241 lines
6.4 KiB
C
241 lines
6.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* handle transition of Linux booting another kernel
|
|
* Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com>
|
|
*/
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/kexec.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/numa.h>
|
|
#include <linux/ftrace.h>
|
|
#include <linux/suspend.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/io.h>
|
|
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/mmu_context.h>
|
|
#include <asm/apic.h>
|
|
#include <asm/io_apic.h>
|
|
#include <asm/cpufeature.h>
|
|
#include <asm/desc.h>
|
|
#include <asm/set_memory.h>
|
|
#include <asm/debugreg.h>
|
|
|
|
static void load_segments(void)
|
|
{
|
|
#define __STR(X) #X
|
|
#define STR(X) __STR(X)
|
|
|
|
__asm__ __volatile__ (
|
|
"\tljmp $"STR(__KERNEL_CS)",$1f\n"
|
|
"\t1:\n"
|
|
"\tmovl $"STR(__KERNEL_DS)",%%eax\n"
|
|
"\tmovl %%eax,%%ds\n"
|
|
"\tmovl %%eax,%%es\n"
|
|
"\tmovl %%eax,%%ss\n"
|
|
: : : "eax", "memory");
|
|
#undef STR
|
|
#undef __STR
|
|
}
|
|
|
|
static void machine_kexec_free_page_tables(struct kimage *image)
|
|
{
|
|
free_pages((unsigned long)image->arch.pgd, PGD_ALLOCATION_ORDER);
|
|
image->arch.pgd = NULL;
|
|
#ifdef CONFIG_X86_PAE
|
|
free_page((unsigned long)image->arch.pmd0);
|
|
image->arch.pmd0 = NULL;
|
|
free_page((unsigned long)image->arch.pmd1);
|
|
image->arch.pmd1 = NULL;
|
|
#endif
|
|
free_page((unsigned long)image->arch.pte0);
|
|
image->arch.pte0 = NULL;
|
|
free_page((unsigned long)image->arch.pte1);
|
|
image->arch.pte1 = NULL;
|
|
}
|
|
|
|
static int machine_kexec_alloc_page_tables(struct kimage *image)
|
|
{
|
|
image->arch.pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
|
|
PGD_ALLOCATION_ORDER);
|
|
#ifdef CONFIG_X86_PAE
|
|
image->arch.pmd0 = (pmd_t *)get_zeroed_page(GFP_KERNEL);
|
|
image->arch.pmd1 = (pmd_t *)get_zeroed_page(GFP_KERNEL);
|
|
#endif
|
|
image->arch.pte0 = (pte_t *)get_zeroed_page(GFP_KERNEL);
|
|
image->arch.pte1 = (pte_t *)get_zeroed_page(GFP_KERNEL);
|
|
if (!image->arch.pgd ||
|
|
#ifdef CONFIG_X86_PAE
|
|
!image->arch.pmd0 || !image->arch.pmd1 ||
|
|
#endif
|
|
!image->arch.pte0 || !image->arch.pte1) {
|
|
return -ENOMEM;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void machine_kexec_page_table_set_one(
|
|
pgd_t *pgd, pmd_t *pmd, pte_t *pte,
|
|
unsigned long vaddr, unsigned long paddr)
|
|
{
|
|
p4d_t *p4d;
|
|
pud_t *pud;
|
|
|
|
pgd += pgd_index(vaddr);
|
|
#ifdef CONFIG_X86_PAE
|
|
if (!(pgd_val(*pgd) & _PAGE_PRESENT))
|
|
set_pgd(pgd, __pgd(__pa(pmd) | _PAGE_PRESENT));
|
|
#endif
|
|
p4d = p4d_offset(pgd, vaddr);
|
|
pud = pud_offset(p4d, vaddr);
|
|
pmd = pmd_offset(pud, vaddr);
|
|
if (!(pmd_val(*pmd) & _PAGE_PRESENT))
|
|
set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
|
|
pte = pte_offset_kernel(pmd, vaddr);
|
|
set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC));
|
|
}
|
|
|
|
static void machine_kexec_prepare_page_tables(struct kimage *image)
|
|
{
|
|
void *control_page;
|
|
pmd_t *pmd = NULL;
|
|
|
|
control_page = page_address(image->control_code_page);
|
|
#ifdef CONFIG_X86_PAE
|
|
pmd = image->arch.pmd0;
|
|
#endif
|
|
machine_kexec_page_table_set_one(
|
|
image->arch.pgd, pmd, image->arch.pte0,
|
|
(unsigned long)control_page, __pa(control_page));
|
|
#ifdef CONFIG_X86_PAE
|
|
pmd = image->arch.pmd1;
|
|
#endif
|
|
machine_kexec_page_table_set_one(
|
|
image->arch.pgd, pmd, image->arch.pte1,
|
|
__pa(control_page), __pa(control_page));
|
|
}
|
|
|
|
/*
|
|
* A architecture hook called to validate the
|
|
* proposed image and prepare the control pages
|
|
* as needed. The pages for KEXEC_CONTROL_PAGE_SIZE
|
|
* have been allocated, but the segments have yet
|
|
* been copied into the kernel.
