initrd: Fix virtual/physical mix-up in overwrite test
authorGeert Uytterhoeven <geert@linux-m68k.org>
Thu, 17 Jul 2008 19:16:36 +0000 (21:16 +0200)
committerLinus Torvalds <torvalds@linux-foundation.org>
Mon, 21 Jul 2008 00:24:40 +0000 (17:24 -0700)
On recent kernels, I get the following error when using an initrd:

| initrd overwritten (0x00b78000 < 0x07668000) - disabling it.

My Amiga 4000 has 12 MiB of RAM at physical address 0x07400000 (virtual
0x00000000).
The initrd is located at the end of RAM: 0x00b78000 - 0x00c00000 (virtual).
The overwrite test compares the (virtual) initrd location to the (physical)
first available memory location, which fails.

This patch converts initrd_start to a page frame number, so it can safely be
compared with min_low_pfn.

Before the introduction of discontiguous memory support on m68k
(12d810c1b8c2b913d48e629e2b5c01d105029839), min_low_pfn was just left
untouched by the m68k-specific code (zero, I guess), and everything worked
fine.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
init/main.c

index edeace036fd96b08de9f5b57fffcb04cf8f7c44c..756eca4b821a8e4406f35de7bddc0588605fd899 100644 (file)
@@ -630,9 +630,10 @@ asmlinkage void __init start_kernel(void)
 
 #ifdef CONFIG_BLK_DEV_INITRD
        if (initrd_start && !initrd_below_start_ok &&
-                       initrd_start < min_low_pfn << PAGE_SHIFT) {
+           page_to_pfn(virt_to_page(initrd_start)) < min_low_pfn) {
                printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
-                   "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
+                   "disabling it.\n",
+                   page_to_pfn(virt_to_page(initrd_start)), min_low_pfn);
                initrd_start = 0;
        }
 #endif