linux-stable/arch/x86/kernel/setup.c
Mike Rapoport f1d4d47c58 x86/setup: Always reserve the first 1M of RAM
There are BIOSes that are known to corrupt the memory under 1M, or more
precisely under 640K because the memory above 640K is anyway reserved
for the EGA/VGA frame buffer and BIOS.

To prevent usage of the memory that will be potentially clobbered by the
kernel, the beginning of the memory is always reserved. The exact size
of the reserved area is determined by CONFIG_X86_RESERVE_LOW build time
and the "reservelow=" command line option. The reserved range may be
from 4K to 640K with the default of 64K. There are also configurations
that reserve the entire 1M range, like machines with SandyBridge graphic
devices or systems that enable crash kernel.

In addition to the potentially clobbered memory, EBDA of unknown size may
be as low as 128K and the memory above that EBDA start is also reserved
early.

It would have been possible to reserve the entire range under 1M unless for
the real mode trampoline that must reside in that area.

To accommodate placement of the real mode trampoline and keep the memory
safe from being clobbered by BIOS, reserve the first 64K of RAM before
memory allocations are possible and then, after the real mode trampoline
is allocated, reserve the entire range from 0 to 1M.

Update trim_snb_memory() and reserve_real_mode() to avoid redundant
reservations of the same memory range.

Also make sure the memory under 1M is not getting freed by
efi_free_boot_services().

 [ bp: Massage commit message and comments. ]

Fixes: a799c2bd29 ("x86/setup: Consolidate early memory reservations")
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Hugh Dickins <hughd@google.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=213177
Link: https://lkml.kernel.org/r/20210601075354.5149-2-rppt@kernel.org
2021-06-03 19:57:55 +02:00

1284 lines
33 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 1995 Linus Torvalds
*
* This file contains the setup_arch() code, which handles the architecture-dependent
* parts of early kernel initialization.
*/
#include <linux/console.h>
#include <linux/crash_dump.h>
#include <linux/dma-map-ops.h>
#include <linux/dmi.h>
#include <linux/efi.h>
#include <linux/init_ohci1394_dma.h>
#include <linux/initrd.h>
#include <linux/iscsi_ibft.h>
#include <linux/memblock.h>
#include <linux/pci.h>
#include <linux/root_dev.h>
#include <linux/hugetlb.h>
#include <linux/tboot.h>
#include <linux/usb/xhci-dbgp.h>
#include <linux/static_call.h>
#include <linux/swiotlb.h>
#include <uapi/linux/mount.h>
#include <xen/xen.h>
#include <asm/apic.h>
#include <asm/numa.h>
#include <asm/bios_ebda.h>
#include <asm/bugs.h>
#include <asm/cpu.h>
#include <asm/efi.h>
#include <asm/gart.h>
#include <asm/hypervisor.h>
#include <asm/io_apic.h>
#include <asm/kasan.h>
#include <asm/kaslr.h>
#include <asm/mce.h>
#include <asm/mtrr.h>
#include <asm/realmode.h>
#include <asm/olpc_ofw.h>
#include <asm/pci-direct.h>
#include <asm/prom.h>
#include <asm/proto.h>
#include <asm/thermal.h>
#include <asm/unwind.h>
#include <asm/vsyscall.h>
#include <linux/vmalloc.h>
/*
* max_low_pfn_mapped: highest directly mapped pfn < 4 GB
* max_pfn_mapped: highest directly mapped pfn > 4 GB
*
* The direct mapping only covers E820_TYPE_RAM regions, so the ranges and gaps are
* represented by pfn_mapped[].
*/
unsigned long max_low_pfn_mapped;
unsigned long max_pfn_mapped;
#ifdef CONFIG_DMI
RESERVE_BRK(dmi_alloc, 65536);
#endif
/*
* Range of the BSS area. The size of the BSS area is determined
* at link time, with RESERVE_BRK() facility reserving additional
* chunks.
