| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * User address space access functions. |
| * The non inlined parts of asm-i386/uaccess.h are here. |
| * |
| * Copyright 1997 Andi Kleen <ak@muc.de> |
| * Copyright 1997 Linus Torvalds |
| */ |
| #include <linux/export.h> |
| #include <linux/uaccess.h> |
| #include <asm/mmx.h> |
| #include <asm/asm.h> |
| |
| #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_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_intel(void __user *to, const void *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) |
| |
| unsigned long __copy_user_ll(void *to, const void *from, unsigned long n) |
| { |
| __uaccess_begin_nospec(); |
| if (movsl_is_ok(to, from, n)) |
| __copy_user(to, from, n); |
| else |
| n = __copy_user_intel(to, from, n); |
| __uaccess_end(); |
| return n; |
| } |
| EXPORT_SYMBOL(__copy_user_ll); |
| |
| unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from, |
| unsigned long n) |
| { |
| __uaccess_begin_nospec(); |
| #ifdef CONFIG_X86_INTEL_USERCOPY |
| if (n > 64 && static_cpu_has(X86_FEATURE_XMM2)) |
| n = __copy_user_intel_nocache(to, from, n); |
| else |
| __copy_user(to, from, n); |
| #else |
| __copy_user(to, from, n); |
| #endif |
| __uaccess_end(); |
| return n; |
| } |
| EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero); |
