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/*
* Copyright (c) 2015-2017, Intel Corporation
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Intel Corporation nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef FLOOD_RUNTIME
#define FLOOD_RUNTIME
#if defined(ARCH_64_BIT)
#define FLOOD_64
#else
#define FLOOD_32
#endif
#define FLOOD_MINIMUM_SIZE 256
#define FLOOD_BACKOFF_START 32
static really_inline
const u8 * nextFloodDetect(const u8 * buf, size_t len, u32 floodBackoff) {
// if we don't have a flood at either the start or end,
// or have a very small buffer, don't bother with flood detection
if (len < FLOOD_MINIMUM_SIZE) {
return buf + len;
}
/* entry points in runtime.c prefetch relevant data */
#ifndef FLOOD_32
u64a x11 = *(const u64a *)ROUNDUP_PTR(buf, 8);
u64a x12 = *(const u64a *)ROUNDUP_PTR(buf+8, 8);
if (x11 == x12) {
return buf + floodBackoff;
}
u64a x21 = *(const u64a *)ROUNDUP_PTR(buf + len/2, 8);
u64a x22 = *(const u64a *)ROUNDUP_PTR(buf + len/2 + 8, 8);
if (x21 == x22) {
return buf + floodBackoff;
}
u64a x31 = *(const u64a *)ROUNDUP_PTR(buf + len - 24, 8);
u64a x32 = *(const u64a *)ROUNDUP_PTR(buf + len - 16, 8);
if (x31 == x32) {
return buf + floodBackoff;
}
#else
u32 x11 = *(const u32 *)ROUNDUP_PTR(buf, 4);
u32 x12 = *(const u32 *)ROUNDUP_PTR(buf+4, 4);
if (x11 == x12) {
return buf + floodBackoff;
}
u32 x21 = *(const u32 *)ROUNDUP_PTR(buf + len/2, 4);
u32 x22 = *(const u32 *)ROUNDUP_PTR(buf + len/2 + 4, 4);
if (x21 == x22) {
return buf + floodBackoff;
}
u32 x31 = *(const u32 *)ROUNDUP_PTR(buf + len - 12, 4);
u32 x32 = *(const u32 *)ROUNDUP_PTR(buf + len - 8, 4);
if (x31 == x32) {
return buf + floodBackoff;
}
#endif
return buf + len;
}
static really_inline
const u8 * floodDetect(const struct FDR * fdr,
const struct FDR_Runtime_Args * a,
const u8 ** ptrPtr,
const u8 * tryFloodDetect,
u32 * floodBackoffPtr,
hwlmcb_rv_t * control,
u32 iterBytes) {
DEBUG_PRINTF("attempting flood detection at %p\n", tryFloodDetect);
const u8 * buf = a->buf;
const size_t len = a->len;
HWLMCallback cb = a->cb;
struct hs_scratch *scratch = a->scratch;
const u8 * ptr = *ptrPtr;
// tryFloodDetect is never put in places where unconditional
// reads a short distance forward or backward here
// TODO: rationale for this line needs to be rediscovered!!
size_t mainLoopLen = len > 2 * iterBytes ? len - 2 * iterBytes : 0;
const u32 i = ptr - buf;
u32 j = i;
// go from c to our FDRFlood structure
u8 c = buf[i];
const u8 * fBase = ((const u8 *)fdr) + fdr->floodOffset;
u32 fIdx = ((const u32 *)fBase)[c];
const struct FDRFlood * fsb = (const struct FDRFlood *)(fBase + sizeof(u32) * 256);
const struct FDRFlood * fl = &fsb[fIdx];
#ifndef FLOOD_32
u64a cmpVal = c;
cmpVal |= cmpVal << 8;
cmpVal |= cmpVal << 16;
cmpVal |= cmpVal << 32;
u64a probe = *(const u64a *)ROUNDUP_PTR(buf+i, 8);
#else
u32 cmpVal = c;
cmpVal |= cmpVal << 8;
cmpVal |= cmpVal << 16;
u32 probe = *(const u32 *)ROUNDUP_PTR(buf+i, 4);
#endif
if ((probe != cmpVal) || (fl->idCount >= FDR_FLOOD_MAX_IDS)) {
*floodBackoffPtr *= 2;
goto floodout;
}
if (i < fl->suffix + 7) {
*floodBackoffPtr *= 2;
goto floodout;
}
j = i - fl->suffix;
#ifndef FLOOD_32
j -= (u32)((uintptr_t)buf + j) & 0x7; // push j back to yield 8-aligned addrs
for (; j + 32 < mainLoopLen; j += 32) {
u64a v = *(const u64a *)(buf + j);
u64a v2 = *(const u64a *)(buf + j + 8);
u64a v3 = *(const u64a *)(buf + j + 16);
u64a v4 = *(const u64a *)(buf + j + 24);
if ((v4 != cmpVal) || (v3 != cmpVal) || (v2 != cmpVal) || (v != cmpVal)) {
break;
}
}
for (; j + 8 < mainLoopLen; j += 8) {
u64a v = *(const u64a *)(buf + j);
if (v != cmpVal) {
break;
}
}
#else
j -= (u32)((size_t)buf + j) & 0x3; // push j back to yield 4-aligned addrs
for (; j + 16 < mainLoopLen; j += 16) {
u32 v = *(const u32 *)(buf + j);
u32 v2 = *(const u32 *)(buf + j + 4);
u32 v3 = *(const u32 *)(buf + j + 8);
u32 v4 = *(const u32 *)(buf + j + 12);
if ((v4 != cmpVal) || (v3 != cmpVal) || (v2 != cmpVal) || (v != cmpVal)) {
break;
}
}
for (; j + 4 < mainLoopLen; j += 4) {