*/
unsigned long _brk_start = (unsigned long)__brk_base;
unsigned long _brk_end = (unsigned long)__brk_base;
struct boot_params boot_params;
/*
* These are the four main kernel memory regions, we put them into
* the resource tree so that kdump tools and other debugging tools
* recover it:
*/
static struct resource rodata_resource = {
.name = "Kernel rodata",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
};
static struct resource data_resource = {
.name = "Kernel data",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
};
static struct resource code_resource = {
.name = "Kernel code",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
};
static struct resource bss_resource = {
.name = "Kernel bss",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
};
#ifdef CONFIG_X86_32
/* CPU data as detected by the assembly code in head_32.S */
struct cpuinfo_x86 new_cpu_data;
/* Common CPU data for all CPUs */
struct cpuinfo_x86 boot_cpu_data __read_mostly;
EXPORT_SYMBOL(boot_cpu_data);
unsigned int def_to_bigsmp;
struct apm_info apm_info;
EXPORT_SYMBOL(apm_info);
#if defined(CONFIG_X86_SPEEDSTEP_SMI) || \
defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
struct ist_info ist_info;
EXPORT_SYMBOL(ist_info);
#else
struct ist_info ist_info;
#endif
#else
struct cpuinfo_x86 boot_cpu_data __read_mostly;
EXPORT_SYMBOL(boot_cpu_data);
#endif
#if !defined(CONFIG_X86_PAE) || defined(CONFIG_X86_64)
__visible unsigned long mmu_cr4_features __ro_after_init;
#else
__visible unsigned long mmu_cr4_features __ro_after_init = X86_CR4_PAE;
#endif
/* Boot loader ID and version as integers, for the benefit of proc_dointvec */
int bootloader_type, bootloader_version;
/*
* Setup options
*/
struct screen_info screen_info;
EXPORT_SYMBOL(screen_info);
struct edid_info edid_info;
EXPORT_SYMBOL_GPL(edid_info);
extern int root_mountflags;
unsigned long saved_video_mode;
#define RAMDISK_IMAGE_START_MASK 0x07FF
#define RAMDISK_PROMPT_FLAG 0x8000
#define RAMDISK_LOAD_FLAG 0x4000
static char __initdata command_line[COMMAND_LINE_SIZE];
#ifdef CONFIG_CMDLINE_BOOL
static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
#endif
#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
struct edd edd;
#ifdef CONFIG_EDD_MODULE
EXPORT_SYMBOL(edd);
#endif
/**
* copy_edd() - Copy the BIOS EDD information
* from boot_params into a safe place.
*
*/
static inline void __init copy_edd(void)
{
memcpy(edd.mbr_signature, boot_params.edd_mbr_sig_buffer,
sizeof(edd.mbr_signature));
memcpy(edd.edd_info, boot_params.eddbuf, sizeof(edd.edd_info));
edd.mbr_signature_nr = boot_params.edd_mbr_sig_buf_entries;
edd.edd_info_nr = boot_params.eddbuf_entries;
}
#else
static inline void __init copy_edd(void)
{
}
#endif
void * __init extend_brk(size_t size, size_t align)
{
size_t mask = align - 1;
void *ret;
BUG_ON(_brk_start == 0);
BUG_ON(align & mask);
_brk_end = (_brk_end + mask) & ~mask;
BUG_ON((char *)(_brk_end + size) > __brk_limit);
ret = (void *)_brk_end;
_brk_end += size;
memset(ret, 0, size);
return ret;
}
#ifdef CONFIG_X86_32
static void __init cleanup_highmap(void)
{
}
#endif
static void __init reserve_brk(void)
{
if (_brk_end > _brk_start)
memblock_reserve(__pa_symbol(_brk_start),
_brk_end - _brk_start);
/* Mark brk area as locked down and no longer taking any
new allocations */
_brk_start = 0;
}
u64 relocated_ramdisk;
#ifdef CONFIG_BLK_DEV_INITRD
static u64 __init get_ramdisk_image(void)
{
u64 ramdisk_image = boot_params.hdr.ramdisk_image;
ramdisk_image |= (u64)boot_params.ext_ramdisk_image << 32;
if (ramdisk_image == 0)
ramdisk_image = phys_initrd_start;
return ramdisk_image;
}
static u64 __init get_ramdisk_size(void)
{
u64 ramdisk_size = boot_params.hdr.ramdisk_size;
ramdisk_size |= (u64)boot_params.ext_ramdisk_size << 32;
if (ramdisk_size == 0)
ramdisk_size = phys_initrd_size;
return ramdisk_size;
}
static void __init relocate_initrd(void)
{
/* Assume only end is not page aligned */
u64 ramdisk_image = get_ramdisk_image();
u64 ramdisk_size = get_ramdisk_size();
u64 area_size = PAGE_ALIGN(ramdisk_size);
/* We need to move the initrd down into directly mapped mem */
relocated_ramdisk = memblock_phys_alloc_range(area_size, PAGE_SIZE, 0,
PFN_PHYS(max_pfn_mapped));
if (!relocated_ramdisk)
panic("Cannot find place for new RAMDISK of size %lld\n",
ramdisk_size);
initrd_start = relocated_ramdisk + PAGE_OFFSET;
initrd_end = initrd_start + ramdisk_size;
