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
  36 long tm_signal_self_context_load(pid_t pid, long *gprs, double *fps, vector int *vms, vector int *vss);
  37
  38 static sig_atomic_t fail, broken;
  39
  40 /* Test only non-volatile registers, i.e. 12 vmx registers from vr20 to vr31 */
  41 vector 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
  56 static 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
  99 static 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
 108         act.sa_sigaction = signal_usr1;
 109         sigemptyset(&act.sa_mask);
 110         act.sa_flags = SA_SIGINFO;
 111         if (sigaction(SIGUSR1, &act, NULL) < 0) {
 112                 perror("sigaction sigusr1");
 113                 exit(1);
 114         }
 115
 116         i = 0;
 117         while (i < MAX_ATTEMPT && !broken) {
 118                 /*
 119                  * tm_signal_self_context_load will set both first and second
 120                  * contexts accordingly to the values passed through non-NULL
 121                  * array pointers to it, in that case 'vms', and invoke the
 122                  * signal handler installed for SIGUSR1.
 123                  */
 124                 rc = tm_signal_self_context_load(pid, NULL, NULL, vms, NULL);
 125                 FAIL_IF(rc != pid);
 126                 i++;
 127         }
 128
 129         return (broken);
 130 }
 131
 132 int main(void)
 133 {
 134         return test_harness(tm_signal_context_chk, "tm_signal_context_chk_vmx");
 135 }