Merge tag 'x86-boot-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 boot updates from Ingo Molnar:

 - Rework PE header generation, primarily to generate a modern, 4k
   aligned kernel image view with narrower W^X permissions.

 - Further refine init-lifetime annotations

 - Misc cleanups & fixes

* tag 'x86-boot-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/boot: efistub: Assign global boot_params variable
  x86/boot: Rename conflicting 'boot_params' pointer to 'boot_params_ptr'
  x86/head/64: Move the __head definition to <asm/init.h>
  x86/head/64: Add missing __head annotation to startup_64_load_idt()
  x86/head/64: Mark 'startup_gdt[]' and 'startup_gdt_descr' as __initdata
  x86/boot: Harmonize the style of array-type parameter for fixup_pointer() calls
  x86/boot: Fix incorrect startup_gdt_descr.size
  x86/boot: Compile boot code with -std=gnu11 too
  x86/boot: Increase section and file alignment to 4k/512
  x86/boot: Split off PE/COFF .data section
  x86/boot: Drop PE/COFF .reloc section
  x86/boot: Construct PE/COFF .text section from assembler
  x86/boot: Derive file size from _edata symbol
  x86/boot: Define setup size in linker script
  x86/boot: Set EFI handover offset directly in header asm
  x86/boot: Grab kernel_info offset from zoffset header directly
  x86/boot: Drop references to startup_64
  x86/boot: Drop redundant code setting the root device
  x86/boot: Omit compression buffer from PE/COFF image memory footprint
  x86/boot: Remove the 'bugger off' message
  ...

arch/x86/Makefile

@@ -43,7 +43,7 @@ endif
 
 # How to compile the 16-bit code.  Note we always compile for -march=i386;
 # that way we can complain to the user if the CPU is insufficient.
-REALMODE_CFLAGS	:= -m16 -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \
+REALMODE_CFLAGS	:= -std=gnu11 -m16 -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \
 		   -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \
 		   -fno-strict-aliasing -fomit-frame-pointer -fno-pic \
 		   -mno-mmx -mno-sse $(call cc-option,-fcf-protection=none)

arch/x86/boot/Makefile

@@ -89,7 +89,7 @@ $(obj)/vmlinux.bin: $(obj)/compressed/vmlinux FORCE
 
 SETUP_OBJS = $(addprefix $(obj)/,$(setup-y))
 
-sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [a-zA-Z] \(startup_32\|startup_64\|efi32_stub_entry\|efi64_stub_entry\|efi_pe_entry\|efi32_pe_entry\|input_data\|kernel_info\|_end\|_ehead\|_text\|z_.*\)$$/\#define ZO_\2 0x\1/p'
+sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [a-zA-Z] \(startup_32\|efi.._stub_entry\|efi\(32\)\?_pe_entry\|input_data\|kernel_info\|_end\|_ehead\|_text\|_e\?data\|z_.*\)$$/\#define ZO_\2 0x\1/p'
 
 quiet_cmd_zoffset = ZOFFSET $@
       cmd_zoffset = $(NM) $< | sed -n $(sed-zoffset) > $@

arch/x86/boot/compressed/acpi.c

@@ -30,13 +30,13 @@ __efi_get_rsdp_addr(unsigned long cfg_tbl_pa, unsigned int cfg_tbl_len)
 	 * Search EFI system tables for RSDP. Preferred is ACPI_20_TABLE_GUID to
 	 * ACPI_TABLE_GUID because it has more features.
 	 */
-	rsdp_addr = efi_find_vendor_table(boot_params, cfg_tbl_pa, cfg_tbl_len,
+	rsdp_addr = efi_find_vendor_table(boot_params_ptr, cfg_tbl_pa, cfg_tbl_len,
 					  ACPI_20_TABLE_GUID);
 	if (rsdp_addr)
 		return (acpi_physical_address)rsdp_addr;
 
 	/* No ACPI_20_TABLE_GUID found, fallback to ACPI_TABLE_GUID. */
-	rsdp_addr = efi_find_vendor_table(boot_params, cfg_tbl_pa, cfg_tbl_len,
+	rsdp_addr = efi_find_vendor_table(boot_params_ptr, cfg_tbl_pa, cfg_tbl_len,
 					  ACPI_TABLE_GUID);
 	if (rsdp_addr)
 		return (acpi_physical_address)rsdp_addr;
@@ -56,15 +56,15 @@ static acpi_physical_address efi_get_rsdp_addr(void)
 	enum efi_type et;
 	int ret;
 
-	et = efi_get_type(boot_params);
+	et = efi_get_type(boot_params_ptr);
 	if (et == EFI_TYPE_NONE)
 		return 0;
 
-	systab_pa = efi_get_system_table(boot_params);
+	systab_pa = efi_get_system_table(boot_params_ptr);
 	if (!systab_pa)
 		error("EFI support advertised, but unable to locate system table.");
 
-	ret = efi_get_conf_table(boot_params, &cfg_tbl_pa, &cfg_tbl_len);
+	ret = efi_get_conf_table(boot_params_ptr, &cfg_tbl_pa, &cfg_tbl_len);
 	if (ret || !cfg_tbl_pa)
 		error("EFI config table not found.");
 
@@ -156,7 +156,7 @@ acpi_physical_address get_rsdp_addr(void)
 {
 	acpi_physical_address pa;
 
-	pa = boot_params->acpi_rsdp_addr;
+	pa = boot_params_ptr->acpi_rsdp_addr;
 
 	if (!pa)
 		pa = efi_get_rsdp_addr();
@@ -210,7 +210,7 @@ static unsigned long get_acpi_srat_table(void)
 	rsdp = (struct acpi_table_rsdp *)get_cmdline_acpi_rsdp();
 	if (!rsdp)
 		rsdp = (struct acpi_table_rsdp *)(long)
-			boot_params->acpi_rsdp_addr;
+			boot_params_ptr->acpi_rsdp_addr;
 
 	if (!rsdp)
 		return 0;

arch/x86/boot/compressed/cmdline.c

@@ -14,9 +14,9 @@ static inline char rdfs8(addr_t addr)
 #include "../cmdline.c"
 unsigned long get_cmd_line_ptr(void)
 {
-	unsigned long cmd_line_ptr = boot_params->hdr.cmd_line_ptr;
+	unsigned long cmd_line_ptr = boot_params_ptr->hdr.cmd_line_ptr;
 
-	cmd_line_ptr |= (u64)boot_params->ext_cmd_line_ptr << 32;
+	cmd_line_ptr |= (u64)boot_params_ptr->ext_cmd_line_ptr << 32;
 
 	return cmd_line_ptr;
 }

arch/x86/boot/compressed/ident_map_64.c

@@ -159,8 +159,9 @@ void initialize_identity_maps(void *rmode)
 	 * or does not touch all the pages covering them.
 	 */
 	kernel_add_identity_map((unsigned long)_head, (unsigned long)_end);
-	boot_params = rmode;
-	kernel_add_identity_map((unsigned long)boot_params, (unsigned long)(boot_params + 1));
+	boot_params_ptr = rmode;
+	kernel_add_identity_map((unsigned long)boot_params_ptr,
+				(unsigned long)(boot_params_ptr + 1));
 	cmdline = get_cmd_line_ptr();
 	kernel_add_identity_map(cmdline, cmdline + COMMAND_LINE_SIZE);
 
@@ -168,7 +169,7 @@ void initialize_identity_maps(void *rmode)
 	 * Also map the setup_data entries passed via boot_params in case they
 	 * need to be accessed by uncompressed kernel via the identity mapping.
 	 */
-	sd = (struct setup_data *)boot_params->hdr.setup_data;
+	sd = (struct setup_data *)boot_params_ptr->hdr.setup_data;
 	while (sd) {
 		unsigned long sd_addr = (unsigned long)sd;
 

arch/x86/boot/compressed/kaslr.c

@@ -63,7 +63,7 @@ static unsigned long get_boot_seed(void)
 	unsigned long hash = 0;
 
 	hash = rotate_xor(hash, build_str, sizeof(build_str));
-	hash = rotate_xor(hash, boot_params, sizeof(*boot_params));
+	hash = rotate_xor(hash, boot_params_ptr, sizeof(*boot_params_ptr));
 
 	return hash;
 }
@@ -383,7 +383,7 @@ static void handle_mem_options(void)
 static void mem_avoid_init(unsigned long input, unsigned long input_size,
 			   unsigned long output)
 {
-	unsigned long init_size = boot_params->hdr.init_size;
+	unsigned long init_size = boot_params_ptr->hdr.init_size;
 	u64 initrd_start, initrd_size;
 	unsigned long cmd_line, cmd_line_size;
 
@@ -395,10 +395,10 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
 	mem_avoid[MEM_AVOID_ZO_RANGE].size = (output + init_size) - input;
 
 	/* Avoid initrd. */
-	initrd_start  = (u64)boot_params->ext_ramdisk_image << 32;
-	initrd_start |= boot_params->hdr.ramdisk_image;
-	initrd_size  = (u64)boot_params->ext_ramdisk_size << 32;
-	initrd_size |= boot_params->hdr.ramdisk_size;
+	initrd_start  = (u64)boot_params_ptr->ext_ramdisk_image << 32;
+	initrd_start |= boot_params_ptr->hdr.ramdisk_image;
+	initrd_size  = (u64)boot_params_ptr->ext_ramdisk_size << 32;
+	initrd_size |= boot_params_ptr->hdr.ramdisk_size;
 	mem_avoid[MEM_AVOID_INITRD].start = initrd_start;
 	mem_avoid[MEM_AVOID_INITRD].size = initrd_size;
 	/* No need to set mapping for initrd, it will be handled in VO. */
@@ -413,8 +413,8 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
 	}
 
 	/* Avoid boot parameters. */
-	mem_avoid[MEM_AVOID_BOOTPARAMS].start = (unsigned long)boot_params;
-	mem_avoid[MEM_AVOID_BOOTPARAMS].size = sizeof(*boot_params);
+	mem_avoid[MEM_AVOID_BOOTPARAMS].start = (unsigned long)boot_params_ptr;
+	mem_avoid[MEM_AVOID_BOOTPARAMS].size = sizeof(*boot_params_ptr);
 
 	/* We don't need to set a mapping for setup_data. */
 
@@ -447,7 +447,7 @@ static bool mem_avoid_overlap(struct mem_vector *img,
 	}
 
 	/* Avoid all entries in the setup_data linked list. */
-	ptr = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
+	ptr = (struct setup_data *)(unsigned long)boot_params_ptr->hdr.setup_data;
 	while (ptr) {
 		struct mem_vector avoid;
 
@@ -706,7 +706,7 @@ static inline bool memory_type_is_free(efi_memory_desc_t *md)
 static bool
 process_efi_entries(unsigned long minimum, unsigned long image_size)
 {
-	struct efi_info *e = &boot_params->efi_info;
+	struct efi_info *e = &boot_params_ptr->efi_info;
 	bool efi_mirror_found = false;
 	struct mem_vector region;
 	efi_memory_desc_t *md;
@@ -777,8 +777,8 @@ static void process_e820_entries(unsigned long minimum,
 	struct boot_e820_entry *entry;
 
 	/* Verify potential e820 positions, appending to slots list. */
-	for (i = 0; i < boot_params->e820_entries; i++) {
-		entry = &boot_params->e820_table[i];
+	for (i = 0; i < boot_params_ptr->e820_entries; i++) {
+		entry = &boot_params_ptr->e820_table[i];
 		/* Skip non-RAM entries. */
 		if (entry->type != E820_TYPE_RAM)
 			continue;
@@ -852,7 +852,7 @@ void choose_random_location(unsigned long input,
 		return;
 	}
 
-	boot_params->hdr.loadflags |= KASLR_FLAG;
+	boot_params_ptr->hdr.loadflags |= KASLR_FLAG;
 
 	if (IS_ENABLED(CONFIG_X86_32))
 		mem_limit = KERNEL_IMAGE_SIZE;

arch/x86/boot/compressed/mem.c

@@ -54,17 +54,17 @@ bool init_unaccepted_memory(void)
 	enum efi_type et;
 	int ret;
 
-	et = efi_get_type(boot_params);
+	et = efi_get_type(boot_params_ptr);
 	if (et == EFI_TYPE_NONE)
 		return false;
 
-	ret = efi_get_conf_table(boot_params, &cfg_table_pa, &cfg_table_len);
+	ret = efi_get_conf_table(boot_params_ptr, &cfg_table_pa, &cfg_table_len);
 	if (ret) {
 		warn("EFI config table not found.");
 		return false;
 	}
 
-	table = (void *)efi_find_vendor_table(boot_params, cfg_table_pa,
+	table = (void *)efi_find_vendor_table(boot_params_ptr, cfg_table_pa,
 					      cfg_table_len, guid);
 	if (!table)
 		return false;

arch/x86/boot/compressed/misc.c

@@ -46,7 +46,7 @@ void *memmove(void *dest, const void *src, size_t n);
 /*
  * This is set up by the setup-routine at boot-time
  */
-struct boot_params *boot_params;
+struct boot_params *boot_params_ptr;
 
 struct port_io_ops pio_ops;
 
@@ -132,8 +132,8 @@ void __putstr(const char *s)
 	if (lines == 0 || cols == 0)
 		return;
 
-	x = boot_params->screen_info.orig_x;
-	y = boot_params->screen_info.orig_y;
+	x = boot_params_ptr->screen_info.orig_x;
+	y = boot_params_ptr->screen_info.orig_y;
 
 	while ((c = *s++) != '\0') {
 		if (c == '\n') {
@@ -154,8 +154,8 @@ void __putstr(const char *s)
 		}
 	}
 
-	boot_params->screen_info.orig_x = x;
-	boot_params->screen_info.orig_y = y;
+	boot_params_ptr->screen_info.orig_x = x;
+	boot_params_ptr->screen_info.orig_y = y;
 
 	pos = (x + cols * y) * 2;	/* Update cursor position */
 	outb(14, vidport);
@@ -382,14 +382,14 @@ asmlinkage __visible void *extract_kernel(void *rmode, unsigned char *output)
 	size_t entry_offset;
 
 	/* Retain x86 boot parameters pointer passed from startup_32/64. */
-	boot_params = rmode;
+	boot_params_ptr = rmode;
 
 	/* Clear flags intended for solely in-kernel use. */
-	boot_params->hdr.loadflags &= ~KASLR_FLAG;
+	boot_params_ptr->hdr.loadflags &= ~KASLR_FLAG;
 
-	sanitize_boot_params(boot_params);
+	sanitize_boot_params(boot_params_ptr);
 
-	if (boot_params->screen_info.orig_video_mode == 7) {
+	if (boot_params_ptr->screen_info.orig_video_mode == 7) {
 		vidmem = (char *) 0xb0000;
 		vidport = 0x3b4;
 	} else {
@@ -397,8 +397,8 @@ asmlinkage __visible void *extract_kernel(void *rmode, unsigned char *output)
 		vidport = 0x3d4;
 	}
 
-	lines = boot_params->screen_info.orig_video_lines;
-	cols = boot_params->screen_info.orig_video_cols;
+	lines = boot_params_ptr->screen_info.orig_video_lines;
+	cols = boot_params_ptr->screen_info.orig_video_cols;
 
 	init_default_io_ops();
 
@@ -417,7 +417,7 @@ asmlinkage __visible void *extract_kernel(void *rmode, unsigned char *output)
 	 * so that early debugging output from the RSDP parsing code can be
 	 * collected.
 	 */
-	boot_params->acpi_rsdp_addr = get_rsdp_addr();
+	boot_params_ptr->acpi_rsdp_addr = get_rsdp_addr();
 
 	debug_putstr("early console in extract_kernel\n");
 

arch/x86/boot/compressed/misc.h

@@ -61,7 +61,6 @@ extern memptr free_mem_ptr;
 extern memptr free_mem_end_ptr;
 void *malloc(int size);
 void free(void *where);
-extern struct boot_params *boot_params;
 void __putstr(const char *s);
 void __puthex(unsigned long value);
 #define error_putstr(__x)  __putstr(__x)

arch/x86/boot/compressed/pgtable_64.c

@@ -28,7 +28,6 @@ static char trampoline_save[TRAMPOLINE_32BIT_SIZE];
  */
 unsigned long *trampoline_32bit __section(".data");
 
-extern struct boot_params *boot_params;
 int cmdline_find_option_bool(const char *option);
 
 static unsigned long find_trampoline_placement(void)
@@ -49,7 +48,7 @@ static unsigned long find_trampoline_placement(void)
 	 *
 	 * Only look for values in the legacy ROM for non-EFI system.
 	 */
-	signature = (char *)&boot_params->efi_info.efi_loader_signature;
+	signature = (char *)&boot_params_ptr->efi_info.efi_loader_signature;
 	if (strncmp(signature, EFI32_LOADER_SIGNATURE, 4) &&
 	    strncmp(signature, EFI64_LOADER_SIGNATURE, 4)) {
 		ebda_start = *(unsigned short *)0x40e << 4;
@@ -65,10 +64,10 @@ static unsigned long find_trampoline_placement(void)
 	bios_start = round_down(bios_start, PAGE_SIZE);
 
 	/* Find the first usable memory region under bios_start. */
-	for (i = boot_params->e820_entries - 1; i >= 0; i--) {
+	for (i = boot_params_ptr->e820_entries - 1; i >= 0; i--) {
 		unsigned long new = bios_start;
 
-		entry = &boot_params->e820_table[i];
+		entry = &boot_params_ptr->e820_table[i];
 
 		/* Skip all entries above bios_start. */
 		if (bios_start <= entry->addr)
@@ -107,7 +106,7 @@ asmlinkage void configure_5level_paging(struct boot_params *bp, void *pgtable)
 	bool l5_required = false;
 
 	/* Initialize boot_params. Required for cmdline_find_option_bool(). */
-	boot_params = bp;
+	boot_params_ptr = bp;
 
 	/*
 	 * Check if LA57 is desired and supported.

arch/x86/boot/compressed/sev.c

@@ -615,7 +615,7 @@ void sev_prep_identity_maps(unsigned long top_level_pgt)
 	 * accessed after switchover.
 	 */
 	if (sev_snp_enabled()) {
-		unsigned long cc_info_pa = boot_params->cc_blob_address;
+		unsigned long cc_info_pa = boot_params_ptr->cc_blob_address;
 		struct cc_blob_sev_info *cc_info;
 
 		kernel_add_identity_map(cc_info_pa, cc_info_pa + sizeof(*cc_info));

arch/x86/boot/compressed/vmlinux.lds.S

@@ -43,11 +43,13 @@ SECTIONS
 		*(.rodata.*)
 		_erodata = . ;
 	}
-	.data :	{
+	.data :	ALIGN(0x1000) {
 		_data = . ;
 		*(.data)
 		*(.data.*)
-		*(.bss.efistub)
+
+		/* Add 4 bytes of extra space for a CRC-32 checksum */
+		. = ALIGN(. + 4, 0x200);
 		_edata = . ;
 	}
 	. = ALIGN(L1_CACHE_BYTES);

arch/x86/boot/header.S

@@ -36,66 +36,20 @@ SYSSEG		= 0x1000		/* historical load address >> 4 */
 #define ROOT_RDONLY 1
 #endif
 
