kernel/tools/testing/selftests/powerpc/tm/tm-syscall.c

   1 /*
   2  * Copyright 2015, Sam Bobroff, IBM Corp.
   3  * Licensed under GPLv2.
   4  *
   5  * Test the kernel's system call code to ensure that a system call
   6  * made from within an active HTM transaction is aborted with the
   7  * correct failure code.
   8  * Conversely, ensure that a system call made from within a
   9  * suspended transaction can succeed.
  10  */
  11
  12 #include <stdio.h>
  13 #include <unistd.h>
  14 #include <sys/syscall.h>
  15 #include <asm/tm.h>
  16 #include <asm/cputable.h>
  17 #include <linux/auxvec.h>
  18 #include <sys/time.h>
  19 #include <stdlib.h>
  20
  21 #include "utils.h"
  22
  23 extern int getppid_tm_active(void);
  24 extern int getppid_tm_suspended(void);
  25
  26 unsigned retries = 0;
  27
  28 #define TEST_DURATION 10 /* seconds */
  29 #define TM_RETRIES 100
  30
  31 long failure_code(void)
  32 {
  33         return __builtin_get_texasru() >> 24;
  34 }
  35
  36 bool failure_is_persistent(void)
  37 {
  38         return (failure_code() & TM_CAUSE_PERSISTENT) == TM_CAUSE_PERSISTENT;
  39 }
  40
  41 bool failure_is_syscall(void)
  42 {
  43         return (failure_code() & TM_CAUSE_SYSCALL) == TM_CAUSE_SYSCALL;
  44 }
  45
  46 pid_t getppid_tm(bool suspend)
  47 {
  48         int i;
  49         pid_t pid;
  50
  51         for (i = 0; i < TM_RETRIES; i++) {
  52                 if (suspend)
  53                         pid = getppid_tm_suspended();
  54                 else
  55                         pid = getppid_tm_active();
  56
  57                 if (pid >= 0)
  58                         return pid;
  59
  60                 if (failure_is_persistent()) {
  61                         if (failure_is_syscall())
  62                                 return -1;
  63
  64                         printf("Unexpected persistent transaction failure.\n");
  65                         printf("TEXASR 0x%016lx, TFIAR 0x%016lx.\n",
  66                                __builtin_get_texasr(), __builtin_get_tfiar());
  67                         exit(-1);
  68                 }
  69
  70                 retries++;
  71         }
  72
  73         printf("Exceeded limit of %d temporary transaction failures.\n", TM_RETRIES);
  74         printf("TEXASR 0x%016lx, TFIAR 0x%016lx.\n",
  75                __builtin_get_texasr(), __builtin_get_tfiar());
  76
  77         exit(-1);
  78 }
  79
  80 static inline bool have_htm_nosc(void)
  81 {
  82 #ifdef PPC_FEATURE2_HTM_NOSC
  83         return ((long)get_auxv_entry(AT_HWCAP2) & PPC_FEATURE2_HTM_NOSC);
  84 #else
  85         printf("PPC_FEATURE2_HTM_NOSC not defined, can't check AT_HWCAP2\n");
  86         return false;
  87 #endif
  88 }
  89
  90 int tm_syscall(void)
  91 {
  92         unsigned count = 0;
  93         struct timeval end, now;
  94
  95         SKIP_IF(!have_htm_nosc());
  96
  97         setbuf(stdout, NULL);
  98
  99         printf("Testing transactional syscalls for %d seconds...\n", TEST_DURATION);
 100
 101         gettimeofday(&end, NULL);
 102         now.tv_sec = TEST_DURATION;
 103         now.tv_usec = 0;
 104         timeradd(&end, &now, &end);
 105
 106         for (count = 0; timercmp(&now, &end, <); count++) {
 107                 /*
 108                  * Test a syscall within a suspended transaction and verify
 109                  * that it succeeds.
 110                  */
 111                 FAIL_IF(getppid_tm(true) == -1); /* Should succeed. */
 112
 113                 /*
 114                  * Test a syscall within an active transaction and verify that
 115                  * it fails with the correct failure code.
 116                  */
 117                 FAIL_IF(getppid_tm(false) != -1);  /* Should fail... */
 118                 FAIL_IF(!failure_is_persistent()); /* ...persistently... */
 119                 FAIL_IF(!failure_is_syscall());    /* ...with code syscall. */
 120                 gettimeofday(&now, 0);
 121         }
 122
 123         printf("%d active and suspended transactions behaved correctly.\n", count);
 124         printf("(There were %d transaction retries.)\n", retries);
 125
 126         return 0;
 127 }
 128
 129 int main(void)
 130 {
 131         return test_harness(tm_syscall, "tm_syscall");
 132 }