cregit-Linux how code gets into the kernel

Release 4.14 arch/xtensa/include/asm/checksum.h

/*
 * include/asm-xtensa/checksum.h
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2001 - 2005 Tensilica Inc.
 */

#ifndef _XTENSA_CHECKSUM_H

#define _XTENSA_CHECKSUM_H

#include <linux/in6.h>
#include <linux/uaccess.h>
#include <variant/core.h>

/*
 * computes the checksum of a memory block at buff, length len,
 * and adds in "sum" (32-bit)
 *
 * returns a 32-bit number suitable for feeding into itself
 * or csum_tcpudp_magic
 *
 * this function must be called with even lengths, except
 * for the last fragment, which may be odd
 *
 * it's best to have buff aligned on a 32-bit boundary
 */
asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum);

/*
 * the same as csum_partial, but copies from src while it
 * checksums, and handles user-space pointer exceptions correctly, when needed.
 *
 * here even more important to align src and dst on a 32-bit (or even
 * better 64-bit) boundary
 */

asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst,
					    int len, __wsum sum,
					    int *src_err_ptr, int *dst_err_ptr);

/*
 *      Note: when you get a NULL pointer exception here this means someone
 *      passed in an incorrect kernel address to one of these functions.
 *
 *      If you use these functions directly please don't forget the access_ok().
 */

static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum) { return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
Chris Zankel3284.21%133.33%
Al Viro410.53%133.33%
Adrian Bunk25.26%133.33%
Total38100.00%3100.00%


static inline __wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *err_ptr) { return csum_partial_copy_generic((__force const void *)src, dst, len, sum, err_ptr, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
Chris Zankel3673.47%133.33%
Al Viro1122.45%133.33%
Adrian Bunk24.08%133.33%
Total49100.00%3100.00%

/* * Fold a partial checksum */
static __inline__ __sum16 csum_fold(__wsum sum) { unsigned int __dummy; __asm__("extui %1, %0, 16, 16\n\t" "extui %0 ,%0, 0, 16\n\t" "add %0, %0, %1\n\t" "slli %1, %0, 16\n\t" "add %0, %0, %1\n\t" "extui %0, %0, 16, 16\n\t" "neg %0, %0\n\t" "addi %0, %0, -1\n\t" "extui %0, %0, 0, 16\n\t" : "=r" (sum), "=&r" (__dummy) : "0" (sum)); return (__force __sum16)sum; }

Contributors

PersonTokensPropCommitsCommitProp
Chris Zankel1672.73%150.00%
Al Viro627.27%150.00%
Total22100.00%2100.00%

/* * This is a version of ip_compute_csum() optimized for IP headers, * which always checksum on 4 octet boundaries. */
static __inline__ __sum16 ip_fast_csum(const void *iph, unsigned int ihl) { unsigned int sum, tmp, endaddr; __asm__ __volatile__( "sub %0, %0, %0\n\t" #if XCHAL_HAVE_LOOPS "loopgtz %2, 2f\n\t" #else "beqz %2, 2f\n\t" "slli %4, %2, 2\n\t" "add %4, %4, %1\n\t" "0:\t" #endif "l32i %3, %1, 0\n\t" "add %0, %0, %3\n\t" "bgeu %0, %3, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "addi %1, %1, 4\n\t" #if !XCHAL_HAVE_LOOPS "blt %1, %4, 0b\n\t" #endif "2:\t" /* Since the input registers which are loaded with iph and ihl are modified, we must also specify them as outputs, or gcc will assume they contain their original values. */ : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmp), "=&r" (endaddr) : "1" (iph), "2" (ihl) : "memory"); return csum_fold(sum); }

Contributors

PersonTokensPropCommitsCommitProp
Chris Zankel5094.34%266.67%
Al Viro35.66%133.33%
Total53100.00%3100.00%


static __inline__ __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len, __u8 proto, __wsum sum) { #ifdef __XTENSA_EL__ unsigned long len_proto = (len + proto) << 8; #elif defined(__XTENSA_EB__) unsigned long len_proto = len + proto; #else # error processor byte order undefined! #endif __asm__("add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "add %0, %0, %2\n\t" "bgeu %0, %2, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "add %0, %0, %3\n\t" "bgeu %0, %3, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" : "=r" (sum), "=r" (len_proto) : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum)); return sum; }

Contributors

PersonTokensPropCommitsCommitProp
Chris Zankel5182.26%133.33%
Al Viro914.52%133.33%
Alexander Duyck23.23%133.33%
Total62100.00%3100.00%

/* * computes the checksum of the TCP/UDP pseudo-header * returns a 16-bit checksum, already complemented */
static __inline__ __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len, __u8 proto, __wsum sum) { return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); }

Contributors

PersonTokensPropCommitsCommitProp
Chris Zankel3384.62%133.33%
Al Viro410.26%133.33%
Alexander Duyck25.13%133.33%
Total39100.00%3100.00%

/* * this routine is used for miscellaneous IP-like checksums, mainly * in icmp.c */
static __inline__ __sum16 ip_compute_csum(const void *buff, int len) { return csum_fold (csum_partial(buff, len, 0)); }

Contributors

PersonTokensPropCommitsCommitProp
Chris Zankel2589.29%150.00%
Al Viro310.71%150.00%
Total28100.00%2100.00%

#define _HAVE_ARCH_IPV6_CSUM
static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, __u32 len, __u8 proto, __wsum sum) { unsigned int __dummy; __asm__("l32i %1, %2, 0\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "l32i %1, %2, 4\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "l32i %1, %2, 8\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "l32i %1, %2, 12\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "l32i %1, %3, 0\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "l32i %1, %3, 4\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "l32i %1, %3, 8\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "l32i %1, %3, 12\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "add %0, %0, %4\n\t" "bgeu %0, %4, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "add %0, %0, %5\n\t" "bgeu %0, %5, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" : "=r" (sum), "=&r" (__dummy) : "r" (saddr), "r" (daddr), "r" (htonl(len)), "r" (htonl(proto)), "0" (sum) : "memory"); return csum_fold(sum); }

Contributors

PersonTokensPropCommitsCommitProp
Chris Zankel3487.18%250.00%
Al Viro410.26%125.00%
Alexander Duyck12.56%125.00%
Total39100.00%4100.00%

/* * Copy and checksum to user */ #define HAVE_CSUM_COPY_USER
static __inline__ __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len, __wsum sum, int *err_ptr) { if (access_ok(VERIFY_WRITE, dst, len)) return csum_partial_copy_generic(src,dst,len,sum,NULL,err_ptr); if (len) *err_ptr = -EFAULT; return (__force __wsum)-1; /* invalid checksum */ }

Contributors

PersonTokensPropCommitsCommitProp
Chris Zankel6487.67%150.00%
Al Viro912.33%150.00%
Total73100.00%2100.00%

#endif

Overall Contributors

PersonTokensPropCommitsCommitProp
Chris Zankel40684.76%436.36%
Al Viro6012.53%19.09%
Alexander Duyck51.04%218.18%
Adrian Bunk40.84%19.09%
Max Filippov20.42%19.09%
Linus Torvalds10.21%19.09%
Jesper Juhl10.21%19.09%
Total479100.00%11100.00%
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