+	.set	salign, 0x1000
+	.set	falign, 0x200
+
 	.code16
 	.section ".bstext", "ax"
-
-	.global bootsect_start
-bootsect_start:
 #ifdef CONFIG_EFI_STUB
 	# "MZ", MS-DOS header
 	.word	MZ_MAGIC
-#endif
-
-	# Normalize the start address
-	ljmp	$BOOTSEG, $start2
-
-start2:
-	movw	%cs, %ax
-	movw	%ax, %ds
-	movw	%ax, %es
-	movw	%ax, %ss
-	xorw	%sp, %sp
-	sti
-	cld
-
-	movw	$bugger_off_msg, %si
-
-msg_loop:
-	lodsb
-	andb	%al, %al
-	jz	bs_die
-	movb	$0xe, %ah
-	movw	$7, %bx
-	int	$0x10
-	jmp	msg_loop
-
-bs_die:
-	# Allow the user to press a key, then reboot
-	xorw	%ax, %ax
-	int	$0x16
-	int	$0x19
-
-	# int 0x19 should never return.  In case it does anyway,
-	# invoke the BIOS reset code...
-	ljmp	$0xf000,$0xfff0
-
-#ifdef CONFIG_EFI_STUB
 	.org	0x38
 	#
 	# Offset to the PE header.
 	#
 	.long	LINUX_PE_MAGIC
 	.long	pe_header
-#endif /* CONFIG_EFI_STUB */
-
-	.section ".bsdata", "a"
-bugger_off_msg:
-	.ascii	"Use a boot loader.\r\n"
-	.ascii	"\n"
-	.ascii	"Remove disk and press any key to reboot...\r\n"
-	.byte	0
-
-#ifdef CONFIG_EFI_STUB
 pe_header:
 	.long	PE_MAGIC
 
@@ -124,30 +78,26 @@ optional_header:
 	.byte	0x02				# MajorLinkerVersion
 	.byte	0x14				# MinorLinkerVersion
 
-	# Filled in by build.c
-	.long	0				# SizeOfCode
+	.long	ZO__data			# SizeOfCode
 
-	.long	0				# SizeOfInitializedData
+	.long	ZO__end - ZO__data		# SizeOfInitializedData
 	.long	0				# SizeOfUninitializedData
 
-	# Filled in by build.c
-	.long	0x0000				# AddressOfEntryPoint
+	.long	setup_size + ZO_efi_pe_entry	# AddressOfEntryPoint
 
-	.long	0x0200				# BaseOfCode
+	.long	setup_size			# BaseOfCode
 #ifdef CONFIG_X86_32
 	.long	0				# data
 #endif
 
 extra_header_fields:
-	# PE specification requires ImageBase to be 64k aligned
-	.set	image_base, (LOAD_PHYSICAL_ADDR + 0xffff) & ~0xffff
 #ifdef CONFIG_X86_32
-	.long	image_base			# ImageBase
+	.long	0				# ImageBase
 #else
-	.quad	image_base			# ImageBase
+	.quad	0				# ImageBase
 #endif
-	.long	0x20				# SectionAlignment
-	.long	0x20				# FileAlignment
+	.long	salign				# SectionAlignment
+	.long	falign				# FileAlignment
 	.word	0				# MajorOperatingSystemVersion
 	.word	0				# MinorOperatingSystemVersion
 	.word	LINUX_EFISTUB_MAJOR_VERSION	# MajorImageVersion
@@ -156,12 +106,10 @@ extra_header_fields:
 	.word	0				# MinorSubsystemVersion
 	.long	0				# Win32VersionValue
 
-	#
-	# The size of the bzImage is written in tools/build.c
-	#
-	.long	0				# SizeOfImage
+	.long	setup_size + ZO__end + pecompat_vsize
+						# SizeOfImage
 
-	.long	0x200				# SizeOfHeaders
+	.long	salign				# SizeOfHeaders
 	.long	0				# CheckSum
 	.word	IMAGE_SUBSYSTEM_EFI_APPLICATION	# Subsystem (EFI application)
 #ifdef CONFIG_EFI_DXE_MEM_ATTRIBUTES
@@ -192,87 +140,78 @@ extra_header_fields:
 
 	# Section table
 section_table:
-	#
-	# The offset & size fields are filled in by build.c.
-	#
 	.ascii	".setup"
 	.byte	0
 	.byte	0
-	.long	0
-	.long	0x0				# startup_{32,64}
-	.long	0				# Size of initialized data
-						# on disk
-	.long	0x0				# startup_{32,64}
-	.long	0				# PointerToRelocations
-	.long	0				# PointerToLineNumbers
-	.word	0				# NumberOfRelocations
-	.word	0				# NumberOfLineNumbers
-	.long	IMAGE_SCN_CNT_CODE		| \
-		IMAGE_SCN_MEM_READ		| \
-		IMAGE_SCN_MEM_EXECUTE		| \
-		IMAGE_SCN_ALIGN_16BYTES		# Characteristics
+	.long	setup_size - salign 		# VirtualSize
+	.long	salign				# VirtualAddress
+	.long	pecompat_fstart - salign	# SizeOfRawData
+	.long	salign				# PointerToRawData
 
-	#
-	# The EFI application loader requires a relocation section
-	# because EFI applications must be relocatable. The .reloc
-	# offset & size fields are filled in by build.c.
-	#
-	.ascii	".reloc"
-	.byte	0
-	.byte	0
-	.long	0
-	.long	0
-	.long	0				# SizeOfRawData
-	.long	0				# PointerToRawData
-	.long	0				# PointerToRelocations
-	.long	0				# PointerToLineNumbers
-	.word	0				# NumberOfRelocations
-	.word	0				# NumberOfLineNumbers
+	.long	0, 0, 0
 	.long	IMAGE_SCN_CNT_INITIALIZED_DATA	| \
 		IMAGE_SCN_MEM_READ		| \
-		IMAGE_SCN_MEM_DISCARDABLE	| \
-		IMAGE_SCN_ALIGN_1BYTES		# Characteristics
+		IMAGE_SCN_MEM_DISCARDABLE	# Characteristics
 
 #ifdef CONFIG_EFI_MIXED
-	#
-	# The offset & size fields are filled in by build.c.
-	#
 	.asciz	".compat"
-	.long	0
-	.long	0x0
-	.long	0				# Size of initialized data
-						# on disk
-	.long	0x0
-	.long	0				# PointerToRelocations
-	.long	0				# PointerToLineNumbers
-	.word	0				# NumberOfRelocations
-	.word	0				# NumberOfLineNumbers
+
+	.long	8				# VirtualSize
+	.long	setup_size + ZO__end		# VirtualAddress
+	.long	pecompat_fsize			# SizeOfRawData
+	.long	pecompat_fstart			# PointerToRawData
+
+	.long	0, 0, 0
 	.long	IMAGE_SCN_CNT_INITIALIZED_DATA	| \
 		IMAGE_SCN_MEM_READ		| \
-		IMAGE_SCN_MEM_DISCARDABLE	| \
-		IMAGE_SCN_ALIGN_1BYTES		# Characteristics
-#endif
+		IMAGE_SCN_MEM_DISCARDABLE	# Characteristics
 
