mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
synced 2025-08-30 03:57:32 +00:00
42c782fae3
Minimum version of binutils required to compile the kernel is 2.25. This version correctly handles the "rep" prefixes, so it is possible to remove the semicolon, which was used to support ancient versions of GNU as. Due to the semicolon, the compiler considers "rep; insn" (or its alternate "rep\n\tinsn" form) as two separate instructions. Removing the semicolon makes asm length calculations more accurate, consequently making scheduling and inlining decisions of the compiler more accurate. Removing the semicolon also enables assembler checks involving "rep" prefixes. Trying to assemble e.g. "rep addl %eax, %ebx" results in: Error: invalid instruction `add' after `rep' Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@kernel.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20250418071437.4144391-2-ubizjak@gmail.com
341 lines
10 KiB
C
341 lines
10 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* User address space access functions.
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* The non inlined parts of asm-i386/uaccess.h are here.
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*
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* Copyright 1997 Andi Kleen <ak@muc.de>
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* Copyright 1997 Linus Torvalds
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*/
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#include <linux/export.h>
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#include <linux/uaccess.h>
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#include <asm/asm.h>
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#ifdef CONFIG_X86_INTEL_USERCOPY
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/*
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* Alignment at which movsl is preferred for bulk memory copies.
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*/
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struct movsl_mask movsl_mask __read_mostly;
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#endif
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static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned long n)
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{
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#ifdef CONFIG_X86_INTEL_USERCOPY
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if (n >= 64 && ((a1 ^ a2) & movsl_mask.mask))
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return 0;
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#endif
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return 1;
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}
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#define movsl_is_ok(a1, a2, n) \
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__movsl_is_ok((unsigned long)(a1), (unsigned long)(a2), (n))
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/*
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* Zero Userspace
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*/
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#define __do_clear_user(addr,size) \
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do { \
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int __d0; \
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might_fault(); \
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__asm__ __volatile__( \
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ASM_STAC "\n" \
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"0: rep stosl\n" \
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" movl %2,%0\n" \
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"1: rep stosb\n" \
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"2: " ASM_CLAC "\n" \
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_ASM_EXTABLE_TYPE_REG(0b, 2b, EX_TYPE_UCOPY_LEN4, %2) \
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_ASM_EXTABLE_UA(1b, 2b) \
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: "=&c"(size), "=&D" (__d0) \
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: "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0)); \
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} while (0)
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/**
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* clear_user - Zero a block of memory in user space.
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* @to: Destination address, in user space.
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* @n: Number of bytes to zero.
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*
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* Zero a block of memory in user space.
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*
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* Return: number of bytes that could not be cleared.
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* On success, this will be zero.
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*/
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unsigned long
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clear_user(void __user *to, unsigned long n)
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{
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might_fault();
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if (access_ok(to, n))
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__do_clear_user(to, n);
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return n;
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}
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EXPORT_SYMBOL(clear_user);
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/**
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* __clear_user - Zero a block of memory in user space, with less checking.
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* @to: Destination address, in user space.
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* @n: Number of bytes to zero.
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*
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* Zero a block of memory in user space. Caller must check
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* the specified block with access_ok() before calling this function.
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*
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* Return: number of bytes that could not be cleared.
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* On success, this will be zero.
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*/
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unsigned long
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__clear_user(void __user *to, unsigned long n)
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{
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__do_clear_user(to, n);
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return n;
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}
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EXPORT_SYMBOL(__clear_user);
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#ifdef CONFIG_X86_INTEL_USERCOPY
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static unsigned long
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__copy_user_intel(void __user *to, const void *from, unsigned long size)
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{
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int d0, d1;
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__asm__ __volatile__(
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" .align 2,0x90\n"
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"1: movl 32(%4), %%eax\n"
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" cmpl $67, %0\n"
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" jbe 3f\n"
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"2: movl 64(%4), %%eax\n"
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" .align 2,0x90\n"
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"3: movl 0(%4), %%eax\n"
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"4: movl 4(%4), %%edx\n"
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"5: movl %%eax, 0(%3)\n"
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"6: movl %%edx, 4(%3)\n"
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"7: movl 8(%4), %%eax\n"
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"8: movl 12(%4),%%edx\n"
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"9: movl %%eax, 8(%3)\n"
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"10: movl %%edx, 12(%3)\n"
