mirror of
https://github.com/torvalds/linux.git
synced 2024-11-16 17:12:06 +00:00
f8b8404337
This patch reworks the UEFI anti-bricking code, including an effective reversion ofcc5a080cand31ff2f20. It turns out that calling QueryVariableInfo() from boot services results in some firmware implementations jumping to physical addresses even after entering virtual mode, so until we have 1:1 mappings for UEFI runtime space this isn't going to work so well. Reverting these gets us back to the situation where we'd refuse to create variables on some systems because they classify deleted variables as "used" until the firmware triggers a garbage collection run, which they won't do until they reach a lower threshold. This results in it being impossible to install a bootloader, which is unhelpful. Feedback from Samsung indicates that the firmware doesn't need more than 5KB of storage space for its own purposes, so that seems like a reasonable threshold. However, there's still no guarantee that a platform will attempt garbage collection merely because it drops below this threshold. It seems that this is often only triggered if an attempt to write generates a genuine EFI_OUT_OF_RESOURCES error. We can force that by attempting to create a variable larger than the remaining space. This should fail, but if it somehow succeeds we can then immediately delete it. I've tested this on the UEFI machines I have available, but I don't have a Samsung and so can't verify that it avoids the bricking problem. Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com> Signed-off-by: Lee, Chun-Y <jlee@suse.com> [ dummy variable cleanup ] Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
169 lines
4.3 KiB
C
169 lines
4.3 KiB
C
#ifndef _ASM_X86_BOOTPARAM_H
|
|
#define _ASM_X86_BOOTPARAM_H
|
|
|
|
/* setup_data types */
|
|
#define SETUP_NONE 0
|
|
#define SETUP_E820_EXT 1
|
|
#define SETUP_DTB 2
|
|
#define SETUP_PCI 3
|
|
|
|
/* ram_size flags */
|
|
#define RAMDISK_IMAGE_START_MASK 0x07FF
|
|
#define RAMDISK_PROMPT_FLAG 0x8000
|
|
#define RAMDISK_LOAD_FLAG 0x4000
|
|
|
|
/* loadflags */
|
|
#define LOADED_HIGH (1<<0)
|
|
#define QUIET_FLAG (1<<5)
|
|
#define KEEP_SEGMENTS (1<<6)
|
|
#define CAN_USE_HEAP (1<<7)
|
|
|
|
/* xloadflags */
|
|
#define XLF_KERNEL_64 (1<<0)
|
|
#define XLF_CAN_BE_LOADED_ABOVE_4G (1<<1)
|
|
#define XLF_EFI_HANDOVER_32 (1<<2)
|
|
#define XLF_EFI_HANDOVER_64 (1<<3)
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/screen_info.h>
|
|
#include <linux/apm_bios.h>
|
|
#include <linux/edd.h>
|
|
#include <asm/e820.h>
|
|
#include <asm/ist.h>
|
|
#include <video/edid.h>
|
|
|
|
/* extensible setup data list node */
|
|
struct setup_data {
|
|
__u64 next;
|
|
__u32 type;
|
|
__u32 len;
|
|
__u8 data[0];
|
|
};
|
|
|
|
struct setup_header {
|
|
__u8 setup_sects;
|
|
__u16 root_flags;
|
|
__u32 syssize;
|
|
__u16 ram_size;
|
|
__u16 vid_mode;
|
|
__u16 root_dev;
|
|
__u16 boot_flag;
|
|
__u16 jump;
|
|
__u32 header;
|
|
__u16 version;
|
|
__u32 realmode_swtch;
|
|
__u16 start_sys;
|
|
__u16 kernel_version;
|
|
__u8 type_of_loader;
|
|
__u8 loadflags;
|
|
__u16 setup_move_size;
|
|
__u32 code32_start;
|
|
__u32 ramdisk_image;
|
|
__u32 ramdisk_size;
|
|
__u32 bootsect_kludge;
|
|
__u16 heap_end_ptr;
|
|