-	#
-	# The offset & size fields are filled in by build.c.
-	#
+	/*
+	 * Put the IA-32 machine type and the associated entry point address in
+	 * the .compat section, so loaders can figure out which other execution
+	 * modes this image supports.
+	 */
+	.pushsection ".pecompat", "a", @progbits
+	.balign	falign
+	.set	pecompat_vsize, salign
+	.globl	pecompat_fstart
+pecompat_fstart:
+	.byte	0x1				# Version
+	.byte	8				# Size
+	.word	IMAGE_FILE_MACHINE_I386		# PE machine type
+	.long	setup_size + ZO_efi32_pe_entry	# Entrypoint
+	.popsection
+#else
+	.set	pecompat_vsize, 0
+	.set	pecompat_fstart, setup_size
+#endif
 	.ascii	".text"
 	.byte	0
 	.byte	0
 	.byte	0
-	.long	0
-	.long	0x0				# startup_{32,64}
-	.long	0				# Size of initialized data
+	.long	ZO__data
+	.long	setup_size
+	.long	ZO__data			# Size of initialized data
 						# on disk
-	.long	0x0				# startup_{32,64}
+	.long	setup_size
 	.long	0				# PointerToRelocations
 	.long	0				# PointerToLineNumbers
 	.word	0				# NumberOfRelocations
 	.word	0				# NumberOfLineNumbers
 	.long	IMAGE_SCN_CNT_CODE		| \
 		IMAGE_SCN_MEM_READ		| \
-		IMAGE_SCN_MEM_EXECUTE		| \
-		IMAGE_SCN_ALIGN_16BYTES		# Characteristics
+		IMAGE_SCN_MEM_EXECUTE		# Characteristics
+
+	.ascii	".data\0\0\0"
+	.long	ZO__end - ZO__data		# VirtualSize
+	.long	setup_size + ZO__data		# VirtualAddress
+	.long	ZO__edata - ZO__data		# SizeOfRawData
+	.long	setup_size + ZO__data		# PointerToRawData
+
+	.long	0, 0, 0
+	.long	IMAGE_SCN_CNT_INITIALIZED_DATA	| \
+		IMAGE_SCN_MEM_READ		| \
+		IMAGE_SCN_MEM_WRITE		# Characteristics
 
 	.set	section_count, (. - section_table) / 40
 #endif /* CONFIG_EFI_STUB */
@@ -286,12 +225,12 @@ sentinel:	.byte 0xff, 0xff        /* Used to detect broken loaders */
 
 	.globl	hdr
 hdr:
-setup_sects:	.byte 0			/* Filled in by build.c */
+		.byte setup_sects - 1
 root_flags:	.word ROOT_RDONLY
-syssize:	.long 0			/* Filled in by build.c */
+syssize:	.long ZO__edata / 16
 ram_size:	.word 0			/* Obsolete */
 vid_mode:	.word SVGA_MODE
-root_dev:	.word 0			/* Filled in by build.c */
+root_dev:	.word 0			/* Default to major/minor 0/0 */
 boot_flag:	.word 0xAA55
 
 	# offset 512, entry point
@@ -579,9 +518,25 @@ pref_address:		.quad LOAD_PHYSICAL_ADDR	# preferred load addr
 # define INIT_SIZE VO_INIT_SIZE
 #endif
 
+	.macro		__handover_offset
+#ifndef CONFIG_EFI_HANDOVER_PROTOCOL
+	.long		0
+#elif !defined(CONFIG_X86_64)
+	.long		ZO_efi32_stub_entry
+#else
+	/* Yes, this is really how we defined it :( */
+	.long		ZO_efi64_stub_entry - 0x200
+#ifdef CONFIG_EFI_MIXED
+	.if		ZO_efi32_stub_entry != ZO_efi64_stub_entry - 0x200
+	.error		"32-bit and 64-bit EFI entry points do not match"
+	.endif
+#endif
+#endif
+	.endm
+
 init_size:		.long INIT_SIZE		# kernel initialization size
-handover_offset:	.long 0			# Filled in by build.c
-kernel_info_offset:	.long 0			# Filled in by build.c
+handover_offset:	__handover_offset
+kernel_info_offset:	.long ZO_kernel_info
 
 # End of setup header #####################################################
 

arch/x86/boot/setup.ld

@@ -10,10 +10,11 @@ ENTRY(_start)
 SECTIONS
 {
 	. = 0;
-	.bstext		: { *(.bstext) }
-	.bsdata		: { *(.bsdata) }
-
+	.bstext	: {
+		*(.bstext)
 		. = 495;
+	} =0xffffffff
+
 	.header		: { *(.header) }
 	.entrytext	: { *(.entrytext) }
 	.inittext	: { *(.inittext) }
@@ -35,11 +36,16 @@ SECTIONS
 	. = ALIGN(16);
 	.data		: { *(.data*) }
 
+	.pecompat	: { *(.pecompat) }
+	PROVIDE(pecompat_fsize = setup_size - pecompat_fstart);
+
 	.signature	: {
 		setup_sig = .;
 		LONG(0x5a5aaa55)
-	}
 
+		setup_size = ALIGN(ABSOLUTE(.), 4096);
+		setup_sects = ABSOLUTE(setup_size / 512);
+	}
 
 	. = ALIGN(16);
 	.bss		:

arch/x86/boot/tools/build.c

@@ -40,10 +40,6 @@ typedef unsigned char  u8;
 typedef unsigned short u16;
 typedef unsigned int   u32;
 
-#define DEFAULT_MAJOR_ROOT 0
-#define DEFAULT_MINOR_ROOT 0
-#define DEFAULT_ROOT_DEV (DEFAULT_MAJOR_ROOT << 8 | DEFAULT_MINOR_ROOT)
-
 /* Minimal number of setup sectors */
 #define SETUP_SECT_MIN 5
 #define SETUP_SECT_MAX 64
@@ -51,22 +47,7 @@ typedef unsigned int   u32;
 /* This must be large enough to hold the entire setup */
 u8 buf[SETUP_SECT_MAX*512];
 
-#define PECOFF_RELOC_RESERVE 0x20
-
-#ifdef CONFIG_EFI_MIXED
-#define PECOFF_COMPAT_RESERVE 0x20
-#else
-#define PECOFF_COMPAT_RESERVE 0x0
-#endif
-
-static unsigned long efi32_stub_entry;
-static unsigned long efi64_stub_entry;
-static unsigned long efi_pe_entry;
-static unsigned long efi32_pe_entry;
-static unsigned long kernel_info;
-static unsigned long startup_64;
-static unsigned long _ehead;
-static unsigned long _end;
+static unsigned long _edata;
 