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"11: movl 16(%4), %%eax\n"
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"12: movl 20(%4), %%edx\n"
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"13: movl %%eax, 16(%3)\n"
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"14: movl %%edx, 20(%3)\n"
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"15: movl 24(%4), %%eax\n"
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"16: movl 28(%4), %%edx\n"
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"17: movl %%eax, 24(%3)\n"
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"18: movl %%edx, 28(%3)\n"
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"19: movl 32(%4), %%eax\n"
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"20: movl 36(%4), %%edx\n"
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"21: movl %%eax, 32(%3)\n"
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"22: movl %%edx, 36(%3)\n"
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"23: movl 40(%4), %%eax\n"
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"24: movl 44(%4), %%edx\n"
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"25: movl %%eax, 40(%3)\n"
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"26: movl %%edx, 44(%3)\n"
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"27: movl 48(%4), %%eax\n"
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"28: movl 52(%4), %%edx\n"
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"29: movl %%eax, 48(%3)\n"
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"30: movl %%edx, 52(%3)\n"
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"31: movl 56(%4), %%eax\n"
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"32: movl 60(%4), %%edx\n"
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"33: movl %%eax, 56(%3)\n"
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"34: movl %%edx, 60(%3)\n"
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" addl $-64, %0\n"
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" addl $64, %4\n"
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" addl $64, %3\n"
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" cmpl $63, %0\n"
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" ja 1b\n"
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"35: movl %0, %%eax\n"
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" shrl $2, %0\n"
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" andl $3, %%eax\n"
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" cld\n"
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"99: rep movsl\n"
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"36: movl %%eax, %0\n"
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"37: rep movsb\n"
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"100:\n"
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_ASM_EXTABLE_UA(1b, 100b)
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_ASM_EXTABLE_UA(2b, 100b)
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_ASM_EXTABLE_UA(3b, 100b)
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_ASM_EXTABLE_UA(4b, 100b)
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_ASM_EXTABLE_UA(5b, 100b)
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_ASM_EXTABLE_UA(6b, 100b)
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_ASM_EXTABLE_UA(7b, 100b)
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_ASM_EXTABLE_UA(8b, 100b)
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_ASM_EXTABLE_UA(9b, 100b)
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_ASM_EXTABLE_UA(10b, 100b)
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_ASM_EXTABLE_UA(11b, 100b)
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_ASM_EXTABLE_UA(12b, 100b)
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_ASM_EXTABLE_UA(13b, 100b)
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_ASM_EXTABLE_UA(14b, 100b)
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_ASM_EXTABLE_UA(15b, 100b)
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_ASM_EXTABLE_UA(16b, 100b)
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_ASM_EXTABLE_UA(17b, 100b)
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_ASM_EXTABLE_UA(18b, 100b)
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_ASM_EXTABLE_UA(19b, 100b)
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_ASM_EXTABLE_UA(20b, 100b)
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_ASM_EXTABLE_UA(21b, 100b)
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_ASM_EXTABLE_UA(22b, 100b)
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_ASM_EXTABLE_UA(23b, 100b)
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_ASM_EXTABLE_UA(24b, 100b)
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_ASM_EXTABLE_UA(25b, 100b)
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_ASM_EXTABLE_UA(26b, 100b)
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_ASM_EXTABLE_UA(27b, 100b)
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_ASM_EXTABLE_UA(28b, 100b)
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_ASM_EXTABLE_UA(29b, 100b)
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_ASM_EXTABLE_UA(30b, 100b)
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_ASM_EXTABLE_UA(31b, 100b)
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_ASM_EXTABLE_UA(32b, 100b)
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_ASM_EXTABLE_UA(33b, 100b)
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_ASM_EXTABLE_UA(34b, 100b)
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_ASM_EXTABLE_UA(35b, 100b)
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_ASM_EXTABLE_UA(36b, 100b)
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_ASM_EXTABLE_UA(37b, 100b)
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_ASM_EXTABLE_TYPE_REG(99b, 100b, EX_TYPE_UCOPY_LEN4, %%eax)
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: "=&c"(size), "=&D" (d0), "=&S" (d1)
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: "1"(to), "2"(from), "0"(size)
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: "eax", "edx", "memory");
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return size;
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}
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static unsigned long __copy_user_intel_nocache(void *to,
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const void __user *from, unsigned long size)
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{
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int d0, d1;
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__asm__ __volatile__(
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" .align 2,0x90\n"
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"0: movl 32(%4), %%eax\n"
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" cmpl $67, %0\n"
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" jbe 2f\n"
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"1: movl 64(%4), %%eax\n"
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" .align 2,0x90\n"
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"2: movl 0(%4), %%eax\n"
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"21: movl 4(%4), %%edx\n"
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" movnti %%eax, 0(%3)\n"
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" movnti %%edx, 4(%3)\n"
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"3: movl 8(%4), %%eax\n"
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"31: movl 12(%4),%%edx\n"
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" movnti %%eax, 8(%3)\n"
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" movnti %%edx, 12(%3)\n"
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"4: movl 16(%4), %%eax\n"
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"41: movl 20(%4), %%edx\n"
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" movnti %%eax, 16(%3)\n"
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" movnti %%edx, 20(%3)\n"
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"10: movl 24(%4), %%eax\n"
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"51: movl 28(%4), %%edx\n"
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" movnti %%eax, 24(%3)\n"
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" movnti %%edx, 28(%3)\n"
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"11: movl 32(%4), %%eax\n"
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"61: movl 36(%4), %%edx\n"
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" movnti %%eax, 32(%3)\n"
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" movnti %%edx, 36(%3)\n"