printk(KERN_INFO "Allocated new RAMDISK: [mem %#010llx-%#010llx]\n",
relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
copy_from_early_mem((void *)initrd_start, ramdisk_image, ramdisk_size);
printk(KERN_INFO "Move RAMDISK from [mem %#010llx-%#010llx] to"
" [mem %#010llx-%#010llx]\n",
ramdisk_image, ramdisk_image + ramdisk_size - 1,
relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
}
static void __init early_reserve_initrd(void)
{
/* Assume only end is not page aligned */
u64 ramdisk_image = get_ramdisk_image();
u64 ramdisk_size = get_ramdisk_size();
u64 ramdisk_end = PAGE_ALIGN(ramdisk_image + ramdisk_size);
if (!boot_params.hdr.type_of_loader ||
!ramdisk_image || !ramdisk_size)
return; /* No initrd provided by bootloader */
memblock_reserve(ramdisk_image, ramdisk_end - ramdisk_image);
}
static void __init reserve_initrd(void)
{
/* Assume only end is not page aligned */
u64 ramdisk_image = get_ramdisk_image();
u64 ramdisk_size = get_ramdisk_size();
u64 ramdisk_end = PAGE_ALIGN(ramdisk_image + ramdisk_size);
if (!boot_params.hdr.type_of_loader ||
!ramdisk_image || !ramdisk_size)
return; /* No initrd provided by bootloader */
initrd_start = 0;
printk(KERN_INFO "RAMDISK: [mem %#010llx-%#010llx]\n", ramdisk_image,
ramdisk_end - 1);
if (pfn_range_is_mapped(PFN_DOWN(ramdisk_image),
PFN_DOWN(ramdisk_end))) {
/* All are mapped, easy case */
initrd_start = ramdisk_image + PAGE_OFFSET;
initrd_end = initrd_start + ramdisk_size;
return;
}
relocate_initrd();
memblock_free(ramdisk_image, ramdisk_end - ramdisk_image);
}
#else
static void __init early_reserve_initrd(void)
{
}
static void __init reserve_initrd(void)
{
}
#endif /* CONFIG_BLK_DEV_INITRD */
static void __init parse_setup_data(void)
{
struct setup_data *data;
u64 pa_data, pa_next;
pa_data = boot_params.hdr.setup_data;
while (pa_data) {
u32 data_len, data_type;
data = early_memremap(pa_data, sizeof(*data));
data_len = data->len + sizeof(struct setup_data);
data_type = data->type;
pa_next = data->next;
early_memunmap(data, sizeof(*data));
switch (data_type) {
case SETUP_E820_EXT:
e820__memory_setup_extended(pa_data, data_len);
break;
case SETUP_DTB:
add_dtb(pa_data);
break;
case SETUP_EFI:
parse_efi_setup(pa_data, data_len);
break;
default:
break;
}
pa_data = pa_next;
}
}
static void __init memblock_x86_reserve_range_setup_data(void)
{
struct setup_data *data;
u64 pa_data;
pa_data = boot_params.hdr.setup_data;
while (pa_data) {
data = early_memremap(pa_data, sizeof(*data));
memblock_reserve(pa_data, sizeof(*data) + data->len);
if (data->type == SETUP_INDIRECT &&
((struct setup_indirect *)data->data)->type != SETUP_INDIRECT)
memblock_reserve(((struct setup_indirect *)data->data)->addr,
((struct setup_indirect *)data->data)->len);
pa_data = data->next;
early_memunmap(data, sizeof(*data));
}
}
/*
* --------- Crashkernel reservation ------------------------------
*/
#ifdef CONFIG_KEXEC_CORE
/* 16M alignment for crash kernel regions */
#define CRASH_ALIGN SZ_16M
/*
* Keep the crash kernel below this limit.
*
* Earlier 32-bits kernels would limit the kernel to the low 512 MB range
* due to mapping restrictions.
*
* 64-bit kdump kernels need to be restricted to be under 64 TB, which is
* the upper limit of system RAM in 4-level paging mode. Since the kdump
* jump could be from 5-level paging to 4-level paging, the jump will fail if
* the kernel is put above 64 TB, and during the 1st kernel bootup there's
* no good way to detect the paging mode of the target kernel which will be
* loaded for dumping.
*/
#ifdef CONFIG_X86_32
# define CRASH_ADDR_LOW_MAX SZ_512M
# define CRASH_ADDR_HIGH_MAX SZ_512M
#else
# define CRASH_ADDR_LOW_MAX SZ_4G
# define CRASH_ADDR_HIGH_MAX SZ_64T
#endif
static int __init reserve_crashkernel_low(void)
{
#ifdef CONFIG_X86_64
unsigned long long base, low_base = 0, low_size = 0;
unsigned long low_mem_limit;
int ret;
low_mem_limit = min(memblock_phys_mem_size(), CRASH_ADDR_LOW_MAX);
/* crashkernel=Y,low */
ret = parse_crashkernel_low(boot_command_line, low_mem_limit, &low_size, &base);
if (ret) {
/*
* two parts from kernel/dma/swiotlb.c:
* -swiotlb size: user-specified with swiotlb= or default.
*
* -swiotlb overflow buffer: now hardcoded to 32k. We round it
* to 8M for other buffers that may need to stay low too. Also
* make sure we allocate enough extra low memory so that we
* don't run out of DMA buffers for 32-bit devices.
