Re: [PATCH] x86 ptrace: fix PTRACE_GETFPXREGS error

[TAKADA Yoshihito <takada@mbf.nifty.com>]

Hi.
The Roland's patch is bettor than mine.
Please apply Roland's only. Don't apply both. Either is enough.


From: Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH] x86 ptrace: fix PTRACE_GETFPXREGS error
Date: Tue, 1 Jul 2008 11:02:04 +0200

> 
> * Roland McGrath <roland@redhat.com> wrote:
> 
> > ptrace has always returned only -EIO for all failures to access 
> > registers.  The user_regset calls are allowed to return a more 
> > meaningful variety of errors.  The REGSET_XFP calls use -ENODEV for 
> > !cpu_has_fxsr hardware.  Make ptrace return the traditional -EIO 
> > instead of the error code from the user_regset call.
> 
> since the original fix is already upstream, i've applied the delta patch 
> below. Should we still do this for v2.6.26 or can we defer it to 
> v2.6.27? As ptrace is the only user of this facility for now this would 
> be an identity transformation AFAICS and the v2.6.26 release is very 
> close.
> 
> 	Ingo
> 
> ---------------->
> Subject: x86 ptrace: fix PTRACE_GETFPXREGS error
> From: Roland McGrath <roland@redhat.com>
> Date: Mon, 30 Jun 2008 14:02:41 -0700 (PDT)
> 
> ptrace has always returned only -EIO for all failures to access
> registers.  The user_regset calls are allowed to return a more
> meaningful variety of errors.  The REGSET_XFP calls use -ENODEV
> for !cpu_has_fxsr hardware.  Make ptrace return the traditional
> -EIO instead of the error code from the user_regset call.
> 
> Signed-off-by: Roland McGrath <roland@redhat.com>
> Cc: stable@kernel.org
> Signed-off-by: Ingo Molnar <mingo@elte.hu>
> ---
>  arch/x86/kernel/i387.c   |    4 ++--
>  arch/x86/kernel/ptrace.c |    4 ++--
>  2 files changed, 4 insertions(+), 4 deletions(-)
> 
> Index: tip/arch/x86/kernel/i387.c
> ===================================================================
> --- tip.orig/arch/x86/kernel/i387.c
> +++ tip/arch/x86/kernel/i387.c
> @@ -162,7 +162,7 @@ int xfpregs_get(struct task_struct *targ
>  	int ret;
>  
>  	if (!cpu_has_fxsr)
> -		return -EIO;
> +		return -ENODEV;
>  
>  	ret = init_fpu(target);
>  	if (ret)
> @@ -179,7 +179,7 @@ int xfpregs_set(struct task_struct *targ
>  	int ret;
>  
>  	if (!cpu_has_fxsr)
> -		return -EIO;
> +		return -ENODEV;
>  
>  	ret = init_fpu(target);
>  	if (ret)
> Index: tip/arch/x86/kernel/ptrace.c
> ===================================================================
> --- tip.orig/arch/x86/kernel/ptrace.c
> +++ tip/arch/x86/kernel/ptrace.c
> @@ -943,13 +943,13 @@ long arch_ptrace(struct task_struct *chi
>  		return copy_regset_to_user(child, &user_x86_32_view,
>  					   REGSET_XFP,
>  					   0, sizeof(struct user_fxsr_struct),
> -					   datap);
> +					   datap) ? -EIO : 0;
>  
>  	case PTRACE_SETFPXREGS:	/* Set the child extended FPU state. */
>  		return copy_regset_from_user(child, &user_x86_32_view,
>  					     REGSET_XFP,
>  					     0, sizeof(struct user_fxsr_struct),
> -					     datap);
> +					     datap) ? -EIO : 0;
>  #endif
>  
>  #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION