linux-stable/arch/x86/platform/efi/efi_32.c
Andy Lutomirski 3fa1cabbc3 x86/efi/32: Fix EFI on systems where the per-cpu GDT is virtually mapped
__pa() on a per-cpu pointer is invalid.  This bug appears to go *waaay*
back, and I guess it's just never been triggered.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/5ba1d3ffca85e1a5b3ac99265ebe55df4cf0dbe4.1490218061.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-23 08:25:07 +01:00

94 lines
2.3 KiB
C

/*
* Extensible Firmware Interface
*
* Based on Extensible Firmware Interface Specification version 1.0
*
* Copyright (C) 1999 VA Linux Systems
* Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
* Copyright (C) 1999-2002 Hewlett-Packard Co.
* David Mosberger-Tang <davidm@hpl.hp.com>
* Stephane Eranian <eranian@hpl.hp.com>
*
* All EFI Runtime Services are not implemented yet as EFI only
* supports physical mode addressing on SoftSDV. This is to be fixed
* in a future version. --drummond 1999-07-20
*
* Implemented EFI runtime services and virtual mode calls. --davidm
*
* Goutham Rao: <goutham.rao@intel.com>
* Skip non-WB memory and ignore empty memory ranges.
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/efi.h>
#include <asm/io.h>
#include <asm/desc.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/efi.h>
/*
* To make EFI call EFI runtime service in physical addressing mode we need
* prolog/epilog before/after the invocation to claim the EFI runtime service
* handler exclusively and to duplicate a memory mapping in low memory space,
* say 0 - 3G.
*/
int __init efi_alloc_page_tables(void)
{
return 0;
}
void efi_sync_low_kernel_mappings(void) {}
void __init efi_dump_pagetable(void) {}
int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
{
return 0;
}
void __init efi_map_region(efi_memory_desc_t *md)
{
old_map_region(md);
}
void __init efi_map_region_fixed(efi_memory_desc_t *md) {}
void __init parse_efi_setup(u64 phys_addr, u32 data_len) {}
pgd_t * __init efi_call_phys_prolog(void)
{
struct desc_ptr gdt_descr;
pgd_t *save_pgd;
/* Current pgd is swapper_pg_dir, we'll restore it later: */
save_pgd = swapper_pg_dir;
load_cr3(initial_page_table);
__flush_tlb_all();
gdt_descr.address = get_cpu_gdt_paddr(0);
gdt_descr.size = GDT_SIZE - 1;
load_gdt(&gdt_descr);
return save_pgd;
}
void __init efi_call_phys_epilog(pgd_t *save_pgd)
{
struct desc_ptr gdt_descr;
gdt_descr.address = (unsigned long)get_cpu_gdt_rw(0);
gdt_descr.size = GDT_SIZE - 1;
load_gdt(&gdt_descr);
load_cr3(save_pgd);
__flush_tlb_all();
}
void __init efi_runtime_update_mappings(void)
{
if (__supported_pte_mask & _PAGE_NX)
runtime_code_page_mkexec();
}