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Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 boot updates from Thomas Gleixner:
 "Assorted updates to kexec/kdump:

   - Proper kexec support for 4/5-level paging and jumping from a
     5-level to a 4-level paging kernel.

   - Make the EFI support for kexec/kdump more robust

   - Enforce that the GDT is properly aligned instead of getting the
     alignment by chance"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kdump/64: Restrict kdump kernel reservation to <64TB
  x86/kexec/64: Prevent kexec from 5-level paging to a 4-level only kernel
  x86/boot: Add xloadflags bits to check for 5-level paging support
  x86/boot: Make the GDT 8-byte aligned
  x86/kexec: Add the ACPI NVS region to the ident map
  x86/boot: Call get_rsdp_addr() after console_init()
  Revert "x86/boot: Disable RSDP parsing temporarily"
  x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernels
  x86/kexec: Add the EFI system tables and ACPI tables to the ident map
This commit is contained in:
Linus Torvalds 2019-07-09 11:35:38 -07:00
parent 608745f124 8ff80fbe7e
commit b7d5c92398
9 changed files with 234 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

143
arch/x86/boot/compressed/acpi.c
View File

@ -44,17 +44,109 @@ static acpi_physical_address get_acpi_rsdp(void)
return addr;
}
/* Search EFI system tables for RSDP. */
static acpi_physical_address efi_get_rsdp_addr(void)
/*
* Search EFI system tables for RSDP. If both ACPI_20_TABLE_GUID and
* ACPI_TABLE_GUID are found, take the former, which has more features.
*/
static acpi_physical_address
__efi_get_rsdp_addr(unsigned long config_tables, unsigned int nr_tables,
bool efi_64)
{
acpi_physical_address rsdp_addr = 0;
#ifdef CONFIG_EFI
unsigned long systab, systab_tables, config_tables;
int i;
/* Get EFI tables from systab. */
for (i = 0; i < nr_tables; i++) {
acpi_physical_address table;
efi_guid_t guid;
if (efi_64) {
efi_config_table_64_t *tbl = (efi_config_table_64_t *)config_tables + i;
guid = tbl->guid;
table = tbl->table;
if (!IS_ENABLED(CONFIG_X86_64) && table >> 32) {
debug_putstr("Error getting RSDP address: EFI config table located above 4GB.\n");
return 0;
}
} else {
efi_config_table_32_t *tbl = (efi_config_table_32_t *)config_tables + i;
guid = tbl->guid;
table = tbl->table;
}
if (!(efi_guidcmp(guid, ACPI_TABLE_GUID)))
rsdp_addr = table;
else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID)))
return table;
}
#endif
return rsdp_addr;
}
/* EFI/kexec support is 64-bit only. */
#ifdef CONFIG_X86_64
static struct efi_setup_data *get_kexec_setup_data_addr(void)
{
struct setup_data *data;
u64 pa_data;
pa_data = boot_params->hdr.setup_data;
while (pa_data) {
data = (struct setup_data *)pa_data;
if (data->type == SETUP_EFI)
return (struct efi_setup_data *)(pa_data + sizeof(struct setup_data));
pa_data = data->next;
}
return NULL;
}
static acpi_physical_address kexec_get_rsdp_addr(void)
{
efi_system_table_64_t *systab;
struct efi_setup_data *esd;
struct efi_info *ei;
char *sig;
esd = (struct efi_setup_data *)get_kexec_setup_data_addr();
if (!esd)
return 0;
if (!esd->tables) {
debug_putstr("Wrong kexec SETUP_EFI data.\n");
return 0;
}
ei = &boot_params->efi_info;
sig = (char *)&ei->efi_loader_signature;
if (strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) {
debug_putstr("Wrong kexec EFI loader signature.\n");
return 0;
}
/* Get systab from boot params. */
systab = (efi_system_table_64_t *) (ei->efi_systab | ((__u64)ei->efi_systab_hi << 32));
if (!systab)
error("EFI system table not found in kexec boot_params.");
return __efi_get_rsdp_addr((unsigned long)esd->tables, systab->nr_tables, true);
}
#else
static acpi_physical_address kexec_get_rsdp_addr(void) { return 0; }
#endif /* CONFIG_X86_64 */
static acpi_physical_address efi_get_rsdp_addr(void)
{
#ifdef CONFIG_EFI
unsigned long systab, config_tables;
unsigned int nr_tables;
struct efi_info *ei;
bool efi_64;
int size, i;
char *sig;
ei = &boot_params->efi_info;
@ -88,49 +180,20 @@ static acpi_physical_address efi_get_rsdp_addr(void)
config_tables = stbl->tables;
nr_tables = stbl->nr_tables;
size = sizeof(efi_config_table_64_t);
} else {
efi_system_table_32_t *stbl = (efi_system_table_32_t *)systab;
config_tables = stbl->tables;
nr_tables = stbl->nr_tables;
size = sizeof(efi_config_table_32_t);
}
if (!config_tables)
error("EFI config tables not found.");
/* Get EFI tables from systab. */
for (i = 0; i < nr_tables; i++) {
acpi_physical_address table;
efi_guid_t guid;
config_tables += size;
if (efi_64) {
efi_config_table_64_t *tbl = (efi_config_table_64_t *)config_tables;
guid = tbl->guid;
table = tbl->table;
if (!IS_ENABLED(CONFIG_X86_64) && table >> 32) {
debug_putstr("Error getting RSDP address: EFI config table located above 4GB.\n");
return 0;
}
} else {
efi_config_table_32_t *tbl = (efi_config_table_32_t *)config_tables;
guid = tbl->guid;
table = tbl->table;
}
if (!(efi_guidcmp(guid, ACPI_TABLE_GUID)))
rsdp_addr = table;
else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID)))
return table;
}
return __efi_get_rsdp_addr(config_tables, nr_tables, efi_64);
#else
return 0;
#endif
return rsdp_addr;
}
static u8 compute_checksum(u8 *buffer, u32 length)
@ -220,6 +283,14 @@ acpi_physical_address get_rsdp_addr(void)
if (!pa)
pa = boot_params->acpi_rsdp_addr;
/*
* Try to get EFI data from setup_data. This can happen when we're a
* kexec'ed kernel and kexec(1) has passed all the required EFI info to
* us.
*/
if (!pa)
pa = kexec_get_rsdp_addr();
if (!pa)
pa = efi_get_rsdp_addr();

1
arch/x86/boot/compressed/head_64.S
View File

@ -659,6 +659,7 @@ no_longmode:
gdt64:
.word gdt_end - gdt
.quad 0
.balign 8
gdt:
.word gdt_end - gdt
.long gdt

11
arch/x86/boot/compressed/misc.c
View File

@ -351,9 +351,6 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
/* Clear flags intended for solely in-kernel use. */
boot_params->hdr.loadflags &= ~KASLR_FLAG;
/* Save RSDP address for later use. */
/* boot_params->acpi_rsdp_addr = get_rsdp_addr(); */
sanitize_boot_params(boot_params);
if (boot_params->screen_info.orig_video_mode == 7) {
@ -368,6 +365,14 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
cols = boot_params->screen_info.orig_video_cols;
console_init();
/*
* Save RSDP address for later use. Have this after console_init()
* so that early debugging output from the RSDP parsing code can be
* collected.
*/
boot_params->acpi_rsdp_addr = get_rsdp_addr();
debug_putstr("early console in extract_kernel\n");
free_mem_ptr = heap; /* Heap */

12
arch/x86/boot/header.S
View File

@ -419,7 +419,17 @@ xloadflags:
# define XLF4 0
#endif
.word XLF0 | XLF1 | XLF23 | XLF4
#ifdef CONFIG_X86_64
#ifdef CONFIG_X86_5LEVEL
#define XLF56 (XLF_5LEVEL|XLF_5LEVEL_ENABLED)
#else
#define XLF56 XLF_5LEVEL
#endif
#else
#define XLF56 0
#endif
.word XLF0 | XLF1 | XLF23 | XLF4 | XLF56
cmdline_size: .long COMMAND_LINE_SIZE-1 #length of the command line,
#added with boot protocol

2
arch/x86/include/uapi/asm/bootparam.h
View File

@ -29,6 +29,8 @@
#define XLF_EFI_HANDOVER_32 (1<<2)
#define XLF_EFI_HANDOVER_64 (1<<3)
#define XLF_EFI_KEXEC (1<<4)
#define XLF_5LEVEL (1<<5)
#define XLF_5LEVEL_ENABLED (1<<6)
#ifndef __ASSEMBLY__

5
arch/x86/kernel/kexec-bzimage64.c
View File

@ -319,6 +319,11 @@ static int bzImage64_probe(const char *buf, unsigned long len)
return ret;
}
if (!(header->xloadflags & XLF_5LEVEL) && pgtable_l5_enabled()) {
pr_err("bzImage cannot handle 5-level paging mode.\n");
return ret;
}
/* I've got a bzImage */
pr_debug("It's a relocatable bzImage64\n");
ret = 0;

