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-vmxcopy.c (2240B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright 2015, Michael Neuling, IBM Corp.
      4 *
      5 * Original: Michael Neuling 4/12/2013
      6 * Edited: Rashmica Gupta 4/12/2015
      7 *
      8 * See if the altivec state is leaked out of an aborted transaction due to
      9 * kernel vmx copy loops.
     10 *
     11 * When the transaction aborts, VSR values should rollback to the values
     12 * they held before the transaction commenced. Using VSRs while transaction
     13 * is suspended should not affect the checkpointed values.
     14 *
     15 * (1) write A to a VSR
     16 * (2) start transaction
     17 * (3) suspend transaction
     18 * (4) change the VSR to B
     19 * (5) trigger kernel vmx copy loop
     20 * (6) abort transaction
     21 * (7) check that the VSR value is A
     22 */
     23
     24#include <inttypes.h>
     25#include <stdio.h>
     26#include <stdlib.h>
     27#include <unistd.h>
     28#include <sys/mman.h>
     29#include <string.h>
     30#include <assert.h>
     31
     32#include "tm.h"
     33#include "utils.h"
     34
     35int test_vmxcopy()
     36{
     37	long double vecin = 1.3;
     38	long double vecout;
     39	unsigned long pgsize = getpagesize();
     40	int i;
     41	int fd;
     42	int size = pgsize*16;
     43	char tmpfile[] = "/tmp/page_faultXXXXXX";
     44	char buf[pgsize];
     45	char *a;
     46	uint64_t aborted = 0;
     47
     48	SKIP_IF(!have_htm());
     49	SKIP_IF(htm_is_synthetic());
     50	SKIP_IF(!is_ppc64le());
     51
     52	fd = mkstemp(tmpfile);
     53	assert(fd >= 0);
     54
     55	memset(buf, 0, pgsize);
     56	for (i = 0; i < size; i += pgsize)
     57		assert(write(fd, buf, pgsize) == pgsize);
     58
     59	unlink(tmpfile);
     60
     61	a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
     62	assert(a != MAP_FAILED);
     63
     64	asm __volatile__(
     65		"lxvd2x 40,0,%[vecinptr];"	/* set 40 to initial value*/
     66		"tbegin.;"
     67		"beq	3f;"
     68		"tsuspend.;"
     69		"xxlxor 40,40,40;"		/* set 40 to 0 */
     70		"std	5, 0(%[map]);"		/* cause kernel vmx copy page */
     71		"tabort. 0;"
     72		"tresume.;"
     73		"tend.;"
     74		"li	%[res], 0;"
     75		"b	5f;"
     76
     77		/* Abort handler */
     78		"3:;"
     79		"li	%[res], 1;"
     80
     81		"5:;"
     82		"stxvd2x 40,0,%[vecoutptr];"
     83		: [res]"=&r"(aborted)
     84		: [vecinptr]"r"(&vecin),
     85		  [vecoutptr]"r"(&vecout),
     86		  [map]"r"(a)
     87		: "memory", "r0", "r3", "r4", "r5", "r6", "r7");
     88
     89	if (aborted && (vecin != vecout)){
     90		printf("FAILED: vector state leaked on abort %f != %f\n",
     91		       (double)vecin, (double)vecout);
     92		return 1;
     93	}
     94
     95	munmap(a, size);
     96
     97	close(fd);
     98
     99	return 0;
    100}
    101
    102int main(void)
    103{
    104	return test_harness(test_vmxcopy, "tm_vmxcopy");
    105}