[Qemu-devel] [PATCH] linux-user: correct handling of break exception for MIPS

[Qemu-devel] [PATCH] linux-user: correct handling of break exception for MIPS

[Petar Jovanovic]

From: Petar Jovanovic <petar.jovanovic@imgtec.com>

Exception with break instruction has not been correctly propagated as
SIGTRAP. This resolves crash issues with examples that use break
instruction on MIPS.

Signed-off-by: Petar Jovanovic <petar.jovanovic@imgtec.com>
---
 linux-user/main.c |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/linux-user/main.c b/linux-user/main.c
index 9192977..c19e7fb 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -2384,6 +2384,10 @@ static int do_break(CPUMIPSState *env, target_siginfo_t *info,
         ret = 0;
         break;
     default:
+        info->si_signo = TARGET_SIGTRAP;
+        info->si_errno = 0;
+        queue_signal(env, info->si_signo, &*info);
+        ret = 0;
         break;
     }
 
-- 
1.7.9.5

Re: [Qemu-devel] [PATCH] linux-user: correct handling of break exception for MIPS

[Andreas Färber]

Hi,

Am 28.02.2014 15:25, schrieb Petar Jovanovic:
> From: Petar Jovanovic <petar.jovanovic@imgtec.com>
> 
> Exception with break instruction has not been correctly propagated as
> SIGTRAP. This resolves crash issues with examples that use break
> instruction on MIPS.
> 
> Signed-off-by: Petar Jovanovic <petar.jovanovic@imgtec.com>
> ---
>  linux-user/main.c |    4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/linux-user/main.c b/linux-user/main.c
> index 9192977..c19e7fb 100644
> --- a/linux-user/main.c
> +++ b/linux-user/main.c
> @@ -2384,6 +2384,10 @@ static int do_break(CPUMIPSState *env, target_siginfo_t *info,
>          ret = 0;
>          break;
>      default:
> +        info->si_signo = TARGET_SIGTRAP;
> +        info->si_errno = 0;
> +        queue_signal(env, info->si_signo, &*info);

This looks strange. Isn't &*info == info?

Other than that seems to touch only MIPS code and looks sensible.

Regards,
Andreas

> +        ret = 0;
>          break;
>      }
>  

-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

Re: [Qemu-devel] [PATCH] linux-user: correct handling of break exception for MIPS

[Petar Jovanovic]

> This looks strange. Isn't &*info == info?

It is. Just a few lines above, queue_signal is called in the same manner
for style/preference reasons I presume, so this patch follows the
pattern. Otherwise, it would require to change the other call site too.

Regards,
Petar

________________________________________
From: Andreas Färber [afaerber@suse.de]
Sent: Friday, February 28, 2014 4:30 PM
To: Petar Jovanovic; qemu-devel@nongnu.org
Cc: riku.voipio@linaro.org; Petar Jovanovic; aurelien@aurel32.net
Subject: Re: [Qemu-devel] [PATCH] linux-user: correct handling of break exception for MIPS

Hi,

Am 28.02.2014 15:25, schrieb Petar Jovanovic:
> From: Petar Jovanovic <petar.jovanovic@imgtec.com>
>
> Exception with break instruction has not been correctly propagated as
> SIGTRAP. This resolves crash issues with examples that use break
> instruction on MIPS.
>
> Signed-off-by: Petar Jovanovic <petar.jovanovic@imgtec.com>
> ---
>  linux-user/main.c |    4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/linux-user/main.c b/linux-user/main.c
> index 9192977..c19e7fb 100644
> --- a/linux-user/main.c
> +++ b/linux-user/main.c
> @@ -2384,6 +2384,10 @@ static int do_break(CPUMIPSState *env, target_siginfo_t *info,
>          ret = 0;
>          break;
>      default:
> +        info->si_signo = TARGET_SIGTRAP;
> +        info->si_errno = 0;
> +        queue_signal(env, info->si_signo, &*info);

This looks strange. Isn't &*info == info?

Other than that seems to touch only MIPS code and looks sensible.

Regards,
Andreas

> +        ret = 0;
>          break;
>      }
>

--
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg