Bug Summary

File:home/bhubbard/working/src/ceph/src/spdk/dpdk/lib/librte_eal/linux/eal/eal_alarm.c
Warning:line 195, column 14
Use of memory after it is freed

Annotated Source Code

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1/* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright(c) 2010-2014 Intel Corporation
3 */
4#include <stdio.h>
5#include <stdint.h>
6#include <signal.h>
7#include <errno(*__errno_location ()).h>
8#include <string.h>
9#include <sys/queue.h>
10#include <sys/time.h>
11#include <sys/timerfd.h>
12
13#include <rte_memory.h>
14#include <rte_interrupts.h>
15#include <rte_alarm.h>
16#include <rte_common.h>
17#include <rte_per_lcore.h>
18#include <rte_eal.h>
19#include <rte_launch.h>
20#include <rte_lcore.h>
21#include <rte_errno(per_lcore__rte_errno).h>
22#include <rte_spinlock.h>
23#include <eal_private.h>
24
25#ifndef TFD_NONBLOCKTFD_NONBLOCK
26#include <fcntl.h>
27#define TFD_NONBLOCKTFD_NONBLOCK O_NONBLOCK
28#endif
29
30#define NS_PER_US1000 1000
31#define US_PER_MS1000 1000
32#define MS_PER_S1000 1000
33#ifndef US_PER_S1000000
34#define US_PER_S1000000 (US_PER_MS1000 * MS_PER_S1000)
35#endif
36
37#ifdef CLOCK_MONOTONIC_RAW4 /* Defined in glibc bits/time.h */
38#define CLOCK_TYPE_ID4 CLOCK_MONOTONIC_RAW4
39#else
40#define CLOCK_TYPE_ID4 CLOCK_MONOTONIC1
41#endif
42
43struct alarm_entry {
44 LIST_ENTRY(alarm_entry)struct { struct alarm_entry *le_next; struct alarm_entry **le_prev
; } next;
45 struct timeval time;
46 rte_eal_alarm_callback cb_fn;
47 void *cb_arg;
48 volatile uint8_t executing;
49 volatile pthread_t executing_id;
50};
51
52static LIST_HEAD(alarm_list, alarm_entry)struct alarm_list { struct alarm_entry *lh_first; } alarm_list = LIST_HEAD_INITIALIZER(){ ((void*)0) };
53static rte_spinlock_t alarm_list_lk = RTE_SPINLOCK_INITIALIZER{ 0 };
54
55static struct rte_intr_handle intr_handle = {.fd = -1 };
56static int handler_registered = 0;
57static void eal_alarm_callback(void *arg);
58
59int
60rte_eal_alarm_init(void)
61{
62 intr_handle.type = RTE_INTR_HANDLE_ALARM;
63 /* create a timerfd file descriptor */
64 intr_handle.fd = timerfd_create(CLOCK_MONOTONIC1, TFD_NONBLOCKTFD_NONBLOCK);
65 if (intr_handle.fd == -1)
66 goto error;
67
68 return 0;
69
70error:
71 rte_errno(per_lcore__rte_errno) = errno(*__errno_location ());
72 return -1;
73}
74
75static void
76eal_alarm_callback(void *arg __rte_unused__attribute__((__unused__)))
77{
78 struct timespec now;
79 struct alarm_entry *ap;
80
81 rte_spinlock_lock(&alarm_list_lk);
82 while ((ap = LIST_FIRST(&alarm_list)((&alarm_list)->lh_first)) !=NULL((void*)0) &&
83 clock_gettime(CLOCK_TYPE_ID4, &now) == 0 &&
84 (ap->time.tv_sec < now.tv_sec || (ap->time.tv_sec == now.tv_sec &&
85 (ap->time.tv_usec * NS_PER_US1000) <= now.tv_nsec))) {
86 ap->executing = 1;
87 ap->executing_id = pthread_self();
88 rte_spinlock_unlock(&alarm_list_lk);
89
90 ap->cb_fn(ap->cb_arg);
91
92 rte_spinlock_lock(&alarm_list_lk);
93
94 LIST_REMOVE(ap, next)do { if ((ap)->next.le_next != ((void*)0)) (ap)->next.le_next
