1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /****************************************************************************** |
3 | * |
4 | * Copyright © International Business Machines Corp., 2009 |
5 | * |
6 | * DESCRIPTION |
7 | * 1. Block a thread using FUTEX_WAIT |
8 | * 2. Attempt to use FUTEX_CMP_REQUEUE_PI on the futex from 1. |
9 | * 3. The kernel must detect the mismatch and return -EINVAL. |
10 | * |
11 | * AUTHOR |
12 | * Darren Hart <dvhart@linux.intel.com> |
13 | * |
14 | * HISTORY |
15 | * 2009-Nov-9: Initial version by Darren Hart <dvhart@linux.intel.com> |
16 | * |
17 | *****************************************************************************/ |
18 | |
19 | #include <errno.h> |
20 | #include <getopt.h> |
21 | #include <pthread.h> |
22 | #include <stdio.h> |
23 | #include <stdlib.h> |
24 | #include <string.h> |
25 | #include <time.h> |
26 | #include "futextest.h" |
27 | #include "logging.h" |
28 | |
29 | #define TEST_NAME "futex-requeue-pi-mismatched-ops" |
30 | |
31 | futex_t f1 = FUTEX_INITIALIZER; |
32 | futex_t f2 = FUTEX_INITIALIZER; |
33 | int child_ret = 0; |
34 | |
35 | void usage(char *prog) |
36 | { |
37 | printf("Usage: %s\n" , prog); |
38 | printf(" -c Use color\n" ); |
39 | printf(" -h Display this help message\n" ); |
40 | printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n" , |
41 | VQUIET, VCRITICAL, VINFO); |
42 | } |
43 | |
44 | void *blocking_child(void *arg) |
45 | { |
46 | child_ret = futex_wait(&f1, f1, NULL, FUTEX_PRIVATE_FLAG); |
47 | if (child_ret < 0) { |
48 | child_ret = -errno; |
49 | error("futex_wait\n" , errno); |
50 | } |
51 | return (void *)&child_ret; |
52 | } |
53 | |
54 | int main(int argc, char *argv[]) |
55 | { |
56 | int ret = RET_PASS; |
57 | pthread_t child; |
58 | int c; |
59 | |
60 | while ((c = getopt(argc, argv, "chv:" )) != -1) { |
61 | switch (c) { |
62 | case 'c': |
63 | log_color(1); |
64 | break; |
65 | case 'h': |
66 | usage(prog: basename(argv[0])); |
67 | exit(0); |
68 | case 'v': |
69 | log_verbosity(atoi(optarg)); |
70 | break; |
71 | default: |
72 | usage(prog: basename(argv[0])); |
73 | exit(1); |
74 | } |
75 | } |
76 | |
77 | ksft_print_header(); |
78 | ksft_set_plan(1); |
79 | ksft_print_msg("%s: Detect mismatched requeue_pi operations\n" , |
80 | basename(argv[0])); |
81 | |
82 | if (pthread_create(&child, NULL, blocking_child, NULL)) { |
83 | error("pthread_create\n" , errno); |
84 | ret = RET_ERROR; |
85 | goto out; |
86 | } |
87 | /* Allow the child to block in the kernel. */ |
88 | sleep(1); |
89 | |
90 | /* |
91 | * The kernel should detect the waiter did not setup the |
92 | * q->requeue_pi_key and return -EINVAL. If it does not, |
93 | * it likely gave the lock to the child, which is now hung |
94 | * in the kernel. |
95 | */ |
96 | ret = futex_cmp_requeue_pi(&f1, f1, &f2, 1, 0, FUTEX_PRIVATE_FLAG); |
97 | if (ret < 0) { |
98 | if (errno == EINVAL) { |
99 | /* |
100 | * The kernel correctly detected the mismatched |
101 | * requeue_pi target and aborted. Wake the child with |
102 | * FUTEX_WAKE. |
103 | */ |
104 | ret = futex_wake(&f1, 1, FUTEX_PRIVATE_FLAG); |
105 | if (ret == 1) { |
106 | ret = RET_PASS; |
107 | } else if (ret < 0) { |
108 | error("futex_wake\n" , errno); |
109 | ret = RET_ERROR; |
110 | } else { |
111 | error("futex_wake did not wake the child\n" , 0); |
112 | ret = RET_ERROR; |
113 | } |
114 | } else { |
115 | error("futex_cmp_requeue_pi\n" , errno); |
116 | ret = RET_ERROR; |
117 | } |
118 | } else if (ret > 0) { |
119 | fail("futex_cmp_requeue_pi failed to detect the mismatch\n" ); |
120 | ret = RET_FAIL; |
121 | } else { |
122 | error("futex_cmp_requeue_pi found no waiters\n" , 0); |
123 | ret = RET_ERROR; |
124 | } |
125 | |
126 | pthread_join(child, NULL); |
127 | |
128 | if (!ret) |
129 | ret = child_ret; |
130 | |
131 | out: |
132 | /* If the kernel crashes, we shouldn't return at all. */ |
133 | print_result(TEST_NAME, ret); |
134 | return ret; |
135 | } |
136 | |