Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753335AbaDRMnd (ORCPT ); Fri, 18 Apr 2014 08:43:33 -0400 Received: from mail-bn1blp0186.outbound.protection.outlook.com ([207.46.163.186]:47996 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753240AbaDRMn2 (ORCPT ); Fri, 18 Apr 2014 08:43:28 -0400 From: Ley Foon Tan To: , , CC: Ley Foon Tan , , Subject: [PATCH 06/28] nios2: Memory management Date: Fri, 18 Apr 2014 20:26:51 +0800 Message-ID: <1397824031-4892-5-git-send-email-lftan@altera.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1397824031-4892-1-git-send-email-lftan@altera.com> References: <1397824031-4892-1-git-send-email-lftan@altera.com> MIME-Version: 1.0 Content-Type: text/plain X-EOPAttributedMessage: 0 X-Forefront-Antispam-Report: CIP:66.35.236.232;CTRY:US;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(10019001)(6009001)(458001)(199002)(189002)(22564002)(76176999)(99396002)(6806004)(50986999)(80022001)(87286001)(93916002)(88136002)(86362001)(575784001)(50466002)(19580405001)(62966002)(2201001)(92566001)(92726001)(77982001)(2009001)(47776003)(20776003)(80976001)(44976005)(48376002)(83322001)(19580395003)(84676001)(81542001)(97736001)(76482001)(81342001)(77156001)(83072002)(85852003)(42186004)(36756003)(4396001)(87936001)(89996001)(50226001)(46102001)(16796002)(74502001)(31966008)(74662001)(21314002);DIR:OUT;SFP:1102;SCL:1;SRVR:BL2FFO11HUB029;H:SJ-ITEXEDGE02.altera.priv.altera.com;FPR:FEADDC58.A0CEDFCC.80F9518F.C317BC7B.20A5E;MLV:sfv;PTR:InfoDomainNonexistent;A:1;MX:1;LANG:en; X-OriginatorOrg: altera.onmicrosoft.com X-Forefront-PRVS: 018577E36E Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch contains the initialisation of the memory blocks, MMU attributes and the memory map. Signed-off-by: Ley Foon Tan --- arch/nios2/include/asm/mmu.h | 18 +++ arch/nios2/include/asm/page.h | 111 +++++++++++++++++++ arch/nios2/include/asm/uaccess.h | 233 +++++++++++++++++++++++++++++++++++++++ arch/nios2/mm/init.c | 152 +++++++++++++++++++++++++ arch/nios2/mm/uaccess.c | 162 +++++++++++++++++++++++++++ 5 files changed, 676 insertions(+) create mode 100644 arch/nios2/include/asm/mmu.h create mode 100644 arch/nios2/include/asm/page.h create mode 100644 arch/nios2/include/asm/uaccess.h create mode 100644 arch/nios2/mm/init.c create mode 100644 arch/nios2/mm/uaccess.c diff --git a/arch/nios2/include/asm/mmu.h b/arch/nios2/include/asm/mmu.h new file mode 100644 index 0000000..96ab052 --- /dev/null +++ b/arch/nios2/include/asm/mmu.h @@ -0,0 +1,18 @@ +/* + * Copyright (C) 2010 Tobias Klauser + * Copyright (C) 2004 Microtronix Datacom Ltd. + * + * Taken from m68knommu. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#ifndef _ASM_NIOS2_MMU_H +#define _ASM_NIOS2_MMU_H + +/* Default "unsigned long" context */ +typedef unsigned long mm_context_t; + +#endif /* _ASM_NIOS2_MMU_H */ diff --git a/arch/nios2/include/asm/page.h b/arch/nios2/include/asm/page.h new file mode 100644 index 0000000..4f25e0fe6cb9666a713dd2738871915f73f9a1d7 --- /dev/null +++ b/arch/nios2/include/asm/page.h @@ -0,0 +1,111 @@ +/* + * Copyright (C) 2011 Tobias Klauser + * Copyright (C) 2004 Microtronix Datacom Ltd. + * + * MMU support based on asm/page.h from mips which is: + * + * Copyright (C) 1994 - 1999, 2000, 03 Ralf Baechle + * Copyright (C) 1999, 2000 Silicon Graphics, Inc. + * + * NOMMU support based on asm/page.h from m68knommu. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#ifndef _ASM_NIOS2_PAGE_H +#define _ASM_NIOS2_PAGE_H + +#include + +/* + * PAGE_SHIFT determines the page size + */ +#define PAGE_SHIFT 12 +#define PAGE_SIZE 4096 +#define PAGE_MASK (~(PAGE_SIZE - 1)) + +/* + * PAGE_OFFSET -- the first address of the first page of memory. + */ +#define PAGE_OFFSET (CONFIG_MEM_BASE + CONFIG_KERNEL_REGION_BASE) + +#ifndef __ASSEMBLY__ + +/* + * This gives the physical RAM offset. + */ +#define PHYS_OFFSET CONFIG_MEM_BASE + +/* + * It's normally defined only for FLATMEM config but it's + * used in our early mem init code for all memory models. + * So always define it. + */ +#define ARCH_PFN_OFFSET PFN_UP(PHYS_OFFSET) + +#define clear_page(page) memset((page), 0, PAGE_SIZE) +#define copy_page(to, from) memcpy((to), (from), PAGE_SIZE) + +struct page; + +extern void clear_user_page(void *addr, unsigned long vaddr, struct page *page); +extern void copy_user_page(void *vto, void *vfrom, unsigned long vaddr, + struct page *to); + +extern unsigned long shm_align_mask; + +/* + * These are used to make use of C type-checking. + */ +typedef struct page *pgtable_t; +typedef struct { unsigned long pte; } pte_t; +typedef struct { unsigned long pgd; } pgd_t; +typedef struct { unsigned long pgprot; } pgprot_t; + +#define pte_val(x) ((x).pte) +#define pgd_val(x) ((x).pgd) +#define pgprot_val(x) ((x).pgprot) + +#define __pte(x) ((pte_t) { (x) }) +#define __pgd(x) ((pgd_t) { (x) }) +#define __pgprot(x) ((pgprot_t) { (x) }) + +extern unsigned long memory_start; +extern unsigned long memory_end; +extern unsigned long memory_size; + +extern struct page *mem_map; + +#endif /* !__ASSEMBLY__ */ + +# define __pa(x) \ + ((unsigned long)(x) - PAGE_OFFSET + PHYS_OFFSET) +# define __va(x) \ + ((void *)((unsigned long)(x) + PAGE_OFFSET - PHYS_OFFSET)) + +#define page_to_virt(page) \ + ((((page) - mem_map) << PAGE_SHIFT) + PAGE_OFFSET) + +# define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) +# define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && \ + (pfn) < (max_mapnr + ARCH_PFN_OFFSET)) + +# define virt_to_page(vaddr) pfn_to_page(PFN_DOWN(virt_to_phys(vaddr))) +# define virt_addr_valid(vaddr) pfn_valid(PFN_DOWN(virt_to_phys(vaddr))) + +# define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \ + VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) + +# define UNCAC_ADDR(addr) \ + ((void *)((unsigned)(addr) | CONFIG_IO_REGION_BASE)) +# define CAC_ADDR(addr) \ + ((void *)(((unsigned)(addr) & ~CONFIG_IO_REGION_BASE) | \ + CONFIG_KERNEL_REGION_BASE)) + +#include + +#include + +#endif /* _ASM_NIOS2_PAGE_H */ diff --git a/arch/nios2/include/asm/uaccess.h b/arch/nios2/include/asm/uaccess.h new file mode 100644 index 0000000..3e36f536afaba24c308a8416a66b8a2573e042a5 --- /dev/null +++ b/arch/nios2/include/asm/uaccess.h @@ -0,0 +1,233 @@ +/* + * User space memory access