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"12: movl 40(%4), %%eax\n"
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"71: movl 44(%4), %%edx\n"
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" movnti %%eax, 40(%3)\n"
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" movnti %%edx, 44(%3)\n"
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"13: movl 48(%4), %%eax\n"
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"81: movl 52(%4), %%edx\n"
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" movnti %%eax, 48(%3)\n"
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" movnti %%edx, 52(%3)\n"
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"14: movl 56(%4), %%eax\n"
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"91: movl 60(%4), %%edx\n"
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" movnti %%eax, 56(%3)\n"
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" movnti %%edx, 60(%3)\n"
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" addl $-64, %0\n"
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" addl $64, %4\n"
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" addl $64, %3\n"
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" cmpl $63, %0\n"
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" ja 0b\n"
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" sfence \n"
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"5: movl %0, %%eax\n"
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" shrl $2, %0\n"
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" andl $3, %%eax\n"
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" cld\n"
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"6: rep movsl\n"
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" movl %%eax,%0\n"
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"7: rep movsb\n"
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"8:\n"
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_ASM_EXTABLE_UA(0b, 8b)
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_ASM_EXTABLE_UA(1b, 8b)
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_ASM_EXTABLE_UA(2b, 8b)
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_ASM_EXTABLE_UA(21b, 8b)
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_ASM_EXTABLE_UA(3b, 8b)
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_ASM_EXTABLE_UA(31b, 8b)
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_ASM_EXTABLE_UA(4b, 8b)
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_ASM_EXTABLE_UA(41b, 8b)
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_ASM_EXTABLE_UA(10b, 8b)
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_ASM_EXTABLE_UA(51b, 8b)
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_ASM_EXTABLE_UA(11b, 8b)
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_ASM_EXTABLE_UA(61b, 8b)
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_ASM_EXTABLE_UA(12b, 8b)
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_ASM_EXTABLE_UA(71b, 8b)
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_ASM_EXTABLE_UA(13b, 8b)
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_ASM_EXTABLE_UA(81b, 8b)
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_ASM_EXTABLE_UA(14b, 8b)
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_ASM_EXTABLE_UA(91b, 8b)
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_ASM_EXTABLE_TYPE_REG(6b, 8b, EX_TYPE_UCOPY_LEN4, %%eax)
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_ASM_EXTABLE_UA(7b, 8b)
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: "=&c"(size), "=&D" (d0), "=&S" (d1)
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: "1"(to), "2"(from), "0"(size)
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: "eax", "edx", "memory");
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return size;
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}
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#else
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/*
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* Leave these declared but undefined. They should not be any references to
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* them
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*/
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unsigned long __copy_user_intel(void __user *to, const void *from,
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unsigned long size);
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#endif /* CONFIG_X86_INTEL_USERCOPY */
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/* Generic arbitrary sized copy. */
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#define __copy_user(to, from, size) \
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do { \
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int __d0, __d1, __d2; \
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__asm__ __volatile__( \
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" cmp $7,%0\n" \
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" jbe 1f\n" \
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" movl %1,%0\n" \
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" negl %0\n" \
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" andl $7,%0\n" \
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" subl %0,%3\n" \
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"4: rep movsb\n" \
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" movl %3,%0\n" \
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" shrl $2,%0\n" \
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" andl $3,%3\n" \
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" .align 2,0x90\n" \
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"0: rep movsl\n" \
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" movl %3,%0\n" \
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"1: rep movsb\n" \
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"2:\n" \
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_ASM_EXTABLE_TYPE_REG(4b, 2b, EX_TYPE_UCOPY_LEN1, %3) \
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_ASM_EXTABLE_TYPE_REG(0b, 2b, EX_TYPE_UCOPY_LEN4, %3) \
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_ASM_EXTABLE_UA(1b, 2b) \
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: "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
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: "3"(size), "0"(size), "1"(to), "2"(from) \
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: "memory"); \
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} while (0)
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unsigned long __copy_user_ll(void *to, const void *from, unsigned long n)
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{
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__uaccess_begin_nospec();
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if (movsl_is_ok(to, from, n))
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__copy_user(to, from, n);
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else
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n = __copy_user_intel(to, from, n);
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__uaccess_end();
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return n;
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}
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EXPORT_SYMBOL(__copy_user_ll);
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unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from,
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unsigned long n)
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{
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__uaccess_begin_nospec();
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#ifdef CONFIG_X86_INTEL_USERCOPY
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if (n > 64 && static_cpu_has(X86_FEATURE_XMM2))
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n = __copy_user_intel_nocache(to, from, n);
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else
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__copy_user(to, from, n);
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#else
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__copy_user(to, from, n);
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#endif
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__uaccess_end();
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return n;
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}
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EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero);
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