arm64: MMU fault handling and page table management
This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Catalin Marinas
Родитель
c1cc155261
Коммит
1d18c47c73
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@ -0,0 +1,67 @@
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/*
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* Based on arch/arm/include/asm/page.h
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*
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* Copyright (C) 1995-2003 Russell King
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* Copyright (C) 2012 ARM Ltd.
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*
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||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef __ASM_PAGE_H
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#define __ASM_PAGE_H
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/* PAGE_SHIFT determines the page size */
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#ifdef CONFIG_ARM64_64K_PAGES
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#define PAGE_SHIFT 16
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#else
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#define PAGE_SHIFT 12
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#endif
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#define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
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#define PAGE_MASK (~(PAGE_SIZE-1))
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/* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
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#define __HAVE_ARCH_GATE_AREA 1
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#ifndef __ASSEMBLY__
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#ifdef CONFIG_ARM64_64K_PAGES
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#include <asm/pgtable-2level-types.h>
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#else
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#include <asm/pgtable-3level-types.h>
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#endif
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extern void __cpu_clear_user_page(void *p, unsigned long user);
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extern void __cpu_copy_user_page(void *to, const void *from,
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unsigned long user);
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extern void copy_page(void *to, const void *from);
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extern void clear_page(void *to);
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#define clear_user_page(addr,vaddr,pg) __cpu_clear_user_page(addr, vaddr)
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#define copy_user_page(to,from,vaddr,pg) __cpu_copy_user_page(to, from, vaddr)
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typedef struct page *pgtable_t;
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#ifdef CONFIG_HAVE_ARCH_PFN_VALID
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extern int pfn_valid(unsigned long);
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#endif
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#include <asm/memory.h>
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#endif /* !__ASSEMBLY__ */
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#define VM_DATA_DEFAULT_FLAGS \
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(((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
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VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
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#include <asm-generic/getorder.h>
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#endif
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@ -0,0 +1,113 @@
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/*
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* Based on arch/arm/include/asm/pgalloc.h
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*
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* Copyright (C) 2000-2001 Russell King
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* Copyright (C) 2012 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
|
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* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
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*
|
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* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
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||||
* You should have received a copy of the GNU General Public License
|
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef __ASM_PGALLOC_H
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#define __ASM_PGALLOC_H
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#include <asm/pgtable-hwdef.h>
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#include <asm/processor.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#define check_pgt_cache() do { } while (0)
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#ifndef CONFIG_ARM64_64K_PAGES
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static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
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{
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return (pmd_t *)get_zeroed_page(GFP_KERNEL | __GFP_REPEAT);
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}
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static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
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{
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BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
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free_page((unsigned long)pmd);
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}
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static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
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{
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set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE));
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}
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#endif /* CONFIG_ARM64_64K_PAGES */
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extern pgd_t *pgd_alloc(struct mm_struct *mm);
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extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
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#define PGALLOC_GFP (GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO)
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static inline pte_t *
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pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr)
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{
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return (pte_t *)__get_free_page(PGALLOC_GFP);
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}
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static inline pgtable_t
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pte_alloc_one(struct mm_struct *mm, unsigned long addr)
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{
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struct page *pte;
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pte = alloc_pages(PGALLOC_GFP, 0);
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if (pte)
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pgtable_page_ctor(pte);
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return pte;
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}
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/*
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* Free a PTE table.
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*/
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static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
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{
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if (pte)
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free_page((unsigned long)pte);
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}
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static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
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{
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pgtable_page_dtor(pte);
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__free_page(pte);
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}
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static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte,
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pmdval_t prot)
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{
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set_pmd(pmdp, __pmd(pte | prot));
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}
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/*
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* Populate the pmdp entry with a pointer to the pte. This pmd is part
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* of the mm address space.
