Re: [Qemu-devel] [PATCHv3] multiboot: copy the cmdline verbatim, unescape module strings

[Eduardo Habkost]

On Thu, Dec 15, 2016 at 02:32:04PM +0200, Vlad Lungu wrote:
> get_opt_value() truncates the value at the first comma
> Use memcpy() instead
> Unescape the module filename and parameters with get_opt_value()
> before calling mb_add_cmdline()
> 
> Signed-off-by: Vlad Lungu <address@hidden>
> ---
>  hw/i386/multiboot.c | 19 +++++++++----------
>  1 file changed, 9 insertions(+), 10 deletions(-)
> 
> diff --git a/hw/i386/multiboot.c b/hw/i386/multiboot.c
> index 387caa6..6b7b5a9 100644
> --- a/hw/i386/multiboot.c
> +++ b/hw/i386/multiboot.c
> @@ -109,7 +109,7 @@ static uint32_t mb_add_cmdline(MultibootState *s, const 
> char *cmdline)
>      hwaddr p = s->offset_cmdlines;
>      char *b = (char *)s->mb_buf + p;
>  
> -    get_opt_value(b, strlen(cmdline) + 1, cmdline);
> +    memcpy(b, cmdline, strlen(cmdline) + 1);
>      s->offset_cmdlines += strlen(b) + 1;
>      return s->mb_buf_phys + p;
>  }
> @@ -287,7 +287,7 @@ int load_multiboot(FWCfgState *fw_cfg,
>      mbs.offset_bootloader = mbs.offset_cmdlines + cmdline_len;
>  
>      if (initrd_filename) {
> -        char *next_initrd, not_last;
> +        char *next_initrd, not_last, tmpbuf[strlen(initrd_filename) + 1];
>  
>          mbs.offset_mods = mbs.mb_buf_size;
>  
> @@ -296,25 +296,24 @@ int load_multiboot(FWCfgState *fw_cfg,
>              int mb_mod_length;
>              uint32_t offs = mbs.mb_buf_size;
>  
> -            next_initrd = (char *)get_opt_value(NULL, 0, initrd_filename);
> +            next_initrd = (char *)get_opt_value(tmpbuf, 
> strlen(initrd_filename) + 1, initrd_filename);

I would prefer to use sizeof(initrd_filename) like Paolo
suggested.

The rest of the patch looks good.

>              not_last = *next_initrd;
> -            *next_initrd = '\0';
>              /* if a space comes after the module filename, treat everything
>                 after that as parameters */
> -            hwaddr c = mb_add_cmdline(&mbs, initrd_filename);
> -            if ((next_space = strchr(initrd_filename, ' ')))
> +            hwaddr c = mb_add_cmdline(&mbs, tmpbuf);
> +            if ((next_space = strchr(tmpbuf, ' ')))
>                  *next_space = '\0';
> -            mb_debug("multiboot loading module: %s\n", initrd_filename);
> -            mb_mod_length = get_image_size(initrd_filename);
> +            mb_debug("multiboot loading module: %s\n", tmpbuf);
> +            mb_mod_length = get_image_size(tmpbuf);
>              if (mb_mod_length < 0) {
> -                fprintf(stderr, "Failed to open file '%s'\n", 
> initrd_filename);
> +                fprintf(stderr, "Failed to open file '%s'\n", tmpbuf);
>                  exit(1);
>              }
>  
>              mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_mod_length + 
> mbs.mb_buf_size);
>              mbs.mb_buf = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
>  
> -            load_image(initrd_filename, (unsigned char *)mbs.mb_buf + offs);
> +            load_image(tmpbuf, (unsigned char *)mbs.mb_buf + offs);
>              mb_add_mod(&mbs, mbs.mb_buf_phys + offs,
>                         mbs.mb_buf_phys + offs + mb_mod_length, c);
>  
> -- 
> 1.9.1
> 

-- 
Eduardo