586 строки
14 KiB
C
586 строки
14 KiB
C
/*
|
|
* handle transition of Linux booting another kernel
|
|
* Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com>
|
|
*
|
|
* This source code is licensed under the GNU General Public License,
|
|
* Version 2. See the file COPYING for more details.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) "kexec: " fmt
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/kexec.h>
|
|
#include <linux/string.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/numa.h>
|
|
#include <linux/ftrace.h>
|
|
#include <linux/io.h>
|
|
#include <linux/suspend.h>
|
|
#include <linux/vmalloc.h>
|
|
|
|
#include <asm/init.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/mmu_context.h>
|
|
#include <asm/io_apic.h>
|
|
#include <asm/debugreg.h>
|
|
#include <asm/kexec-bzimage64.h>
|
|
#include <asm/setup.h>
|
|
|
|
#ifdef CONFIG_KEXEC_FILE
|
|
static struct kexec_file_ops *kexec_file_loaders[] = {
|
|
&kexec_bzImage64_ops,
|
|
};
|
|
#endif
|
|
|
|
static void free_transition_pgtable(struct kimage *image)
|
|
{
|
|
free_page((unsigned long)image->arch.pud);
|
|
free_page((unsigned long)image->arch.pmd);
|
|
free_page((unsigned long)image->arch.pte);
|
|
}
|
|
|
|
static int init_transition_pgtable(struct kimage *image, pgd_t *pgd)
|
|
{
|
|
pud_t *pud;
|
|
pmd_t *pmd;
|
|
pte_t *pte;
|
|
unsigned long vaddr, paddr;
|
|
int result = -ENOMEM;
|
|
|
|
vaddr = (unsigned long)relocate_kernel;
|
|
paddr = __pa(page_address(image->control_code_page)+PAGE_SIZE);
|
|
pgd += pgd_index(vaddr);
|
|
if (!pgd_present(*pgd)) {
|
|
pud = (pud_t *)get_zeroed_page(GFP_KERNEL);
|
|
if (!pud)
|
|
goto err;
|
|
image->arch.pud = pud;
|
|
set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
|
|
}
|
|
pud = pud_offset(pgd, vaddr);
|
|
if (!pud_present(*pud)) {
|
|
pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL);
|
|
if (!pmd)
|
|
goto err;
|
|
image->arch.pmd = pmd;
|
|
set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
|
|
}
|
|
pmd = pmd_offset(pud, vaddr);
|
|
if (!pmd_present(*pmd)) {
|
|
pte = (pte_t *)get_zeroed_page(GFP_KERNEL);
|
|
if (!pte)
|
|
goto err;
|
|
image->arch.pte = pte;
|
|
set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE));
|
|
}
|
|
pte = pte_offset_kernel(pmd, vaddr);
|
|
set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC));
|
|
return 0;
|
|
err:
|
|
free_transition_pgtable(image);
|
|
return result;
|
|
}
|
|
|
|
static void *alloc_pgt_page(void *data)
|
|
{
|
|
struct kimage *image = (struct kimage *)data;
|
|
struct page *page;
|
|
void *p = NULL;
|
|
|
|
page = kimage_alloc_control_pages(image, 0);
|
|
if (page) {
|
|
p = page_address(page);
|
|
clear_page(p);
|
|
}
|
|
|
|
return p;
|
|
}
|
|
|
|
static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
|
|
{
|
|
struct x86_mapping_info info = {
|
|
.alloc_pgt_page = alloc_pgt_page,
|
|
.context = image,
|
|
.pmd_flag = __PAGE_KERNEL_LARGE_EXEC,
|
|
};
|
|
unsigned long mstart, mend;
|
|
pgd_t *level4p;
|
|
int result;
|
|
int i;
|
|
|
|
level4p = (pgd_t *)__va(start_pgtable);
|
|
clear_page(level4p);
|
|
for (i = 0; i < nr_pfn_mapped; i++) {
|
|
mstart = pfn_mapped[i].start << PAGE_SHIFT;
|
|
mend = pfn_mapped[i].end << PAGE_SHIFT;
|
|
|
|
result = kernel_ident_mapping_init(&info,
|
|
level4p, mstart, mend);
|
|
if (result)
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* segments's mem ranges could be outside 0 ~ max_pfn,
|
|
* for example when jump back to original kernel from kexeced kernel.
|
|
* or first kernel is booted with user mem map, and second kernel
|
|
* could be loaded out of that range.
|
|
*/
|
|
for (i = 0; i < image->nr_segments; i++) {
|
|
mstart = image->segment[i].mem;
|
|
mend = mstart + image->segment[i].memsz;
|
|
|
|
result = kernel_ident_mapping_init(&info,
|
|
level4p, mstart, mend);
|
|
|
|
if (result)
|
|
return result;
|
|
}
|
|
|
|
return init_transition_pgtable(image, level4p);
|
|
}
|
|
|
|
static void set_idt(void *newidt, u16 limit)
|
|
{
|
|
struct desc_ptr curidt;
|
|
|
|
/* x86-64 supports unaliged loads & stores */
|
|
curidt.size = limit;
|
|
curidt.address = (unsigned long)newidt;
|
|
|
|
__asm__ __volatile__ (
|
|
"lidtq %0\n"
|
|
: : "m" (curidt)
|
|
);
|
|
};
|
|
|
|
|
|
static void set_gdt(void *newgdt, u16 limit)
|
|
{
|
|
struct desc_ptr curgdt;
|
|
|
|
/* x86-64 supports unaligned loads & stores */
|
|
curgdt.size = limit;
|
|
curgdt.address = (unsigned long)newgdt;
|
|
|
|
__asm__ __volatile__ (
|
|
"lgdtq %0\n"
|
|
: : "m" (curgdt)
|
|
);
|
|
};
|
|
|
|
static void load_segments(void)
|
|
{
|
|
__asm__ __volatile__ (
|
|
"\tmovl %0,%%ds\n"
|
|
"\tmovl %0,%%es\n"
|
|
"\tmovl %0,%%ss\n"
|
|
"\tmovl %0,%%fs\n"
|
|
"\tmovl %0,%%gs\n"
|
|
: : "a" (__KERNEL_DS) : "memory"
|
|
);
|
|
}
|
|
|
|
#ifdef CONFIG_KEXEC_FILE
|
|
/* Update purgatory as needed after various image segments have been prepared */
|
|
static int arch_update_purgatory(struct kimage *image)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (!image->file_mode)
|
|
return 0;
|
|
|
|
/* Setup copying of backup region */
|
|
if (image->type == KEXEC_TYPE_CRASH) {
|
|
ret = kexec_purgatory_get_set_symbol(image, "backup_dest",
|
|
&image->arch.backup_load_addr,
|
|
sizeof(image->arch.backup_load_addr), 0);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = kexec_purgatory_get_set_symbol(image, "backup_src",
|
|
&image->arch.backup_src_start,
|
|
sizeof(image->arch.backup_src_start), 0);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = kexec_purgatory_get_set_symbol(image, "backup_sz",
|
|
&image->arch.backup_src_sz,
|
|
sizeof(image->arch.backup_src_sz), 0);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
#else /* !CONFIG_KEXEC_FILE */
|
|
static inline int arch_update_purgatory(struct kimage *image)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_KEXEC_FILE */
|
|
|
|
int machine_kexec_prepare(struct kimage *image)
|
|
{
|
|
unsigned long start_pgtable;
|
|
int result;
|
|
|
|
/* Calculate the offsets */
|
|
start_pgtable = page_to_pfn(image->control_code_page) << PAGE_SHIFT;
|
|
|
|
/* Setup the identity mapped 64bit page table */
|
|
result = init_pgtable(image, start_pgtable);
|
|
if (result)
|
|
return result;
|
|
|
|
/* update purgatory as needed */
|
|
result = arch_update_purgatory(image);
|
|
if (result)
|
|
return result;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void machine_kexec_cleanup(struct kimage *image)
|
|
{
|
|
free_transition_pgtable(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;
|
|
|
|
#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 disable_IO_APIC() in
|
|
* one form or other. kexec jump path also need
|
|
* one.
|
|
*/
|
|
disable_IO_APIC();
|
|
#endif
|
|
}
|
|
|
|
control_page = page_address(image->control_code_page) + PAGE_SIZE;
|
|
memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE);
|
|
|
|
page_list[PA_CONTROL_PAGE] = virt_to_phys(control_page);
|
|
page_list[VA_CONTROL_PAGE] = (unsigned long)control_page;
|
|
page_list[PA_TABLE_PAGE] =
|
|
(unsigned long)__pa(page_address(image->control_code_page));
|
|
|
|
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.