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*/
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static inline void
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pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
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{
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/*
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* The pmd must be loaded with the physical address of the PTE table
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*/
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__pmd_populate(pmdp, __pa(ptep), PMD_TYPE_TABLE);
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}
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static inline void
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pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
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||||
{
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__pmd_populate(pmdp, page_to_phys(ptep), PMD_TYPE_TABLE);
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}
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#define pmd_pgtable(pmd) pmd_page(pmd)
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#endif
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@ -0,0 +1,34 @@
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/*
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* Based on arch/arm/mm/copypage.c
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*
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* Copyright (C) 2002 Deep Blue Solutions Ltd, All Rights Reserved.
|
||||
* Copyright (C) 2012 ARM Ltd.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*/
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#include <linux/mm.h>
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#include <asm/page.h>
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#include <asm/cacheflush.h>
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void __cpu_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr)
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{
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copy_page(kto, kfrom);
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__flush_dcache_area(kto, PAGE_SIZE);
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}
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void __cpu_clear_user_page(void *kaddr, unsigned long vaddr)
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{
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clear_page(kaddr);
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}
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@ -0,0 +1,17 @@
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/*
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* Based on arch/arm/mm/extable.c
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*/
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#include <linux/module.h>
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#include <linux/uaccess.h>
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int fixup_exception(struct pt_regs *regs)
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{
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const struct exception_table_entry *fixup;
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fixup = search_exception_tables(instruction_pointer(regs));
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if (fixup)
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regs->pc = fixup->fixup;
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return fixup != NULL;
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}
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|
|
@ -0,0 +1,534 @@
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/*
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* Based on arch/arm/mm/fault.c
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*
|
||||
* Copyright (C) 1995 Linus Torvalds
|
||||
* Copyright (C) 1995-2004 Russell King
|
||||
* Copyright (C) 2012 ARM Ltd.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*/
|
||||
|
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#include <linux/module.h>
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#include <linux/signal.h>
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#include <linux/mm.h>
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#include <linux/hardirq.h>
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#include <linux/init.h>
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#include <linux/kprobes.h>
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#include <linux/uaccess.h>
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#include <linux/page-flags.h>
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#include <linux/sched.h>
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#include <linux/highmem.h>
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#include <linux/perf_event.h>
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#include <asm/exception.h>
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#include <asm/debug-monitors.h>
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#include <asm/system_misc.h>
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#include <asm/pgtable.h>
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#include <asm/tlbflush.h>
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/*
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* Dump out the page tables associated with 'addr' in mm 'mm'.
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*/
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void show_pte(struct mm_struct *mm, unsigned long addr)
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{
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pgd_t *pgd;
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if (!mm)
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mm = &init_mm;
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|
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pr_alert("pgd = %p\n", mm->pgd);
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pgd = pgd_offset(mm, addr);
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pr_alert("[%08lx] *pgd=%016llx", addr, pgd_val(*pgd));
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do {
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte;
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|
||||
if (pgd_none_or_clear_bad(pgd))
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||||
break;
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||||
|
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pud = pud_offset(pgd, addr);
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||||
if (pud_none_or_clear_bad(pud))
|
||||
break;
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||||
|
||||
pmd = pmd_offset(pud, addr);
|
||||
printk(", *pmd=%016llx", pmd_val(*pmd));
|
||||
if (pmd_none_or_clear_bad(pmd))
|
||||
break;
|
||||
|
||||
pte = pte_offset_map(pmd, addr);
|
||||
printk(", *pte=%016llx", pte_val(*pte));
|
||||
pte_unmap(pte);
|
||||
} while(0);
|
||||
|
||||
printk("\n");
|
||||
}
|
||||
|
||||
/*
|
||||
* The kernel tried to access some page that wasn't present.
|
||||
*/
|
||||
static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr,
|
||||
unsigned int esr, struct pt_regs *regs)
|
||||
{
|
||||
/*
|
||||
* Are we prepared to handle this kernel fault?
|
||||
*/
|
||||
if (fixup_exception(regs))
|
||||
return;
|
||||
|
||||
/*
|
||||
* No handler, we'll have to terminate things with extreme prejudice.