->next.le_prev = (ap)->next.le_prev; *(ap)->next.le_prev
= (ap)->next.le_next; } while ( 0);
95 free(ap);
96 }
97
98 if (!LIST_EMPTY(&alarm_list)((&alarm_list)->lh_first == ((void*)0))) {
99 struct itimerspec atime = { .it_interval = { 0, 0 } };
100
101 ap = LIST_FIRST(&alarm_list)((&alarm_list)->lh_first);
102 atime.it_value.tv_sec = ap->time.tv_sec;
103 atime.it_value.tv_nsec = ap->time.tv_usec * NS_PER_US1000;
104 /* perform borrow for subtraction if necessary */
105 if (now.tv_nsec > (ap->time.tv_usec * NS_PER_US1000))
106 atime.it_value.tv_sec--, atime.it_value.tv_nsec += US_PER_S1000000 * NS_PER_US1000;
107
108 atime.it_value.tv_sec -= now.tv_sec;
109 atime.it_value.tv_nsec -= now.tv_nsec;
110 timerfd_settime(intr_handle.fd, 0, &atime, NULL((void*)0));
111 }
112 rte_spinlock_unlock(&alarm_list_lk);
113}
114
115int
116rte_eal_alarm_set(uint64_t us, rte_eal_alarm_callback cb_fn, void *cb_arg)
117{
118 struct timespec now;
119 int ret = 0;
120 struct alarm_entry *ap, *new_alarm;
121
122 /* Check parameters, including that us won't cause a uint64_t overflow */
123 if (us < 1 || us > (UINT64_MAX(18446744073709551615UL) - US_PER_S1000000) || cb_fn == NULL((void*)0))
124 return -EINVAL22;
125
126 new_alarm = calloc(1, sizeof(*new_alarm));
127 if (new_alarm == NULL((void*)0))
128 return -ENOMEM12;
129
130 /* use current time to calculate absolute time of alarm */
131 clock_gettime(CLOCK_TYPE_ID4, &now);
132
133 new_alarm->cb_fn = cb_fn;
134 new_alarm->cb_arg = cb_arg;
135 new_alarm->time.tv_usec = ((now.tv_nsec / NS_PER_US1000) + us) % US_PER_S1000000;
136 new_alarm->time.tv_sec = now.tv_sec + (((now.tv_nsec / NS_PER_US1000) + us) / US_PER_S1000000);
137
138 rte_spinlock_lock(&alarm_list_lk);
139 if (!handler_registered) {
140 ret |= rte_intr_callback_register(&intr_handle,
141 eal_alarm_callback, NULL((void*)0));
142 handler_registered = (ret == 0) ? 1 : 0;
143 }
144
145 if (LIST_EMPTY(&alarm_list)((&alarm_list)->lh_first == ((void*)0)))
146 LIST_INSERT_HEAD(&alarm_list, new_alarm, next)do { if (((new_alarm)->next.le_next = (&alarm_list)->
lh_first) != ((void*)0)) (&alarm_list)->lh_first->next
.le_prev = &(new_alarm)->next.le_next; (&alarm_list
)->lh_first = (new_alarm); (new_alarm)->next.le_prev = &
(&alarm_list)->lh_first; } while ( 0);
147 else {
148 LIST_FOREACH(ap, &alarm_list, next)for ((ap) = ((&alarm_list)->lh_first); (ap); (ap) = ((
ap)->next.le_next)) {
149 if (ap->time.tv_sec > new_alarm->time.tv_sec ||
150 (ap->time.tv_sec == new_alarm->time.tv_sec &&
151 ap->time.tv_usec > new_alarm->time.tv_usec)){
152 LIST_INSERT_BEFORE(ap, new_alarm, next)do { (new_alarm)->next.le_prev = (ap)->next.le_prev; (new_alarm
)->next.le_next = (ap); *(ap)->next.le_prev = (new_alarm
); (ap)->next.le_prev = &(new_alarm)->next.le_next;
} while ( 0);
153 break;
154 }
155 if (LIST_NEXT(ap, next)((ap)->next.le_next) == NULL((void*)0)) {
156 LIST_INSERT_AFTER(ap, new_alarm, next)do { if (((new_alarm)->next.le_next = (ap)->next.le_next
) != ((void*)0)) (ap)->next.le_next->next.le_prev = &
(new_alarm)->next.le_next; (ap)->next.le_next = (new_alarm
