From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/arch/x86/lib/usercopy_32.c | 691 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 691 insertions(+) create mode 100644 kernel/arch/x86/lib/usercopy_32.c (limited to 'kernel/arch/x86/lib/usercopy_32.c') diff --git a/kernel/arch/x86/lib/usercopy_32.c b/kernel/arch/x86/lib/usercopy_32.c new file mode 100644 index 000000000..91d93b95b --- /dev/null +++ b/kernel/arch/x86/lib/usercopy_32.c @@ -0,0 +1,691 @@ +/* + * User address space access functions. + * The non inlined parts of asm-i386/uaccess.h are here. + * + * Copyright 1997 Andi Kleen + * Copyright 1997 Linus Torvalds + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#ifdef CONFIG_X86_INTEL_USERCOPY +/* + * Alignment at which movsl is preferred for bulk memory copies. + */ +struct movsl_mask movsl_mask __read_mostly; +#endif + +static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned long n) +{ +#ifdef CONFIG_X86_INTEL_USERCOPY + if (n >= 64 && ((a1 ^ a2) & movsl_mask.mask)) + return 0; +#endif + return 1; +} +#define movsl_is_ok(a1, a2, n) \ + __movsl_is_ok((unsigned long)(a1), (unsigned long)(a2), (n)) + +/* + * Zero Userspace + */ + +#define __do_clear_user(addr,size) \ +do { \ + int __d0; \ + might_fault(); \ + __asm__ __volatile__( \ + ASM_STAC "\n" \ + "0: rep; stosl\n" \ + " movl %2,%0\n" \ + "1: rep; stosb\n" \ + "2: " ASM_CLAC "\n" \ + ".section .fixup,\"ax\"\n" \ + "3: lea 0(%2,%0,4),%0\n" \ + " jmp 2b\n" \ + ".previous\n" \ + _ASM_EXTABLE(0b,3b) \ + _ASM_EXTABLE(1b,2b) \ + : "=&c"(size), "=&D" (__d0) \ + : "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0)); \ +} while (0) + +/** + * clear_user: - Zero a block of memory in user space. + * @to: Destination address, in user space. + * @n: Number of bytes to zero. + * + * Zero a block of memory in user space. + * + * Returns number of bytes that could not be cleared. + * On success, this will be zero. + */ +unsigned long +clear_user(void __user *to, unsigned long n) +{ + might_fault(); + if (access_ok(VERIFY_WRITE, to, n)) + __do_clear_user(to, n); + return n; +} +EXPORT_SYMBOL(clear_user); + +/** + * __clear_user: - Zero a block of memory in user space, with less checking. + * @to: Destination address, in user space. + * @n: Number of bytes to zero. + * + * Zero a block of memory in user space. Caller must check + * the specified block with access_ok() before calling this function. + * + * Returns number of bytes that could not be cleared. + * On success, this will be zero. + */ +unsigned long +__clear_user(void __user *to, unsigned long n) +{ + __do_clear_user(to, n); + return n; +} +EXPORT_SYMBOL(__clear_user); + +#ifdef CONFIG_X86_INTEL_USERCOPY +static unsigned long +__copy_user_intel(void __user *to, const void *from, unsigned long size) +{ + int d0, d1; + __asm__ __volatile__( + " .align 2,0x90\n" + "1: