LXR linux/tools/testing/selftests/powerpc/tm/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}
 137