Hi!
What do you think of adding this kind of checks? I know it's not a
perfect safegard, but it can save your day in some situations (it helped
me during i386/ieee1275 port, when link address was 0x100000).
--
Robert Millan
<GPLv2> I know my rights; I want my phone call!
<DRM> What use is a phone call… if you are unable to speak?
(as seen on /.)
--- ../../grub2/kern/powerpc/ieee1275/init.c 2008-01-14 15:30:59.000000000 +0100
+++ kern/powerpc/ieee1275/init.c 2008-01-20 15:20:23.000000000 +0100
@@ -143,6 +143,17 @@
(total + (HEAP_MAX_ADDR - addr) > HEAP_MIN_SIZE)) /* only limit ourselves when we can afford to */
len = HEAP_MAX_ADDR - addr;
+ /* In theory, firmware should already prevent this from happening by not
+ listing our own image in /memory/available. The check below is intended
+ as a safegard in case that doesn't happen. It does, however, not protect
+ us from corrupting our module area, which extends up to a
+ yet-undetermined region above _end. */
+ if ((addr < _end) && ((addr + len) > _start))
+ {
+ grub_printf ("Warning: attempt to claim over our own code!\n");
+ len = 0;
+ }
+
if (len)
{
/* Claim and use it. */
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