functions for Nios II + * + * Copyright (C) 2010-2011, Tobias Klauser + * Copyright (C) 2009, Wind River Systems Inc + * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com + * + * Based on asm/uaccess.h from m68knommu + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#ifndef _ASM_NIOS2_UACCESS_H +#define _ASM_NIOS2_UACCESS_H + +#include +#include +#include + +#include + +#define VERIFY_READ 0 +#define VERIFY_WRITE 1 + +/* + * The exception table consists of pairs of addresses: the first is the + * address of an instruction that is allowed to fault, and the second is + * the address at which the program should continue. No registers are + * modified, so it is entirely up to the continuation code to figure out + * what to do. + * + * All the routines below use bits of fixup code that are out of line + * with the main instruction path. This means when everything is well, + * we don't even have to jump over them. Further, they do not intrude + * on our cache or tlb entries. + */ +struct exception_table_entry { + unsigned long insn; + unsigned long fixup; +}; + +extern int fixup_exception(struct pt_regs *regs); + +/* + * Segment stuff + */ +#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) +#define USER_DS MAKE_MM_SEG(0x80000000UL) +#define KERNEL_DS MAKE_MM_SEG(0) + +#define get_ds() (KERNEL_DS) + +#define get_fs() (current_thread_info()->addr_limit) +#define set_fs(seg) (current_thread_info()->addr_limit = (seg)) + +#define segment_eq(a, b) ((a).seg == (b).seg) + +#define __access_ok(addr, len) \ + (((signed long)(((long)get_fs().seg) & \ + ((long)(addr) | (((long)(addr)) + (len)) | (len)))) == 0) + +#define access_ok(type, addr, len) \ + likely(__access_ok((unsigned long)(addr), (unsigned long)(len))) + +# define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" + +/* + * Zero Userspace + */ + +static inline unsigned long __must_check __clear_user(void __user *to, + unsigned long n) +{ + __asm__ __volatile__ ( + "1: stb zero, 0(%1)\n" + " addi %0, %0, -1\n" + " addi %1, %1, 1\n" + " bne %0, zero, 1b\n" + "2:\n" + __EX_TABLE_SECTION + ".word 1b, 2b\n" + ".previous\n" + : "=r" (n), "=r" (to) + : "0" (n), "1" (to) + ); + + return n; +} + +static inline unsigned long __must_check clear_user(void __user *to, + unsigned long n) +{ + if (!access_ok(VERIFY_WRITE, to, n)) + return n; + return __clear_user(to, n); +} + +extern long __copy_from_user(void *to, const void __user *from, + unsigned long n); +extern long __copy_to_user(void __user *to, const void *from, unsigned long n); + +static inline long copy_from_user(void *to, const void __user *from, + unsigned long n) +{ + if (!access_ok(VERIFY_READ, from, n)) + return n; + return __copy_from_user(to, from, n); +} + +static inline long copy_to_user(void __user *to, const void *from, + unsigned long n) +{ + if (!access_ok(VERIFY_WRITE, to, n)) + return n; + return __copy_to_user(to, from, n); +} + +extern long strncpy_from_user(char *__to, const char __user *__from, + long __len); +extern long strnlen_user(const char __user *s, long n); + +#define __copy_from_user_inatomic __copy_from_user +#define __copy_to_user_inatomic __copy_to_user + +/* Optimized macros */ +#define __get_user_asm(val, insn, addr, err) \ +{ \ + __asm__ __volatile__( \ + " movi %0, %3\n" \ + "1: " insn " %1, 0(%2)\n" \ + " movi %0, 0\n" \ + "2:\n" \ + " .section __ex_table,\"a\"\n" \ + " .word 1b, 2b\n" \ + " .previous" \ + : "=&r" (err), "=r" (val) \ + : "r" (addr), "i" (-EFAULT)); \ +} + +#define __get_user_unknown(val, size, ptr, err) do { \ + err = 0; \ + if (copy_from_user(&(val), ptr, size)) { \ + err = -EFAULT; \ + } \ + } while (0) + +#define __get_user_common(val, size, ptr, err) \ +do { \ + switch (size) { \ + case 1: \ + __get_user_asm(val, "ldbu", ptr, err); \ + break; \ + case 2: \ + __get_user_asm(val, "ldhu", ptr, err); \ + break; \ + case 4: \ + __get_user_asm(val, "ldw", ptr, err); \ + break; \ + default: \ + __get_user_unknown(val, size, ptr, err); \ + break; \ + } \ +} while (0) + +#define __get_user(x, ptr) \ + ({ \ + long __gu_err = -EFAULT; \ + const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ + unsigned long __gu_val; \ + __get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\ + (x) = (__typeof__(x))__gu_val; \ + __gu_err; \ + }) + +#define get_user(x, ptr) \ +({ \ + long __gu_err = -EFAULT; \ + const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ + unsigned long __gu_val = 0; \ + if (access_ok(VERIFY_READ, __gu_ptr, sizeof(*__gu_ptr))) \ + __get_user_common(__gu_val, sizeof(*__gu_ptr), \ + __gu_ptr, __gu_err); \ + (x) = (__typeof__(x))__gu_val; \ + __gu_err; \ +}) + +#define __put_user_asm(val, insn, ptr, err) \ +{ \ + __asm__ __volatile__( \ + " movi %0, %3\n" \ + "1: " insn " %1, 0(%2)\n" \ + " movi %0, 0\n" \ + "2:\n" \ + " .section __ex_table,\"a\"\n" \ + " .word 1b, 2b\n" \ + " .previous\n" \ + : "=&r" (err) \ + : "r" (val), "r" (ptr), "i" (-EFAULT)); \ +} + +#define put_user(x, ptr) \ +({ \ + long __pu_err = -EFAULT; \ + __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \ + __typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x); \ + if (access_ok(VERIFY_WRITE, __pu_ptr, sizeof(*__pu_ptr))) { \ + switch (sizeof(*__pu_ptr)) { \ + case 1: \ + __put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \ + break; \ + case 2: \ + __put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \ + break; \ + case 4: \ + __put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \ + break; \ + default: \ + /* XXX: This looks wrong... */ \ + __pu_err = 0; \ + if (copy_to_user(__pu_ptr, &(__pu_val), \ + sizeof(*__pu_ptr))) \ + __pu_err = -EFAULT; \ + break; \ + } \ + } \ + __pu_err; \ +}) + +#define __put_user(x, ptr) put_user(x, ptr) + +#endif /* _ASM_NIOS2_UACCESS_H */ diff --git a/arch/nios2/mm/init.c b/arch/nios2/mm/init.c new file mode 100644 index 0000000..4c4538dbbea7e461ae049122957765ea89fa9ded --- /dev/null +++ b/arch/nios2/mm/init.c @@ -0,0 +1,152 @@ +/* + * Copyright (C) 2013 Altera Corporation + * Copyright (C) 2010 Tobias Klauser + * Copyright (C) 2009 Wind River Systems Inc + * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com + * Copyright (C) 2004 Microtronix Datacom Ltd + * + * based on arch/m68k/mm/init.c + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include + +pgd_t *pgd_current; + +/* + * paging_init() continues the virtual memory environment setup which + * was begun by the code in arch/head.S. + * The parameters are pointers to where to stick the starting and ending + * addresses of available kernel virtual memory. + */ +void __init paging_init(void) +{ + unsigned long zones_size[MAX_NR_ZONES]; + unsigned long start_mem, end_mem; + + memset(zones_size, 0, sizeof(zones_size)); + + /* + * Make sure start_mem is page aligned, otherwise bootmem and + * page_alloc get different views of the world. + */ + start_mem = PHYS_OFFSET; + end_mem = memory_end; + + pagetable_init(); + pgd_current = swapper_pg_dir; + + /* + * Set up SFC/DFC registers (user data space). + */ + zones_size[ZONE_DMA] = ((end_mem - start_mem) >> PAGE_SHIFT); + + /* pass the memory from the bootmem allocator to the main allocator */ + free_area_init(zones_size); +} + +void __init mem_init(void) +{ + unsigned long end_mem = memory_end; /* this must not include + kernel stack at top */ + + pr_debug("mem_init: start=%lx, end=%lx\n", memory_start, memory_end); + + end_mem &= PAGE_MASK; + high_memory = __va(end_mem); + + max_mapnr = ((unsigned long)end_mem) >> PAGE_SHIFT; + + /* this will put all memory onto the freelists */ + free_all_bootmem(); + mem_init_print_info(NULL); +} + +void __init mmu_init(void) +{ + flush_tlb_all(); +} + +#ifdef CONFIG_BLK_DEV_INITRD +void __init free_initrd_mem(unsigned long start, unsigned long end) +{ + free_reserved_area((void *)start, (void *)end, -1, "initrd"); +} +#endif + +void __init_refok free_initmem(void) +{ + free_initmem_default(-1); +} + +#define __page_aligned(order) __aligned(PAGE_SIZE << (order)) +pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER); +pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER); +static struct page *kuser_page[1]; + +static int alloc_kuser_page(void) +{ + extern char __kuser_helper_start[], __kuser_helper_end[]; + int kuser_sz = __kuser_helper_end - __kuser_helper_start; + unsigned long vpage; + + vpage = get_zeroed_page(GFP_ATOMIC); + if (!vpage) + return -ENOMEM; + + /* Copy kuser helpers */ + memcpy((void *)vpage, __kuser_helper_start, kuser_sz); + + flush_icache_range(vpage, vpage + KUSER_SIZE); + kuser_page[0] = virt_to_page(vpage); + + return 0; +} +arch_initcall(alloc_kuser_page); + +int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) +{ + struct mm_struct *mm = current->mm; + int ret; + + down_write(&mm->mmap_sem); + + /* Map kuser helpers to user space address */ + ret = install_special_mapping(mm, KUSER_BASE, KUSER_SIZE, + VM_READ | VM_EXEC | VM_MAYREAD | + VM_MAYEXEC, kuser_page); + + up_write(&mm->mmap_sem); + + return ret; +} + +const char *arch_vma_name(struct vm_area_struct *vma) +{ + return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL; +} diff --git a/arch/nios2/mm/uaccess.c b/arch/nios2/mm/uaccess.c new file mode 100644 index 0000000..4a38ad37c18b4e10792df094d81087a3f32cd9e9 --- /dev/null +++ b/arch/nios2/mm/uaccess.c @@ -0,0 +1,162 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2009, Wind River Systems Inc + * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com + */ + +#include +#include + +asm(".global __copy_from_user\n" + " .type __copy_from_user, @function\n" + "__copy_from_user:\n" + " movi r2,7\n" + " mov r3,r4\n" + " bge r2,r6,1f\n" + " xor r2,r4,r5\n" + " andi r2,r2,3\n" + " movi r7,3\n" + " beq r2,zero,4f\n" + "1: addi r6,r6,-1\n" + " movi r2,-1\n" + " beq r6,r2,3f\n" + " mov r7,r2\n" + "2: ldbu r2,0(r5)\n" + " addi r6,r6,-1\n" + " addi r5,r5,1\n" + " stb r2,0(r3)\n" + " addi r3,r3,1\n" + " bne r6,r7,2b\n" + "3:\n" + " addi r2,r6,1\n" + " ret\n" + "13:mov r2,r6\n" + " ret\n" + "4: andi r2,r4,1\n" + " cmpeq r2,r2,zero\n" + " beq r2,zero,7f\n" + "5: andi r2,r3,2\n" + " beq r2,zero,6f\n" + "9: ldhu r2,0(r5)\n" + " addi r6,r6,-2\n" + " addi r5,r5,2\n" + " sth r2,0(r3)\n" + " addi r3,r3,2\n" + "6: bge r7,r6,1b\n" + "10:ldw r2,0(r5)\n" + " addi r6,r6,-4\n" + " addi r5,r5,4\n" + " stw r2,0(r3)\n" + " addi r3,r3,4\n" + " br 6b\n" + "7: ldbu r2,0(r5)\n" + " addi r6,r6,-1\n" + " addi r5,r5,1\n" + " addi r3,r4,1\n" + " stb r2,0(r4)\n" + " br 5b\n" + ".section __ex_table,\"a\"\n" + ".word 2b,3b\n" + ".word 9b,13b\n" + ".word 10b,13b\n" + ".word 7b,13b\n" + ".previous\n" + ); +EXPORT_SYMBOL(__copy_from_user); + +asm( + " .global __copy_to_user\n" + " .type __copy_to_user, @function\n" + "__copy_to_user:\n" + " movi r2,7\n" + " mov r3,r4\n" + " bge r2,r6,1f\n" + " xor r2,r4,r5\n" + " andi r2,r2,3\n" + " movi r7,3\n" + " beq r2,zero,4f\n" + /* Bail if we try to copy zero bytes */ + "1: addi r6,r6,-1\n" + " movi r2,-1\n" + " beq r6,r2,3f\n" + /* Copy byte by byte for small copies and if src^dst != 0 */ + " mov r7,r2\n" + "2: ldbu r2,0(r5)\n" + " addi r5,r5,1\n" + "9: stb r2,0(r3)\n" + " addi r6,r6,-1\n" + " addi r3,r3,1\n" + " bne r6,r7,2b\n" + "3: addi r2,r6,1\n" + " ret\n" + "13:mov r2,r6\n" + " ret\n" + /* If 'to' is an odd address byte copy */ + "4: andi r2,r4,1\n" + " cmpeq r2,r2,zero\n" + " beq r2,zero,7f\n" + /* If 'to' is not divideable by four copy halfwords */ + "5: andi r2,r3,2\n" + " beq r2,zero,6f\n" + " ldhu r2,0(r5)\n" + " addi r5,r5,2\n" + "10:sth r2,0(r3)\n" + " addi r6,r6,-2\n" + " addi r3,r3,2\n" + /* Copy words */ + "6: bge r7,r6,1b\n" + " ldw r2,0(r5)\n" + " addi r5,r5,4\n" + "11:stw r2,0(r3)\n" + " addi r6,r6,-4\n" + " addi r3,r3,4\n" + " br 6b\n" + /* Copy remaining bytes */ + "7: ldbu r2,0(r5)\n" + " addi r5,r5,1\n" + " addi r3,r4,1\n" + "12: stb r2,0(r4)\n" + " addi r6,r6,-1\n" + " br 5b\n" + ".section __ex_table,\"a\"\n" + ".word 9b,3b\n" + ".word 10b,13b\n" + ".word 11b,13b\n" + ".word 12b,13b\n" + ".previous\n"); +EXPORT_SYMBOL(__copy_to_user); + +long strncpy_from_user(char *__to, const char __user *__from, long __len) +{ + int l = strnlen_user(__from, __len); + int is_zt = 1; + + if (l > __len) { + is_zt = 0; + l = __len; + } + + if (l == 0 || copy_from_user(__to, __from, l)) + return -EFAULT; + + if (is_zt) + l--; + return l; +} + +long strnlen_user(const char __user *s, long n) +{ + long i; + + for (i = 0; i < n; i++) { + char c; + if (get_user(c, s + i) == -EFAULT) + return 0; + if (c == 0) + return i + 1; + } + return n + 1; +} -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/