Commit c3710de5 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Ingo Molnar
Browse files

efi/libstub/x86: Drop __efi_early() export and efi_config struct 



The various pointers we stash in the efi_config struct which we
retrieve using __efi_early() are simply copies of the ones in
the EFI system table, which we have started accessing directly
in the previous patch. So drop all the __efi_early() related
plumbing, as well as all the assembly code dealing with efi_config,
which allows us to move the PE/COFF entry point to C code as well.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191224151025.32482-18-ardb@kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent dc29da14

arch/x86/boot/compressed/eboot.c

+30 −52
Original line number Diff line number Diff line
@@ -19,32 +19,17 @@ 
#include "eboot.h"



static efi_system_table_t *sys_table;



static struct efi_config *efi_early;



__pure const struct efi_config *__efi_early(void)

{

	return efi_early;

}

static bool efi_is64 = IS_ENABLED(CONFIG_X86_64);



__pure efi_system_table_t *efi_system_table(void)

{

	return sys_table;

}



#define BOOT_SERVICES(bits)						\

static void setup_boot_services##bits(struct efi_config *c)		\

{									\

	efi_system_table_##bits##_t *table;				\

									\

	table = (typeof(table))sys_table;				\

									\

	c->runtime_services	= table->runtime;			\

	c->boot_services	= table->boottime;			\

	c->text_output		= table->con_out;			\

__pure bool efi_is_64bit(void)

{

	return efi_is64;

}

BOOT_SERVICES(32);

BOOT_SERVICES(64);



static efi_status_t

preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
@@ -367,21 +352,24 @@ void setup_graphics(struct boot_params *boot_params) 
	}

}



void startup_32(struct boot_params *boot_params);



void __noreturn efi_stub_entry(efi_handle_t handle,

			       efi_system_table_t *sys_table_arg,

			       struct boot_params *boot_params);



/*

 * Because the x86 boot code expects to be passed a boot_params we

 * need to create one ourselves (usually the bootloader would create

 * one for us).

 *

 * The caller is responsible for filling out ->code32_start in the

 * returned boot_params.

 */

struct boot_params *make_boot_params(struct efi_config *c)

efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,

				   efi_system_table_t *sys_table_arg)

{

	struct boot_params *boot_params;

	struct apm_bios_info *bi;

	struct setup_header *hdr;

	efi_loaded_image_t *image;

	void *handle;

	efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;

	int options_size = 0;

	efi_status_t status;
@@ -389,31 +377,24 @@ struct boot_params *make_boot_params(struct efi_config *c) 
	unsigned long ramdisk_addr;

	unsigned long ramdisk_size;



	efi_early = c;

	sys_table = (efi_system_table_t *)(unsigned long)efi_early->table;

	handle = (void *)(unsigned long)efi_early->image_handle;

	sys_table = sys_table_arg;



	/* Check if we were booted by the EFI firmware */

	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)

		return NULL;



	if (efi_is_64bit())

		setup_boot_services64(efi_early);

	else

		setup_boot_services32(efi_early);

		return EFI_INVALID_PARAMETER;



	status = efi_call_early(handle_protocol, handle,

				&proto, (void *)&image);

	if (status != EFI_SUCCESS) {

		efi_printk(sys_table, "Failed to get handle for LOADED_IMAGE_PROTOCOL\n");

		return NULL;

		return status;

	}



	status = efi_low_alloc(sys_table, 0x4000, 1,

			       (unsigned long *)&boot_params);

	if (status != EFI_SUCCESS) {

		efi_printk(sys_table, "Failed to allocate lowmem for boot params\n");

		return NULL;

		return status;

	}



	memset(boot_params, 0x0, 0x4000);
@@ -474,14 +455,17 @@ struct boot_params *make_boot_params(struct efi_config *c) 
	boot_params->ext_ramdisk_image = (u64)ramdisk_addr >> 32;

	boot_params->ext_ramdisk_size  = (u64)ramdisk_size >> 32;



	return boot_params;

	hdr->code32_start = (u32)(unsigned long)startup_32;



	efi_stub_entry(handle, sys_table, boot_params);

	/* not reached */



fail2:

	efi_free(sys_table, options_size, hdr->cmd_line_ptr);

fail:

	efi_free(sys_table, 0x4000, (unsigned long)boot_params);



	return NULL;

	return status;

}



static void add_e820ext(struct boot_params *params,
@@ -737,33 +721,26 @@ static efi_status_t exit_boot(struct boot_params *boot_params, void *handle) 
 * On success we return a pointer to a boot_params structure, and NULL

 * on failure.