 /*----------------------------------------------------------------------*/
 
@@ -152,180 +133,6 @@ static void usage(void)
 	die("Usage: build setup system zoffset.h image");
 }
 
-#ifdef CONFIG_EFI_STUB
-
-static void update_pecoff_section_header_fields(char *section_name, u32 vma, u32 size, u32 datasz, u32 offset)
-{
-	unsigned int pe_header;
-	unsigned short num_sections;
-	u8 *section;
-
-	pe_header = get_unaligned_le32(&buf[0x3c]);
-	num_sections = get_unaligned_le16(&buf[pe_header + 6]);
-
-#ifdef CONFIG_X86_32
-	section = &buf[pe_header + 0xa8];
-#else
-	section = &buf[pe_header + 0xb8];
-#endif
-
-	while (num_sections > 0) {
-		if (strncmp((char*)section, section_name, 8) == 0) {
-			/* section header size field */
-			put_unaligned_le32(size, section + 0x8);
-
-			/* section header vma field */
-			put_unaligned_le32(vma, section + 0xc);
-
-			/* section header 'size of initialised data' field */
-			put_unaligned_le32(datasz, section + 0x10);
-
-			/* section header 'file offset' field */
-			put_unaligned_le32(offset, section + 0x14);
-
-			break;
-		}
-		section += 0x28;
-		num_sections--;
-	}
-}
-
-static void update_pecoff_section_header(char *section_name, u32 offset, u32 size)
-{
-	update_pecoff_section_header_fields(section_name, offset, size, size, offset);
-}
-
-static void update_pecoff_setup_and_reloc(unsigned int size)
-{
-	u32 setup_offset = 0x200;
-	u32 reloc_offset = size - PECOFF_RELOC_RESERVE - PECOFF_COMPAT_RESERVE;
-#ifdef CONFIG_EFI_MIXED
-	u32 compat_offset = reloc_offset + PECOFF_RELOC_RESERVE;
-#endif
-	u32 setup_size = reloc_offset - setup_offset;
-
-	update_pecoff_section_header(".setup", setup_offset, setup_size);
-	update_pecoff_section_header(".reloc", reloc_offset, PECOFF_RELOC_RESERVE);
-
-	/*
-	 * Modify .reloc section contents with a single entry. The
-	 * relocation is applied to offset 10 of the relocation section.
-	 */
-	put_unaligned_le32(reloc_offset + 10, &buf[reloc_offset]);
-	put_unaligned_le32(10, &buf[reloc_offset + 4]);
-
-#ifdef CONFIG_EFI_MIXED
-	update_pecoff_section_header(".compat", compat_offset, PECOFF_COMPAT_RESERVE);
-
-	/*
-	 * Put the IA-32 machine type (0x14c) and the associated entry point
-	 * address in the .compat section, so loaders can figure out which other
-	 * execution modes this image supports.
-	 */
-	buf[compat_offset] = 0x1;
-	buf[compat_offset + 1] = 0x8;
-	put_unaligned_le16(0x14c, &buf[compat_offset + 2]);
-	put_unaligned_le32(efi32_pe_entry + size, &buf[compat_offset + 4]);
-#endif
-}
-
-static void update_pecoff_text(unsigned int text_start, unsigned int file_sz,
-			       unsigned int init_sz)
-{
-	unsigned int pe_header;
-	unsigned int text_sz = file_sz - text_start;
-	unsigned int bss_sz = init_sz - file_sz;
-
-	pe_header = get_unaligned_le32(&buf[0x3c]);
-
-	/*
-	 * The PE/COFF loader may load the image at an address which is
-	 * misaligned with respect to the kernel_alignment field in the setup
-	 * header.
-	 *
-	 * In order to avoid relocating the kernel to correct the misalignment,
-	 * add slack to allow the buffer to be aligned within the declared size
-	 * of the image.
-	 */
-	bss_sz	+= CONFIG_PHYSICAL_ALIGN;
-	init_sz	+= CONFIG_PHYSICAL_ALIGN;
-
-	/*
-	 * Size of code: Subtract the size of the first sector (512 bytes)
-	 * which includes the header.
-	 */
-	put_unaligned_le32(file_sz - 512 + bss_sz, &buf[pe_header + 0x1c]);
-
-	/* Size of image */
-	put_unaligned_le32(init_sz, &buf[pe_header + 0x50]);
-
-	/*
-	 * Address of entry point for PE/COFF executable
-	 */
-	put_unaligned_le32(text_start + efi_pe_entry, &buf[pe_header + 0x28]);
-
-	update_pecoff_section_header_fields(".text", text_start, text_sz + bss_sz,
-					    text_sz, text_start);
-}
-
-static int reserve_pecoff_reloc_section(int c)
-{
-	/* Reserve 0x20 bytes for .reloc section */
-	memset(buf+c, 0, PECOFF_RELOC_RESERVE);
-	return PECOFF_RELOC_RESERVE;
-}
-
-static void efi_stub_defaults(void)
-{
-	/* Defaults for old kernel */
-#ifdef CONFIG_X86_32
-	efi_pe_entry = 0x10;
-#else
-	efi_pe_entry = 0x210;
-	startup_64 = 0x200;
-#endif
-}
-
-static void efi_stub_entry_update(void)
-{
-	unsigned long addr = efi32_stub_entry;
-
-#ifdef CONFIG_EFI_HANDOVER_PROTOCOL
-#ifdef CONFIG_X86_64
-	/* Yes, this is really how we defined it :( */
-	addr = efi64_stub_entry - 0x200;
-#endif
-
-#ifdef CONFIG_EFI_MIXED
-	if (efi32_stub_entry != addr)
-		die("32-bit and 64-bit EFI entry points do not match\n");
-#endif
-#endif
-	put_unaligned_le32(addr, &buf[0x264]);
-}
-
-#else
-
-static inline void update_pecoff_setup_and_reloc(unsigned int size) {}
-static inline void update_pecoff_text(unsigned int text_start,
-				      unsigned int file_sz,
-				      unsigned int init_sz) {}
-static inline void efi_stub_defaults(void) {}
-static inline void efi_stub_entry_update(void) {}
-
-static inline int reserve_pecoff_reloc_section(int c)
-{
-	return 0;
-}
-#endif /* CONFIG_EFI_STUB */
-
-static int reserve_pecoff_compat_section(int c)
-{
-	/* Reserve 0x20 bytes for .compat section */
-	memset(buf+c, 0, PECOFF_COMPAT_RESERVE);
-	return PECOFF_COMPAT_RESERVE;
-}
-
 /*
  * Parse zoffset.h and find the entry points. We could just #include zoffset.h
  * but that would mean tools/build would have to be rebuilt every time. It's
@@ -354,14 +161,7 @@ static void parse_zoffset(char *fname)
 	p = (char *)buf;
 