*/
low_size = max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20);
} else {
/* passed with crashkernel=0,low ? */
if (!low_size)
return 0;
}
low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, CRASH_ADDR_LOW_MAX);
if (!low_base) {
pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n",
(unsigned long)(low_size >> 20));
return -ENOMEM;
}
pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (low RAM limit: %ldMB)\n",
(unsigned long)(low_size >> 20),
(unsigned long)(low_base >> 20),
(unsigned long)(low_mem_limit >> 20));
crashk_low_res.start = low_base;
crashk_low_res.end = low_base + low_size - 1;
insert_resource(&iomem_resource, &crashk_low_res);
#endif
return 0;
}
static void __init reserve_crashkernel(void)
{
unsigned long long crash_size, crash_base, total_mem;
bool high = false;
int ret;
total_mem = memblock_phys_mem_size();
/* crashkernel=XM */
ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base);
if (ret != 0 || crash_size <= 0) {
/* crashkernel=X,high */
ret = parse_crashkernel_high(boot_command_line, total_mem,
&crash_size, &crash_base);
if (ret != 0 || crash_size <= 0)
return;
high = true;
}
if (xen_pv_domain()) {
pr_info("Ignoring crashkernel for a Xen PV domain\n");
return;
}
/* 0 means: find the address automatically */
if (!crash_base) {
/*
* Set CRASH_ADDR_LOW_MAX upper bound for crash memory,
* crashkernel=x,high reserves memory over 4G, also allocates
* 256M extra low memory for DMA buffers and swiotlb.
* But the extra memory is not required for all machines.
* So try low memory first and fall back to high memory
* unless "crashkernel=size[KMG],high" is specified.
*/
if (!high)
crash_base = memblock_phys_alloc_range(crash_size,
CRASH_ALIGN, CRASH_ALIGN,
CRASH_ADDR_LOW_MAX);
if (!crash_base)
crash_base = memblock_phys_alloc_range(crash_size,
CRASH_ALIGN, CRASH_ALIGN,
CRASH_ADDR_HIGH_MAX);
if (!crash_base) {
pr_info("crashkernel reservation failed - No suitable area found.\n");
return;
}
} else {
unsigned long long start;
start = memblock_phys_alloc_range(crash_size, SZ_1M, crash_base,
crash_base + crash_size);
if (start != crash_base) {
pr_info("crashkernel reservation failed - memory is in use.\n");
return;
}
}
if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
memblock_free(crash_base, crash_size);
return;
}
pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n",
(unsigned long)(crash_size >> 20),
(unsigned long)(crash_base >> 20),
(unsigned long)(total_mem >> 20));
crashk_res.start = crash_base;
crashk_res.end = crash_base + crash_size - 1;
insert_resource(&iomem_resource, &crashk_res);
}
#else
static void __init reserve_crashkernel(void)
{
}
#endif
static struct resource standard_io_resources[] = {
{ .name = "dma1", .start = 0x00, .end = 0x1f,
.flags = IORESOURCE_BUSY | IORESOURCE_IO },
{ .name = "pic1", .start = 0x20, .end = 0x21,
.flags = IORESOURCE_BUSY | IORESOURCE_IO },
{ .name = "timer0", .start = 0x40, .end = 0x43,
.flags = IORESOURCE_BUSY | IORESOURCE_IO },
{ .name = "timer1", .start = 0x50, .end = 0x53,
.flags = IORESOURCE_BUSY | IORESOURCE_IO },
{ .name = "keyboard", .start = 0x60, .end = 0x60,
.flags = IORESOURCE_BUSY | IORESOURCE_IO },
{ .name = "keyboard", .start = 0x64, .end = 0x64,
.flags = IORESOURCE_BUSY | IORESOURCE_IO },
{ .name = "dma page reg", .start = 0x80, .end = 0x8f,
.flags = IORESOURCE_BUSY | IORESOURCE_IO },
{ .name = "pic2", .start = 0xa0, .end = 0xa1,
.flags = IORESOURCE_BUSY | IORESOURCE_IO },
{ .name = "dma2", .start = 0xc0, .end = 0xdf,
.flags = IORESOURCE_BUSY | IORESOURCE_IO },
{ .name = "fpu", .start = 0xf0, .end = 0xff,
.flags = IORESOURCE_BUSY | IORESOURCE_IO }
};
void __init reserve_standard_io_resources(void)
{
int i;
/* request I/O space for devices used on all i[345]86 PCs */
for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
request_resource(&ioport_resource, &standard_io_resources[i]);
}
static __init void reserve_ibft_region(void)
{
unsigned long addr, size = 0;
addr = find_ibft_region(&size);
if (size)
memblock_reserve(addr, size);
}
static bool __init snb_gfx_workaround_needed(void)
{
#ifdef CONFIG_PCI
int i;
u16 vendor, devid;
static const __initconst u16 snb_ids[] = {
0x0102,
0x0112,
0x0122,
0x0106,
0x0116,
0x0126,
0x010a,
};
/* Assume no if something weird is going on with PCI */
if (!early_pci_allowed())
return false;
vendor = read_pci_config_16(0, 2, 0, PCI_VENDOR_ID);
if (vendor != 0x8086)
return false;
devid = read_pci_config_16(0, 2, 0, PCI_DEVICE_ID);
for (i = 0; i < ARRAY_SIZE(snb_ids); i++)
if (devid == snb_ids[i])
return true;
#endif
return false;
}
/*
* Sandy Bridge graphics has trouble with certain ranges, exclude
* them from allocation.
