt' generates an EXP_DEBUG exception to allow
> QEMU gdb server to intercept and manage the operation with an external
> debugger.
> 
> In softmmu mode, the instruction must generate an illegal instruction
> exception as it is on real hardware to be managed by the kernel.
> 
> Buglink:https://gitlab.com/qemu-project/qemu/-/issues/146
> Signed-off-by: Laurent Vivier<laurent@vivier.eu>
> ---
>   target/m68k/translate.c | 4 ++++
>   1 file changed, 4 insertions(+)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

Re: [PATCH] m68k: fix 'bkpt' instruction in softmmu mode

[Mark Cave-Ayland]

On 26/01/2023 12:52, Laurent Vivier wrote:

> In linux-user mode, 'bkpt' generates an EXP_DEBUG exception to allow
> QEMU gdb server to intercept and manage the operation with an external
> debugger.
> 
> In softmmu mode, the instruction must generate an illegal instruction
> exception as it is on real hardware to be managed by the kernel.
> 
> Buglink: https://gitlab.com/qemu-project/qemu/-/issues/146

Hi Laurent,

I think this should be https://gitlab.com/qemu-project/qemu/-/issues/1462?

> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
> ---
>   target/m68k/translate.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/target/m68k/translate.c b/target/m68k/translate.c
> index 18418312b14b..31178c3b1d17 100644
> --- a/target/m68k/translate.c
> +++ b/target/m68k/translate.c
> @@ -2774,7 +2774,11 @@ DISAS_INSN(swap)
>   
>   DISAS_INSN(bkpt)
>   {
> +#if defined(CONFIG_SOFTMMU)
> +    gen_exception(s, s->base.pc_next, EXCP_ILLEGAL);
> +#else
>       gen_exception(s, s->base.pc_next, EXCP_DEBUG);
> +#endif
>   }
>   
>   DISAS_INSN(pea)


ATB,

Mark.

Re: [PATCH] m68k: fix 'bkpt' instruction in softmmu mode

[Laurent Vivier]

Le 26/01/2023 à 23:12, Mark Cave-Ayland a écrit :
> On 26/01/2023 12:52, Laurent Vivier wrote:
> 
>> In linux-user mode, 'bkpt' generates an EXP_DEBUG exception to allow
>> QEMU gdb server to intercept and manage the operation with an external
>> debugger.
>>
>> In softmmu mode, the instruction must generate an illegal instruction
>> exception as it is on real hardware to be managed by the kernel.
>>
>> Buglink: https://gitlab.com/qemu-project/qemu/-/issues/146
> 
> Hi Laurent,
> 
> I think this should be https://gitlab.com/qemu-project/qemu/-/issues/1462?

oh, yes, thank you

Laurent