LXR linux/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 <sys/time.h>
  17#include <stdlib.h>
  18
  19#include "utils.h"
  20#include "tm.h"
  21
  22extern int getppid_tm_active(void);
  23extern int getppid_tm_suspended(void);
  24
  25unsigned retries = 0;
  26
  27#define TEST_DURATION 10 /* seconds */
  28#define TM_RETRIES 100
  29
  30long failure_code(void)
  31{
  32        return __builtin_get_texasru() >> 24;
  33}
  34
  35bool failure_is_persistent(void)
  36{
  37        return (failure_code() & TM_CAUSE_PERSISTENT) == TM_CAUSE_PERSISTENT;
  38}
  39
  40bool failure_is_syscall(void)
  41{
  42        return (failure_code() & TM_CAUSE_SYSCALL) == TM_CAUSE_SYSCALL;
  43}
  44
  45pid_t getppid_tm(bool suspend)
  46{
  47        int i;
  48        pid_t pid;
  49
  50        for (i = 0; i < TM_RETRIES; i++) {
  51                if (suspend)
  52                        pid = getppid_tm_suspended();
  53                else
  54                        pid = getppid_tm_active();
  55
  56                if (pid >= 0)
  57                        return pid;
  58
  59                if (failure_is_persistent()) {
  60                        if (failure_is_syscall())
  61                                return -1;
  62
  63                        printf("Unexpected persistent transaction failure.\n");
  64                        printf("TEXASR 0x%016lx, TFIAR 0x%016lx.\n",
  65                               __builtin_get_texasr(), __builtin_get_tfiar());
  66                        exit(-1);
  67                }
  68
  69                retries++;
  70        }
  71
  72        printf("Exceeded limit of %d temporary transaction failures.\n", TM_RETRIES);
  73        printf("TEXASR 0x%016lx, TFIAR 0x%016lx.\n",
  74               __builtin_get_texasr(), __builtin_get_tfiar());
  75
  76        exit(-1);
  77}
  78
  79int tm_syscall(void)
  80{
  81        unsigned count = 0;
  82        struct timeval end, now;
  83
  84        SKIP_IF(!have_htm_nosc());
  85
  86        setbuf(stdout, NULL);
  87
  88        printf("Testing transactional syscalls for %d seconds...\n", TEST_DURATION);
  89
  90        gettimeofday(&end, NULL);
  91        now.tv_sec = TEST_DURATION;
  92        now.tv_usec = 0;
  93        timeradd(&end, &now, &end);
  94
  95        for (count = 0; timercmp(&now, &end, <); count++) {
  96                /*
  97                 * Test a syscall within a suspended transaction and verify
  98                 * that it succeeds.
  99                 */
 100                FAIL_IF(getppid_tm(true) == -1); /* Should succeed. */
 101
 102                /*
 103                 * Test a syscall within an active transaction and verify that
 104                 * it fails with the correct failure code.
 105                 */
 106                FAIL_IF(getppid_tm(false) != -1);  /* Should fail... */
 107                FAIL_IF(!failure_is_persistent()); /* ...persistently... */
 108                FAIL_IF(!failure_is_syscall());    /* ...with code syscall. */
 109                gettimeofday(&now, 0);
 110        }
 111
 112        printf("%d active and suspended transactions behaved correctly.\n", count);
 113        printf("(There were %d transaction retries.)\n", retries);
 114
 115        return 0;
 116}
 117
 118int main(void)
 119{
 120        return test_harness(tm_syscall, "tm_syscall");
 121}
 122