*/
static void __init trim_snb_memory(void)
{
static const __initconst unsigned long bad_pages[] = {
0x20050000,
0x20110000,
0x20130000,
0x20138000,
0x40004000,
};
int i;
if (!snb_gfx_workaround_needed())
return;
printk(KERN_DEBUG "reserving inaccessible SNB gfx pages\n");
/*
* SandyBridge integrated graphics devices have a bug that prevents
* them from accessing certain memory ranges, namely anything below
* 1M and in the pages listed in bad_pages[] above.
*
* To avoid these pages being ever accessed by SNB gfx devices reserve
* bad_pages that have not already been reserved at boot time.
* All memory below the 1 MB mark is anyway reserved later during
* setup_arch(), so there is no need to reserve it here.
*/
for (i = 0; i < ARRAY_SIZE(bad_pages); i++) {
if (memblock_reserve(bad_pages[i], PAGE_SIZE))
printk(KERN_WARNING "failed to reserve 0x%08lx\n",
bad_pages[i]);
}
}
static void __init trim_bios_range(void)
{
/*
* A special case is the first 4Kb of memory;
* This is a BIOS owned area, not kernel ram, but generally
* not listed as such in the E820 table.
*
* This typically reserves additional memory (64KiB by default)
* since some BIOSes are known to corrupt low memory. See the
* Kconfig help text for X86_RESERVE_LOW.
*/
e820__range_update(0, PAGE_SIZE, E820_TYPE_RAM, E820_TYPE_RESERVED);
/*
* special case: Some BIOSes report the PC BIOS
* area (640Kb -> 1Mb) as RAM even though it is not.
* take them out.
*/
e820__range_remove(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_TYPE_RAM, 1);
e820__update_table(e820_table);
}
/* called before trim_bios_range() to spare extra sanitize */
static void __init e820_add_kernel_range(void)
{
u64 start = __pa_symbol(_text);
u64 size = __pa_symbol(_end) - start;
/*
* Complain if .text .data and .bss are not marked as E820_TYPE_RAM and
* attempt to fix it by adding the range. We may have a confused BIOS,
* or the user may have used memmap=exactmap or memmap=xxM$yyM to
* exclude kernel range. If we really are running on top non-RAM,
* we will crash later anyways.
*/
if (e820__mapped_all(start, start + size, E820_TYPE_RAM))
return;
pr_warn(".text .data .bss are not marked as E820_TYPE_RAM!\n");
e820__range_remove(start, size, E820_TYPE_RAM, 0);
e820__range_add(start, size, E820_TYPE_RAM);
}
static unsigned reserve_low = CONFIG_X86_RESERVE_LOW << 10;
static int __init parse_reservelow(char *p)
{
unsigned long long size;
if (!p)
return -EINVAL;
size = memparse(p, &p);
if (size < 4096)
size = 4096;
if (size > 640*1024)
size = 640*1024;
reserve_low = size;
return 0;
}
early_param("reservelow", parse_reservelow);
static void __init early_reserve_memory(void)
{
/*
* Reserve the memory occupied by the kernel between _text and
* __end_of_kernel_reserve symbols. Any kernel sections after the
* __end_of_kernel_reserve symbol must be explicitly reserved with a
* separate memblock_reserve() or they will be discarded.
*/
memblock_reserve(__pa_symbol(_text),
(unsigned long)__end_of_kernel_reserve - (unsigned long)_text);
/*
* The first 4Kb of memory is a BIOS owned area, but generally it is
* not listed as such in the E820 table.
*
* Reserve the first 64K of memory since some BIOSes are known to
* corrupt low memory. After the real mode trampoline is allocated the
* rest of the memory below 640k is reserved.
*
* In addition, make sure page 0 is always reserved because on
* systems with L1TF its contents can be leaked to user processes.
*/
memblock_reserve(0, SZ_64K);
early_reserve_initrd();
if (efi_enabled(EFI_BOOT))
efi_memblock_x86_reserve_range();
memblock_x86_reserve_range_setup_data();
reserve_ibft_region();
reserve_bios_regions();
trim_snb_memory();
}
/*
* Dump out kernel offset information on panic.