); (new_alarm)->next.le_prev = &(ap)->next.le_next;
} while ( 0);
157 break;
158 }
159 }
160 }
161
162 if (LIST_FIRST(&alarm_list)((&alarm_list)->lh_first) == new_alarm) {
163 struct itimerspec alarm_time = {
164 .it_interval = {0, 0},
165 .it_value = {
166 .tv_sec = us / US_PER_S1000000,
167 .tv_nsec = (us % US_PER_S1000000) * NS_PER_US1000,
168 },
169 };
170 ret |= timerfd_settime(intr_handle.fd, 0, &alarm_time, NULL((void*)0));
171 }
172 rte_spinlock_unlock(&alarm_list_lk);
173
174 return ret;
175}
176
177int
178rte_eal_alarm_cancel(rte_eal_alarm_callback cb_fn, void *cb_arg)
179{
180 struct alarm_entry *ap, *ap_prev;
181 int count = 0;
182 int err = 0;
183 int executing;
184
185 if (!cb_fn) {
1
Assuming 'cb_fn' is non-null
→
2
←
Taking false branch
→
186 rte_errno(per_lcore__rte_errno) = EINVAL22;
187 return -1;
188 }
189
190 do {
191 executing = 0;
192 rte_spinlock_lock(&alarm_list_lk);
193 /* remove any matches at the start of the list */
194 while ((ap = LIST_FIRST(&alarm_list)((&alarm_list)->lh_first)) != NULL((void*)0) &&
3
←
Assuming the condition is true
→
7
←
Loop condition is true. Entering loop body
→
195 cb_fn == ap->cb_fn &&
4
←
Assuming the condition is true
→
11
←
Use of memory after it is freed
196 (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) {
5
←
Assuming the condition is false
→
6
←
Assuming the condition is true
→
197
198 if (ap->executing == 0) {
8
←
Assuming the condition is true
→
9
←
Taking true branch
→
199 LIST_REMOVE(ap, next)do { if ((ap)->next.le_next != ((void*)0)) (ap)->next.le_next
->next.le_prev = (ap)->next.le_prev; *(ap)->next.le_prev
= (ap)->next.le_next; } while ( 0);
200 free(ap);
10
←
Memory is released
→
201 count++;
202 } else {
203 /* If calling from other context, mark that alarm is executing
204 * so loop can spin till it finish. Otherwise we are trying to
205 * cancel our self - mark it by EINPROGRESS */
206 if (pthread_equal(ap->executing_id, pthread_self()) == 0)
207 executing++;
208 else
209 err = EINPROGRESS115;
210
211 break;
212 }
213 }
214 ap_prev = ap;
215
216 /* now go through list, removing entries not at start */
217 LIST_FOREACH(ap, &alarm_list, next)for ((ap) = ((&alarm_list)->lh_first); (ap); (ap) = ((
ap)->next.le_next)) {
218 /* this won't be true first time through */
219 if (cb_fn == ap->cb_fn &&
220 (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) {
221
222 if (ap->executing == 0) {
223 LIST_REMOVE(ap, next)do { if ((ap)->next.le_next != ((void*)0)) (ap)->next.le_next
->next.le_prev = (ap)->next.le_prev; *(ap)->next.le_prev
= (ap)->next.le_next; } while ( 0);
224 free(ap);
225 count++;
226 ap = ap_prev;
227 } else if (pthread_equal(ap->executing_id, pthread_self()) == 0)
228 executing++;
229 else
230 err = EINPROGRESS115;
231 }
232 ap_prev = ap;
233 }
234 rte_spinlock_unlock(&alarm_list_lk);
235 } while (executing != 0);
236
237 if (count == 0 && err == 0)
238 rte_errno(per_lcore__rte_errno) = ENOENT2;
239 else if (err)
240 rte_errno(per_lcore__rte_errno) = err;
241
242 return count;
243}