movl 32(%4), %%eax\n" + " cmpl $67, %0\n" + " jbe 3f\n" + "2: movl 64(%4), %%eax\n" + " .align 2,0x90\n" + "3: movl 0(%4), %%eax\n" + "4: movl 4(%4), %%edx\n" + "5: movl %%eax, 0(%3)\n" + "6: movl %%edx, 4(%3)\n" + "7: movl 8(%4), %%eax\n" + "8: movl 12(%4),%%edx\n" + "9: movl %%eax, 8(%3)\n" + "10: movl %%edx, 12(%3)\n" + "11: movl 16(%4), %%eax\n" + "12: movl 20(%4), %%edx\n" + "13: movl %%eax, 16(%3)\n" + "14: movl %%edx, 20(%3)\n" + "15: movl 24(%4), %%eax\n" + "16: movl 28(%4), %%edx\n" + "17: movl %%eax, 24(%3)\n" + "18: movl %%edx, 28(%3)\n" + "19: movl 32(%4), %%eax\n" + "20: movl 36(%4), %%edx\n" + "21: movl %%eax, 32(%3)\n" + "22: movl %%edx, 36(%3)\n" + "23: movl 40(%4), %%eax\n" + "24: movl 44(%4), %%edx\n" + "25: movl %%eax, 40(%3)\n" + "26: movl %%edx, 44(%3)\n" + "27: movl 48(%4), %%eax\n" + "28: movl 52(%4), %%edx\n" + "29: movl %%eax, 48(%3)\n" + "30: movl %%edx, 52(%3)\n" + "31: movl 56(%4), %%eax\n" + "32: movl 60(%4), %%edx\n" + "33: movl %%eax, 56(%3)\n" + "34: movl %%edx, 60(%3)\n" + " addl $-64, %0\n" + " addl $64, %4\n" + " addl $64, %3\n" + " cmpl $63, %0\n" + " ja 1b\n" + "35: movl %0, %%eax\n" + " shrl $2, %0\n" + " andl $3, %%eax\n" + " cld\n" + "99: rep; movsl\n" + "36: movl %%eax, %0\n" + "37: rep; movsb\n" + "100:\n" + ".section .fixup,\"ax\"\n" + "101: lea 0(%%eax,%0,4),%0\n" + " jmp 100b\n" + ".previous\n" + _ASM_EXTABLE(1b,100b) + _ASM_EXTABLE(2b,100b) + _ASM_EXTABLE(3b,100b) + _ASM_EXTABLE(4b,100b) + _ASM_EXTABLE(5b,100b) + _ASM_EXTABLE(6b,100b) + _ASM_EXTABLE(7b,100b) + _ASM_EXTABLE(8b,100b) + _ASM_EXTABLE(9b,100b) + _ASM_EXTABLE(10b,100b) + _ASM_EXTABLE(11b,100b) + _ASM_EXTABLE(12b,100b) + _ASM_EXTABLE(13b,100b) + _ASM_EXTABLE(14b,100b) + _ASM_EXTABLE(15b,100b) + _ASM_EXTABLE(16b,100b) + _ASM_EXTABLE(17b,100b) + _ASM_EXTABLE(18b,100b) + _ASM_EXTABLE(19b,100b) + _ASM_EXTABLE(20b,100b) + _ASM_EXTABLE(21b,100b) + _ASM_EXTABLE(22b,100b) + _ASM_EXTABLE(23b,100b) + _ASM_EXTABLE(24b,100b) + _ASM_EXTABLE(25b,100b) + _ASM_EXTABLE(26b,100b) + _ASM_EXTABLE(27b,100b) + _ASM_EXTABLE(28b,100b) + _ASM_EXTABLE(29b,100b) + _ASM_EXTABLE(30b,100b) + _ASM_EXTABLE(31b,100b) + _ASM_EXTABLE(32b,100b) + _ASM_EXTABLE(33b,100b) + _ASM_EXTABLE(34b,100b) + _ASM_EXTABLE(35b,100b) + _ASM_EXTABLE(36b,100b) + _ASM_EXTABLE(37b,100b) + _ASM_EXTABLE(99b,101b) + : "=&c"(size), "=&D" (d0), "=&S" (d1) + : "1"(to), "2"(from), "0"(size) + : "eax", "edx", "memory"); + return size; +} + +static unsigned long +__copy_user_zeroing_intel(void *to, const void __user *from, unsigned long size) +{ + int d0, d1; + __asm__ __volatile__( + " .align 2,0x90\n" + "0: movl 32(%4), %%eax\n" + " cmpl $67, %0\n" + " jbe 2f\n" + "1: movl 64(%4), %%eax\n" + " .align 2,0x90\n" + "2: movl 0(%4), %%eax\n" + "21: movl 4(%4), %%edx\n" + " movl %%eax, 0(%3)\n" + " movl %%edx, 4(%3)\n" + "3: movl 8(%4), %%eax\n" + "31: movl 