|
||||
*/
|
||||
bust_spinlocks(1);
|
||||
pr_alert("Unable to handle kernel %s at virtual address %08lx\n",
|
||||
(addr < PAGE_SIZE) ? "NULL pointer dereference" :
|
||||
"paging request", addr);
|
||||
|
||||
show_pte(mm, addr);
|
||||
die("Oops", regs, esr);
|
||||
bust_spinlocks(0);
|
||||
do_exit(SIGKILL);
|
||||
}
|
||||
|
||||
/*
|
||||
* Something tried to access memory that isn't in our memory map. User mode
|
||||
* accesses just cause a SIGSEGV
|
||||
*/
|
||||
static void __do_user_fault(struct task_struct *tsk, unsigned long addr,
|
||||
unsigned int esr, unsigned int sig, int code,
|
||||
struct pt_regs *regs)
|
||||
{
|
||||
struct siginfo si;
|
||||
|
||||
if (show_unhandled_signals) {
|
||||
pr_info("%s[%d]: unhandled page fault (%d) at 0x%08lx, code 0x%03x\n",
|
||||
tsk->comm, task_pid_nr(tsk), sig, addr, esr);
|
||||
show_pte(tsk->mm, addr);
|
||||
show_regs(regs);
|
||||
}
|
||||
|
||||
tsk->thread.fault_address = addr;
|
||||
si.si_signo = sig;
|
||||
si.si_errno = 0;
|
||||
si.si_code = code;
|
||||
si.si_addr = (void __user *)addr;
|
||||
force_sig_info(sig, &si, tsk);
|
||||
}
|
||||
|
||||
void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
|
||||
{
|
||||
struct task_struct *tsk = current;
|
||||
struct mm_struct *mm = tsk->active_mm;
|
||||
|
||||
/*
|
||||
* If we are in kernel mode at this point, we have no context to
|
||||
* handle this fault with.
|
||||
*/
|
||||
if (user_mode(regs))
|
||||
__do_user_fault(tsk, addr, esr, SIGSEGV, SEGV_MAPERR, regs);
|
||||
else
|
||||
__do_kernel_fault(mm, addr, esr, regs);
|
||||
}
|
||||
|
||||
#define VM_FAULT_BADMAP 0x010000
|
||||
#define VM_FAULT_BADACCESS 0x020000
|
||||
|
||||
#define ESR_WRITE (1 << 6)
|
||||
#define ESR_LNX_EXEC (1 << 24)
|
||||
|
||||
/*
|
||||
* Check that the permissions on the VMA allow for the fault which occurred.
|
||||
* If we encountered a write fault, we must have write permission, otherwise
|
||||
* we allow any permission.
|
||||
*/
|
||||
static inline bool access_error(unsigned int esr, struct vm_area_struct *vma)
|
||||
{
|
||||
unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
|
||||
|
||||
if (esr & ESR_WRITE)
|
||||
mask = VM_WRITE;
|
||||
if (esr & ESR_LNX_EXEC)
|
||||
mask = VM_EXEC;
|
||||
|
||||
return vma->vm_flags & mask ? false : true;
|
||||
}
|
||||
|
||||
static int __do_page_fault(struct mm_struct *mm, unsigned long addr,
|
||||
unsigned int esr, unsigned int flags,
|
||||
struct task_struct *tsk)
|
||||
{
|
||||
struct vm_area_struct *vma;
|
||||
int fault;
|
||||
|
||||
vma = find_vma(mm, addr);
|
||||
fault = VM_FAULT_BADMAP;
|
||||
if (unlikely(!vma))
|
||||
goto out;
|
||||
if (unlikely(vma->vm_start > addr))
|
||||
goto check_stack;
|
||||
|
||||
/*
|
||||
* Ok, we have a good vm_area for this memory access, so we can handle
|
||||
* it.
