tm-signal-context-chk-vmx.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright 2016, Cyril Bur, IBM Corp.
  4 *
  5 * Test the kernel's signal frame code.
  6 *
  7 * The kernel sets up two sets of ucontexts if the signal was to be
  8 * delivered while the thread was in a transaction (referred too as
  9 * first and second contexts).
 10 * Expected behaviour is that the checkpointed state is in the user
 11 * context passed to the signal handler (first context). The speculated
 12 * state can be accessed with the uc_link pointer (second context).
 13 *
 14 * The rationale for this is that if TM unaware code (which linked
 15 * against TM libs) installs a signal handler it will not know of the
 16 * speculative nature of the 'live' registers and may infer the wrong
 17 * thing.
 18 */
 19
 20#include <stdlib.h>
 21#include <stdio.h>
 22#include <string.h>
 23#include <signal.h>
 24#include <unistd.h>
 25
 26#include <altivec.h>
 27
 28#include "utils.h"
 29#include "tm.h"
 30
 31#define MAX_ATTEMPT 500000
 32
 33#define NV_VMX_REGS 12 /* Number of non-volatile VMX registers */
 34#define VMX20 20 /* First non-volatile register to check in vr20-31 subset */
 35
 36long tm_signal_self_context_load(pid_t pid, long *gprs, double *fps, vector int *vms, vector int *vss);
 37
 38static sig_atomic_t fail, broken;
 39
 40/* Test only non-volatile registers, i.e. 12 vmx registers from vr20 to vr31 */
 41vector int vms[] = {
 42	/* First context will be set with these values, i.e. non-speculative */
 43	/* VMX20     ,  VMX21      , ... */
 44	{ 1, 2, 3, 4},{ 5, 6, 7, 8},{ 9,10,11,12},
 45	{13,14,15,16},{17,18,19,20},{21,22,23,24},
 46	{25,26,27,28},{29,30,31,32},{33,34,35,36},
 47	{37,38,39,40},{41,42,43,44},{45,46,47,48},
 48	/* Second context will be set with these values, i.e. speculative */
 49	/* VMX20        , VMX21            , ... */
 50	{ -1, -2, -3, -4},{ -5, -6, -7, -8},{ -9,-10,-11,-12},
 51	{-13,-14,-15,-16},{-17,-18,-19,-20},{-21,-22,-23,-24},
 52	{-25,-26,-27,-28},{-29,-30,-31,-32},{-33,-34,-35,-36},
 53	{-37,-38,-39,-40},{-41,-42,-43,-44},{-45,-46,-47,-48}
 54};
 55
 56static void signal_usr1(int signum, siginfo_t *info, void *uc)
 57{
 58	int i, j;
 59	ucontext_t *ucp = uc;
 60	ucontext_t *tm_ucp = ucp->uc_link;
 61
 62	for (i = 0; i < NV_VMX_REGS; i++) {
 63		/* Check first context. Print all mismatches. */
 64		fail = memcmp(ucp->uc_mcontext.v_regs->vrregs[VMX20 + i],
 65				&vms[i], sizeof(vector int));
 66		if (fail) {
 67			broken = 1;
 68			printf("VMX%d (1st context) == 0x", VMX20 + i);
 69			/* Print actual value in first context. */
 70			for (j = 0; j < 4; j++)
 71				printf("%08x", ucp->uc_mcontext.v_regs->vrregs[VMX20 + i][j]);
 72			printf(" instead of 0x");
 73			/* Print expected value. */
 74			for (j = 0; j < 4; j++)
 75				printf("%08x", vms[i][j]);
 76			printf(" (expected)\n");
 77		}
 78	}
 79
 80	for (i = 0; i < NV_VMX_REGS; i++)  {
 81		/* Check second context. Print all mismatches. */
 82		fail = memcmp(tm_ucp->uc_mcontext.v_regs->vrregs[VMX20 + i],
 83				&vms[NV_VMX_REGS + i], sizeof (vector int));
 84		if (fail) {
 85			broken = 1;
 86			printf("VMX%d (2nd context) == 0x", NV_VMX_REGS + i);
 87			/* Print actual value in second context. */
 88			for (j = 0; j < 4; j++)
 89				printf("%08x", tm_ucp->uc_mcontext.v_regs->vrregs[VMX20 + i][j]);
 90			printf(" instead of 0x");
 91			/* Print expected value. */
 92			for (j = 0; j < 4; j++)
 93				printf("%08x", vms[NV_VMX_REGS + i][j]);
 94			printf(" (expected)\n");
 95		}
 96	}
 97}
 98
 99static int tm_signal_context_chk()
100{
101	struct sigaction act;
102	int i;
103	long rc;
104	pid_t pid = getpid();
105
106	SKIP_IF(!have_htm());
107	SKIP_IF(htm_is_synthetic());
108
109	act.sa_sigaction = signal_usr1;
110	sigemptyset(&act.sa_mask);
111	act.sa_flags = SA_SIGINFO;
112	if (sigaction(SIGUSR1, &act, NULL) < 0) {
113		perror("sigaction sigusr1");
114		exit(1);
115	}
116
117	i = 0;
118	while (i < MAX_ATTEMPT && !broken) {
119		/*
120		 * tm_signal_self_context_load will set both first and second
121		 * contexts accordingly to the values passed through non-NULL
122		 * array pointers to it, in that case 'vms', and invoke the
123		 * signal handler installed for SIGUSR1.
124		 */
125		rc = tm_signal_self_context_load(pid, NULL, NULL, vms, NULL);
126		FAIL_IF(rc != pid);
127		i++;
128	}
129
130	return (broken);
131}
132
133int main(void)
134{
135	return test_harness(tm_signal_context_chk, "tm_signal_context_chk_vmx");
136}