|
|
*
|
|
* Do what every setup is needed on image and the
|
|
* reboot code buffer to allow us to avoid allocations
|
|
* later.
|
|
*
|
|
* - Make control page executable.
|
|
* - Allocate page tables
|
|
* - Setup page tables
|
|
*/
|
|
int machine_kexec_prepare(struct kimage *image)
|
|
{
|
|
int error;
|
|
|
|
set_memory_x((unsigned long)page_address(image->control_code_page), 1);
|
|
error = machine_kexec_alloc_page_tables(image);
|
|
if (error)
|
|
return error;
|
|
machine_kexec_prepare_page_tables(image);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Undo anything leftover by machine_kexec_prepare
|
|
* when an image is freed.
|
|
*/
|
|
void machine_kexec_cleanup(struct kimage *image)
|
|
{
|
|
set_memory_nx((unsigned long)page_address(image->control_code_page), 1);
|
|
machine_kexec_free_page_tables(image);
|
|
}
|
|
|
|
/*
|
|
* Do not allocate memory (or fail in any way) in machine_kexec().
|
|
* We are past the point of no return, committed to rebooting now.
|
|
*/
|
|
void machine_kexec(struct kimage *image)
|
|
{
|
|
unsigned long page_list[PAGES_NR];
|
|
void *control_page;
|
|
int save_ftrace_enabled;
|
|
asmlinkage unsigned long
|
|
(*relocate_kernel_ptr)(unsigned long indirection_page,
|
|
unsigned long control_page,
|
|
unsigned long start_address,
|
|
unsigned int has_pae,
|
|
unsigned int preserve_context);
|
|
|
|
#ifdef CONFIG_KEXEC_JUMP
|
|
if (image->preserve_context)
|
|
save_processor_state();
|
|
#endif
|
|
|
|
save_ftrace_enabled = __ftrace_enabled_save();
|
|
|
|
/* Interrupts aren't acceptable while we reboot */
|
|
local_irq_disable();
|
|
hw_breakpoint_disable();
|
|
|
|
if (image->preserve_context) {
|
|
#ifdef CONFIG_X86_IO_APIC
|
|
/*
|
|
* We need to put APICs in legacy mode so that we can
|
|
* get timer interrupts in second kernel. kexec/kdump
|
|
* paths already have calls to restore_boot_irq_mode()
|
|
* in one form or other. kexec jump path also need one.
|
|
*/
|
|
clear_IO_APIC();
|
|
restore_boot_irq_mode();
|
|
#endif
|
|
}
|
|
|
|
control_page = page_address(image->control_code_page);
|
|
memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE);
|
|
|
|
relocate_kernel_ptr = control_page;
|
|
page_list[PA_CONTROL_PAGE] = __pa(control_page);
|
|
page_list[VA_CONTROL_PAGE] = (unsigned long)control_page;
|
|
page_list[PA_PGD] = __pa(image->arch.pgd);
|
|
|
|
if (image->type == KEXEC_TYPE_DEFAULT)
|
|
page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page)
|
|
<< PAGE_SHIFT);
|
|
|
|
/*
|
|
* The segment registers are funny things, they have both a
|
|
* visible and an invisible part. Whenever the visible part is
|
|
* set to a specific selector, the invisible part is loaded
|
|
* with from a table in memory. At no other time is the
|
|
* descriptor table in memory accessed.
|
|
*
|
|
* I take advantage of this here by force loading the
|
|
* segments, before I zap the gdt with an invalid value.
|
|
*/
|
|
load_segments();
|
|
/*
|
|
* The gdt & idt are now invalid.
|
|
* If you want to load them you must set up your own idt & gdt.
|
|
*/
|
|
native_idt_invalidate();
|
|
native_gdt_invalidate();
|
|
|
|
/* now call it */
|
|
image->start = relocate_kernel_ptr((unsigned long)image->head,
|
|
(unsigned long)page_list,
|
|
image->start,
|
|
boot_cpu_has(X86_FEATURE_PAE),
|
|
image->preserve_context);
|
|
|
|
#ifdef CONFIG_KEXEC_JUMP
|
|
if (image->preserve_context)
|
|
restore_processor_state();
|
|
#endif
|
|
|
|
__ftrace_enabled_restore(save_ftrace_enabled);
|
|
}
|