*/
static int
dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
{
if (kaslr_enabled()) {
pr_emerg("Kernel Offset: 0x%lx from 0x%lx (relocation range: 0x%lx-0x%lx)\n",
kaslr_offset(),
__START_KERNEL,
__START_KERNEL_map,
MODULES_VADDR-1);
} else {
pr_emerg("Kernel Offset: disabled\n");
}
return 0;
}
/*
* Determine if we were loaded by an EFI loader. If so, then we have also been
* passed the efi memmap, systab, etc., so we should use these data structures
* for initialization. Note, the efi init code path is determined by the
* global efi_enabled. This allows the same kernel image to be used on existing
* systems (with a traditional BIOS) as well as on EFI systems.
*/
/*
* setup_arch - architecture-specific boot-time initializations
*
* Note: On x86_64, fixmaps are ready for use even before this is called.
*/
void __init setup_arch(char **cmdline_p)
{
#ifdef CONFIG_X86_32
memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
/*
* copy kernel address range established so far and switch
* to the proper swapper page table
*/
clone_pgd_range(swapper_pg_dir + KERNEL_PGD_BOUNDARY,
initial_page_table + KERNEL_PGD_BOUNDARY,
KERNEL_PGD_PTRS);
load_cr3(swapper_pg_dir);
/*
* Note: Quark X1000 CPUs advertise PGE incorrectly and require
* a cr3 based tlb flush, so the following __flush_tlb_all()
* will not flush anything because the CPU quirk which clears
* X86_FEATURE_PGE has not been invoked yet. Though due to the
* load_cr3() above the TLB has been flushed already. The
* quirk is invoked before subsequent calls to __flush_tlb_all()
* so proper operation is guaranteed.
*/
__flush_tlb_all();
#else
printk(KERN_INFO "Command line: %s\n", boot_command_line);
boot_cpu_data.x86_phys_bits = MAX_PHYSMEM_BITS;
#endif
/*
* If we have OLPC OFW, we might end up relocating the fixmap due to
* reserve_top(), so do this before touching the ioremap area.
*/
olpc_ofw_detect();
idt_setup_early_traps();
early_cpu_init();
jump_label_init();
static_call_init();
early_ioremap_init();
setup_olpc_ofw_pgd();
ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
screen_info = boot_params.screen_info;
edid_info = boot_params.edid_info;
#ifdef CONFIG_X86_32
apm_info.bios = boot_params.apm_bios_info;
ist_info = boot_params.ist_info;
#endif
saved_video_mode = boot_params.hdr.vid_mode;
bootloader_type = boot_params.hdr.type_of_loader;
if ((bootloader_type >> 4) == 0xe) {
bootloader_type &= 0xf;
bootloader_type |= (boot_params.hdr.ext_loader_type+0x10) << 4;
}
bootloader_version = bootloader_type & 0xf;
bootloader_version |= boot_params.hdr.ext_loader_ver << 4;
#ifdef CONFIG_BLK_DEV_RAM
rd_image_start = boot_params.hdr.ram_size & RAMDISK_IMAGE_START_MASK;
#endif
#ifdef CONFIG_EFI
if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
EFI32_LOADER_SIGNATURE, 4)) {
set_bit(EFI_BOOT, &efi.flags);
} else if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
EFI64_LOADER_SIGNATURE, 4)) {
set_bit(EFI_BOOT, &efi.flags);
set_bit(EFI_64BIT, &efi.flags);
}
#endif
x86_init.oem.arch_setup();
iomem_resource.end = (1ULL << boot_cpu_data.x86_phys_bits) - 1;
e820__memory_setup();
parse_setup_data();
copy_edd();
if (!boot_params.hdr.root_flags)
root_mountflags &= ~MS_RDONLY;
init_mm.start_code = (unsigned long) _text;
init_mm.end_code = (unsigned long) _etext;
init_mm.end_data = (unsigned long) _edata;
init_mm.brk = _brk_end;
code_resource.start = __pa_symbol(_text);
code_resource.end = __pa_symbol(_etext)-1;
rodata_resource.start = __pa_symbol(__start_rodata);
rodata_resource.end = __pa_symbol(__end_rodata)-1;
data_resource.start = __pa_symbol(_sdata);
data_resource.end = __pa_symbol(_edata)-1;
bss_resource.start = __pa_symbol(__bss_start);
bss_resource.end = __pa_symbol(__bss_stop)-1;
#ifdef CONFIG_CMDLINE_BOOL
#ifdef CONFIG_CMDLINE_OVERRIDE
strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
#else
if (builtin_cmdline[0]) {
/* append boot loader cmdline to builtin */
strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
}
#endif
#endif
strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;
/*
* x86_configure_nx() is called before parse_early_param() to detect
* whether hardware doesn't support NX (so that the early EHCI debug
* console setup can safely call set_fixmap()). It may then be called
* again from within noexec_setup() during parsing early parameters
* to honor the respective command line option.
