cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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tm-tar.c (2008B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright 2015, Michael Neuling, IBM Corp.
      4 * Original: Michael Neuling 19/7/2013
      5 * Edited: Rashmica Gupta 01/12/2015
      6 *
      7 * Do some transactions, see if the tar is corrupted.
      8 * If the transaction is aborted, the TAR should be rolled back to the
      9 * checkpointed value before the transaction began. The value written to
     10 * TAR in suspended mode should only remain in TAR if the transaction
     11 * completes.
     12 */
     13
     14#include <stdio.h>
     15#include <stdlib.h>
     16#include <unistd.h>
     17#include <string.h>
     18
     19#include "tm.h"
     20#include "utils.h"
     21
     22int	num_loops	= 10000;
     23
     24int test_tar(void)
     25{
     26	int i;
     27
     28	SKIP_IF(!have_htm());
     29	SKIP_IF(htm_is_synthetic());
     30	SKIP_IF(!is_ppc64le());
     31
     32	for (i = 0; i < num_loops; i++)
     33	{
     34		uint64_t result = 0;
     35		asm __volatile__(
     36			"li	7, 1;"
     37			"mtspr	%[tar], 7;"	/* tar = 1 */
     38			"tbegin.;"
     39			"beq	3f;"
     40			"li	4, 0x7000;"	/* Loop lots, to use time */
     41			"2:;"			/* Start loop */
     42			"li	7, 2;"
     43			"mtspr	%[tar], 7;"	/* tar = 2 */
     44			"tsuspend.;"
     45			"li	7, 3;"
     46			"mtspr	%[tar], 7;"	/* tar = 3 */
     47			"tresume.;"
     48			"subi	4, 4, 1;"
     49			"cmpdi	4, 0;"
     50			"bne	2b;"
     51			"tend.;"
     52
     53			/* Transaction sucess! TAR should be 3 */
     54			"mfspr  7, %[tar];"
     55			"ori	%[res], 7, 4;"  // res = 3|4 = 7
     56			"b	4f;"
     57
     58			/* Abort handler. TAR should be rolled back to 1 */
     59			"3:;"
     60			"mfspr  7, %[tar];"
     61			"ori	%[res], 7, 8;"	// res = 1|8 = 9
     62			"4:;"
     63
     64			: [res]"=r"(result)
     65			: [tar]"i"(SPRN_TAR)
     66			   : "memory", "r0", "r4", "r7");
     67
     68		/* If result is anything else other than 7 or 9, the tar
     69		 * value must have been corrupted. */
     70		if ((result != 7) && (result != 9))
     71			return 1;
     72	}
     73	return 0;
     74}
     75
     76int main(int argc, char *argv[])
     77{
     78	/* A low number of iterations (eg 100) can cause a false pass */
     79	if (argc > 1) {
     80		if (strcmp(argv[1], "-h") == 0) {
     81			printf("Syntax:\n\t%s [<num loops>]\n",
     82			       argv[0]);
     83			return 1;
     84		} else {
     85			num_loops = atoi(argv[1]);
     86		}
     87	}
     88
     89	printf("Starting, %d loops\n", num_loops);
     90
     91	return test_harness(test_tar, "tm_tar");
     92}