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Make more functions friendly to Address Sanitizer

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This commit is contained in:
Justine Tunney 2021-02-02 03:45:31 -08:00
parent 3ab76b2312
commit cbfd4ccd1e
70 changed files with 1267 additions and 291 deletions
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100
libc/str/memset-pure.c Normal file
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@ -0,0 +1,100 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2021 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/str/str.h"
/**
* Sets memory.
*
* @param p is memory address
* @param c is masked with 255 and used as repeated byte
* @param n is byte length
* @return p
* @asyncsignalsafe
*/
void *memset$pure(void *p, int c, size_t n) {
char *b;
uint64_t x;
b = p;
x = 0x0101010101010101 * (c & 0xff);
switch (n) {
case 0:
return p;
case 1:
__builtin_memcpy(b, &x, 1);
return p;
case 2:
__builtin_memcpy(b, &x, 2);
return p;
case 3:
__builtin_memcpy(b, &x, 2);
__builtin_memcpy(b + 1, &x, 2);
return p;
case 4:
__builtin_memcpy(b, &x, 4);
return p;
case 5 ... 7:
__builtin_memcpy(b, &x, 4);
__builtin_memcpy(b + n - 4, &x, 4);
return p;
case 8:
__builtin_memcpy(b, &x, 8);
return p;
case 9 ... 16:
__builtin_memcpy(b, &x, 8);
__builtin_memcpy(b + n - 8, &x, 8);
return p;
default:
do {
n -= 16;
__builtin_memcpy(b + n, &x, 8);
asm volatile("" ::: "memory");
__builtin_memcpy(b + n + 8, &x, 8);
} while (n >= 16);
switch (n) {
case 0:
return p;
case 1:
__builtin_memcpy(b, &x, 1);
return p;
case 2:
__builtin_memcpy(b, &x, 2);
return p;
case 3:
__builtin_memcpy(b, &x, 2);
__builtin_memcpy(b + 1, &x, 2);
return p;
case 4:
__builtin_memcpy(b, &x, 4);
return p;
case 5 ... 7:
__builtin_memcpy(b, &x, 4);
__builtin_memcpy(b + n - 4, &x, 4);
return p;
case 8:
__builtin_memcpy(b, &x, 8);
return p;
case 9 ... 15:
__builtin_memcpy(b, &x, 8);
__builtin_memcpy(b + n - 8, &x, 8);
return p;
default:
unreachable;
}
}
}