Re: Experimental fix for my memcpy_{to,from}fs problem

[Miguel Bolanos <mike@linuxlabs.com>]

Applied, but i did some changes on the patch, please read bellow.

On Wed, 2004-06-02 at 10:25, Eduardo Pereira Habkost wrote:
> On Tue, Jun 01, 2004 at 08:57:06PM -0600, Miguel Bolanos wrote:
> <snip>
> > 
> > Yes the fix is ok.. but it will break dev86 <= 0.16.0 versions... this
> > fact makes me hesitate a bit because Bruce does warn that 0.16.15 can
> > behave a bit unstable.
> > But we will see.
> 
> Yes, and bcc >= 0.16.8 variable offset macros are broken, anyway.
> 
> The original code didn't used the offset macros for accessing the
> variables. It will work only on:
> 
> - dev86 < 0.16.8
> - any dev86 version if not using optimization
> 
> And it will not work if the bcc variable offset macros bug is fixed,
> because the offsets really changed, with the optimized code.
> 
> The fix I've sent before really broke systems with dev86 <= 0.16.8.
> 
> The following patch against the current CVS code (that already has the
> "wrong" fix) change the asm code to access the variables using the
> "right way", that is: the variable offset macros.
> 
> It will work for:
> - dev86 < 0.16.8
> - any dev86 version if not using optimization
> - dev86 >= 0.16.8 with the previous patch I sent (Fix variable offset macros)
> - dev86 with the patch Robert sent
> 
> So please apply.
> 
> --
> Eduardo
> 
> 
> --- elks/arch/i86/mm/user.c	2 Jun 2004 03:06:01 -0000	1.16
> +++ elks/arch/i86/mm/user.c	2 Jun 2004 15:10:16 -0000
> @@ -39,11 +39,11 @@
>  	mov	dx,es
>  	mov	bx,ds
>  	mov	es,bx
> -	mov	ax,[bp-2]	! source segment (local variable)
> +	mov	ax,[bp+.memcpy_fromfs.ds]	! source segment (local variable)
>  	mov	ds,ax
> -	mov	di,[bp+4]	! destination address
> -	mov	si,[bp+6]	! source address
> -	mov	cx,[bp+8]	! number of bytes to copy
> +	mov	di,[bp+.memcpy_fromfs.daddr]	! destination address
> +	mov	si,[bp+.memcpy_fromfs.saddr]	! source address
> +	mov	cx,[bp+.memcpy_fromfs.len]	! number of bytes to copy
>  	cld
>  	rep
>  	movsb

This was already applied on a the previous patch

> @@ -77,11 +77,11 @@
>  	push	si
>  	push	di
>  	mov	dx,es
> -	mov	ax,[bp-2]	! source segment (local variable)
> +	mov	ax,[bp+.memcpy_tofs.es]	! source segment (local variable)
>  	mov	es,ax
> -	mov	di,[bp+4]	! destination address
> -	mov	si,[bp+6]	! source address
> -	mov	cx,[bp+8]	! number of bytes to copy
> +	mov	di,[bp+.memcpy_tofs.daddr]	! destination address
> +	mov	si,[bp+.memcpy_tofs.saddr]	! source address
> +	mov	cx,[bp+.memcpy_tofs.len]	! number of bytes to copy
>  	cld
>  	rep
>  	movsb

This was already done as well.

> @@ -167,17 +167,17 @@
>  #ifndef S_SPLINT_S
>  #asm
>  
> -	mov	ax,[bp-6]	! source segment (local variable)
> +	mov	ax,[bp+.strlen_fromfs.ds]	! source segment (local variable)
>  	mov	es,ax
> -	mov	di,[bp+4]	! source address
> +	mov	di,[bp+.strlen_fromfs.saddr]	! source address
>  	cld
>  	xor	al,al		! search for NULL byte
>  	mov	cx,#-1
>  	rep
>  	scasb
> -	sub	di,[bp+4]	! calc len +1
> +	sub	di,[bp+.strlen_fromfs.saddr]	! calc len +1
>  	dec	di
> -	mov	[bp-6],di	! save in local var ds
> +	mov	[bp+.strlen_fromfs.ds],di	! save in local var ds
>  #endasm
>  #endif
>  

This part was applied.

thanks a lot.

-- 
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