[PATCH] ppc64: Fix zImage boot

The zImage wrapper has a bug where it doesn't claim() the memory for the
kernel properly, it forgets to take into account the offset between the ELF
header and the kernel itself.  This results on some machines, like G5s,
into a kernel that crashes at boot when clearing the BSS.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ppc64/boot/main.c

@@ -203,8 +203,15 @@ void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
 		if (elf64ph->p_type == PT_LOAD && elf64ph->p_offset != 0)
 			break;
 	}
-	vmlinux.size = (unsigned long)elf64ph->p_filesz;
-	vmlinux.memsize = (unsigned long)elf64ph->p_memsz;
+	vmlinux.size = (unsigned long)elf64ph->p_filesz +
+		(unsigned long)elf64ph->p_offset;
+	/* We need to claim the memsize plus the file offset since gzip
+	 * will expand the header (file offset), then the kernel, then
+	 * possible rubbish we don't care about. But the kernel bss must
+	 * be claimed (it will be zero'd by the kernel itself)
+	 */
+	vmlinux.memsize = (unsigned long)elf64ph->p_memsz +
+		(unsigned long)elf64ph->p_offset;
 	printf("Allocating 0x%lx bytes for kernel ...\n\r", vmlinux.memsize);
 	vmlinux.addr = try_claim(vmlinux.memsize);
 	if (vmlinux.addr == 0) {