|
|
*/
|
|
set_gdt(phys_to_virt(0), 0);
|
|
set_idt(phys_to_virt(0), 0);
|
|
|
|
/* now call it */
|
|
image->start = relocate_kernel((unsigned long)image->head,
|
|
(unsigned long)page_list,
|
|
image->start,
|
|
image->preserve_context);
|
|
|
|
#ifdef CONFIG_KEXEC_JUMP
|
|
if (image->preserve_context)
|
|
restore_processor_state();
|
|
#endif
|
|
|
|
__ftrace_enabled_restore(save_ftrace_enabled);
|
|
}
|
|
|
|
void arch_crash_save_vmcoreinfo(void)
|
|
{
|
|
VMCOREINFO_SYMBOL(phys_base);
|
|
VMCOREINFO_SYMBOL(init_level4_pgt);
|
|
|
|
#ifdef CONFIG_NUMA
|
|
VMCOREINFO_SYMBOL(node_data);
|
|
VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
|
|
#endif
|
|
vmcoreinfo_append_str("KERNELOFFSET=%lx\n",
|
|
kaslr_offset());
|
|
}
|
|
|
|
/* arch-dependent functionality related to kexec file-based syscall */
|
|
|
|
#ifdef CONFIG_KEXEC_FILE
|
|
int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
|
|
unsigned long buf_len)
|
|
{
|
|
int i, ret = -ENOEXEC;
|
|
struct kexec_file_ops *fops;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) {
|
|
fops = kexec_file_loaders[i];
|
|
if (!fops || !fops->probe)
|
|
continue;
|
|
|
|
ret = fops->probe(buf, buf_len);
|
|
if (!ret) {
|
|
image->fops = fops;
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
void *arch_kexec_kernel_image_load(struct kimage *image)
|
|
{
|
|
vfree(image->arch.elf_headers);
|
|
image->arch.elf_headers = NULL;
|
|
|
|
if (!image->fops || !image->fops->load)
|
|
return ERR_PTR(-ENOEXEC);
|
|
|
|
return image->fops->load(image, image->kernel_buf,
|
|
image->kernel_buf_len, image->initrd_buf,
|
|
image->initrd_buf_len, image->cmdline_buf,
|
|
image->cmdline_buf_len);
|
|
}
|
|
|
|
int arch_kimage_file_post_load_cleanup(struct kimage *image)
|
|
{
|
|
if (!image->fops || !image->fops->cleanup)
|
|
return 0;
|
|
|
|
return image->fops->cleanup(image->image_loader_data);
|
|
}
|
|
|
|
#ifdef CONFIG_KEXEC_VERIFY_SIG
|
|
int arch_kexec_kernel_verify_sig(struct kimage *image, void *kernel,
|
|
unsigned long kernel_len)
|
|
{
|
|
if (!image->fops || !image->fops->verify_sig) {
|
|
pr_debug("kernel loader does not support signature verification.");
|
|
return -EKEYREJECTED;
|
|
}
|
|
|
|
return image->fops->verify_sig(kernel, kernel_len);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Apply purgatory relocations.
|
|
*
|
|
* ehdr: Pointer to elf headers
|
|
* sechdrs: Pointer to section headers.
|
|
* relsec: section index of SHT_RELA section.
|
|
*
|
|
* TODO: Some of the code belongs to generic code. Move that in kexec.c.
|
|
*/
|
|
int arch_kexec_apply_relocations_add(const Elf64_Ehdr *ehdr,
|
|
Elf64_Shdr *sechdrs, unsigned int relsec)
|
|
{
|
|
unsigned int i;
|
|
Elf64_Rela *rel;
|
|
Elf64_Sym *sym;
|
|
void *location;
|
|
Elf64_Shdr *section, *symtabsec;
|
|
unsigned long address, sec_base, value;
|
|
const char *strtab, *name, *shstrtab;
|
|
|
|
/*
|
|
* ->sh_offset has been modified to keep the pointer to section
|
|
* contents in memory
|
|
*/
|
|
rel = (void *)sechdrs[relsec].sh_offset;
|
|
|
|
/* Section to which relocations apply */
|
|
section = &sechdrs[sechdrs[relsec].sh_info];
|
|
|
|
pr_debug("Applying relocate section %u to %u\n", relsec,
|
|
sechdrs[relsec].sh_info);
|
|
|
|
/* Associated symbol table */
|
|
symtabsec = &sechdrs[sechdrs[relsec].sh_link];
|
|
|
|
/* String table */
|
|
if (symtabsec->sh_link >= ehdr->e_shnum) {
|
|
/* Invalid strtab section number */
|
|
pr_err("Invalid string table section index %d\n",
|
|
symtabsec->sh_link);
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
strtab = (char *)sechdrs[symtabsec->sh_link].sh_offset;
|
|
|
|
/* section header string table */
|
|
shstrtab = (char *)sechdrs[ehdr->e_shstrndx].sh_offset;
|
|
|
|
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
|
|
|
|
/*
|
|
* rel[i].r_offset contains byte offset from beginning
|
|
* of section to the storage unit affected.
|
|
*
|
|
* This is location to update (->sh_offset). This is temporary
|
|
* buffer where section is currently loaded. This will finally
|
|
* be loaded to a different address later, pointed to by
|
|
* ->sh_addr. kexec takes care of moving it
|
|
* (kexec_load_segment()).
