linux_dsm_epyc7002/arch/x86/include/asm/pgtable_32.h
Thomas Gleixner 945fd17ab6 x86/cpu_entry_area: Sync cpu_entry_area to initial_page_table
The separation of the cpu_entry_area from the fixmap missed the fact that
on 32bit non-PAE kernels the cpu_entry_area mapping might not be covered in
initial_page_table by the previous synchronizations.

This results in suspend/resume failures because 32bit utilizes initial page
table for resume. The absence of the cpu_entry_area mapping results in a
triple fault, aka. insta reboot.

With PAE enabled this works by chance because the PGD entry which covers
the fixmap and other parts incindentally provides the cpu_entry_area
mapping as well.

Synchronize the initial page table after setting up the cpu entry
area. Instead of adding yet another copy of the same code, move it to a
function and invoke it from the various places.

It needs to be investigated if the existing calls in setup_arch() and
setup_per_cpu_areas() can be replaced by the later invocation from
setup_cpu_entry_areas(), but that's beyond the scope of this fix.

Fixes: 92a0f81d89 ("x86/cpu_entry_area: Move it out of the fixmap")
Reported-by: Woody Suwalski <terraluna977@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Woody Suwalski <terraluna977@gmail.com>
Cc: William Grant <william.grant@canonical.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1802282137290.1392@nanos.tec.linutronix.de
2018-03-01 09:48:27 +01:00

112 lines
3.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_PGTABLE_32_H
#define _ASM_X86_PGTABLE_32_H
#include <asm/pgtable_32_types.h>
/*
* The Linux memory management assumes a three-level page table setup. On
* the i386, we use that, but "fold" the mid level into the top-level page
* table, so that we physically have the same two-level page table as the
* i386 mmu expects.
*
* This file contains the functions and defines necessary to modify and use
* the i386 page table tree.
*/
#ifndef __ASSEMBLY__
#include <asm/processor.h>
#include <linux/threads.h>
#include <asm/paravirt.h>
#include <linux/bitops.h>
#include <linux/list.h>
#include <linux/spinlock.h>
struct mm_struct;
struct vm_area_struct;
extern pgd_t swapper_pg_dir[1024];
extern pgd_t initial_page_table[1024];
extern pmd_t initial_pg_pmd[];
static inline void pgtable_cache_init(void) { }
static inline void check_pgt_cache(void) { }
void paging_init(void);
void sync_initial_page_table(void);
/*
* Define this if things work differently on an i386 and an i486:
* it will (on an i486) warn about kernel memory accesses that are
* done without a 'access_ok(VERIFY_WRITE,..)'
*/
#undef TEST_ACCESS_OK
#ifdef CONFIG_X86_PAE
# include <asm/pgtable-3level.h>
#else
# include <asm/pgtable-2level.h>
#endif
#if defined(CONFIG_HIGHPTE)
#define pte_offset_map(dir, address) \
((pte_t *)kmap_atomic(pmd_page(*(dir))) + \
pte_index((address)))
#define pte_unmap(pte) kunmap_atomic((pte))
#else
#define pte_offset_map(dir, address) \
((pte_t *)page_address(pmd_page(*(dir))) + pte_index((address)))
#define pte_unmap(pte) do { } while (0)
#endif
/* Clear a kernel PTE and flush it from the TLB */
#define kpte_clear_flush(ptep, vaddr) \
do { \
pte_clear(&init_mm, (vaddr), (ptep)); \
__flush_tlb_one_kernel((vaddr)); \
} while (0)
#endif /* !__ASSEMBLY__ */
/*
* kern_addr_valid() is (1) for FLATMEM and (0) for
* SPARSEMEM and DISCONTIGMEM
*/
#ifdef CONFIG_FLATMEM
#define kern_addr_valid(addr) (1)
#else
#define kern_addr_valid(kaddr) (0)
#endif
/*
* This is how much memory in addition to the memory covered up to
* and including _end we need mapped initially.
* We need:
* (KERNEL_IMAGE_SIZE/4096) / 1024 pages (worst case, non PAE)
* (KERNEL_IMAGE_SIZE/4096) / 512 + 4 pages (worst case for PAE)
*
* Modulo rounding, each megabyte assigned here requires a kilobyte of
* memory, which is currently unreclaimed.
*
* This should be a multiple of a page.
*
* KERNEL_IMAGE_SIZE should be greater than pa(_end)
* and small than max_low_pfn, otherwise will waste some page table entries
*/
#if PTRS_PER_PMD > 1
#define PAGE_TABLE_SIZE(pages) (((pages) / PTRS_PER_PMD) + PTRS_PER_PGD)
#else
#define PAGE_TABLE_SIZE(pages) ((pages) / PTRS_PER_PGD)
#endif
/*
* Number of possible pages in the lowmem region.
*
* We shift 2 by 31 instead of 1 by 32 to the left in order to avoid a
* gas warning about overflowing shift count when gas has been compiled
* with only a host target support using a 32-bit type for internal
* representation.
*/
#define LOWMEM_PAGES ((((2<<31) - __PAGE_OFFSET) >> PAGE_SHIFT))
#endif /* _ASM_X86_PGTABLE_32_H */