![Borislav Petkov](/assets/img/avatar_default.png)
... instead of naked numbers. Stuff in sysrq.c used to set it to 8 which is supposed to mean above default level so set it to DEBUG instead as we're terminating/killing all tasks and we want to be verbose there. Also, correct the check in x86_64_start_kernel which should be >= as we're clearly issuing the string there for all debug levels, not only the magical 10. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Cc: Joe Perches <joe@perches.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
195 lines
5 KiB
C
195 lines
5 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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#include <asm/microcode.h>
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/*
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* Manage page tables very early on.
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*/
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extern pgd_t early_level4_pgt[PTRS_PER_PGD];
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extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD];
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static unsigned int __initdata next_early_pgt = 2;
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pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX);
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/* Wipe all early page tables except for the kernel symbol map */
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static void __init reset_early_page_tables(void)
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{
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unsigned long i;
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for (i = 0; i < PTRS_PER_PGD-1; i++)
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early_level4_pgt[i].pgd = 0;
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next_early_pgt = 0;
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write_cr3(__pa(early_level4_pgt));
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}
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/* Create a new PMD entry */
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int __init early_make_pgtable(unsigned long address)
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{
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unsigned long physaddr = address - __PAGE_OFFSET;
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unsigned long i;
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pgdval_t pgd, *pgd_p;
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pudval_t pud, *pud_p;
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pmdval_t pmd, *pmd_p;
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/* Invalid address or early pgt is done ? */
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if (physaddr >= MAXMEM || read_cr3() != __pa(early_level4_pgt))
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return -1;
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again:
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pgd_p = &early_level4_pgt[pgd_index(address)].pgd;
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pgd = *pgd_p;
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/*
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* The use of __START_KERNEL_map rather than __PAGE_OFFSET here is
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* critical -- __PAGE_OFFSET would point us back into the dynamic
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* range and we might end up looping forever...
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*/
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if (pgd)
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pud_p = (pudval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
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else {
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if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
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reset_early_page_tables();
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goto again;
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}
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pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++];
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for (i = 0; i < PTRS_PER_PUD; i++)
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pud_p[i] = 0;
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*pgd_p = (pgdval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
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}
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pud_p += pud_index(address);
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pud = *pud_p;
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if (pud)
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pmd_p = (pmdval_t *)((pud & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
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else {
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if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
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reset_early_page_tables();
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goto again;
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}
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pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++];
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for (i = 0; i < PTRS_PER_PMD; i++)
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pmd_p[i] = 0;
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*pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
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}
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pmd = (physaddr & PMD_MASK) + early_pmd_flags;
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pmd_p[pmd_index(address)] = pmd;
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return 0;
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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 unsigned long get_cmd_line_ptr(void)
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{
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unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr;
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cmd_line_ptr |= (u64)boot_params.ext_cmd_line_ptr << 32;
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return cmd_line_ptr;
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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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unsigned long cmd_line_ptr;
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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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cmd_line_ptr = get_cmd_line_ptr();
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if (cmd_line_ptr) {
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command_line = __va(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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asmlinkage __visible 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 < __START_KERNEL_map);
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BUILD_BUG_ON(MODULES_VADDR - __START_KERNEL_map < 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((__START_KERNEL_map & ~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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/* Kill off the identity-map trampoline */
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reset_early_page_tables();
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/* clear bss before set_intr_gate with early_idt_handler */
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clear_bss();
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for (i = 0; i < NUM_EXCEPTION_VECTORS; i++)
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set_intr_gate(i, early_idt_handlers[i]);
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load_idt((const struct desc_ptr *)&idt_descr);
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copy_bootdata(__va(real_mode_data));
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/*
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* Load microcode early on BSP.
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*/
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load_ucode_bsp();
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if (console_loglevel >= CONSOLE_LOGLEVEL_DEBUG)
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early_printk("Kernel alive\n");
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clear_page(init_level4_pgt);
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/* set init_level4_pgt kernel high mapping*/
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init_level4_pgt[511] = early_level4_pgt[511];
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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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/* version is always not zero if it is copied */
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if (!boot_params.hdr.version)
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copy_bootdata(__va(real_mode_data));
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reserve_ebda_region();
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start_kernel();
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}
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