 */

struct boot_params *

efi_main(struct efi_config *c, struct boot_params *boot_params)

struct boot_params *efi_main(efi_handle_t handle,

			     efi_system_table_t *sys_table_arg,

			     struct boot_params *boot_params,

			     bool is64)

{

	struct desc_ptr *gdt = NULL;

	struct setup_header *hdr = &boot_params->hdr;

	efi_status_t status;

	struct desc_struct *desc;

	void *handle;

	efi_system_table_t *_table;

	unsigned long cmdline_paddr;



	efi_early = c;



	_table = (efi_system_table_t *)(unsigned long)efi_early->table;

	handle = (void *)(unsigned long)efi_early->image_handle;

	sys_table = sys_table_arg;



	sys_table = _table;

	if (IS_ENABLED(CONFIG_EFI_MIXED))

		efi_is64 = is64;



	/* Check if we were booted by the EFI firmware */

	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)

		goto fail;



	if (efi_is_64bit())

		setup_boot_services64(efi_early);

	else

		setup_boot_services32(efi_early);



	/*

	 * make_boot_params() may have been called before efi_main(), in which

	 * case this is the second time we parse the cmdline. This is ok,
@@ -925,5 +902,6 @@ efi_main(struct efi_config *c, struct boot_params *boot_params) 
fail:

	efi_printk(sys_table, "efi_main() failed!\n");



	return NULL;

	for (;;)

		asm("hlt");

}

arch/x86/boot/compressed/head_32.S

+2 −56
Original line number Diff line number Diff line
@@ -145,63 +145,16 @@ SYM_FUNC_START(startup_32) 
SYM_FUNC_END(startup_32)



#ifdef CONFIG_EFI_STUB

/*

 * We don't need the return address, so set up the stack so efi_main() can find

 * its arguments.

 */

SYM_FUNC_START(efi_pe_entry)

	add	$0x4, %esp



	call	1f

1:	popl	%esi

	subl	$1b, %esi



	popl	%ecx

	movl	%ecx, efi32_config(%esi)	/* Handle */

	popl	%ecx

	movl	%ecx, efi32_config+8(%esi)	/* EFI System table pointer */



	leal	efi32_config(%esi), %eax

	pushl	%eax



	call	make_boot_params

	cmpl	$0, %eax

	je	fail

	movl	%esi, BP_code32_start(%eax)

	popl	%ecx

	pushl	%eax

	pushl	%ecx

	jmp	2f		/* Skip efi_config initialization */

SYM_FUNC_END(efi_pe_entry)



SYM_FUNC_START(efi32_stub_entry)

SYM_FUNC_START_ALIAS(efi_stub_entry)

	add	$0x4, %esp

	popl	%ecx

	popl	%edx



	call	1f

1:	popl	%esi

	subl	$1b, %esi



	movl	%ecx, efi32_config(%esi)	/* Handle */

	movl	%edx, efi32_config+8(%esi)	/* EFI System table pointer */



	leal	efi32_config(%esi), %eax

	pushl	%eax

2:

	call	efi_main

	cmpl	$0, %eax

	movl	%eax, %esi

	jne	2f

fail:

	/* EFI init failed, so hang. */

	hlt

	jmp	fail

2:

	movl	BP_code32_start(%esi), %eax

	leal	startup_32(%eax), %eax

	jmp	*%eax

SYM_FUNC_END(efi32_stub_entry)

SYM_FUNC_END_ALIAS(efi_stub_entry)

#endif



	.text
@@ -258,13 +211,6 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated) 
	jmp	*%eax

SYM_FUNC_END(.Lrelocated)



#ifdef CONFIG_EFI_STUB

	.data

efi32_config:

	.fill 5,8,0

	.byte 0

#endif



/*

 * Stack and heap for uncompression

 */

arch/x86/boot/compressed/head_64.S

+13 −61
Original line number Diff line number Diff line
@@ -208,10 +208,14 @@ SYM_FUNC_START(startup_32) 
	pushl	$__KERNEL_CS

	leal	startup_64(%ebp), %eax

#ifdef CONFIG_EFI_MIXED

	movl	efi32_config(%ebp), %ebx

	movl	efi32_boot_args(%ebp), %ebx

	cmp	$0, %ebx

	jz	1f

	leal	handover_entry(%ebp), %eax

	movl	0(%ebx), %edi

	movl	4(%ebx), %esi

	movl	8(%ebx), %edx

	movl	$0x0, %ecx

1:

#endif

	pushl	%eax
@@ -228,22 +232,14 @@ SYM_FUNC_END(startup_32) 
	.org 0x190

SYM_FUNC_START(efi32_stub_entry)

	add	$0x4, %esp		/* Discard return address */

	popl	%ecx

	popl	%edx

	popl	%esi



	leal	(BP_scratch+4)(%esi), %esp

	call	1f

1:	pop	%ebp

	subl	$1b, %ebp



	movl	%ecx, efi32_config(%ebp)

	movl	%edx, efi32_config+8(%ebp)

	movl	%esp, efi32_boot_args(%ebp)

	sgdtl	efi32_boot_gdt(%ebp)



	leal	efi32_config(%ebp), %eax

	movl	%eax, efi_config(%ebp)



	/* Disable paging */

	movl	%cr0, %eax

	btrl	$X86_CR0_PG_BIT, %eax
@@ -450,51 +446,19 @@ trampoline_return: 
SYM_CODE_END(startup_64)



