Bug Summary

File:src/time/timer_create.c
Location:line 104, column 8
Description:Assigned value is garbage or undefined

Annotated Source Code

1#include <time.h>
2#include <setjmpsetjmp.h>
3#include "pthread_impl.h"
4
5struct ksigevent {
6 union sigval sigev_value;
7 int sigev_signo;
8 int sigev_notify;
9 int sigev_tid;
10};
11
12struct start_args {
13 pthread_barrier_t b;
14 struct sigevent *sev;
15};
16
17static void dummy_1(pthread_t self)
18{
19}
20weak_alias(dummy_1, __pthread_tsd_run_dtors)extern __typeof(dummy_1) __pthread_tsd_run_dtors __attribute__
((weak, alias("dummy_1")));
21
22void __reset_tls();
23
24static void cleanup_fromsig(void *p)
25{
26 pthread_t self = __pthread_self();
27 __pthread_tsd_run_dtors(self);
28 self->cancel = 0;
29 self->cancelbuf = 0;
30 self->canceldisable = 0;
31 self->cancelasync = 0;
32 self->unblock_cancel = 0;
33 __reset_tls();
34 longjmp(p, 1);
35}
36
37static void timer_handler(int sig, siginfo_t *si, void *ctx)
38{
39 pthread_t self = __pthread_self();
40 jmp_buf jb;
41 void (*notify)(union sigval) = (void (*)(union sigval))self->start;
42 union sigval val = { .sival_ptr = self->start_arg };
43
44 if (!setjmpsetjmp(jb) && si->si_code == SI_TIMER(-2)) {
45 pthread_cleanup_push(cleanup_fromsig, jb)do { struct __ptcb __cb; _pthread_cleanup_push(&__cb, cleanup_fromsig
, jb);;
46 notify(val);
47 pthread_cleanup_pop(1)_pthread_cleanup_pop(&__cb, (1)); } while(0);
48 }
49}
50
51static void install_handler()
52{
53 struct sigaction sa = {
54 .sa_sigaction__sa_handler.sa_sigaction = timer_handler,
55 .sa_flags = SA_SIGINFO4 | SA_RESTART0x10000000
56 };
57 __libc_sigaction(SIGTIMER32, &sa, 0);
58}
59
60static void *start(void *arg)
61{
62 pthread_t self = __pthread_self();
63 struct start_args *args = arg;
64 int id;
65
66 /* Reuse no-longer-needed thread structure fields to avoid
67 * needing the timer address in the signal handler. */
68 self->start = (void *(*)(void *))args->sev->sigev_notify_function;
69 self->start_arg = args->sev->sigev_value.sival_ptr;
70
71 pthread_barrier_wait(&args->b);
72 if ((id = self->timer_id) >= 0) {
73 __syscall(SYS_rt_sigprocmask, SIG_UNBLOCK,__syscall4(175,((long) (1)),((long) (((sigset_t *)(const unsigned
long [65/8/sizeof(long)]){ 0x80000000 }))),((long) (0)),((long
) (65/8)))
74 SIGTIMER_SET, 0, _NSIG/8)__syscall4(175,((long) (1)),((long) (((sigset_t *)(const unsigned
long [65/8/sizeof(long)]){ 0x80000000 }))),((long) (0)),((long
) (65/8)));
75 __wait(&self->timer_id, 0, id, 1);
76 __syscall(SYS_timer_delete, id)__syscall1(261,((long) (id)));
77 }
78 return 0;
79}
80
81int timer_create(clockid_t clk, struct sigevent *restrict evp, timer_t *restrict res)
82{
83 static pthread_once_t once = PTHREAD_ONCE_INIT0;
84 pthread_t td;
85 pthread_attr_t attr;
86 int r;
87 struct start_args args;
88 struct ksigevent ksev, *ksevp=0;
89 int timerid;
1
'timerid' declared without an initial value
→
90 sigset_t set;
91
92 switch (evp ? evp->sigev_notify : SIGEV_SIGNAL0) {
2
←
Assuming 'evp' is null
→
3
←
'?' condition is false
→
4
←
Control jumps to 'case 0:' at line 94
→
93 case SIGEV_NONE1:
94 case SIGEV_SIGNAL0:
95 if (evp) {
5
←
Taking false branch
→
96 ksev.sigev_value = evp->sigev_value;
97 ksev.sigev_signo = evp->sigev_signo;
98 ksev.sigev_notify = evp->sigev_notify;
99 ksev.sigev_tid = 0;
100 ksevp = &ksev;
101 }
102 if (syscall(SYS_timer_create, clk, ksevp, &timerid)__syscall_ret(__syscall3(257,((long) (clk)),((long) (ksevp)),
((long) (&timerid)))) < 0)
6
←
Taking false branch
→
103 return -1;
104 *res = (void *)(intptr_t)timerid;
7
←
Assigned value is garbage or undefined
105 break;
106 case SIGEV_THREAD2:
107 pthread_once(&once, install_handler);
108 if (evp->sigev_notify_attributes)
109 attr = *evp->sigev_notify_attributes;
110 else
111 pthread_attr_init(&attr);
112 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED1);
113 pthread_barrier_init(&args.b, 0, 2);
114 args.sev = evp;
115
116 __block_app_sigs(&set);
117 r = pthread_create(&td, &attr, start, &args);
118 __restore_sigs(&set);
119 if (r) {
120 errno(*__errno_location()) = r;
121 return -1;
122 }
123
124 ksev.sigev_value.sival_ptr = 0;
125 ksev.sigev_signo = SIGTIMER32;
126 ksev.sigev_notify = 4; /* SIGEV_THREAD_ID */
127 ksev.sigev_tid = td->tid;
128 if (syscall(SYS_timer_create, clk, &ksev, &timerid)__syscall_ret(__syscall3(257,((long) (clk)),((long) (&ksev
)),((long) (&timerid)))) < 0)
129 timerid = -1;
130 td->timer_id = timerid;
131 pthread_barrier_wait(&args.b);
132 if (timerid < 0) return -1;
133 *res = (void *)(INTPTR_MIN(-1-0x7fffffff) | (uintptr_t)td>>1);
134 break;
135 default:
136 errno(*__errno_location()) = EINVAL22;
137 return -1;
138 }
139
140 return 0;
141}