![Rafael J. Wysocki](/assets/img/avatar_default.png)
Impact: fix crash during hibernation on 32-bit NUMA The NUMA code on x86_32 creates special memory mapping that allows each node's pgdat to be located in this node's memory. For this purpose it allocates a memory area at the end of each node's memory and maps this area so that it is accessible with virtual addresses belonging to low memory. As a result, if there is high memory, these NUMA-allocated areas are physically located in high memory, although they are mapped to low memory addresses. Our hibernation code does not take that into account and for this reason hibernation fails on all x86_32 systems with CONFIG_NUMA=y and with high memory present. Fix this by adding a special mapping for the NUMA-allocated memory areas to the temporary page tables created during the last phase of resume. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
176 lines
3.9 KiB
C
176 lines
3.9 KiB
C
/*
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* Hibernation support specific for i386 - temporary page tables
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*
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* Distribute under GPLv2
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*
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* Copyright (c) 2006 Rafael J. Wysocki <rjw@sisk.pl>
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*/
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#include <linux/suspend.h>
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#include <linux/bootmem.h>
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#include <asm/system.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/mmzone.h>
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/* Defined in hibernate_asm_32.S */
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extern int restore_image(void);
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/* References to section boundaries */
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extern const void __nosave_begin, __nosave_end;
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/* Pointer to the temporary resume page tables */
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pgd_t *resume_pg_dir;
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/* The following three functions are based on the analogous code in
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* arch/x86/mm/init_32.c
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*/
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/*
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* Create a middle page table on a resume-safe page and put a pointer to it in
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* the given global directory entry. This only returns the gd entry
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* in non-PAE compilation mode, since the middle layer is folded.
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*/
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static pmd_t *resume_one_md_table_init(pgd_t *pgd)
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{
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pud_t *pud;
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pmd_t *pmd_table;
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#ifdef CONFIG_X86_PAE
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pmd_table = (pmd_t *)get_safe_page(GFP_ATOMIC);
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if (!pmd_table)
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return NULL;
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set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
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pud = pud_offset(pgd, 0);
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BUG_ON(pmd_table != pmd_offset(pud, 0));
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#else
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pud = pud_offset(pgd, 0);
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pmd_table = pmd_offset(pud, 0);
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#endif
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return pmd_table;
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}
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/*
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* Create a page table on a resume-safe page and place a pointer to it in
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* a middle page directory entry.
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*/
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static pte_t *resume_one_page_table_init(pmd_t *pmd)
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{
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if (pmd_none(*pmd)) {
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pte_t *page_table = (pte_t *)get_safe_page(GFP_ATOMIC);
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if (!page_table)
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return NULL;
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set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
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BUG_ON(page_table != pte_offset_kernel(pmd, 0));
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return page_table;
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}
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return pte_offset_kernel(pmd, 0);
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}
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/*
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* This maps the physical memory to kernel virtual address space, a total
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* of max_low_pfn pages, by creating page tables starting from address
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* PAGE_OFFSET. The page tables are allocated out of resume-safe pages.
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*/
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static int resume_physical_mapping_init(pgd_t *pgd_base)
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{
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unsigned long pfn;
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pgd_t *pgd;
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pmd_t *pmd;
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pte_t *pte;
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int pgd_idx, pmd_idx;
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pgd_idx = pgd_index(PAGE_OFFSET);
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pgd = pgd_base + pgd_idx;
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pfn = 0;
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for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
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pmd = resume_one_md_table_init(pgd);
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if (!pmd)
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return -ENOMEM;
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if (pfn >= max_low_pfn)
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continue;
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for (pmd_idx = 0; pmd_idx < PTRS_PER_PMD; pmd++, pmd_idx++) {
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if (pfn >= max_low_pfn)
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break;
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/* Map with big pages if possible, otherwise create
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* normal page tables.
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* NOTE: We can mark everything as executable here
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*/
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if (cpu_has_pse) {
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set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE_EXEC));
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pfn += PTRS_PER_PTE;
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} else {
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pte_t *max_pte;
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pte = resume_one_page_table_init(pmd);
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if (!pte)
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return -ENOMEM;
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max_pte = pte + PTRS_PER_PTE;
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for (; pte < max_pte; pte++, pfn++) {
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if (pfn >= max_low_pfn)
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break;
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set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC));
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}
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}
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}
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}
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resume_map_numa_kva(pgd_base);
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return 0;
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}
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static inline void resume_init_first_level_page_table(pgd_t *pg_dir)
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{
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#ifdef CONFIG_X86_PAE
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int i;
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/* Init entries of the first-level page table to the zero page */
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for (i = 0; i < PTRS_PER_PGD; i++)
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set_pgd(pg_dir + i,
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__pgd(__pa(empty_zero_page) | _PAGE_PRESENT));
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#endif
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}
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int swsusp_arch_resume(void)
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{
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int error;
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resume_pg_dir = (pgd_t *)get_safe_page(GFP_ATOMIC);
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if (!resume_pg_dir)
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return -ENOMEM;
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resume_init_first_level_page_table(resume_pg_dir);
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error = resume_physical_mapping_init(resume_pg_dir);
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if (error)
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return error;
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/* We have got enough memory and from now on we cannot recover */
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restore_image();
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return 0;
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}
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/*
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* pfn_is_nosave - check if given pfn is in the 'nosave' section
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*/
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int pfn_is_nosave(unsigned long pfn)
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{
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unsigned long nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT;
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unsigned long nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;
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return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
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}
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