*/
x86_configure_nx();
parse_early_param();
/*
* Do some memory reservations *before* memory is added to
* memblock, so memblock allocations won't overwrite it.
* Do it after early param, so we could get (unlikely) panic from
* serial.
*
* After this point everything still needed from the boot loader or
* firmware or kernel text should be early reserved or marked not
* RAM in e820. All other memory is free game.
*/
early_reserve_memory();
#ifdef CONFIG_MEMORY_HOTPLUG
/*
* Memory used by the kernel cannot be hot-removed because Linux
* cannot migrate the kernel pages. When memory hotplug is
* enabled, we should prevent memblock from allocating memory
* for the kernel.
*
* ACPI SRAT records all hotpluggable memory ranges. But before
* SRAT is parsed, we don't know about it.
*
* The kernel image is loaded into memory at very early time. We
* cannot prevent this anyway. So on NUMA system, we set any
* node the kernel resides in as un-hotpluggable.
*
* Since on modern servers, one node could have double-digit
* gigabytes memory, we can assume the memory around the kernel
* image is also un-hotpluggable. So before SRAT is parsed, just
* allocate memory near the kernel image to try the best to keep
* the kernel away from hotpluggable memory.
*/
if (movable_node_is_enabled())
memblock_set_bottom_up(true);
#endif
x86_report_nx();
if (acpi_mps_check()) {
#ifdef CONFIG_X86_LOCAL_APIC
disable_apic = 1;
#endif
setup_clear_cpu_cap(X86_FEATURE_APIC);
}
e820__reserve_setup_data();
e820__finish_early_params();
if (efi_enabled(EFI_BOOT))
efi_init();
dmi_setup();
/*
* VMware detection requires dmi to be available, so this
* needs to be done after dmi_setup(), for the boot CPU.
*/
init_hypervisor_platform();
tsc_early_init();
x86_init.resources.probe_roms();
/* after parse_early_param, so could debug it */
insert_resource(&iomem_resource, &code_resource);
insert_resource(&iomem_resource, &rodata_resource);
insert_resource(&iomem_resource, &data_resource);
insert_resource(&iomem_resource, &bss_resource);
e820_add_kernel_range();
trim_bios_range();
#ifdef CONFIG_X86_32
if (ppro_with_ram_bug()) {
e820__range_update(0x70000000ULL, 0x40000ULL, E820_TYPE_RAM,
E820_TYPE_RESERVED);
e820__update_table(e820_table);
printk(KERN_INFO "fixed physical RAM map:\n");
e820__print_table("bad_ppro");
}
#else
early_gart_iommu_check();
#endif
/*
* partially used pages are not usable - thus
* we are rounding upwards:
*/
max_pfn = e820__end_of_ram_pfn();
/* update e820 for memory not covered by WB MTRRs */
mtrr_bp_init();
if (mtrr_trim_uncached_memory(max_pfn))
max_pfn = e820__end_of_ram_pfn();
max_possible_pfn = max_pfn;
/*
* This call is required when the CPU does not support PAT. If
* mtrr_bp_init() invoked it already via pat_init() the call has no
* effect.
*/
init_cache_modes();
/*
* Define random base addresses for memory sections after max_pfn is
* defined and before each memory section base is used.
*/
kernel_randomize_memory();
#ifdef CONFIG_X86_32
/* max_low_pfn get updated here */
find_low_pfn_range();
#else
check_x2apic();
/* How many end-of-memory variables you have, grandma! */
/* need this before calling reserve_initrd */
if (max_pfn > (1UL<<(32 - PAGE_SHIFT)))
max_low_pfn = e820__end_of_low_ram_pfn();
else
max_low_pfn = max_pfn;
high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
#endif
/*
* Find and reserve possible boot-time SMP configuration:
*/
find_smp_config();
early_alloc_pgt_buf();
/*
* Need to conclude brk, before e820__memblock_setup()
* it could use memblock_find_in_range, could overlap with
* brk area.
*/
reserve_brk();
cleanup_highmap();
memblock_set_current_limit(ISA_END_ADDRESS);
e820__memblock_setup();
/*
* Needs to run after memblock setup because it needs the physical
* memory size.
*/
sev_setup_arch();
efi_fake_memmap();
efi_find_mirror();
efi_esrt_init();
efi_mokvar_table_init();
/*
* The EFI specification says that boot service code won't be
* called after ExitBootServices(). This is, in fact, a lie.
*/
efi_reserve_boot_services();
/* preallocate 4k for mptable mpc */
e820__memblock_alloc_reserved_mpc_new();
#ifdef CONFIG_X86_CHECK_BIOS_CORRUPTION
setup_bios_corruption_check();
#endif
#ifdef CONFIG_X86_32
printk(KERN_DEBUG "initial memory mapped: [mem 0x00000000-%#010lx]\n",
(max_pfn_mapped<<PAGE_SHIFT) - 1);
#endif
/*
* Find free memory for the real mode trampoline and place it
* there.
