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x86/boot/64: Extract efi_pe_entry() from startup_64()

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Similarly to the 32-bit code, efi_pe_entry body() is somehow squashed into
startup_64().

In the old days, we forced startup_64() to start at offset 0x200 and efi_pe_entry()
to start at 0x210. But this requirement was removed long time ago, in:

  99f857db88 ("x86, build: Dynamically find entry points in compressed startup code")

The way it is now makes the code less readable and illogical. Given
we can now safely extract the inlined efi_pe_entry() body from
startup_64() into a separate function, we do so.

We also annotate the function appropriatelly by ENTRY+ENDPROC.

ABI offsets are preserved:

  0000000000000000 T startup_32
  0000000000000200 T startup_64
  0000000000000390 T efi64_stub_entry

On the top-level, it looked like:

	.org 0x200
	ENTRY(startup_64)
	#ifdef CONFIG_EFI_STUB		; start of inlined
		jmp     preferred_addr
	GLOBAL(efi_pe_entry)
		... ; a lot of assembly (efi_pe_entry)
		leaq    preferred_addr(%rax), %rax
		jmp     *%rax
	preferred_addr:
	#endif				; end of inlined
		... ; a lot of assembly (startup_64)
	ENDPROC(startup_64)

And it is now converted into:

	.org 0x200
	ENTRY(startup_64)
		... ; a lot of assembly (startup_64)
	ENDPROC(startup_64)

	#ifdef CONFIG_EFI_STUB
	ENTRY(efi_pe_entry)
		... ; a lot of assembly (efi_pe_entry)
		leaq    startup_64(%rax), %rax
		jmp     *%rax
	ENDPROC(efi_pe_entry)
	#endif

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: ard.biesheuvel@linaro.org
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170824073327.4129-2-jslaby@suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Jiri Slaby 2017-08-24 09:33:27 +02:00 committed by Ingo Molnar
parent f4dee0bb65
commit 9e085cefc6
1 changed files with 53 additions and 59 deletions
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112
arch/x86/boot/compressed/head_64.S
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@ -243,65 +243,6 @@ ENTRY(startup_64)
* that maps our entire kernel(text+data+bss+brk), zero page
* and command line.
*/
#ifdef CONFIG_EFI_STUB
/*
* The entry point for the PE/COFF executable is efi_pe_entry, so
* only legacy boot loaders will execute this jmp.
*/
jmp preferred_addr
ENTRY(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)
call 1f
1: popq %rbp
subq $1b, %rbp
/*
* Relocate efi_config->call().
*/
addq %rbp, efi64_config+40(%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)
jmp 2f /* Skip the relocation */
handover_entry:
call 1f
1: popq %rbp
subq $1b, %rbp
/*
* Relocate efi_config->call().
*/
movq efi_config(%rip), %rax
addq %rbp, 40(%rax)
2:
movq efi_config(%rip), %rdi
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 preferred_addr(%rax), %rax
jmp *%rax
preferred_addr:
#endif
/* Setup data segments. */
xorl %eax, %eax
@ -413,6 +354,59 @@ lvl5:
jmp *%rax
#ifdef CONFIG_EFI_STUB
/* The entry point for the PE/COFF executable is efi_pe_entry. */
ENTRY(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)
call 1f
1: popq %rbp
subq $1b, %rbp
/*
* Relocate efi_config->call().
*/
addq %rbp, efi64_config+40(%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)
jmp 2f /* Skip the relocation */
handover_entry:
call 1f
1: popq %rbp
subq $1b, %rbp
/*
* Relocate efi_config->call().
*/
movq efi_config(%rip), %rax
addq %rbp, 40(%rax)
2:
movq efi_config(%rip), %rdi
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
ENDPROC(efi_pe_entry)
.org 0x390
ENTRY(efi64_stub_entry)
movq %rdi, efi64_config(%rip) /* Handle */