cf40361ede
Commiteeb89e2bb1("x86/efi: Load fixmap GDT in efi_call_phys_epilog()") moved loading the fixmap in efi_call_phys_epilog() after load_cr3() since it was assumed to be more logical. Turns out this is incorrect: In efi_call_phys_prolog(), the gdt with its physical address is loaded first, and when the %cr3 is reloaded in _epilog from initial_page_table to swapper_pg_dir again the gdt is no longer mapped. This results in a triple fault if an interrupt occurs after load_cr3() and before load_fixmap_gdt(0). Calling load_fixmap_gdt(0) first restores the execution order prior to commiteeb89e2bb1and fixes the problem. Fixes:eeb89e2bb1("x86/efi: Load fixmap GDT in efi_call_phys_epilog()") Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: linux-efi@vger.kernel.org Cc: Andy Lutomirski <luto@amacapital.net> Cc: Joerg Roedel <jroedel@suse.de> Link: https://lkml.kernel.org/r/1536689892-21538-1-git-send-email-linux@roeck-us.net
98 lines
2.3 KiB
C
98 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* 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)
|
|
{
|
|
#ifdef CONFIG_EFI_PGT_DUMP
|
|
ptdump_walk_pgd_level(NULL, swapper_pg_dir);
|
|
#endif
|
|
}
|
|
|
|
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)
|
|
{
|
|
load_fixmap_gdt(0);
|
|
load_cr3(save_pgd);
|
|
__flush_tlb_all();
|
|
}
|
|
|
|
void __init efi_runtime_update_mappings(void)
|
|
{
|
|
if (__supported_pte_mask & _PAGE_NX)
|
|
runtime_code_page_mkexec();
|
|
}
|