12(%4),%%edx\n" + " movl %%eax, 8(%3)\n" + " movl %%edx, 12(%3)\n" + "4: movl 16(%4), %%eax\n" + "41: movl 20(%4), %%edx\n" + " movl %%eax, 16(%3)\n" + " movl %%edx, 20(%3)\n" + "10: movl 24(%4), %%eax\n" + "51: movl 28(%4), %%edx\n" + " movl %%eax, 24(%3)\n" + " movl %%edx, 28(%3)\n" + "11: movl 32(%4), %%eax\n" + "61: movl 36(%4), %%edx\n" + " movl %%eax, 32(%3)\n" + " movl %%edx, 36(%3)\n" + "12: movl 40(%4), %%eax\n" + "71: movl 44(%4), %%edx\n" + " movl %%eax, 40(%3)\n" + " movl %%edx, 44(%3)\n" + "13: movl 48(%4), %%eax\n" + "81: movl 52(%4), %%edx\n" + " movl %%eax, 48(%3)\n" + " movl %%edx, 52(%3)\n" + "14: movl 56(%4), %%eax\n" + "91: movl 60(%4), %%edx\n" + " movl %%eax, 56(%3)\n" + " movl %%edx, 60(%3)\n" + " addl $-64, %0\n" + " addl $64, %4\n" + " addl $64, %3\n" + " cmpl $63, %0\n" + " ja 0b\n" + "5: movl %0, %%eax\n" + " shrl $2, %0\n" + " andl $3, %%eax\n" + " cld\n" + "6: rep; movsl\n" + " movl %%eax,%0\n" + "7: rep; movsb\n" + "8:\n" + ".section .fixup,\"ax\"\n" + "9: lea 0(%%eax,%0,4),%0\n" + "16: pushl %0\n" + " pushl %%eax\n" + " xorl %%eax,%%eax\n" + " rep; stosb\n" + " popl %%eax\n" + " popl %0\n" + " jmp 8b\n" + ".previous\n" + _ASM_EXTABLE(0b,16b) + _ASM_EXTABLE(1b,16b) + _ASM_EXTABLE(2b,16b) + _ASM_EXTABLE(21b,16b) + _ASM_EXTABLE(3b,16b) + _ASM_EXTABLE(31b,16b) + _ASM_EXTABLE(4b,16b) + _ASM_EXTABLE(41b,16b) + _ASM_EXTABLE(10b,16b) + _ASM_EXTABLE(51b,16b) + _ASM_EXTABLE(11b,16b) + _ASM_EXTABLE(61b,16b) + _ASM_EXTABLE(12b,16b) + _ASM_EXTABLE(71b,16b) + _ASM_EXTABLE(13b,16b) + _ASM_EXTABLE(81b,16b) + _ASM_EXTABLE(14b,16b) + _ASM_EXTABLE(91b,16b) + _ASM_EXTABLE(6b,9b) + _ASM_EXTABLE(7b,16b) + : "=&c"(size), "=&D" (d0), "=&S" (d1) + : "1"(to), "2"(from), "0"(size) + : "eax", "edx", "memory"); + return size; +} + +/* + * Non Temporal Hint version of __copy_user_zeroing_intel. It is cache aware. + * hyoshiok@miraclelinux.com + */ + +static unsigned long __copy_user_zeroing_intel_nocache(void *to, + const void __user *from, unsigned long size) +{ + int d0, d1; + + __asm__ __volatile__( + " .align 2,0x90\n" + "0: movl 32(%4), %%eax\n" + " cmpl $67, %0\n" + " jbe 2f\n" + "1: movl 64(%4), %%eax\n" + " .align 2,0x90\n" + "2: movl 0(%4), %%eax\n" + "21: movl 4(%4), %%edx\n" + " movnti %%eax, 0(%3)\n" + " movnti %%edx, 4(%3)\n" + "3: movl 8(%4), %%eax\n" + "31: movl 12(%4),%%edx\n" + " movnti %%eax, 8(%3)\n" + " movnti %%edx, 12(%3)\n" + "4: movl 16(%4), %%eax\n" + "41: movl 20(%4), %%edx\n" + " movnti %%eax, 16(%3)\n" + " movnti %%edx, 20(%3)\n" + "10: movl 24(%4), %%eax\n" + "51: movl 28(%4), %%edx\n" + " movnti %%eax, 24(%3)\n" + " movnti %%edx, 28(%3)\n" + "11: movl 32(%4), %%eax\n" + "61: movl 36(%4), %%edx\n" + " movnti %%eax, 32(%3)\n" + " movnti %%edx, 36(%3)\n" + "12: movl 40(%4), %%eax\n" + "71: movl 44(%4), %%edx\n" + " movnti %%eax, 40(%3)\n" + " movnti %%edx, 44(%3)\n" + "13: movl 48(%4), %%eax\n" + "81: movl 52(%4), %%edx\n" + " movnti %%eax, 48(%3)\n" + " movnti %%edx, 52(%3)\n" + "14: movl 56(%4), %%eax\n" + "91: movl 60(%4), %%edx\n" + " movnti %%eax, 56(%3)\n" + " movnti %%edx, 60(%3)\n" + " addl $-64, %0\n" + " addl $64, %4\n" + " addl $64, %3\n" + " cmpl $63, %0\n" + " ja 0b\n" + " sfence \n" + "5: movl %0, %%eax\n" + " shrl $2, %0\n" + " andl $3, %%eax\n" + " cld\n" + "6: rep; movsl\n" + " movl %%eax,%0\n" + "7: rep; movsb\n" + "8:\n" + ".section .fixup,\"ax\"\n" + "9: lea 0(%%eax,%0,4),%0\n" + "16: pushl %0\n" + " pushl %%eax\n" + " xorl %%eax,%%eax\n" + " rep; stosb\n" + " popl %%eax\n" + " popl %0\n" + " jmp 8b\n" + ".previous\n" + _ASM_EXTABLE(0b,16b) + _ASM_EXTABLE(1b,16b) + _ASM_EXTABLE(2b,16b) + _ASM_EXTABLE(21b,16b) + _ASM_EXTABLE(3b,16b) + _ASM_EXTABLE(31b,16b) + _ASM_EXTABLE(4b,16b) + _ASM_EXTABLE(41b,16b) + _ASM_EXTABLE(10b,16b) + _ASM_EXTABLE(51b,16b) + _ASM_EXTABLE(11b,16b) + _ASM_EXTABLE(61b,16b) + _ASM_EXTABLE(12b,16b) + _ASM_EXTABLE(71b,16b) + _ASM_EXTABLE(13b,16b) + _ASM_EXTABLE(81b,16b) + _ASM_EXTABLE(14b,16b) + _ASM_EXTABLE(91b,16b) + _ASM_EXTABLE(6b,9b) + _ASM_EXTABLE(7b,16b) + : "=&c"(size), "=&D" (d0), "=&S" (d1) + : "1"(to), "2"(from), "0"(size) + : "eax", "edx", "memory"); + return size; +} + +static unsigned long __copy_user_intel_nocache(void *to, + const void __user *from, unsigned long size) +{ + int d0, d1; + + __asm__ __volatile__( + " .align 2,0x90\n" + "0: movl 32(%4), %%eax\n" + " cmpl $67, %0\n" + " jbe 2f\n" + "1: movl 64(%4), %%eax\n" + " .align 2,0x90\n" + "2: movl 0(%4), %%eax\n" + "21: movl 4(%4), %%edx\n" + " movnti %%eax, 0(%3)\n" + " movnti %%edx, 4(%3)\n" + "3: movl 8(%4), %%eax\n" + "31: movl 12(%4),%%edx\n" + " movnti %%eax, 8(%3)\n" + " movnti %%edx, 12(%3)\n" + "4: movl 16(%4), %%eax\n" + "41: movl 20(%4), %%edx\n" + " movnti %%eax, 16(%3)\n" + " movnti %%edx, 20(%3)\n" + "10: movl 24(%4), %%eax\n" + "51: movl 28(%4), %%edx\n" + " movnti %%eax, 24(%3)\n" + " movnti %%edx, 28(%3)\n" + "11: movl 32(%4), %%eax\n" + "61: movl 36(%4), %%edx\n" + " movnti %%eax, 32(%3)\n" + " movnti %%edx, 36(%3)\n" + "12: movl 40(%4), %%eax\n" + "71: movl 44(%4), %%edx\n" + " movnti %%eax, 40(%3)\n" + " movnti %%edx, 44(%3)\n" + "13: movl 48(%4), %%eax\n" + "81: movl 52(%4), %%edx\n" + " movnti %%eax, 48(%3)\n" + " movnti %%edx, 52(%3)\n" + "14: movl 56(%4), %%eax\n" + "91: movl 60(%4), %%edx\n" + " movnti %%eax, 56(%3)\n" + " movnti %%edx, 60(%3)\n" + " addl $-64, %0\n" + " addl $64, %4\n" + " addl $64, %3\n" + " cmpl $63, %0\n" + " ja 0b\n" + " sfence \n" + "5: movl %0, %%eax\n" + " shrl $2, %0\n" + " andl $3, %%eax\n" + " cld\n" + "6: rep; movsl\n" + " movl %%eax,%0\n" + "7: rep; movsb\n" + "8:\n" + ".section .fixup,\"ax\"\n" + "9: lea 0(%%eax,%0,4),%0\n" + "16: jmp 