__u8 ext_loader_ver;
|
|
__u8 ext_loader_type;
|
|
__u32 cmd_line_ptr;
|
|
__u32 initrd_addr_max;
|
|
__u32 kernel_alignment;
|
|
__u8 relocatable_kernel;
|
|
__u8 min_alignment;
|
|
__u16 xloadflags;
|
|
__u32 cmdline_size;
|
|
__u32 hardware_subarch;
|
|
__u64 hardware_subarch_data;
|
|
__u32 payload_offset;
|
|
__u32 payload_length;
|
|
__u64 setup_data;
|
|
__u64 pref_address;
|
|
__u32 init_size;
|
|
__u32 handover_offset;
|
|
} __attribute__((packed));
|
|
|
|
struct sys_desc_table {
|
|
__u16 length;
|
|
__u8 table[14];
|
|
};
|
|
|
|
/* Gleaned from OFW's set-parameters in cpu/x86/pc/linux.fth */
|
|
struct olpc_ofw_header {
|
|
__u32 ofw_magic; /* OFW signature */
|
|
__u32 ofw_version;
|
|
__u32 cif_handler; /* callback into OFW */
|
|
__u32 irq_desc_table;
|
|
} __attribute__((packed));
|
|
|
|
struct efi_info {
|
|
__u32 efi_loader_signature;
|
|
__u32 efi_systab;
|
|
__u32 efi_memdesc_size;
|
|
__u32 efi_memdesc_version;
|
|
__u32 efi_memmap;
|
|
__u32 efi_memmap_size;
|
|
__u32 efi_systab_hi;
|
|
__u32 efi_memmap_hi;
|
|
};
|
|
|
|
/* The so-called "zeropage" */
|
|
struct boot_params {
|
|
struct screen_info screen_info; /* 0x000 */
|
|
struct apm_bios_info apm_bios_info; /* 0x040 */
|
|
__u8 _pad2[4]; /* 0x054 */
|
|
__u64 tboot_addr; /* 0x058 */
|
|
struct ist_info ist_info; /* 0x060 */
|
|
__u8 _pad3[16]; /* 0x070 */
|
|
__u8 hd0_info[16]; /* obsolete! */ /* 0x080 */
|
|
__u8 hd1_info[16]; /* obsolete! */ /* 0x090 */
|
|
struct sys_desc_table sys_desc_table; /* 0x0a0 */
|
|
struct olpc_ofw_header olpc_ofw_header; /* 0x0b0 */
|
|
__u32 ext_ramdisk_image; /* 0x0c0 */
|
|
__u32 ext_ramdisk_size; /* 0x0c4 */
|
|
__u32 ext_cmd_line_ptr; /* 0x0c8 */
|
|
__u8 _pad4[116]; /* 0x0cc */
|
|
struct edid_info edid_info; /* 0x140 */
|
|
struct efi_info efi_info; /* 0x1c0 */
|
|
__u32 alt_mem_k; /* 0x1e0 */
|
|
__u32 scratch; /* Scratch field! */ /* 0x1e4 */
|
|
__u8 e820_entries; /* 0x1e8 */
|
|
__u8 eddbuf_entries; /* 0x1e9 */
|
|
__u8 edd_mbr_sig_buf_entries; /* 0x1ea */
|
|
__u8 kbd_status; /* 0x1eb */
|
|
__u8 _pad5[3]; /* 0x1ec */
|
|
/*
|
|
* The sentinel is set to a nonzero value (0xff) in header.S.
|
|
*
|
|
* A bootloader is supposed to only take setup_header and put
|
|
* it into a clean boot_params buffer. If it turns out that
|
|
* it is clumsy or too generous with the buffer, it most
|
|
* probably will pick up the sentinel variable too. The fact
|
|
* that this variable then is still 0xff will let kernel
|
|
* know that some variables in boot_params are invalid and
|
|
* kernel should zero out certain portions of boot_params.
|
|
*/
|
|
__u8 sentinel; /* 0x1ef */
|
|
__u8 _pad6[1]; /* 0x1f0 */
|
|
struct setup_header hdr; /* setup header */ /* 0x1f1 */
|
|
__u8 _pad7[0x290-0x1f1-sizeof(struct setup_header)];
|
|
__u32 edd_mbr_sig_buffer[EDD_MBR_SIG_MAX]; /* 0x290 */
|
|
struct e820entry e820_map[E820MAX]; /* 0x2d0 */
|
|
__u8 _pad8[48]; /* 0xcd0 */
|
|
struct edd_info eddbuf[EDDMAXNR]; /* 0xd00 */
|
|
__u8 _pad9[276]; /* 0xeec */
|
|
} __attribute__((packed));
|
|
|
|
enum {
|
|
X86_SUBARCH_PC = 0,
|
|
X86_SUBARCH_LGUEST,
|
|
X86_SUBARCH_XEN,
|
|
X86_SUBARCH_MRST,
|
|
X86_SUBARCH_CE4100,
|
|
X86_NR_SUBARCHS,
|
|
};
|
|
|
|
#endif /* __ASSEMBLY__ */
|
|
|
|
#endif /* _ASM_X86_BOOTPARAM_H */
|