u32 v = *(const u32 *)(buf + j);
if (v != cmpVal) {
break;
}
}
#endif
for (; j < mainLoopLen; j++) {
u8 v = *(const u8 *)(buf + j);
if (v != c) {
break;
}
}
if (j > i ) {
j--; // needed for some reaches
u32 itersAhead = (j-i)/iterBytes;
u32 floodSize = itersAhead*iterBytes;
DEBUG_PRINTF("flooding %u size j %u i %u fl->idCount %hu "
"*control %016llx fl->allGroups %016llx\n",
floodSize, j, i, fl->idCount, *control, fl->allGroups);
DEBUG_PRINTF("mainloopLen %zu mainStart ??? mainEnd ??? len %zu\n",
mainLoopLen, len);
if (fl->idCount && (*control & fl->allGroups)) {
switch (fl->idCount) {
#if !defined(FLOOD_DEBUG)
// Carefully unrolled code
case 1:
for (u32 t = 0; t < floodSize && (*control & fl->allGroups);
t += 4) {
DEBUG_PRINTF("aaa %u %llx\n", t, fl->groups[0]);
if (*control & fl->groups[0]) {
*control = cb(i + t + 0, fl->ids[0], scratch);
}
if (*control & fl->groups[0]) {
*control = cb(i + t + 1, fl->ids[0], scratch);
}
if (*control & fl->groups[0]) {
*control = cb(i + t + 2, fl->ids[0], scratch);
}
if (*control & fl->groups[0]) {
*control = cb(i + t + 3, fl->ids[0], scratch);
}
}
break;
case 2:
for (u32 t = 0; t < floodSize && (*control & fl->allGroups); t += 4) {
if (*control & fl->groups[0]) {
*control = cb(i + t, fl->ids[0], scratch);
}
if (*control & fl->groups[1]) {
*control = cb(i + t, fl->ids[1], scratch);
}
if (*control & fl->groups[0]) {
*control =
cb(i + t + 1, fl->ids[0], scratch);
}
if (*control & fl->groups[1]) {
*control = cb(i + t + 1, fl->ids[1], scratch);
}
if (*control & fl->groups[0]) {
*control = cb(i + t + 2, fl->ids[0], scratch);
}
if (*control & fl->groups[1]) {
*control = cb(i + t + 2, fl->ids[1], scratch);
}
if (*control & fl->groups[0]) {
*control = cb(i + t + 3, fl->ids[0], scratch);
}
if (*control & fl->groups[1]) {
*control = cb(i + t + 3, fl->ids[1], scratch);
}
}
break;
case 3:
for (u32 t = 0; t < floodSize && (*control & fl->allGroups); t += 2) {
if (*control & fl->groups[0]) {
*control = cb(i + t, fl->ids[0], scratch);
}
if (*control & fl->groups[1]) {
*control = cb(i + t, fl->ids[1], scratch);
}
if (*control & fl->groups[2]) {
*control = cb(i + t, fl->ids[2], scratch);
}
if (*control & fl->groups[0]) {
*control = cb(i + t + 1, fl->ids[0], scratch);
}
if (*control & fl->groups[1]) {
*control = cb(i + t + 1, fl->ids[1], scratch);
}
if (*control & fl->groups[2]) {
*control = cb(i + t + 1, fl->ids[2], scratch);
}
}
break;
default:
// slow generalized loop
for (u32 t = 0; t < floodSize && (*control & fl->allGroups); t += 2) {
if (*control & fl->groups[0]) {
*control = cb(i + t, fl->ids[0], scratch);
}
if (*control & fl->groups[1]) {
*control = cb(i + t, fl->ids[1], scratch);
}
if (*control & fl->groups[2]) {
*control = cb(i + t, fl->ids[2], scratch);
}
if (*control & fl->groups[3]) {
*control = cb(i + t, fl->ids[3], scratch);
}
for (u32 t2 = 4; t2 < fl->idCount; t2++) {
if (*control & fl->groups[t2]) {
*control = cb(i + t, fl->ids[t2], scratch);
}
}
if (*control & fl->groups[0]) {
*control = cb(i + t + 1, fl->ids[0], scratch);
}
if (*control & fl->groups[1]) {
*control = cb(i + t + 1, fl->ids[1], scratch);
}
if (*control & fl->groups[2]) {
*control = cb(i + t + 1, fl->ids[2], scratch);
}
if (*control & fl->groups[3]) {
*control = cb(i + t + 1, fl->ids[3], scratch);
}
for (u32 t2 = 4; t2 < fl->idCount; t2++) {
if (*control & fl->groups[t2]) {
*control = cb(i + t + 1, fl->ids[t2], scratch);
}
}
}
break;
#else
// Fallback for debugging
default:
for (u32 t = 0; t < floodSize && (*control & fl->allGroups); t++) {
for (u32 t2 = 0; t2 < fl->idCount; t2++) {
if (*control & fl->groups[t2]) {
*control = cb(i + t, fl->ids[t2], scratch);
}
}
}
#endif
}
}
ptr += floodSize;
} else {
*floodBackoffPtr *= 2;
}
floodout:
if (j + *floodBackoffPtr < mainLoopLen - 128) {
tryFloodDetect = buf + MAX(i,j) + *floodBackoffPtr;
} else {
tryFloodDetect = buf + mainLoopLen; // set so we never do another flood detect
}
*ptrPtr = ptr;
DEBUG_PRINTF("finished flood detection at %p (next check %p)\n",
ptr, tryFloodDetect);
return tryFloodDetect;
}
#endif
|