|
||||
*/
|
||||
good_area:
|
||||
if (access_error(esr, vma)) {
|
||||
fault = VM_FAULT_BADACCESS;
|
||||
goto out;
|
||||
}
|
||||
|
||||
return handle_mm_fault(mm, vma, addr & PAGE_MASK, flags);
|
||||
|
||||
check_stack:
|
||||
if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
|
||||
goto good_area;
|
||||
out:
|
||||
return fault;
|
||||
}
|
||||
|
||||
static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
|
||||
struct pt_regs *regs)
|
||||
{
|
||||
struct task_struct *tsk;
|
||||
struct mm_struct *mm;
|
||||
int fault, sig, code;
|
||||
int write = esr & ESR_WRITE;
|
||||
unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
|
||||
(write ? FAULT_FLAG_WRITE : 0);
|
||||
|
||||
tsk = current;
|
||||
mm = tsk->mm;
|
||||
|
||||
/* Enable interrupts if they were enabled in the parent context. */
|
||||
if (interrupts_enabled(regs))
|
||||
local_irq_enable();
|
||||
|
||||
/*
|
||||
* If we're in an interrupt or have no user context, we must not take
|
||||
* the fault.
|
||||
*/
|
||||
if (in_atomic() || !mm)
|
||||
goto no_context;
|
||||
|
||||
/*
|
||||
* As per x86, we may deadlock here. However, since the kernel only
|
||||
* validly references user space from well defined areas of the code,
|
||||
* we can bug out early if this is from code which shouldn't.
|
||||
*/
|
||||
if (!down_read_trylock(&mm->mmap_sem)) {
|
||||
if (!user_mode(regs) && !search_exception_tables(regs->pc))
|
||||
goto no_context;
|
||||
retry:
|
||||
down_read(&mm->mmap_sem);
|
||||
} else {
|
||||
/*
|
||||
* The above down_read_trylock() might have succeeded in which
|
||||
* case, we'll have missed the might_sleep() from down_read().
|
||||
*/
|
||||
might_sleep();
|
||||
#ifdef CONFIG_DEBUG_VM
|
||||
if (!user_mode(regs) && !search_exception_tables(regs->pc))
|
||||
goto no_context;
|
||||
#endif
|
||||
}
|
||||
|
||||
fault = __do_page_fault(mm, addr, esr, flags, tsk);
|
||||
|
||||
/*
|
||||
* If we need to retry but a fatal signal is pending, handle the
|
||||
* signal first. We do not need to release the mmap_sem because it
|
||||
* would already be released in __lock_page_or_retry in mm/filemap.c.
|
||||
*/
|
||||
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
|
||||
return 0;
|
||||
|
||||
/*
|
||||
* Major/minor page fault accounting is only done on the initial
|
||||
* attempt. If we go through a retry, it is extremely likely that the
|
||||
* page will be found in page cache at that point.
|
||||
*/
|
||||
|
||||
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
|
||||
if (flags & FAULT_FLAG_ALLOW_RETRY) {
|
||||
if (fault & VM_FAULT_MAJOR) {
|
||||
tsk->maj_flt++;
|
||||
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs,
|
||||
addr);
|
||||
} else {
|
||||
tsk->min_flt++;
|
||||
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs,
|
||||
addr);
|
||||
}
|
||||
if (fault & VM_FAULT_RETRY) {
|
||||
/*
|
||||
* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of
|
||||
* starvation.
|
||||
*/
|
||||
flags &= ~FAULT_FLAG_ALLOW_RETRY;
|
||||
goto retry;
|
||||
}
|
||||
}
|
||||
|
||||
up_read(&mm->mmap_sem);
|
||||
|
||||
/*
|
||||
* Handle the "normal" case first - VM_FAULT_MAJOR / VM_FAULT_MINOR
|
||||
*/
|
||||
if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP |
|
||||
VM_FAULT_BADACCESS))))
|
||||
return 0;
|
||||
|
||||
if (fault & VM_FAULT_OOM) {
|
||||
/*
|
||||
* We ran out of memory, call the OOM killer, and return to
|
||||
* userspace (which will retry the fault, or kill us if we got
|
||||
* oom-killed).
