Re: [PATCH] kern: fix mig_strncpy

[Samuel Thibault]

Justus Winter, le Sat 22 Feb 2014 11:25:14 +0100, a écrit :
> Previously, the function mig_strncpy would always zero-terminate the
> destination string.  Make mig_strncpy behave like mig_strncpy and
> strncpy in the glibc.  Also fix the implementation of mig_strncpy to
> return the length of the written string to align the implementation
> with the declaration in include/mach/mig_support.h.
> 
> * kern/ipc_mig.c (mig_strncpy): Do not zero-terminate the destination
> string.  Return length of destination string.

Ack.

> ---
>  kern/ipc_mig.c | 36 ++++++++++++++++++++----------------
>  1 file changed, 20 insertions(+), 16 deletions(-)
> 
> diff --git a/kern/ipc_mig.c b/kern/ipc_mig.c
> index bbc38cf..f2c3f45 100644
> --- a/kern/ipc_mig.c
> +++ b/kern/ipc_mig.c
> @@ -272,10 +272,10 @@ mig_put_reply_port(
>  /*
>   * mig_strncpy.c - by Joshua Block
>   *
> - * mig_strncp -- Bounded string copy.  Does what the library routine strncpy
> - * OUGHT to do:  Copies the (null terminated) string in src into dest, a
> - * buffer of length len.  Assures that the copy is still null terminated
> - * and doesn't overflow the buffer, truncating the copy if necessary.
> + * mig_strncpy -- Bounded string copy.  Does what the library routine
> + * strncpy does: Copies the (null terminated) string in src into dest,
> + * a buffer of length len.  Returns the length of the destination
> + * string excluding the terminating null.
>   *
>   * Parameters:
>   *
> @@ -285,22 +285,26 @@ mig_put_reply_port(
>   *
>   *     len - Length of destination buffer.
>   */
> -void mig_strncpy(dest, src, len)
> -char *dest;
> -const char *src;
> -int len;
> +vm_size_t
> +mig_strncpy(dest, src, len)
> +     char *dest;
> +     const char *src;
> +     int len;
>  {
> -    int i;
> +     char *dest_ = dest;
> +     int i;
>  
> -    if (len <= 0)
> -     return;
> +     if (len <= 0)
> +             return 0;
>  
> -    for (i=1; i<len; i++)
> -     if (! (*dest++ = *src++))
> -         return;
> +     for (i = 0; i < len; i++) {
> +             if (! (*dest = *src))
> +                     break;
> +             dest++;
> +             src++;
> +     }
>  
> -    *dest = '\0';
> -    return;
> +     return dest - dest_;
>  }
>  
>  #define      fast_send_right_lookup(name, port, abort)                       
> \
> -- 
> 1.8.5.2
> 

-- 
Samuel
 > Subject: pb fvwm95-2 comment l'installer le compiler???
 > Merci d'avance
 je te conseille d'être un peu plus précis dans l'exposé de ton pb...
 -+- EJ in guide du linuxien pervers :"Les modéros sont sympas !" -+-