mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-25 20:14:25 +08:00
c967da6a0b
When CONFIG_NO_BOOTMEM=y, it could use memory more effiently, or
in a more compact fashion.
Example:
Allocated new RAMDISK: 00ec2000 - 0248ce57
Move RAMDISK from 000000002ea04000 - 000000002ffcee56 to 00ec2000 - 0248ce56
The new RAMDISK's end is not page aligned.
Last page could be shared with other users.
When free_init_pages are called for initrd or .init, the page
could be freed and we could corrupt other data.
code segment in free_init_pages():
| for (; addr < end; addr += PAGE_SIZE) {
| ClearPageReserved(virt_to_page(addr));
| init_page_count(virt_to_page(addr));
| memset((void *)(addr & ~(PAGE_SIZE-1)),
| POISON_FREE_INITMEM, PAGE_SIZE);
| free_page(addr);
| totalram_pages++;
| }
last half page could be used as one whole free page.
So page align the boundaries.
-v2: make the original initramdisk to be aligned, according to
Johannes, otherwise we have the chance to lose one page.
we still need to keep initrd_end not aligned, otherwise it could
confuse decompressor.
-v3: change to WARN_ON instead, suggested by Johannes.
-v4: use PAGE_ALIGN, suggested by Johannes.
We may fix that macro name later to PAGE_ALIGN_UP, and PAGE_ALIGN_DOWN
Add comments about assuming ramdisk start is aligned
in relocate_initrd(), change to re get ramdisk_image instead of save it
to make diff smaller. Add warning for wrong range, suggested by Johannes.
-v6: remove one WARN()
We need to align beginning in free_init_pages()
do not copy more than ramdisk_size, noticed by Johannes
Reported-by: Stanislaw Gruszka <sgruszka@redhat.com>
Tested-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1269830604-26214-3-git-send-email-yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
74 lines
2.0 KiB
C
74 lines
2.0 KiB
C
/*
|
|
* linux/arch/i386/kernel/head32.c -- prepare to run common code
|
|
*
|
|
* Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
|
|
* Copyright (C) 2007 Eric Biederman <ebiederm@xmission.com>
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/start_kernel.h>
|
|
#include <linux/mm.h>
|
|
|
|
#include <asm/setup.h>
|
|
#include <asm/sections.h>
|
|
#include <asm/e820.h>
|
|
#include <asm/page.h>
|
|
#include <asm/trampoline.h>
|
|
#include <asm/apic.h>
|
|
#include <asm/io_apic.h>
|
|
#include <asm/bios_ebda.h>
|
|
|
|
static void __init i386_default_early_setup(void)
|
|
{
|
|
/* Initilize 32bit specific setup functions */
|
|
x86_init.resources.probe_roms = probe_roms;
|
|
x86_init.resources.reserve_resources = i386_reserve_resources;
|
|
x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc;
|
|
|
|
reserve_ebda_region();
|
|
}
|
|
|
|
void __init i386_start_kernel(void)
|
|
{
|
|
#ifdef CONFIG_X86_TRAMPOLINE
|
|
/*
|
|
* But first pinch a few for the stack/trampoline stuff
|
|
* FIXME: Don't need the extra page at 4K, but need to fix
|
|
* trampoline before removing it. (see the GDT stuff)
|
|
*/
|
|
reserve_early_overlap_ok(PAGE_SIZE, PAGE_SIZE + PAGE_SIZE,
|
|
"EX TRAMPOLINE");
|
|
#endif
|
|
|
|
reserve_early(__pa_symbol(&_text), __pa_symbol(&__bss_stop), "TEXT DATA BSS");
|
|
|
|
#ifdef CONFIG_BLK_DEV_INITRD
|
|
/* Reserve INITRD */
|
|
if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
|
|
/* Assume only end is not page aligned */
|
|
u64 ramdisk_image = boot_params.hdr.ramdisk_image;
|
|
u64 ramdisk_size = boot_params.hdr.ramdisk_size;
|
|
u64 ramdisk_end = PAGE_ALIGN(ramdisk_image + ramdisk_size);
|
|
reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
|
|
}
|
|
#endif
|
|
|
|
/* Call the subarch specific early setup function */
|
|
switch (boot_params.hdr.hardware_subarch) {
|
|
case X86_SUBARCH_MRST:
|
|
x86_mrst_early_setup();
|
|
break;
|
|
default:
|
|
i386_default_early_setup();
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* At this point everything still needed from the boot loader
|
|
* or BIOS or kernel text should be early reserved or marked not
|
|
* RAM in e820. All other memory is free game.
|
|
*/
|
|
|
|
start_kernel();
|
|
}
|