|
||||
*/
|
||||
pagefault_out_of_memory();
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* If we are in kernel mode at this point, we have no context to
|
||||
* handle this fault with.
|
||||
*/
|
||||
if (!user_mode(regs))
|
||||
goto no_context;
|
||||
|
||||
if (fault & VM_FAULT_SIGBUS) {
|
||||
/*
|
||||
* We had some memory, but were unable to successfully fix up
|
||||
* this page fault.
|
||||
*/
|
||||
sig = SIGBUS;
|
||||
code = BUS_ADRERR;
|
||||
} else {
|
||||
/*
|
||||
* Something tried to access memory that isn't in our memory
|
||||
* map.
|
||||
*/
|
||||
sig = SIGSEGV;
|
||||
code = fault == VM_FAULT_BADACCESS ?
|
||||
SEGV_ACCERR : SEGV_MAPERR;
|
||||
}
|
||||
|
||||
__do_user_fault(tsk, addr, esr, sig, code, regs);
|
||||
return 0;
|
||||
|
||||
no_context:
|
||||
__do_kernel_fault(mm, addr, esr, regs);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* First Level Translation Fault Handler
|
||||
*
|
||||
* We enter here because the first level page table doesn't contain a valid
|
||||
* entry for the address.
|
||||
*
|
||||
* If the address is in kernel space (>= TASK_SIZE), then we are probably
|
||||
* faulting in the vmalloc() area.
|
||||
*
|
||||
* If the init_task's first level page tables contains the relevant entry, we
|
||||
* copy the it to this task. If not, we send the process a signal, fixup the
|
||||
* exception, or oops the kernel.
|
||||
*
|
||||
* NOTE! We MUST NOT take any locks for this case. We may be in an interrupt
|
||||
* or a critical region, and should only copy the information from the master
|
||||
* page table, nothing more.
|
||||
*/
|
||||
static int __kprobes do_translation_fault(unsigned long addr,
|
||||
unsigned int esr,
|
||||
struct pt_regs *regs)
|
||||
{
|
||||
if (addr < TASK_SIZE)
|
||||
return do_page_fault(addr, esr, regs);
|
||||
|
||||
do_bad_area(addr, esr, regs);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Some section permission faults need to be handled gracefully. They can
|
||||
* happen due to a __{get,put}_user during an oops.
|
||||
*/
|
||||
static int do_sect_fault(unsigned long addr, unsigned int esr,
|
||||
struct pt_regs *regs)
|
||||
{
|
||||
do_bad_area(addr, esr, regs);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* This abort handler always returns "fault".
