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>
73 lines
2 KiB
C
73 lines
2 KiB
C
/*
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* linux/arch/i386/kernel/head32.c -- prepare to run common code
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*
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* Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
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* Copyright (C) 2007 Eric Biederman <ebiederm@xmission.com>
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*/
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#include <linux/init.h>
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#include <linux/start_kernel.h>
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#include <linux/mm.h>
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#include <asm/setup.h>
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#include <asm/sections.h>
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#include <asm/e820.h>
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#include <asm/page.h>
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#include <asm/trampoline.h>
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#include <asm/apic.h>
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#include <asm/io_apic.h>
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#include <asm/bios_ebda.h>
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static void __init i386_default_early_setup(void)
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{
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/* Initilize 32bit specific setup functions */
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x86_init.resources.probe_roms = probe_roms;
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x86_init.resources.reserve_resources = i386_reserve_resources;
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x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc;
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reserve_ebda_region();
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}
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void __init i386_start_kernel(void)
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{
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#ifdef CONFIG_X86_TRAMPOLINE
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/*
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* But first pinch a few for the stack/trampoline stuff
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* FIXME: Don't need the extra page at 4K, but need to fix
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* trampoline before removing it. (see the GDT stuff)
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*/
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reserve_early_overlap_ok(PAGE_SIZE, PAGE_SIZE + PAGE_SIZE,
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"EX TRAMPOLINE");
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#endif
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reserve_early(__pa_symbol(&_text), __pa_symbol(&__bss_stop), "TEXT DATA BSS");
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#ifdef CONFIG_BLK_DEV_INITRD
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/* Reserve INITRD */
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if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
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/* Assume only end is not page aligned */
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u64 ramdisk_image = boot_params.hdr.ramdisk_image;
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u64 ramdisk_size = boot_params.hdr.ramdisk_size;
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u64 ramdisk_end = PAGE_ALIGN(ramdisk_image + ramdisk_size);
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reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
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}
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#endif
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/* Call the subarch specific early setup function */
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switch (boot_params.hdr.hardware_subarch) {
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case X86_SUBARCH_MRST:
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x86_mrst_early_setup();
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break;
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default:
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i386_default_early_setup();
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break;
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}
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/*
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* At this point everything still needed from the boot loader
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* or BIOS or kernel text should be early reserved or marked not
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* RAM in e820. All other memory is free game.
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*/
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start_kernel();
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}
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