20.06.2014 13:51, Peter Maydell пишет:
> [cc'ing Riku as the linux-user maintainer.]
>
> On 20 June 2014 10:14, Hunter Laux <hunterl...@gmail.com> wrote:
>
> Thanks for writing this patch. It mostly looks good
> but there are some minor admin/format tweaks we need.
>
> You need to provide a Signed-off-by: line here, or
> we can't take this patch, I'm afraid. (We work the same
> way as the Linux kernel for this; see
> http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/SubmittingPatches?id=f6f94e2ab1b33f0082ac22d71f66385a60d8157f#n297
> for more details, but basically it says you wrote the code
> and are willing to contribute it under our licensing terms.)
>
> It could also use a little more explanation in the commit
> message.
>
> FWIW, this is an obscure syscall that dates back to before
> the architecture provided an official breakpoint instruction;
> apparently it's still used by Steel Bank Common Lisp.
>
> This is the kernel implementation:
> http://lxr.free-electrons.com/source/arch/arm/kernel/traps.c#L598
>
>> ---
>> linux-user/arm/syscall.h | 1 +
>> linux-user/main.c | 4 ++++
>> 2 files changed, 5 insertions(+)
>>
>> diff --git a/linux-user/arm/syscall.h b/linux-user/arm/syscall.h
>> index ce2c2a8..e0d2cc3 100644
>> --- a/linux-user/arm/syscall.h
>> +++ b/linux-user/arm/syscall.h
>> @@ -29,6 +29,7 @@ struct target_pt_regs {
>> #define ARM_THUMB_SYSCALL 0
>>
>> #define ARM_NR_BASE 0xf0000
>> +#define ARM_NR_breakpoint (ARM_NR_BASE + 1)
>> #define ARM_NR_cacheflush (ARM_NR_BASE + 2)
>> #define ARM_NR_set_tls (ARM_NR_BASE + 5)
>>
>> diff --git a/linux-user/main.c b/linux-user/main.c
>> index a87c6f7..831b363 100644
>> --- a/linux-user/main.c
>> +++ b/linux-user/main.c
>> @@ -807,6 +807,9 @@ void cpu_loop(CPUARMState *env)
>> cpu_set_tls(env, env->regs[0]);
>> env->regs[0] = 0;
>> break;
>> + case ARM_NR_breakpoint:
>> + env->regs[15] -= env->thumb ? 2 : 4;
>> + goto excp_debug;
>> default:
>> gemu_log("qemu: Unsupported ARM syscall:
>> 0x%x\n",
>> n);
>> @@ -850,6 +853,7 @@ void cpu_loop(CPUARMState *env)
>> }
>> break;
>> case EXCP_DEBUG:
>> + excp_debug:
>
> The indent on this label isn't quite right; it should
> be 4 columns to the left.
Isn't whole thing - using label and goto like this, intermixing
two switch statements with goto - a bit flawed? At best it makes
the code unclean...
>> {
>> int sig;
>
> Those minor issues aside, the code looks right to me.
There was another submission of the same patch, but with
a S-o-b line.
Thanks,
/mjt