|
||||
*/
|
||||
static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs)
|
||||
{
|
||||
return 1;
|
||||
}
|
||||
|
||||
static struct fault_info {
|
||||
int (*fn)(unsigned long addr, unsigned int esr, struct pt_regs *regs);
|
||||
int sig;
|
||||
int code;
|
||||
const char *name;
|
||||
} fault_info[] = {
|
||||
{ do_bad, SIGBUS, 0, "ttbr address size fault" },
|
||||
{ do_bad, SIGBUS, 0, "level 1 address size fault" },
|
||||
{ do_bad, SIGBUS, 0, "level 2 address size fault" },
|
||||
{ do_bad, SIGBUS, 0, "level 3 address size fault" },
|
||||
{ do_translation_fault, SIGSEGV, SEGV_MAPERR, "input address range fault" },
|
||||
{ do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" },
|
||||
{ do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" },
|
||||
{ do_page_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" },
|
||||
{ do_bad, SIGBUS, 0, "reserved access flag fault" },
|
||||
{ do_bad, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" },
|
||||
{ do_bad, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
|
||||
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" },
|
||||
{ do_bad, SIGBUS, 0, "reserved permission fault" },
|
||||
{ do_bad, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" },
|
||||
{ do_sect_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
|
||||
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" },
|
||||
{ do_bad, SIGBUS, 0, "synchronous external abort" },
|
||||
{ do_bad, SIGBUS, 0, "asynchronous external abort" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 18" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 19" },
|
||||
{ do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
|
||||
{ do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
|
||||
{ do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
|
||||
{ do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
|
||||
{ do_bad, SIGBUS, 0, "synchronous parity error" },
|
||||
{ do_bad, SIGBUS, 0, "asynchronous parity error" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 26" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 27" },
|
||||
{ do_bad, SIGBUS, 0, "synchronous parity error (translation table walk" },
|
||||
{ do_bad, SIGBUS, 0, "synchronous parity error (translation table walk" },
|
||||
{ do_bad, SIGBUS, 0, "synchronous parity error (translation table walk" },
|
||||
{ do_bad, SIGBUS, 0, "synchronous parity error (translation table walk" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 32" },
|
||||
{ do_bad, SIGBUS, BUS_ADRALN, "alignment fault" },
|
||||
{ do_bad, SIGBUS, 0, "debug event" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 35" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 36" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 37" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 38" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 39" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 40" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 41" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 42" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 43" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 44" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 45" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 46" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 47" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 48" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 49" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 50" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 51" },
|
||||
{ do_bad, SIGBUS, 0, "implementation fault (lockdown abort)" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 53" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 54" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 55" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 56" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 57" },
|
||||
{ do_bad, SIGBUS, 0, "implementation fault (coprocessor abort)" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 59" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 60" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 61" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 62" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 63" },
|
||||
};
|
||||
|
||||
/*
|
||||
* Dispatch a data abort to the relevant handler.
|
||||
*/
|
||||
asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr,
|
||||
struct pt_regs *regs)
|
||||
{
|
||||
const struct fault_info *inf = fault_info + (esr & 63);
|
||||
struct siginfo info;
|
||||
|
||||
if (!inf->fn(addr, esr, regs))
|
||||
return;
|
||||
|
||||
pr_alert("Unhandled fault: %s (0x%08x) at 0x%016lx\n",
|
||||
inf->name, esr, addr);
|
||||
|
||||
info.si_signo = inf->sig;
|
||||
info.si_errno = 0;
|
||||
info.si_code = inf->code;
|
||||
info.si_addr = (void __user *)addr;
|
||||
arm64_notify_die("", regs, &info, esr);
|
||||
}
|
||||
|
||||
/*
|
||||
* Handle stack alignment exceptions.
