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

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This reverts commit b73adb60852034d84092d123b323196ca42529cd 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: Ben 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Greg Kroah-Hartman 2017-12-14 21:23:48 +01:00
parent 1dfe268df5
commit 34933c2ce9
3 changed files with 56 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
arch/x86/include/asm/efi.h
View File

@ -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; \

24
arch/x86/platform/efi/efi_64.c
View File

@ -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);

43
arch/x86/platform/efi/efi_stub_64.S
View File

@ -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