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- // 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 <[email protected]>
- * Copyright 1997 Linus Torvalds
- */
- #include <linux/export.h>
- #include <linux/uaccess.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" \
- _ASM_EXTABLE_TYPE_REG(0b, 2b, EX_TYPE_UCOPY_LEN4, %2) \
- _ASM_EXTABLE_UA(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.
- *
- * Return: 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(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.
- *
- * Return: 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"
- _ASM_EXTABLE_UA(1b, 100b)
- _ASM_EXTABLE_UA(2b, 100b)
- _ASM_EXTABLE_UA(3b, 100b)
- _ASM_EXTABLE_UA(4b, 100b)
- _ASM_EXTABLE_UA(5b, 100b)
- _ASM_EXTABLE_UA(6b, 100b)
- _ASM_EXTABLE_UA(7b, 100b)
- _ASM_EXTABLE_UA(8b, 100b)
- _ASM_EXTABLE_UA(9b, 100b)
- _ASM_EXTABLE_UA(10b, 100b)
- _ASM_EXTABLE_UA(11b, 100b)
- _ASM_EXTABLE_UA(12b, 100b)
- _ASM_EXTABLE_UA(13b, 100b)
- _ASM_EXTABLE_UA(14b, 100b)
- _ASM_EXTABLE_UA(15b, 100b)
- _ASM_EXTABLE_UA(16b, 100b)
- _ASM_EXTABLE_UA(17b, 100b)
- _ASM_EXTABLE_UA(18b, 100b)
- _ASM_EXTABLE_UA(19b, 100b)
- _ASM_EXTABLE_UA(20b, 100b)
- _ASM_EXTABLE_UA(21b, 100b)
- _ASM_EXTABLE_UA(22b, 100b)
- _ASM_EXTABLE_UA(23b, 100b)
- _ASM_EXTABLE_UA(24b, 100b)
- _ASM_EXTABLE_UA(25b, 100b)
- _ASM_EXTABLE_UA(26b, 100b)
- _ASM_EXTABLE_UA(27b, 100b)
- _ASM_EXTABLE_UA(28b, 100b)
- _ASM_EXTABLE_UA(29b, 100b)
- _ASM_EXTABLE_UA(30b, 100b)
- _ASM_EXTABLE_UA(31b, 100b)
- _ASM_EXTABLE_UA(32b, 100b)
- _ASM_EXTABLE_UA(33b, 100b)
- _ASM_EXTABLE_UA(34b, 100b)
- _ASM_EXTABLE_UA(35b, 100b)
- _ASM_EXTABLE_UA(36b, 100b)
- _ASM_EXTABLE_UA(37b, 100b)
- _ASM_EXTABLE_TYPE_REG(99b, 100b, EX_TYPE_UCOPY_LEN4, %%eax)
- : "=&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"
- _ASM_EXTABLE_UA(0b, 8b)
- _ASM_EXTABLE_UA(1b, 8b)
- _ASM_EXTABLE_UA(2b, 8b)
- _ASM_EXTABLE_UA(21b, 8b)
- _ASM_EXTABLE_UA(3b, 8b)
- _ASM_EXTABLE_UA(31b, 8b)
- _ASM_EXTABLE_UA(4b, 8b)
- _ASM_EXTABLE_UA(41b, 8b)
- _ASM_EXTABLE_UA(10b, 8b)
- _ASM_EXTABLE_UA(51b, 8b)
- _ASM_EXTABLE_UA(11b, 8b)
- _ASM_EXTABLE_UA(61b, 8b)
- _ASM_EXTABLE_UA(12b, 8b)
- _ASM_EXTABLE_UA(71b, 8b)
- _ASM_EXTABLE_UA(13b, 8b)
- _ASM_EXTABLE_UA(81b, 8b)
- _ASM_EXTABLE_UA(14b, 8b)
- _ASM_EXTABLE_UA(91b, 8b)
- _ASM_EXTABLE_TYPE_REG(6b, 8b, EX_TYPE_UCOPY_LEN4, %%eax)
- _ASM_EXTABLE_UA(7b, 8b)
- : "=&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" \
- _ASM_EXTABLE_TYPE_REG(4b, 2b, EX_TYPE_UCOPY_LEN1, %3) \
- _ASM_EXTABLE_TYPE_REG(0b, 2b, EX_TYPE_UCOPY_LEN4, %3) \
- _ASM_EXTABLE_UA(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);
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