8b\n" + ".previous\n" + _ASM_EXTABLE(0b,16b) + _ASM_EXTABLE(1b,16b) + _ASM_EXTABLE(2b,16b) + _ASM_EXTABLE(21b,16b) + _ASM_EXTABLE(3b,16b) + _ASM_EXTABLE(31b,16b) + _ASM_EXTABLE(4b,16b) + _ASM_EXTABLE(41b,16b) + _ASM_EXTABLE(10b,16b) + _ASM_EXTABLE(51b,16b) + _ASM_EXTABLE(11b,16b) + _ASM_EXTABLE(61b,16b) + _ASM_EXTABLE(12b,16b) + _ASM_EXTABLE(71b,16b) + _ASM_EXTABLE(13b,16b) + _ASM_EXTABLE(81b,16b) + _ASM_EXTABLE(14b,16b) + _ASM_EXTABLE(91b,16b) + _ASM_EXTABLE(6b,9b) + _ASM_EXTABLE(7b,16b) + : "=&c"(size), "=&D" (d0), "=&S" (d1) + : "1"(to), "2"(from), "0"(size) + : "eax", "edx", "memory"); + return size; +} + +#else + +/* + * Leave these declared but undefined. They should not be any references to + * them + */ +unsigned long __copy_user_zeroing_intel(void *to, const void __user *from, + unsigned long size); +unsigned long __copy_user_intel(void __user *to, const void *from, + unsigned long size); +unsigned long __copy_user_zeroing_intel_nocache(void *to, + const void __user *from, unsigned long size); +#endif /* CONFIG_X86_INTEL_USERCOPY */ + +/* Generic arbitrary sized copy. */ +#define __copy_user(to, from, size) \ +do { \ + int __d0, __d1, __d2; \ + __asm__ __volatile__( \ + " cmp $7,%0\n" \ + " jbe 1f\n" \ + " movl %1,%0\n" \ + " negl %0\n" \ + " andl $7,%0\n" \ + " subl %0,%3\n" \ + "4: rep; movsb\n" \ + " movl %3,%0\n" \ + " shrl $2,%0\n" \ + " andl $3,%3\n" \ + " .align 2,0x90\n" \ + "0: rep; movsl\n" \ + " movl %3,%0\n" \ + "1: rep; movsb\n" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "5: addl %3,%0\n" \ + " jmp 2b\n" \ + "3: lea 0(%3,%0,4),%0\n" \ + " jmp 2b\n" \ + ".previous\n" \ + _ASM_EXTABLE(4b,5b) \ + _ASM_EXTABLE(0b,3b) \ + _ASM_EXTABLE(1b,2b) \ + : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \ + : "3"(size), "0"(size), "1"(to), "2"(from) \ + : "memory"); \ +} while (0) + +#define __copy_user_zeroing(to, from, size) \ +do { \ + int __d0, __d1, __d2; \ + __asm__ __volatile__( \ + " cmp $7,%0\n" \ + " jbe 1f\n" \ + " movl %1,%0\n" \ + " negl %0\n" \ + " andl $7,%0\n" \ + " subl %0,%3\n" \ + "4: rep; movsb\n" \ + " movl %3,%0\n" \ + " shrl $2,%0\n" \ + " andl $3,%3\n" \ + " .align 2,0x90\n" \ + "0: rep; movsl\n" \ + " movl %3,%0\n" \ + "1: rep; movsb\n" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "5: addl %3,%0\n" \ + " jmp 6f\n" \ + "3: lea 0(%3,%0,4),%0\n" \ + "6: pushl %0\n" \ + " pushl %%eax\n" \ + " xorl %%eax,%%eax\n" \ + " rep; stosb\n" \ + " popl %%eax\n" \ + " popl %0\n" \ + " jmp 2b\n" \ + ".previous\n" \ + _ASM_EXTABLE(4b,5b) \ + _ASM_EXTABLE(0b,3b) \ + _ASM_EXTABLE(1b,6b) \ + : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \ + : "3"(size), "0"(size), "1"(to), "2"(from) \ + : "memory"); \ +} while (0) + +unsigned long __copy_to_user_ll(void __user *to, const void *from, + unsigned long n) +{ + stac(); + if (movsl_is_ok(to, from, n)) + __copy_user(to, from, n); + else + n = __copy_user_intel(to, from, n); + clac(); + return n; +} +EXPORT_SYMBOL(__copy_to_user_ll); + +unsigned long __copy_from_user_ll(void *to, const void __user *from, + unsigned long n) +{ + stac(); + if (movsl_is_ok(to, from, n)) + __copy_user_zeroing(to, from, n); + else + n = __copy_user_zeroing_intel(to, from, n); + clac(); + return n; +} +EXPORT_SYMBOL(__copy_from_user_ll); + +unsigned long __copy_from_user_ll_nozero(void *to, const void __user *from, + unsigned long n) +{ + stac(); + if (movsl_is_ok(to, from, n)) + __copy_user(to, from, n); + else + n = __copy_user_intel((void __user *)to, + (const void *)from, n); + clac(); + return n; +} +EXPORT_SYMBOL(__copy_from_user_ll_nozero); + +unsigned long __copy_from_user_ll_nocache(void *to, const void __user *from, + unsigned long n) +{ + stac(); +#ifdef CONFIG_X86_INTEL_USERCOPY + if (n > 64 && cpu_has_xmm2) + n = __copy_user_zeroing_intel_nocache(to, from, n); + else + __copy_user_zeroing(to, from, n); +#else + __copy_user_zeroing(to, from, n); +#endif + clac(); + return n; +} +EXPORT_SYMBOL(__copy_from_user_ll_nocache); + +unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from, + unsigned long n) +{ + stac(); +#ifdef CONFIG_X86_INTEL_USERCOPY + if (n > 64 && cpu_has_xmm2) + n = __copy_user_intel_nocache(to, from, n); + else + __copy_user(to, from, n); +#else + __copy_user(to, from, n); +#endif + clac(); + return n; +} +EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero); + +/** + * copy_to_user: - Copy a block of data into user space. + * @to: Destination address, in user space. + * @from: Source address, in kernel space. + * @n: Number of bytes to copy. + * + * Context: User context only. This function may sleep if pagefaults are + * enabled. + * + * Copy data from kernel space to user space. + * + * Returns number of bytes that could not be copied. + * On success, this will be zero. + */ +unsigned long _copy_to_user(void __user *to, const void *from, unsigned n) +{ + if (access_ok(VERIFY_WRITE, to, n)) + n = __copy_to_user(to, from, n); + return n; +} +EXPORT_SYMBOL(_copy_to_user); + +/** + * copy_from_user: - Copy a block of data from user space. + * @to: Destination address, in kernel space. + * @from: Source address, in user space. + * @n: Number of bytes to copy. + * + * Context: User context only. This function may sleep if pagefaults are + * enabled. + * + * Copy data from user space to kernel space. + * + * Returns number of bytes that could not be copied. + * On success, this will be zero. + * + * If some data could not be copied, this function will pad the copied + * data to the requested size using zero bytes. + */ +unsigned long _copy_from_user(void *to, const void __user *from, unsigned n) +{ + if (access_ok(VERIFY_READ, from, n)) + n = __copy_from_user(to, from, n); + else + memset(to, 0, n); + return n; +} +EXPORT_SYMBOL(_copy_from_user); -- cgit 1.2.3-korg