|
||||
*/
|
||||
asmlinkage void __exception do_sp_pc_abort(unsigned long addr,
|
||||
unsigned int esr,
|
||||
struct pt_regs *regs)
|
||||
{
|
||||
struct siginfo info;
|
||||
|
||||
info.si_signo = SIGBUS;
|
||||
info.si_errno = 0;
|
||||
info.si_code = BUS_ADRALN;
|
||||
info.si_addr = (void __user *)addr;
|
||||
arm64_notify_die("", regs, &info, esr);
|
||||
}
|
||||
|
||||
static struct fault_info debug_fault_info[] = {
|
||||
{ do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" },
|
||||
{ do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" },
|
||||
{ do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 3" },
|
||||
{ do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" },
|
||||
{ do_bad, SIGTRAP, 0, "aarch32 vector catch" },
|
||||
{ do_bad, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" },
|
||||
{ do_bad, SIGBUS, 0, "unknown 7" },
|
||||
};
|
||||
|
||||
void __init hook_debug_fault_code(int nr,
|
||||
int (*fn)(unsigned long, unsigned int, struct pt_regs *),
|
||||
int sig, int code, const char *name)
|
||||
{
|
||||
BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info));
|
||||
|
||||
debug_fault_info[nr].fn = fn;
|
||||
debug_fault_info[nr].sig = sig;
|
||||
debug_fault_info[nr].code = code;
|
||||
debug_fault_info[nr].name = name;
|
||||
}
|
||||
|
||||
asmlinkage int __exception do_debug_exception(unsigned long addr,
|
||||
unsigned int esr,
|
||||
struct pt_regs *regs)
|
||||
{
|
||||
const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr);
|
||||
struct siginfo info;
|
||||
|
||||
if (!inf->fn(addr, esr, regs))
|
||||
return 1;
|
||||
|
||||
pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n",
|
||||
inf->name, esr, addr);
|
||||
|
||||
info.si_signo = inf->sig;
|
||||
info.si_errno = 0;
|
||||
info.si_code = inf->code;
|
||||
info.si_addr = (void __user *)addr;
|
||||
arm64_notify_die("", regs, &info, esr);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -0,0 +1,2 @@
|
|||
extern void __flush_dcache_page(struct page *page);
|
||||
extern void __init bootmem_init(void);
|
||||
|
|
@ -0,0 +1,144 @@
|
|||
/*
|
||||
* Based on arch/arm/mm/mmap.c
|
||||
*
|
||||
* Copyright (C) 2012 ARM Ltd.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*/
|
||||
|
||||
#include <linux/elf.h>
|
||||
#include <linux/fs.h>
|
||||
#include <linux/mm.h>
|
||||
#include <linux/mman.h>
|
||||
#include <linux/export.h>
|
||||
#include <linux/shm.h>
|
||||
#include <linux/sched.h>
|
||||
#include <linux/io.h>
|
||||
#include <linux/personality.h>
|
||||
#include <linux/random.h>
|
||||
|
||||
#include <asm/cputype.h>
|
||||
|
||||
/*
|
||||
* Leave enough space between the mmap area and the stack to honour ulimit in
|
||||
* the face of randomisation.
|
||||
*/
|
||||
#define MIN_GAP (SZ_128M + ((STACK_RND_MASK << PAGE_SHIFT) + 1))
|
||||
#define MAX_GAP (STACK_TOP/6*5)
|
||||
|
||||
static int mmap_is_legacy(void)
|
||||
{
|
||||
if (current->personality & ADDR_COMPAT_LAYOUT)
|
||||
return 1;
|
||||
|
||||
if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
|
||||
return 1;
|
||||
|
||||
return sysctl_legacy_va_layout;
|
||||
}
|
||||
|
||||
/*
|
||||
* Since get_random_int() returns the same value within a 1 jiffy window, we
|
||||
* will almost always get the same randomisation for the stack and mmap
|
||||
* region. This will mean the relative distance between stack and mmap will be
|
||||
* the same.
|
||||
*
|
||||
* To avoid this we can shift the randomness by 1 bit.
|
||||
*/
|
||||
static unsigned long mmap_rnd(void)
|
||||
{
|
||||
unsigned long rnd = 0;
|
||||
|
||||
if (current->flags & PF_RANDOMIZE)
|
||||
rnd = (long)get_random_int() & (STACK_RND_MASK >> 1);
|
||||
|
||||
return rnd << (PAGE_SHIFT + 1);
|
||||
}
|
||||
|
||||
static unsigned long mmap_base(void)
|
||||
{
|
||||
unsigned long gap = rlimit(RLIMIT_STACK);
|
||||
|
||||
if (gap < MIN_GAP)
|
||||
gap = MIN_GAP;
|
||||
else if (gap > MAX_GAP)
|
||||
gap = MAX_GAP;
|
||||
|
||||
return PAGE_ALIGN(STACK_TOP - gap - mmap_rnd());
|
||||
}
|
||||
|
||||
/*
|
||||
* This function, called very early during the creation of a new process VM
|
||||
* image, sets up which VM layout function to use:
|
||||
*/
|
||||
void arch_pick_mmap_layout(struct mm_struct *mm)
|
||||
{
|
||||
/*
|
||||
* Fall back to the standard layout if the personality bit is set, or
|
||||
* if the expected stack growth is unlimited:
|
||||
*/
|
||||
if (mmap_is_legacy()) {
|
||||
mm->mmap_base = TASK_UNMAPPED_BASE;
|
||||
mm->get_unmapped_area = arch_get_unmapped_area;
|
||||
mm->unmap_area = arch_unmap_area;
|
||||
} else {
|
||||
mm->mmap_base = mmap_base();
|
||||
mm->get_unmapped_area = arch_get_unmapped_area_topdown;
|
||||
mm->unmap_area = arch_unmap_area_topdown;
|
||||
}
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(arch_pick_mmap_layout);
|
||||
|
||||
|
||||
/*
|
||||
* You really shouldn't be using read() or write() on /dev/mem. This might go
|
||||
* away in the future.
