Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 34933c2c authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

Revert "x86/efi: Hoist page table switching code into efi_call_virt()" 



This reverts commit b73adb60 which is
commit c9f2a9a65e4855b74d92cdad688f6ee4a1a323ff upstream.

Turns there was too many other issues with this patch to make it viable
for the stable tree.

Reported-by: default avatarBen Hutchings <ben.hutchings@codethink.co.uk>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-efi@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Ghannam, Yazen" <Yazen.Ghannam@amd.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 1dfe268d

arch/x86/include/asm/efi.h

+0 −25
Original line number Diff line number Diff line
@@ -3,7 +3,6 @@ 


#include <asm/fpu/api.h>

#include <asm/pgtable.h>

#include <asm/tlb.h>



/*

 * We map the EFI regions needed for runtime services non-contiguously,
@@ -65,17 +64,6 @@ extern u64 asmlinkage efi_call(void *fp, ...); 


#define efi_call_phys(f, args...)		efi_call((f), args)



/*

 * Scratch space used for switching the pagetable in the EFI stub

 */

struct efi_scratch {

	u64	r15;

	u64	prev_cr3;

	pgd_t	*efi_pgt;

	bool	use_pgd;

	u64	phys_stack;

} __packed;



#define efi_call_virt(f, ...)						\

({									\

	efi_status_t __s;						\
@@ -83,20 +71,7 @@ struct efi_scratch { 
	efi_sync_low_kernel_mappings();					\

	preempt_disable();						\

	__kernel_fpu_begin();						\

									\

	if (efi_scratch.use_pgd) {					\

		efi_scratch.prev_cr3 = read_cr3();			\

		write_cr3((unsigned long)efi_scratch.efi_pgt);		\

		__flush_tlb_all();					\

	}								\

									\

	__s = efi_call((void *)efi.systab->runtime->f, __VA_ARGS__);	\

									\

	if (efi_scratch.use_pgd) {					\

		write_cr3(efi_scratch.prev_cr3);			\

		__flush_tlb_all();					\

	}								\

									\

	__kernel_fpu_end();						\

	preempt_enable();						\

	__s;								\

arch/x86/platform/efi/efi_64.c

+13 −11
Original line number Diff line number Diff line
@@ -47,7 +47,16 @@ 
 */

static u64 efi_va = EFI_VA_START;



struct efi_scratch efi_scratch;

/*

 * Scratch space used for switching the pagetable in the EFI stub

 */

struct efi_scratch {

	u64 r15;

	u64 prev_cr3;

	pgd_t *efi_pgt;

	bool use_pgd;

	u64 phys_stack;

} __packed;



static void __init early_code_mapping_set_exec(int executable)

{
@@ -74,11 +83,8 @@ pgd_t * __init efi_call_phys_prolog(void) 
	int pgd;

	int n_pgds;



	if (!efi_enabled(EFI_OLD_MEMMAP)) {

		save_pgd = (pgd_t *)read_cr3();

		write_cr3((unsigned long)efi_scratch.efi_pgt);

		goto out;

	}

	if (!efi_enabled(EFI_OLD_MEMMAP))

		return NULL;



	early_code_mapping_set_exec(1);
@@ -90,7 +96,6 @@ pgd_t * __init efi_call_phys_prolog(void) 
		vaddress = (unsigned long)__va(pgd * PGDIR_SIZE);

		set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), *pgd_offset_k(vaddress));

	}

out:

	__flush_tlb_all();



	return save_pgd;
@@ -104,11 +109,8 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd) 
	int pgd_idx;

	int nr_pgds;



	if (!efi_enabled(EFI_OLD_MEMMAP)) {

		write_cr3((unsigned long)save_pgd);

		__flush_tlb_all();

	if (!save_pgd)

		return;

	}



	nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);

arch/x86/platform/efi/efi_stub_64.S

+43 −0
Original line number Diff line number Diff line
@@ -38,6 +38,41 @@ 
	mov %rsi, %cr0;			\

	mov (%rsp), %rsp



	/* stolen from gcc */

	.macro FLUSH_TLB_ALL

	movq %r15, efi_scratch(%rip)

	movq %r14, efi_scratch+8(%rip)

	movq %cr4, %r15

	movq %r15, %r14

	andb $0x7f, %r14b

	movq %r14, %cr4

	movq %r15, %cr4

	movq efi_scratch+8(%rip), %r14

	movq efi_scratch(%rip), %r15

	.endm



	.macro SWITCH_PGT

	cmpb $0, efi_scratch+24(%rip)

	je 1f

	movq %r15, efi_scratch(%rip)		# r15

	# save previous CR3

	movq %cr3, %r15

	movq %r15, efi_scratch+8(%rip)		# prev_cr3

	movq efi_scratch+16(%rip), %r15		# EFI pgt

	movq %r15, %cr3

	1:

	.endm



	.macro RESTORE_PGT

	cmpb $0, efi_scratch+24(%rip)

	je 2f

	movq efi_scratch+8(%rip), %r15

	movq %r15, %cr3

	movq efi_scratch(%rip), %r15

	FLUSH_TLB_ALL

	2:

	.endm



ENTRY(efi_call)

	SAVE_XMM

	mov (%rsp), %rax
@@ -48,8 +83,16 @@ ENTRY(efi_call) 
	mov %r8, %r9

	mov %rcx, %r8

	mov %rsi, %rcx

	SWITCH_PGT

	call *%rdi

	RESTORE_PGT

	addq $48, %rsp

	RESTORE_XMM

	ret

ENDPROC(efi_call)



	.data

ENTRY(efi_scratch)

	.fill 3,8,0

	.byte 0

	.quad 0