tools/testing/selftests/powerpc/tm/tm-signal-context-chk-fpu.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 <signal.h>
  23 #include <unistd.h>
  24
  25 #include <altivec.h>
  26
  27 #include "utils.h"
  28 #include "tm.h"
  29
  30 #define MAX_ATTEMPT 500000
  31
  32 #define NV_FPU_REGS 18 /* Number of non-volatile FP registers */
  33 #define FPR14 14 /* First non-volatile FP register to check in f14-31 subset */
  34
  35 long tm_signal_self_context_load(pid_t pid, long *gprs, double *fps, vector int *vms, vector int *vss);
  36
  37 /* Test only non-volatile registers, i.e. 18 fpr registers from f14 to f31 */
  38 static double fps[] = {
  39         /* First context will be set with these values, i.e. non-speculative */
  40          1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
  41         /* Second context will be set with these values, i.e. speculative */
  42         -1,-2,-3,-4,-5,-6,-7,-8,-9,-10,-11,-12,-13,-14,-15,-16,-17,-18
  43 };
  44
  45 static sig_atomic_t fail, broken;
  46
  47 static void signal_usr1(int signum, siginfo_t *info, void *uc)
  48 {
  49         int i;
  50         ucontext_t *ucp = uc;
  51         ucontext_t *tm_ucp = ucp->uc_link;
  52
  53         for (i = 0; i < NV_FPU_REGS; i++) {
  54                 /* Check first context. Print all mismatches. */
  55                 fail = (ucp->uc_mcontext.fp_regs[FPR14 + i] != fps[i]);
  56                 if (fail) {
  57                         broken = 1;
  58                         printf("FPR%d (1st context) == %g instead of %g (expected)\n",
  59                                 FPR14 + i, ucp->uc_mcontext.fp_regs[FPR14 + i], fps[i]);
  60                 }
  61         }
  62
  63         for (i = 0; i < NV_FPU_REGS; i++) {
  64                 /* Check second context. Print all mismatches. */
  65                 fail = (tm_ucp->uc_mcontext.fp_regs[FPR14 + i] != fps[NV_FPU_REGS + i]);
  66                 if (fail) {
  67                         broken = 1;
  68                         printf("FPR%d (2nd context) == %g instead of %g (expected)\n",
  69                                 FPR14 + i, tm_ucp->uc_mcontext.fp_regs[FPR14 + i], fps[NV_FPU_REGS + i]);
  70                 }
  71         }
  72 }
  73
  74 static int tm_signal_context_chk_fpu()
  75 {
  76         struct sigaction act;
  77         int i;
  78         long rc;
  79         pid_t pid = getpid();
  80
  81         SKIP_IF(!have_htm());
  82
  83         act.sa_sigaction = signal_usr1;
  84         sigemptyset(&act.sa_mask);
  85         act.sa_flags = SA_SIGINFO;
  86         if (sigaction(SIGUSR1, &act, NULL) < 0) {
  87                 perror("sigaction sigusr1");
  88                 exit(1);
  89         }
  90
  91         i = 0;
  92         while (i < MAX_ATTEMPT && !broken) {
  93                 /*
  94                  * tm_signal_self_context_load will set both first and second
  95                  * contexts accordingly to the values passed through non-NULL
  96                  * array pointers to it, in that case 'fps', and invoke the
  97                  * signal handler installed for SIGUSR1.
  98                  */
  99                 rc = tm_signal_self_context_load(pid, NULL, fps, NULL, NULL);
 100                 FAIL_IF(rc != pid);
 101                 i++;
 102         }
 103
 104         return (broken);
 105 }
 106
 107 int main(void)
 108 {
 109         return test_harness(tm_signal_context_chk_fpu, "tm_signal_context_chk_fpu");
 110 }