87
arch/x86/kernel/machine_kexec_64.c
View File

@ -16,6 +16,7 @@
#include <linux/io.h>
#include <linux/suspend.h>
#include <linux/vmalloc.h>
#include <linux/efi.h>
#include <asm/init.h>
#include <asm/pgtable.h>
@ -27,6 +28,55 @@
#include <asm/setup.h>
#include <asm/set_memory.h>
#ifdef CONFIG_ACPI
/*
* Used while adding mapping for ACPI tables.
* Can be reused when other iomem regions need be mapped
*/
struct init_pgtable_data {
struct x86_mapping_info *info;
pgd_t *level4p;
};
static int mem_region_callback(struct resource *res, void *arg)
{
struct init_pgtable_data *data = arg;
unsigned long mstart, mend;
mstart = res->start;
mend = mstart + resource_size(res) - 1;
return kernel_ident_mapping_init(data->info, data->level4p, mstart, mend);
}
static int
map_acpi_tables(struct x86_mapping_info *info, pgd_t *level4p)
{
struct init_pgtable_data data;
unsigned long flags;
int ret;
data.info = info;
data.level4p = level4p;
flags = IORESOURCE_MEM | IORESOURCE_BUSY;
ret = walk_iomem_res_desc(IORES_DESC_ACPI_TABLES, flags, 0, -1,
&data, mem_region_callback);
if (ret && ret != -EINVAL)
return ret;
/* ACPI tables could be located in ACPI Non-volatile Storage region */
ret = walk_iomem_res_desc(IORES_DESC_ACPI_NV_STORAGE, flags, 0, -1,
&data, mem_region_callback);
if (ret && ret != -EINVAL)
return ret;
return 0;
}
#else
static int map_acpi_tables(struct x86_mapping_info *info, pgd_t *level4p) { return 0; }
#endif
#ifdef CONFIG_KEXEC_FILE
const struct kexec_file_ops * const kexec_file_loaders[] = {
&kexec_bzImage64_ops,
@ -34,6 +84,31 @@ const struct kexec_file_ops * const kexec_file_loaders[] = {
};
#endif
static int
map_efi_systab(struct x86_mapping_info *info, pgd_t *level4p)
{
#ifdef CONFIG_EFI
unsigned long mstart, mend;
if (!efi_enabled(EFI_BOOT))
return 0;
mstart = (boot_params.efi_info.efi_systab |
((u64)boot_params.efi_info.efi_systab_hi<<32));
if (efi_enabled(EFI_64BIT))
mend = mstart + sizeof(efi_system_table_64_t);
else
mend = mstart + sizeof(efi_system_table_32_t);
if (!mstart)
return 0;
return kernel_ident_mapping_init(info, level4p, mstart, mend);
#endif
return 0;
}
static void free_transition_pgtable(struct kimage *image)
{
free_page((unsigned long)image->arch.p4d);
@ -157,6 +232,18 @@ static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
return result;
}
/*
* Prepare EFI systab and ACPI tables for kexec kernel since they are
* not covered by pfn_mapped.
*/
result = map_efi_systab(&info, level4p);
if (result)
return result;
result = map_acpi_tables(&info, level4p);
if (result)
return result;
return init_transition_pgtable(image, level4p);
}

15
arch/x86/kernel/setup.c
View File

@ -453,15 +453,24 @@ static void __init memblock_x86_reserve_range_setup_data(void)
#define CRASH_ALIGN SZ_16M
/*
* Keep the crash kernel below this limit. On 32 bits earlier kernels
* would limit the kernel to the low 512 MiB due to mapping restrictions.
* Keep the crash kernel below this limit.
*
* On 32 bits earlier kernels would limit the kernel to the low 512 MiB
* due to mapping restrictions.
*
* On 64bit, kdump kernel need be restricted to be under 64TB, which is
* the upper limit of system RAM in 4-level paing mode. Since the kdump
* jumping could be from 5-level to 4-level, the jumping will fail if
* kernel is put above 64TB, and there's no way to detect the paging mode
* of the kernel which will be loaded for dumping during the 1st kernel
* bootup.
*/
#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 MAXMEM
# define CRASH_ADDR_HIGH_MAX SZ_64T
#endif
static int __init reserve_crashkernel_low(void)

1
include/linux/sizes.h
View File

@ -44,5 +44,6 @@
#define SZ_2G 0x80000000
#define SZ_4G _AC(0x100000000, ULL)
#define SZ_64T _AC(0x400000000000, ULL)
#endif /* __LINUX_SIZES_H__ */