Re: [RFC] Don't pass filename in multiboot command line

[Robert Millan <rmh@aybabtu.com>]

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On Sat, Aug 01, 2009 at 05:13:27PM +0200, Vladimir 'phcoder' Serbinenko wrote:
> >> > There's a much simpler way to address this.  Just add something like:
> >> >
> >> >  cmdline_argv = argv + 1;
> >> >  cmdline_argc = argc - 1;
> >> >
> >> > at the beginning, and then use cmdline_argv and cmdline_argc instead of
> >> > correcting the off-by-one every time.
> >> Correcting the numbers is actually smaller part of the patch. The most
> >> of it is to make empty commandlines to be handled correctly (this
> >> couldn't happen previously)
> >
> > Either there's an extra argv member that is always present and we want
> > to remove, or there's the possibility that the command-line is empty.
> > AFAICS we can't have both problems.
> >
> No. Now we have an extra element that is always present and we want to
> remove but when we remove command line can be empty and code must
> handle it correctly.

Please try this patch.

-- 
Robert Millan

  The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
  how) you may access your data; but nobody's threatening your freedom: we
  still allow you to remove your data and not access it at all."

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Index: loader/i386/multiboot.c
===================================================================
--- loader/i386/multiboot.c	(revision 2465)
+++ loader/i386/multiboot.c	(working copy)
@@ -201,6 +201,8 @@
   grub_ssize_t len, cmdline_length, boot_loader_name_length;
   grub_uint32_t mmap_length;
   int i;
+  int cmdline_argc;
+  char **cmdline_argv;
 
   grub_loader_unset ();
 
@@ -256,9 +258,12 @@
 
   mmap_length = grub_get_multiboot_mmap_len ();
 
+  cmdline_argv = argv + 1;
+  cmdline_argc = argc - 1;
+
   /* Figure out cmdline length.  */
-  for (i = 0, cmdline_length = 0; i < argc; i++)
-    cmdline_length += grub_strlen (argv[i]) + 1;
+  for (i = 0, cmdline_length = 0; i < cmdline_argc; i++)
+    cmdline_length += grub_strlen (cmdline_argv[i]) + 1;
 
   boot_loader_name_length = sizeof(PACKAGE_STRING);
 
@@ -351,9 +356,9 @@
   if (! cmdline)
     goto fail;
 
-  for (i = 0; i < argc; i++)
+  for (i = 0; i < cmdline_argc; i++)
     {
-      p = grub_stpcpy (p, argv[i]);
+      p = grub_stpcpy (p, cmdline_argv[i]);
       *(p++) = ' ';
     }