|
|
*/
|
|
location = (void *)(section->sh_offset + rel[i].r_offset);
|
|
|
|
/* Final address of the location */
|
|
address = section->sh_addr + rel[i].r_offset;
|
|
|
|
/*
|
|
* rel[i].r_info contains information about symbol table index
|
|
* w.r.t which relocation must be made and type of relocation
|
|
* to apply. ELF64_R_SYM() and ELF64_R_TYPE() macros get
|
|
* these respectively.
|
|
*/
|
|
sym = (Elf64_Sym *)symtabsec->sh_offset +
|
|
ELF64_R_SYM(rel[i].r_info);
|
|
|
|
if (sym->st_name)
|
|
name = strtab + sym->st_name;
|
|
else
|
|
name = shstrtab + sechdrs[sym->st_shndx].sh_name;
|
|
|
|
pr_debug("Symbol: %s info: %02x shndx: %02x value=%llx size: %llx\n",
|
|
name, sym->st_info, sym->st_shndx, sym->st_value,
|
|
sym->st_size);
|
|
|
|
if (sym->st_shndx == SHN_UNDEF) {
|
|
pr_err("Undefined symbol: %s\n", name);
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
if (sym->st_shndx == SHN_COMMON) {
|
|
pr_err("symbol '%s' in common section\n", name);
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
if (sym->st_shndx == SHN_ABS)
|
|
sec_base = 0;
|
|
else if (sym->st_shndx >= ehdr->e_shnum) {
|
|
pr_err("Invalid section %d for symbol %s\n",
|
|
sym->st_shndx, name);
|
|
return -ENOEXEC;
|
|
} else
|
|
sec_base = sechdrs[sym->st_shndx].sh_addr;
|
|
|
|
value = sym->st_value;
|
|
value += sec_base;
|
|
value += rel[i].r_addend;
|
|
|
|
switch (ELF64_R_TYPE(rel[i].r_info)) {
|
|
case R_X86_64_NONE:
|
|
break;
|
|
case R_X86_64_64:
|
|
*(u64 *)location = value;
|
|
break;
|
|
case R_X86_64_32:
|
|
*(u32 *)location = value;
|
|
if (value != *(u32 *)location)
|
|
goto overflow;
|
|
break;
|
|
case R_X86_64_32S:
|
|
*(s32 *)location = value;
|
|
if ((s64)value != *(s32 *)location)
|
|
goto overflow;
|
|
break;
|
|
case R_X86_64_PC32:
|
|
value -= (u64)address;
|
|
*(u32 *)location = value;
|
|
break;
|
|
default:
|
|
pr_err("Unknown rela relocation: %llu\n",
|
|
ELF64_R_TYPE(rel[i].r_info));
|
|
return -ENOEXEC;
|
|
}
|
|
}
|
|
return 0;
|
|
|
|
overflow:
|
|
pr_err("Overflow in relocation type %d value 0x%lx\n",
|
|
(int)ELF64_R_TYPE(rel[i].r_info), value);
|
|
return -ENOEXEC;
|
|
}
|
|
#endif /* CONFIG_KEXEC_FILE */
|
|
|
|
static int
|
|
kexec_mark_range(unsigned long start, unsigned long end, bool protect)
|
|
{
|
|
struct page *page;
|
|
unsigned int nr_pages;
|
|
|
|
/*
|
|
* For physical range: [start, end]. We must skip the unassigned
|
|
* crashk resource with zero-valued "end" member.
|
|
*/
|
|
if (!end || start > end)
|
|
return 0;
|
|
|
|
page = pfn_to_page(start >> PAGE_SHIFT);
|
|
nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
|
|
if (protect)
|
|
return set_pages_ro(page, nr_pages);
|
|
else
|
|
return set_pages_rw(page, nr_pages);
|
|
}
|
|
|
|
static void kexec_mark_crashkres(bool protect)
|
|
{
|
|
unsigned long control;
|
|
|
|
kexec_mark_range(crashk_low_res.start, crashk_low_res.end, protect);
|
|
|
|
/* Don't touch the control code page used in crash_kexec().*/
|
|
control = PFN_PHYS(page_to_pfn(kexec_crash_image->control_code_page));
|
|
/* Control code page is located in the 2nd page. */
|
|
kexec_mark_range(crashk_res.start, control + PAGE_SIZE - 1, protect);
|
|
control += KEXEC_CONTROL_PAGE_SIZE;
|
|
kexec_mark_range(control, crashk_res.end, protect);
|
|
}
|
|
|
|
void arch_kexec_protect_crashkres(void)
|
|
{
|
|
kexec_mark_crashkres(true);
|
|
}
|
|
|
|
void arch_kexec_unprotect_crashkres(void)
|
|
{
|
|
kexec_mark_crashkres(false);
|
|
}
|