 	while (p && *p) {
-		PARSE_ZOFS(p, efi32_stub_entry);
-		PARSE_ZOFS(p, efi64_stub_entry);
-		PARSE_ZOFS(p, efi_pe_entry);
-		PARSE_ZOFS(p, efi32_pe_entry);
-		PARSE_ZOFS(p, kernel_info);
-		PARSE_ZOFS(p, startup_64);
-		PARSE_ZOFS(p, _ehead);
-		PARSE_ZOFS(p, _end);
+		PARSE_ZOFS(p, _edata);
 
 		p = strchr(p, '\n');
 		while (p && (*p == '\r' || *p == '\n'))
@@ -371,17 +171,14 @@ static void parse_zoffset(char *fname)
 
 int main(int argc, char ** argv)
 {
-	unsigned int i, sz, setup_sectors, init_sz;
+	unsigned int i, sz, setup_sectors;
 	int c;
-	u32 sys_size;
 	struct stat sb;
 	FILE *file, *dest;
 	int fd;
 	void *kernel;
 	u32 crc = 0xffffffffUL;
 
-	efi_stub_defaults();
-
 	if (argc != 5)
 		usage();
 	parse_zoffset(argv[3]);
@@ -403,72 +200,27 @@ int main(int argc, char ** argv)
 		die("Boot block hasn't got boot flag (0xAA55)");
 	fclose(file);
 
-	c += reserve_pecoff_compat_section(c);
-	c += reserve_pecoff_reloc_section(c);
-
 	/* Pad unused space with zeros */
-	setup_sectors = (c + 511) / 512;
+	setup_sectors = (c + 4095) / 4096;
+	setup_sectors *= 8;
 	if (setup_sectors < SETUP_SECT_MIN)
 		setup_sectors = SETUP_SECT_MIN;
 	i = setup_sectors*512;
 	memset(buf+c, 0, i-c);
 
-	update_pecoff_setup_and_reloc(i);
-
-	/* Set the default root device */
-	put_unaligned_le16(DEFAULT_ROOT_DEV, &buf[508]);
-
 	/* Open and stat the kernel file */
 	fd = open(argv[2], O_RDONLY);
 	if (fd < 0)
 		die("Unable to open `%s': %m", argv[2]);
 	if (fstat(fd, &sb))
 		die("Unable to stat `%s': %m", argv[2]);
-	sz = sb.st_size;
+	if (_edata != sb.st_size)
+		die("Unexpected file size `%s': %u != %u", argv[2], _edata,
+		    sb.st_size);
+	sz = _edata - 4;
 	kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0);
 	if (kernel == MAP_FAILED)
 		die("Unable to mmap '%s': %m", argv[2]);
-	/* Number of 16-byte paragraphs, including space for a 4-byte CRC */
-	sys_size = (sz + 15 + 4) / 16;
-#ifdef CONFIG_EFI_STUB
-	/*
-	 * COFF requires minimum 32-byte alignment of sections, and
-	 * adding a signature is problematic without that alignment.
-	 */
-	sys_size = (sys_size + 1) & ~1;
-#endif
-
-	/* Patch the setup code with the appropriate size parameters */
-	buf[0x1f1] = setup_sectors-1;
-	put_unaligned_le32(sys_size, &buf[0x1f4]);
-
-	init_sz = get_unaligned_le32(&buf[0x260]);
-#ifdef CONFIG_EFI_STUB
-	/*
-	 * The decompression buffer will start at ImageBase. When relocating
-	 * the compressed kernel to its end, we must ensure that the head
-	 * section does not get overwritten.  The head section occupies
-	 * [i, i + _ehead), and the destination is [init_sz - _end, init_sz).
-	 *
-	 * At present these should never overlap, because 'i' is at most 32k
-	 * because of SETUP_SECT_MAX, '_ehead' is less than 1k, and the
-	 * calculation of INIT_SIZE in boot/header.S ensures that
-	 * 'init_sz - _end' is at least 64k.
-	 *
-	 * For future-proofing, increase init_sz if necessary.
-	 */
-
-	if (init_sz - _end < i + _ehead) {
-		init_sz = (i + _ehead + _end + 4095) & ~4095;
-		put_unaligned_le32(init_sz, &buf[0x260]);
-	}
-#endif
-	update_pecoff_text(setup_sectors * 512, i + (sys_size * 16), init_sz);
-
-	efi_stub_entry_update();
-
-	/* Update kernel_info offset. */
-	put_unaligned_le32(kernel_info, &buf[0x268]);
 
 	crc = partial_crc32(buf, i, crc);
 	if (fwrite(buf, 1, i, dest) != i)
@@ -479,13 +231,6 @@ int main(int argc, char ** argv)
 	if (fwrite(kernel, 1, sz, dest) != sz)
 		die("Writing kernel failed");
 
-	/* Add padding leaving 4 bytes for the checksum */
-	while (sz++ < (sys_size*16) - 4) {
-		crc = partial_crc32_one('\0', crc);
-		if (fwrite("\0", 1, 1, dest) != 1)
-			die("Writing padding failed");
-	}
-
 	/* Write the CRC */
 	put_unaligned_le32(crc, buf);
 	if (fwrite(buf, 1, 4, dest) != 4)

arch/x86/include/asm/boot.h

@@ -85,6 +85,8 @@ extern const unsigned long kernel_total_size;
 
 unsigned long decompress_kernel(unsigned char *outbuf, unsigned long virt_addr,
 				void (*error)(char *x));
+
+extern struct boot_params *boot_params_ptr;
 #endif
 
 #endif /* _ASM_X86_BOOT_H */

arch/x86/include/asm/init.h

@@ -2,6 +2,8 @@
 #ifndef _ASM_X86_INIT_H
 #define _ASM_X86_INIT_H
 
+#define __head	__section(".head.text")
+
 struct x86_mapping_info {
 	void *(*alloc_pgt_page)(void *); /* allocate buf for page table */
 	void *context;			 /* context for alloc_pgt_page */

arch/x86/kernel/head64.c

@@ -41,6 +41,7 @@
 #include <asm/trapnr.h>
 #include <asm/sev.h>
 #include <asm/tdx.h>
+#include <asm/init.h>
 
