c693cc4676
All callers of these primitives will * discard anything we might've copied in case of error * ignore the csum value in case of error * always pass 0xffffffff as the initial sum, so the resulting csum value (in case of success, that is) will never be 0. That suggest the following calling conventions: * don't pass err_ptr - just return 0 on error. * don't bother with zeroing destination, etc. in case of error * don't pass the initial sum - just use 0xffffffff. This commit does the minimal conversion in the instances of csum_and_copy_...(); the changes of actual asm code behind them are done later in the series. Note that this asm code is often shared with csum_partial_copy_nocheck(); the difference is that csum_partial_copy_nocheck() passes 0 for initial sum while csum_and_copy_..._user() pass 0xffffffff. Fortunately, we are free to pass 0xffffffff in all cases and subsequent patches will use that freedom without any special comments. A part that could be split off: parisc and uml/i386 claimed to have csum_and_copy_to_user() instances of their own, but those were identical to the generic one, so we simply drop them. Not sure if it's worth a separate commit... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
151 lines
3.4 KiB
C
151 lines
3.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _M68K_CHECKSUM_H
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#define _M68K_CHECKSUM_H
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#include <linux/in6.h>
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#ifdef CONFIG_GENERIC_CSUM
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#include <asm-generic/checksum.h>
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#else
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/*
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* computes the checksum of a memory block at buff, length len,
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* and adds in "sum" (32-bit)
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*
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* returns a 32-bit number suitable for feeding into itself
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* or csum_tcpudp_magic
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*
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* this function must be called with even lengths, except
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* for the last fragment, which may be odd
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*
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* it's best to have buff aligned on a 32-bit boundary
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*/
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__wsum csum_partial(const void *buff, int len, __wsum sum);
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/*
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* the same as csum_partial, but copies from src while it
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* checksums
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*
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* here even more important to align src and dst on a 32-bit (or even
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* better 64-bit) boundary
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*/
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#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
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#define _HAVE_ARCH_CSUM_AND_COPY
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extern __wsum csum_and_copy_from_user(const void __user *src,
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void *dst,
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int len);
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extern __wsum csum_partial_copy_nocheck(const void *src,
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void *dst, int len);
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/*
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* This is a version of ip_fast_csum() optimized for IP headers,
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* which always checksum on 4 octet boundaries.
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*/
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static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
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{
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unsigned int sum = 0;
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unsigned long tmp;
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__asm__ ("subqw #1,%2\n"
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"1:\t"
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"movel %1@+,%3\n\t"
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"addxl %3,%0\n\t"
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"dbra %2,1b\n\t"
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"movel %0,%3\n\t"
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"swap %3\n\t"
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"addxw %3,%0\n\t"
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"clrw %3\n\t"
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"addxw %3,%0\n\t"
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: "=d" (sum), "=&a" (iph), "=&d" (ihl), "=&d" (tmp)
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: "0" (sum), "1" (iph), "2" (ihl)
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: "memory");
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return (__force __sum16)~sum;
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}
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static inline __sum16 csum_fold(__wsum sum)
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{
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unsigned int tmp = (__force u32)sum;
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__asm__("swap %1\n\t"
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"addw %1, %0\n\t"
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"clrw %1\n\t"
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"addxw %1, %0"
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: "=&d" (sum), "=&d" (tmp)
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: "0" (sum), "1" (tmp));
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return (__force __sum16)~sum;
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}
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static inline __wsum
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csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
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unsigned short proto, __wsum sum)
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{
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__asm__ ("addl %2,%0\n\t"
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"addxl %3,%0\n\t"
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"addxl %4,%0\n\t"
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"clrl %1\n\t"
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"addxl %1,%0"
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: "=&d" (sum), "=d" (saddr)
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: "g" (daddr), "1" (saddr), "d" (len + proto),
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"0" (sum));
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return sum;
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}
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/*
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* computes the checksum of the TCP/UDP pseudo-header
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* returns a 16-bit checksum, already complemented
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*/
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static inline __sum16
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csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
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unsigned short proto, __wsum sum)
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{
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return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
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}
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/*
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* this routine is used for miscellaneous IP-like checksums, mainly
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* in icmp.c
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*/
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static inline __sum16 ip_compute_csum(const void *buff, int len)
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{
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return csum_fold (csum_partial(buff, len, 0));
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}
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#define _HAVE_ARCH_IPV6_CSUM
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static __inline__ __sum16
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csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
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__u32 len, __u8 proto, __wsum sum)
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{
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register unsigned long tmp;
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__asm__("addl %2@,%0\n\t"
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"movel %2@(4),%1\n\t"
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"addxl %1,%0\n\t"
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"movel %2@(8),%1\n\t"
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"addxl %1,%0\n\t"
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"movel %2@(12),%1\n\t"
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"addxl %1,%0\n\t"
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"movel %3@,%1\n\t"
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"addxl %1,%0\n\t"
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"movel %3@(4),%1\n\t"
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"addxl %1,%0\n\t"
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"movel %3@(8),%1\n\t"
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"addxl %1,%0\n\t"
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"movel %3@(12),%1\n\t"
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"addxl %1,%0\n\t"
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"addxl %4,%0\n\t"
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"clrl %1\n\t"
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"addxl %1,%0"
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: "=&d" (sum), "=&d" (tmp)
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: "a" (saddr), "a" (daddr), "d" (len + proto),
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"0" (sum));
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return csum_fold(sum);
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}
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#endif /* CONFIG_GENERIC_CSUM */
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#endif /* _M68K_CHECKSUM_H */
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