* If there is not enough free memory under 1M, on EFI-enabled
* systems there will be additional attempt to reclaim the memory
* for the real mode trampoline at efi_free_boot_services().
*
* Unconditionally reserve the entire first 1M of RAM because
* BIOSes are know to corrupt low memory and several
* hundred kilobytes are not worth complex detection what memory gets
* clobbered. Moreover, on machines with SandyBridge graphics or in
* setups that use crashkernel the entire 1M is reserved anyway.
*/
reserve_real_mode();
init_mem_mapping();
idt_setup_early_pf();
/*
* Update mmu_cr4_features (and, indirectly, trampoline_cr4_features)
* with the current CR4 value. This may not be necessary, but
* auditing all the early-boot CR4 manipulation would be needed to
* rule it out.
*
* Mask off features that don't work outside long mode (just
* PCIDE for now).
*/
mmu_cr4_features = __read_cr4() & ~X86_CR4_PCIDE;
memblock_set_current_limit(get_max_mapped());
/*
* NOTE: On x86-32, only from this point on, fixmaps are ready for use.
*/
#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
if (init_ohci1394_dma_early)
init_ohci1394_dma_on_all_controllers();
#endif
/* Allocate bigger log buffer */
setup_log_buf(1);
if (efi_enabled(EFI_BOOT)) {
switch (boot_params.secure_boot) {
case efi_secureboot_mode_disabled:
pr_info("Secure boot disabled\n");
break;
case efi_secureboot_mode_enabled:
pr_info("Secure boot enabled\n");
break;
default:
pr_info("Secure boot could not be determined\n");
break;
}
}
reserve_initrd();
acpi_table_upgrade();
/* Look for ACPI tables and reserve memory occupied by them. */
acpi_boot_table_init();
vsmp_init();
io_delay_init();
early_platform_quirks();
early_acpi_boot_init();
initmem_init();
dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
if (boot_cpu_has(X86_FEATURE_GBPAGES))
hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
/*
* Reserve memory for crash kernel after SRAT is parsed so that it
* won't consume hotpluggable memory.
*/
reserve_crashkernel();
memblock_find_dma_reserve();
if (!early_xdbc_setup_hardware())
early_xdbc_register_console();
x86_init.paging.pagetable_init();
kasan_init();
/*
* Sync back kernel address range.
*
* FIXME: Can the later sync in setup_cpu_entry_areas() replace
* this call?
*/
sync_initial_page_table();
tboot_probe();
map_vsyscall();
generic_apic_probe();
early_quirks();
/*
* Read APIC and some other early information from ACPI tables.
*/
acpi_boot_init();
x86_dtb_init();
/*
* get boot-time SMP configuration:
*/
get_smp_config();
/*
* Systems w/o ACPI and mptables might not have it mapped the local
* APIC yet, but prefill_possible_map() might need to access it.
*/
init_apic_mappings();
prefill_possible_map();
init_cpu_to_node();
init_gi_nodes();
io_apic_init_mappings();
x86_init.hyper.guest_late_init();
e820__reserve_resources();
e820__register_nosave_regions(max_pfn);
x86_init.resources.reserve_resources();
e820__setup_pci_gap();
#ifdef CONFIG_VT
#if defined(CONFIG_VGA_CONSOLE)
if (!efi_enabled(EFI_BOOT) || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
conswitchp = &vga_con;
#endif
#endif
x86_init.oem.banner();
x86_init.timers.wallclock_init();
/*
* This needs to run before setup_local_APIC() which soft-disables the
* local APIC temporarily and that masks the thermal LVT interrupt,
* leading to softlockups on machines which have configured SMI
* interrupt delivery.
*/
therm_lvt_init();
mcheck_init();
register_refined_jiffies(CLOCK_TICK_RATE);
#ifdef CONFIG_EFI
if (efi_enabled(EFI_BOOT))
efi_apply_memmap_quirks();
#endif
unwind_init();
}
#ifdef CONFIG_X86_32
static struct resource video_ram_resource = {
.name = "Video RAM area",
.start = 0xa0000,
.end = 0xbffff,
.flags = IORESOURCE_BUSY | IORESOURCE_MEM
};
void __init i386_reserve_resources(void)
{
request_resource(&iomem_resource, &video_ram_resource);
reserve_standard_io_resources();
}
#endif /* CONFIG_X86_32 */
static struct notifier_block kernel_offset_notifier = {
.notifier_call = dump_kernel_offset
};
static int __init register_kernel_offset_dumper(void)
{
atomic_notifier_chain_register(&panic_notifier_list,
&kernel_offset_notifier);
return 0;
}
__initcall(register_kernel_offset_dumper);