#ifdef CONFIG_EFI_STUB



/* The entry point for the PE/COFF executable is efi_pe_entry. */

SYM_FUNC_START(efi_pe_entry)

	movq	%rcx, efi64_config(%rip)	/* Handle */

	movq	%rdx, efi64_config+8(%rip) /* EFI System table pointer */



	leaq	efi64_config(%rip), %rax

	movq	%rax, efi_config(%rip)



	movq	%rax, %rdi

	call	make_boot_params

	cmpq	$0,%rax

	je	fail

	mov	%rax, %rsi

	leaq	startup_32(%rip), %rax

	movl	%eax, BP_code32_start(%rsi)



handover_entry:

	movq	efi_config(%rip), %rdi

	.org 0x390

SYM_FUNC_START(efi64_stub_entry)

SYM_FUNC_START_ALIAS(efi_stub_entry)

	movq	$1, %rcx

SYM_INNER_LABEL(handover_entry, SYM_L_LOCAL)

	and	$~0xf, %rsp			/* realign the stack */

	call	efi_main

	movq	%rax,%rsi

	cmpq	$0,%rax

	jne	2f

fail:

	/* EFI init failed, so hang. */

	hlt

	jmp	fail

2:

	movl	BP_code32_start(%esi), %eax

	leaq	startup_64(%rax), %rax

	jmp	*%rax

SYM_FUNC_END(efi_pe_entry)



	.org 0x390

SYM_FUNC_START(efi64_stub_entry)

	movq	%rdi, efi64_config(%rip)	/* Handle */

	movq	%rsi, efi64_config+8(%rip) /* EFI System table pointer */



	leaq	efi64_config(%rip), %rax

	movq	%rax, efi_config(%rip)



	movq	%rdx, %rsi

	jmp	handover_entry

SYM_FUNC_END(efi64_stub_entry)

SYM_FUNC_END_ALIAS(efi_stub_entry)

#endif



	.text
@@ -663,22 +627,10 @@ SYM_DATA_START_LOCAL(gdt) 
	.quad   0x0000000000000000	/* TS continued */

SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end)



#ifdef CONFIG_EFI_STUB

SYM_DATA_LOCAL(efi_config, .quad 0)



#ifdef CONFIG_EFI_MIXED

SYM_DATA_START(efi32_config)

	.fill	5,8,0

	.byte	0

SYM_DATA_END(efi32_config)

SYM_DATA_LOCAL(efi32_boot_args, .long 0)

#endif



SYM_DATA_START(efi64_config)

	.fill	5,8,0

	.byte	1

SYM_DATA_END(efi64_config)

#endif /* CONFIG_EFI_STUB */



/*

 * Stack and heap for uncompression

 */

arch/x86/include/asm/efi.h

+9 −29
Original line number Diff line number Diff line
@@ -200,32 +200,14 @@ static inline efi_status_t efi_thunk_set_virtual_address_map( 


/* arch specific definitions used by the stub code */



struct efi_config {

	u64 image_handle;

	u64 table;

	u64 runtime_services;

	u64 boot_services;

	u64 text_output;

	bool is64;

} __packed;



__pure const struct efi_config *__efi_early(void);



static inline bool efi_is_64bit(void)

{

	if (!IS_ENABLED(CONFIG_X86_64))

		return false;



	if (!IS_ENABLED(CONFIG_EFI_MIXED))

		return true;



	return __efi_early()->is64;

}

__pure bool efi_is_64bit(void);



static inline bool efi_is_native(void)

{

	if (!IS_ENABLED(CONFIG_X86_64))

		return true;

	if (!IS_ENABLED(CONFIG_EFI_MIXED))

		return true;

	return efi_is_64bit();

}
@@ -252,18 +234,16 @@ static inline bool efi_is_native(void) 


#define efi_call_early(f, ...)						\

	(efi_is_native()						\

		? ((efi_boot_services_t *)(unsigned long)		\

			__efi_early()->boot_services)->f(__VA_ARGS__)	\

		: efi64_thunk(((efi_boot_services_t *)(unsigned long)	\

			__efi_early()->boot_services)->mixed_mode.f,	\

		? efi_system_table()->boottime->f(__VA_ARGS__)		\

		: efi64_thunk(efi_table_attr(efi_boot_services,		\

			boottime, efi_system_table())->mixed_mode.f,	\

			__VA_ARGS__))



#define efi_call_runtime(f, ...)					\

	(efi_is_native()						\

		? ((efi_runtime_services_t *)(unsigned long)		\

			__efi_early()->runtime_services)->f(__VA_ARGS__)\

		: efi64_thunk(((efi_runtime_services_t *)(unsigned long)\

			__efi_early()->runtime_services)->mixed_mode.f,	\

		? efi_system_table()->runtime->f(__VA_ARGS__)		\

		: efi64_thunk(efi_table_attr(efi_runtime_services,	\

			runtime, efi_system_table())->mixed_mode.f,	\

			__VA_ARGS__))



extern bool efi_reboot_required(void);

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