|
||||
*/
|
||||
int valid_phys_addr_range(unsigned long addr, size_t size)
|
||||
{
|
||||
if (addr < PHYS_OFFSET)
|
||||
return 0;
|
||||
if (addr + size > __pa(high_memory - 1) + 1)
|
||||
return 0;
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
/*
|
||||
* Do not allow /dev/mem mappings beyond the supported physical range.
|
||||
*/
|
||||
int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
|
||||
{
|
||||
return !(((pfn << PAGE_SHIFT) + size) & ~PHYS_MASK);
|
||||
}
|
||||
|
||||
#ifdef CONFIG_STRICT_DEVMEM
|
||||
|
||||
#include <linux/ioport.h>
|
||||
|
||||
/*
|
||||
* devmem_is_allowed() checks to see if /dev/mem access to a certain address
|
||||
* is valid. The argument is a physical page number. We mimic x86 here by
|
||||
* disallowing access to system RAM as well as device-exclusive MMIO regions.
|
||||
* This effectively disable read()/write() on /dev/mem.
|
||||
*/
|
||||
int devmem_is_allowed(unsigned long pfn)
|
||||
{
|
||||
if (iomem_is_exclusive(pfn << PAGE_SHIFT))
|
||||
return 0;
|
||||
if (!page_is_ram(pfn))
|
||||
return 1;
|
||||
return 0;
|
||||
}
|
||||
|
||||
#endif
|
||||
|
|
@ -0,0 +1,54 @@
|
|||
/*
|
||||
* PGD allocation/freeing
|
||||
*
|
||||
* Copyright (C) 2012 ARM Ltd.
|
||||
* Author: Catalin Marinas <catalin.marinas@arm.com>
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*/
|
||||
|
||||
#include <linux/mm.h>
|
||||
#include <linux/gfp.h>
|
||||
#include <linux/highmem.h>
|
||||
#include <linux/slab.h>
|
||||
|
||||
#include <asm/pgalloc.h>
|
||||
#include <asm/page.h>
|
||||
#include <asm/tlbflush.h>
|
||||
|
||||
#include "mm.h"
|
||||
|
||||
#define PGD_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
|
||||
|
||||
pgd_t *pgd_alloc(struct mm_struct *mm)
|
||||
{
|
||||
pgd_t *new_pgd;
|
||||
|
||||
if (PGD_SIZE == PAGE_SIZE)
|
||||
new_pgd = (pgd_t *)get_zeroed_page(GFP_KERNEL);
|
||||
else
|
||||
new_pgd = kzalloc(PGD_SIZE, GFP_KERNEL);
|
||||
|
||||
if (!new_pgd)
|
||||
return NULL;
|
||||
|
||||
return new_pgd;
|
||||
}
|
||||
|
||||
void pgd_free(struct mm_struct *mm, pgd_t *pgd)
|
||||
{
|
||||
if (PGD_SIZE == PAGE_SIZE)
|
||||
free_page((unsigned long)pgd);
|
||||
else
|
||||
kfree(pgd);
|
||||
}
|
||||
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