cregit-Linux how code gets into the kernel

Release 4.10 tools/testing/selftests/powerpc/tm/tm-vmxcopy.c

/*
 * Copyright 2015, Michael Neuling, IBM Corp.
 * Licensed under GPLv2.
 *
 * Original: Michael Neuling 4/12/2013
 * Edited: Rashmica Gupta 4/12/2015
 *
 * See if the altivec state is leaked out of an aborted transaction due to
 * kernel vmx copy loops.
 *
 * When the transaction aborts, VSR values should rollback to the values
 * they held before the transaction commenced. Using VSRs while transaction
 * is suspended should not affect the checkpointed values.
 *
 * (1) write A to a VSR
 * (2) start transaction
 * (3) suspend transaction
 * (4) change the VSR to B
 * (5) trigger kernel vmx copy loop
 * (6) abort transaction
 * (7) check that the VSR value is A
 */

#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
#include <string.h>
#include <assert.h>

#include "tm.h"
#include "utils.h"


int test_vmxcopy() { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; SKIP_IF(!have_htm()); fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr];" /* set 40 to initial value*/ "tbegin.;" "beq 3f;" "tsuspend.;" "xxlxor 40,40,40;" /* set 40 to 0 */ "std 5, 0(%[map]);" /* cause kernel vmx copy page */ "tabort. 0;" "tresume.;" "tend.;" "li %[res], 0;" "b 5f;" /* Abort handler */ "3:;" "li %[res], 1;" "5:;" "stxvd2x 40,0,%[vecoutptr];" : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); return 1; } munmap(a, size); close(fd); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
rashmica guptarashmica gupta201100.00%1100.00%
Total201100.00%1100.00%


int main(void) { return test_harness(test_vmxcopy, "tm_vmxcopy"); }

Contributors

PersonTokensPropCommitsCommitProp
rashmica guptarashmica gupta15100.00%1100.00%
Total15100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
rashmica guptarashmica gupta244100.00%1100.00%
Total244100.00%1100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.