tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
23extern int getppid_tm_active(void);
24extern int getppid_tm_suspended(void);
25
26unsigned retries = 0;
27
28#define TEST_DURATION 10 /* seconds */
29#define TM_RETRIES 100
30
31long failure_code(void)
32{
33 return __builtin_get_texasru() >> 24;
34}
35
36bool failure_is_persistent(void)
37{
38 return (failure_code() & TM_CAUSE_PERSISTENT) == TM_CAUSE_PERSISTENT;
39}
40
41bool failure_is_syscall(void)
42{
43 return (failure_code() & TM_CAUSE_SYSCALL) == TM_CAUSE_SYSCALL;
44}
45
46pid_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
80int tm_syscall(void)
81{
82 unsigned count = 0;
83 struct timeval end, now;
84
85 SKIP_IF(!((long)get_auxv_entry(AT_HWCAP2)
86 & PPC_FEATURE2_HTM_NOSC));
87 setbuf(stdout, NULL);
88
89 printf("Testing transactional syscalls for %d seconds...\n", TEST_DURATION);
90
91 gettimeofday(&end, NULL);
92 now.tv_sec = TEST_DURATION;
93 now.tv_usec = 0;
94 timeradd(&end, &now, &end);
95
96 for (count = 0; timercmp(&now, &end, <); count++) {
97 /*
98 * Test a syscall within a suspended transaction and verify
99 * that it succeeds.
100 */
101 FAIL_IF(getppid_tm(true) == -1); /* Should succeed. */
102
103 /*
104 * Test a syscall within an active transaction and verify that
105 * it fails with the correct failure code.
106 */
107 FAIL_IF(getppid_tm(false) != -1); /* Should fail... */
108 FAIL_IF(!failure_is_persistent()); /* ...persistently... */
109 FAIL_IF(!failure_is_syscall()); /* ...with code syscall. */
110 gettimeofday(&now, 0);
111 }
112
113 printf("%d active and suspended transactions behaved correctly.\n", count);
114 printf("(There were %d transaction retries.)\n", retries);
115
116 return 0;
117}
118
119int main(void)
120{
121 return test_harness(tm_syscall, "tm_syscall");
122}