 /*
  * Manage page tables very early on.
@@ -69,7 +70,7 @@ EXPORT_SYMBOL(vmemmap_base);
 /*
  * GDT used on the boot CPU before switching to virtual addresses.
  */
-static struct desc_struct startup_gdt[GDT_ENTRIES] = {
+static struct desc_struct startup_gdt[GDT_ENTRIES] __initdata = {
 	[GDT_ENTRY_KERNEL32_CS]         = GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
 	[GDT_ENTRY_KERNEL_CS]           = GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
 	[GDT_ENTRY_KERNEL_DS]           = GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
@@ -79,13 +80,11 @@ static struct desc_struct startup_gdt[GDT_ENTRIES] = {
  * Address needs to be set at runtime because it references the startup_gdt
  * while the kernel still uses a direct mapping.
  */
-static struct desc_ptr startup_gdt_descr = {
-	.size = sizeof(startup_gdt),
+static struct desc_ptr startup_gdt_descr __initdata = {
+	.size = sizeof(startup_gdt)-1,
 	.address = 0,
 };
 
-#define __head	__section(".head.text")
-
 static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
 {
 	return ptr - (void *)_text + (void *)physaddr;
@@ -211,7 +210,7 @@ unsigned long __head __startup_64(unsigned long physaddr,
 
 	/* Fixup the physical addresses in the page table */
 
-	pgd = fixup_pointer(&early_top_pgt, physaddr);
+	pgd = fixup_pointer(early_top_pgt, physaddr);
 	p = pgd + pgd_index(__START_KERNEL_map);
 	if (la57)
 		*p = (unsigned long)level4_kernel_pgt;
@@ -220,11 +219,11 @@ unsigned long __head __startup_64(unsigned long physaddr,
 	*p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
 
 	if (la57) {
-		p4d = fixup_pointer(&level4_kernel_pgt, physaddr);
+		p4d = fixup_pointer(level4_kernel_pgt, physaddr);
 		p4d[511] += load_delta;
 	}
 
-	pud = fixup_pointer(&level3_kernel_pgt, physaddr);
+	pud = fixup_pointer(level3_kernel_pgt, physaddr);
 	pud[510] += load_delta;
 	pud[511] += load_delta;
 
@@ -588,7 +587,7 @@ static void set_bringup_idt_handler(gate_desc *idt, int n, void *handler)
 }
 
 /* This runs while still in the direct mapping */
-static void startup_64_load_idt(unsigned long physbase)
+static void __head startup_64_load_idt(unsigned long physbase)
 {
 	struct desc_ptr *desc = fixup_pointer(&bringup_idt_descr, physbase);
 	gate_desc *idt = fixup_pointer(bringup_idt_table, physbase);

drivers/firmware/efi/libstub/Makefile

@@ -108,13 +108,6 @@ lib-y				:= $(patsubst %.o,%.stub.o,$(lib-y))
 # https://bugs.llvm.org/show_bug.cgi?id=46480
 STUBCOPY_FLAGS-y		+= --remove-section=.note.gnu.property
 
-#
-# For x86, bootloaders like systemd-boot or grub-efi do not zero-initialize the
-# .bss section, so the .bss section of the EFI stub needs to be included in the
-# .data section of the compressed kernel to ensure initialization. Rename the
-# .bss section here so it's easy to pick out in the linker script.
-#
-STUBCOPY_FLAGS-$(CONFIG_X86)	+= --rename-section .bss=.bss.efistub,load,alloc
 STUBCOPY_RELOC-$(CONFIG_X86_32)	:= R_386_32
 STUBCOPY_RELOC-$(CONFIG_X86_64)	:= R_X86_64_64
 

drivers/firmware/efi/libstub/x86-stub.c

@@ -449,9 +449,8 @@ void __noreturn efi_stub_entry(efi_handle_t handle,
 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 				   efi_system_table_t *sys_table_arg)
 {
-	struct boot_params *boot_params;
-	struct setup_header *hdr;
-	void *image_base;
+	static struct boot_params boot_params __page_aligned_bss;
+	struct setup_header *hdr = &boot_params.hdr;
 	efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
 	int options_size = 0;
 	efi_status_t status;
@@ -469,30 +468,9 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 		efi_exit(handle, status);
 	}
 
-	image_base = efi_table_attr(image, image_base);
-
-	status = efi_allocate_pages(sizeof(struct boot_params),
-				    (unsigned long *)&boot_params, ULONG_MAX);
-	if (status != EFI_SUCCESS) {
-		efi_err("Failed to allocate lowmem for boot params\n");
-		efi_exit(handle, status);
-	}
-
-	memset(boot_params, 0x0, sizeof(struct boot_params));
-
-	hdr = &boot_params->hdr;
-
-	/* Copy the setup header from the second sector to boot_params */
-	memcpy(&hdr->jump, image_base + 512,
-	       sizeof(struct setup_header) - offsetof(struct setup_header, jump));
-
-	/*
-	 * Fill out some of the header fields ourselves because the
-	 * EFI firmware loader doesn't load the first sector.
-	 */
+	/* Assign the setup_header fields that the kernel actually cares about */
 	hdr->root_flags	= 1;
 	hdr->vid_mode	= 0xffff;
-	hdr->boot_flag	= 0xAA55;
 
 	hdr->type_of_loader = 0x21;
 
@@ -501,25 +479,13 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 	if (!cmdline_ptr)
 		goto fail;
 
-	efi_set_u64_split((unsigned long)cmdline_ptr,
-			  &hdr->cmd_line_ptr, &boot_params->ext_cmd_line_ptr);
-
-	hdr->ramdisk_image = 0;
-	hdr->ramdisk_size = 0;
-
-	/*
-	 * Disregard any setup data that was provided by the bootloader:
-	 * setup_data could be pointing anywhere, and we have no way of
-	 * authenticating or validating the payload.
-	 */
-	hdr->setup_data = 0;
+	efi_set_u64_split((unsigned long)cmdline_ptr, &hdr->cmd_line_ptr,
+			  &boot_params.ext_cmd_line_ptr);
 
-	efi_stub_entry(handle, sys_table_arg, boot_params);
+	efi_stub_entry(handle, sys_table_arg, &boot_params);
 	/* not reached */
 
 fail:
-	efi_free(sizeof(struct boot_params), (unsigned long)boot_params);
-
 	efi_exit(handle, status);
 }
 
@@ -849,7 +815,7 @@ void __noreturn efi_stub_entry(efi_handle_t handle,
 	unsigned long kernel_entry;
 	efi_status_t status;
 
-	boot_params_pointer = boot_params;
+	boot_params_ptr = boot_params;
 
 	efi_system_table = sys_table_arg;
 	/* Check if we were booted by the EFI firmware */

drivers/firmware/efi/libstub/x86-stub.h

@@ -2,8 +2,6 @@
 
 #include <linux/efi.h>
 
-extern struct boot_params *boot_params_pointer asm("boot_params");
-
 extern void trampoline_32bit_src(void *, bool);
 extern const u16 trampoline_ljmp_imm_offset;