cregit-Linux how code gets into the kernel

Release 4.11 arch/x86/lib/usercopy_64.c

Directory: arch/x86/lib
/* 
 * User address space access functions.
 *
 * Copyright 1997 Andi Kleen <ak@muc.de>
 * Copyright 1997 Linus Torvalds
 * Copyright 2002 Andi Kleen <ak@suse.de>
 */
#include <linux/export.h>
#include <linux/uaccess.h>

/*
 * Zero Userspace
 */


unsigned long __clear_user(void __user *addr, unsigned long size) { long __d0; might_fault(); /* no memory constraint because it doesn't change any memory gcc knows about */ stac(); asm volatile( " testq %[size8],%[size8]\n" " jz 4f\n" "0: movq %[zero],(%[dst])\n" " addq %[eight],%[dst]\n" " decl %%ecx ; jnz 0b\n" "4: movq %[size1],%%rcx\n" " testl %%ecx,%%ecx\n" " jz 2f\n" "1: movb %b[zero],(%[dst])\n" " incq %[dst]\n" " decl %%ecx ; jnz 1b\n" "2:\n" ".section .fixup,\"ax\"\n" "3: lea 0(%[size1],%[size8],8),%[size8]\n" " jmp 2b\n" ".previous\n" _ASM_EXTABLE(0b,3b) _ASM_EXTABLE(1b,2b) : [size8] "=&c"(size), [dst] "=&D" (__d0) : [size1] "r"(size & 7), "[size8]" (size / 8), "[dst]"(addr), [zero] "r" (0UL), [eight] "r" (8UL)); clac(); return size; }

Contributors

PersonTokensPropCommitsCommitProp
Andi Kleen2676.47%457.14%
H. Peter Anvin617.65%114.29%
Nicholas Piggin12.94%114.29%
Al Viro12.94%114.29%
Total34100.00%7100.00%

EXPORT_SYMBOL(__clear_user);
unsigned long clear_user(void __user *to, unsigned long n) { if (access_ok(VERIFY_WRITE, to, n)) return __clear_user(to, n); return n; }

Contributors

PersonTokensPropCommitsCommitProp
Andi Kleen3697.30%266.67%
Al Viro12.70%133.33%
Total37100.00%3100.00%

EXPORT_SYMBOL(clear_user);
unsigned long copy_in_user(void __user *to, const void __user *from, unsigned len) { if (access_ok(VERIFY_WRITE, to, len) && access_ok(VERIFY_READ, from, len)) { return copy_user_generic((__force void *)to, (__force void *)from, len); } return len; }

Contributors

PersonTokensPropCommitsCommitProp
Andi Kleen5381.54%133.33%
Al Viro1218.46%266.67%
Total65100.00%3100.00%

EXPORT_SYMBOL(copy_in_user); /* * Try to copy last bytes and clear the rest if needed. * Since protection fault in copy_from/to_user is not a normal situation, * it is not necessary to optimize tail handling. */
__visible unsigned long copy_user_handle_tail(char *to, char *from, unsigned len) { for (; len; --len, to++) { char c; if (__get_user_nocheck(c, from++, sizeof(char))) break; if (__put_user_nocheck(c, to, sizeof(char))) break; } clac(); /* If the destination is a kernel buffer, we always clear the end */ if (!__addr_ok(to)) memset(to, 0, len); return len; }

Contributors

PersonTokensPropCommitsCommitProp
Vitaly Mayatskikh6775.28%116.67%
Linus Torvalds1719.10%233.33%
CQ Tang33.37%116.67%
Andi Kleen11.12%116.67%
H. Peter Anvin11.12%116.67%
Total89100.00%6100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Andi Kleen13755.02%741.18%
Vitaly Mayatskikh6827.31%15.88%
Linus Torvalds176.83%211.76%
Al Viro145.62%211.76%
H. Peter Anvin72.81%15.88%
CQ Tang31.20%15.88%
Andrew Lutomirski10.40%15.88%
Nicholas Piggin10.40%15.88%
Paul Gortmaker10.40%15.88%
Total249100.00%17100.00%
Directory: arch/x86/lib
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