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5dcd14ecd4
Use the new sentinel field to detect bootloaders which fail to follow protocol and don't initialize fields in struct boot_params that they do not explicitly initialize to zero. Based on an original patch and research by Yinghai Lu. Changed by hpa to be invoked both in the decompression path and in the kernel proper; the latter for the case where a bootloader takes over decompression. Originally-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1359058816-7615-26-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
126 lines
3.3 KiB
C
126 lines
3.3 KiB
C
/*
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* 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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*/
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#include <linux/init.h>
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#include <linux/linkage.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/percpu.h>
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#include <linux/start_kernel.h>
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#include <linux/io.h>
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#include <linux/memblock.h>
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#include <asm/processor.h>
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#include <asm/proto.h>
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#include <asm/smp.h>
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#include <asm/setup.h>
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#include <asm/desc.h>
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#include <asm/pgtable.h>
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#include <asm/tlbflush.h>
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#include <asm/sections.h>
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#include <asm/kdebug.h>
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#include <asm/e820.h>
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#include <asm/bios_ebda.h>
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#include <asm/bootparam_utils.h>
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static void __init zap_identity_mappings(void)
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{
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pgd_t *pgd = pgd_offset_k(0UL);
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pgd_clear(pgd);
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__flush_tlb_all();
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}
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/* Don't add a printk in there. printk relies on the PDA which is not initialized
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yet. */
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static void __init clear_bss(void)
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{
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memset(__bss_start, 0,
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(unsigned long) __bss_stop - (unsigned long) __bss_start);
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}
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static void __init copy_bootdata(char *real_mode_data)
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{
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char * command_line;
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memcpy(&boot_params, real_mode_data, sizeof boot_params);
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sanitize_boot_params(&boot_params);
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if (boot_params.hdr.cmd_line_ptr) {
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command_line = __va(boot_params.hdr.cmd_line_ptr);
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memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
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}
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}
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void __init x86_64_start_kernel(char * real_mode_data)
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{
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int i;
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/*
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* Build-time sanity checks on the kernel image and module
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* area mappings. (these are purely build-time and produce no code)
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*/
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BUILD_BUG_ON(MODULES_VADDR < KERNEL_IMAGE_START);
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BUILD_BUG_ON(MODULES_VADDR-KERNEL_IMAGE_START < KERNEL_IMAGE_SIZE);
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BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE);
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BUILD_BUG_ON((KERNEL_IMAGE_START & ~PMD_MASK) != 0);
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BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
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BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
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BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
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(__START_KERNEL & PGDIR_MASK)));
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BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
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/* clear bss before set_intr_gate with early_idt_handler */
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clear_bss();
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/* Make NULL pointers segfault */
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zap_identity_mappings();
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max_pfn_mapped = KERNEL_IMAGE_SIZE >> PAGE_SHIFT;
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for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) {
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#ifdef CONFIG_EARLY_PRINTK
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set_intr_gate(i, &early_idt_handlers[i]);
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#else
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set_intr_gate(i, early_idt_handler);
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#endif
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}
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load_idt((const struct desc_ptr *)&idt_descr);
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if (console_loglevel == 10)
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early_printk("Kernel alive\n");
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x86_64_start_reservations(real_mode_data);
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}
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void __init x86_64_start_reservations(char *real_mode_data)
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{
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copy_bootdata(__va(real_mode_data));
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memblock_reserve(__pa_symbol(&_text),
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__pa_symbol(&__bss_stop) - __pa_symbol(&_text));
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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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unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
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unsigned long ramdisk_size = boot_params.hdr.ramdisk_size;
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unsigned long ramdisk_end = PAGE_ALIGN(ramdisk_image + ramdisk_size);
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memblock_reserve(ramdisk_image, ramdisk_end - ramdisk_image);
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}
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#endif
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reserve_ebda_region();
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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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