// 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 * Copyright 1997 Linus Torvalds */ #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_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) { 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_user_ll); 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 && 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 clac(); return n; } EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero);