Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/kernel/itimer.c
Parent Directory | Revision Log
Revision 630 -
(show annotations)
(download)
Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
File MIME type: text/plain
File size: 6918 byte(s)
Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
File MIME type: text/plain
File size: 6918 byte(s)
Tag kernel26-2.6.12-alx-r9
1 | /* |
2 | * linux/kernel/itimer.c |
3 | * |
4 | * Copyright (C) 1992 Darren Senn |
5 | */ |
6 | |
7 | /* These are all the functions necessary to implement itimers */ |
8 | |
9 | #include <linux/mm.h> |
10 | #include <linux/smp_lock.h> |
11 | #include <linux/interrupt.h> |
12 | #include <linux/syscalls.h> |
13 | #include <linux/time.h> |
14 | #include <linux/posix-timers.h> |
15 | |
16 | #include <asm/uaccess.h> |
17 | |
18 | static unsigned long it_real_value(struct signal_struct *sig) |
19 | { |
20 | unsigned long val = 0; |
21 | if (timer_pending(&sig->real_timer)) { |
22 | val = sig->real_timer.expires - jiffies; |
23 | |
24 | /* look out for negative/zero itimer.. */ |
25 | if ((long) val <= 0) |
26 | val = 1; |
27 | } |
28 | return val; |
29 | } |
30 | |
31 | int do_getitimer(int which, struct itimerval *value) |
32 | { |
33 | struct task_struct *tsk = current; |
34 | unsigned long interval, val; |
35 | cputime_t cinterval, cval; |
36 | |
37 | switch (which) { |
38 | case ITIMER_REAL: |
39 | spin_lock_irq(&tsk->sighand->siglock); |
40 | interval = tsk->signal->it_real_incr; |
41 | val = it_real_value(tsk->signal); |
42 | spin_unlock_irq(&tsk->sighand->siglock); |
43 | jiffies_to_timeval(val, &value->it_value); |
44 | jiffies_to_timeval(interval, &value->it_interval); |
45 | break; |
46 | case ITIMER_VIRTUAL: |
47 | read_lock(&tasklist_lock); |
48 | spin_lock_irq(&tsk->sighand->siglock); |
49 | cval = tsk->signal->it_virt_expires; |
50 | cinterval = tsk->signal->it_virt_incr; |
51 | if (!cputime_eq(cval, cputime_zero)) { |
52 | struct task_struct *t = tsk; |
53 | cputime_t utime = tsk->signal->utime; |
54 | do { |
55 | utime = cputime_add(utime, t->utime); |
56 | t = next_thread(t); |
57 | } while (t != tsk); |
58 | if (cputime_le(cval, utime)) { /* about to fire */ |
59 | cval = jiffies_to_cputime(1); |
60 | } else { |
61 | cval = cputime_sub(cval, utime); |
62 | } |
63 | } |
64 | spin_unlock_irq(&tsk->sighand->siglock); |
65 | read_unlock(&tasklist_lock); |
66 | cputime_to_timeval(cval, &value->it_value); |
67 | cputime_to_timeval(cinterval, &value->it_interval); |
68 | break; |
69 | case ITIMER_PROF: |
70 | read_lock(&tasklist_lock); |
71 | spin_lock_irq(&tsk->sighand->siglock); |
72 | cval = tsk->signal->it_prof_expires; |
73 | cinterval = tsk->signal->it_prof_incr; |
74 | if (!cputime_eq(cval, cputime_zero)) { |
75 | struct task_struct *t = tsk; |
76 | cputime_t ptime = cputime_add(tsk->signal->utime, |
77 | tsk->signal->stime); |
78 | do { |
79 | ptime = cputime_add(ptime, |
80 | cputime_add(t->utime, |
81 | t->stime)); |
82 | t = next_thread(t); |
83 | } while (t != tsk); |
84 | if (cputime_le(cval, ptime)) { /* about to fire */ |
85 | cval = jiffies_to_cputime(1); |
86 | } else { |
87 | cval = cputime_sub(cval, ptime); |
88 | } |
89 | } |
90 | spin_unlock_irq(&tsk->sighand->siglock); |
91 | read_unlock(&tasklist_lock); |
92 | cputime_to_timeval(cval, &value->it_value); |
93 | cputime_to_timeval(cinterval, &value->it_interval); |
94 | break; |
95 | default: |
96 | return(-EINVAL); |
97 | } |
98 | return 0; |
99 | } |
100 | |
101 | asmlinkage long sys_getitimer(int which, struct itimerval __user *value) |
102 | { |
103 | int error = -EFAULT; |
104 | struct itimerval get_buffer; |
105 | |
106 | if (value) { |
107 | error = do_getitimer(which, &get_buffer); |
108 | if (!error && |
109 | copy_to_user(value, &get_buffer, sizeof(get_buffer))) |
110 | error = -EFAULT; |
111 | } |
112 | return error; |
113 | } |
114 | |
115 | /* |
116 | * Called with P->sighand->siglock held and P->signal->real_timer inactive. |
117 | * If interval is nonzero, arm the timer for interval ticks from now. |
118 | */ |
119 | static inline void it_real_arm(struct task_struct *p, unsigned long interval) |
120 | { |
121 | p->signal->it_real_value = interval; /* XXX unnecessary field?? */ |
122 | if (interval == 0) |
123 | return; |
124 | if (interval > (unsigned long) LONG_MAX) |
125 | interval = LONG_MAX; |
126 | /* the "+ 1" below makes sure that the timer doesn't go off before |
127 | * the interval requested. This could happen if |
128 | * time requested % (usecs per jiffy) is more than the usecs left |
129 | * in the current jiffy */ |
130 | p->signal->real_timer.expires = jiffies + interval + 1; |
131 | add_timer(&p->signal->real_timer); |
132 | } |
133 | |
134 | void it_real_fn(unsigned long __data) |
135 | { |
136 | struct task_struct * p = (struct task_struct *) __data; |
137 | |
138 | send_group_sig_info(SIGALRM, SEND_SIG_PRIV, p); |
139 | |
140 | /* |
141 | * Now restart the timer if necessary. We don't need any locking |
142 | * here because do_setitimer makes sure we have finished running |
143 | * before it touches anything. |
144 | */ |
145 | it_real_arm(p, p->signal->it_real_incr); |
146 | } |
147 | |
148 | int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue) |
149 | { |
150 | struct task_struct *tsk = current; |
151 | unsigned long val, interval; |
152 | cputime_t cval, cinterval, nval, ninterval; |
153 | |
154 | switch (which) { |
155 | case ITIMER_REAL: |
156 | spin_lock_irq(&tsk->sighand->siglock); |
157 | interval = tsk->signal->it_real_incr; |
158 | val = it_real_value(tsk->signal); |
159 | if (val) |
160 | del_timer_sync(&tsk->signal->real_timer); |
161 | tsk->signal->it_real_incr = |
162 | timeval_to_jiffies(&value->it_interval); |
163 | it_real_arm(tsk, timeval_to_jiffies(&value->it_value)); |
164 | spin_unlock_irq(&tsk->sighand->siglock); |
165 | if (ovalue) { |
166 | jiffies_to_timeval(val, &ovalue->it_value); |
167 | jiffies_to_timeval(interval, |
168 | &ovalue->it_interval); |
169 | } |
170 | break; |
171 | case ITIMER_VIRTUAL: |
172 | nval = timeval_to_cputime(&value->it_value); |
173 | ninterval = timeval_to_cputime(&value->it_interval); |
174 | read_lock(&tasklist_lock); |
175 | spin_lock_irq(&tsk->sighand->siglock); |
176 | cval = tsk->signal->it_virt_expires; |
177 | cinterval = tsk->signal->it_virt_incr; |
178 | if (!cputime_eq(cval, cputime_zero) || |
179 | !cputime_eq(nval, cputime_zero)) { |
180 | if (cputime_gt(nval, cputime_zero)) |
181 | nval = cputime_add(nval, |
182 | jiffies_to_cputime(1)); |
183 | set_process_cpu_timer(tsk, CPUCLOCK_VIRT, |
184 | &nval, &cval); |
185 | } |
186 | tsk->signal->it_virt_expires = nval; |
187 | tsk->signal->it_virt_incr = ninterval; |
188 | spin_unlock_irq(&tsk->sighand->siglock); |
189 | read_unlock(&tasklist_lock); |
190 | if (ovalue) { |
191 | cputime_to_timeval(cval, &ovalue->it_value); |
192 | cputime_to_timeval(cinterval, &ovalue->it_interval); |
193 | } |
194 | break; |
195 | case ITIMER_PROF: |
196 | nval = timeval_to_cputime(&value->it_value); |
197 | ninterval = timeval_to_cputime(&value->it_interval); |
198 | read_lock(&tasklist_lock); |
199 | spin_lock_irq(&tsk->sighand->siglock); |
200 | cval = tsk->signal->it_prof_expires; |
201 | cinterval = tsk->signal->it_prof_incr; |
202 | if (!cputime_eq(cval, cputime_zero) || |
203 | !cputime_eq(nval, cputime_zero)) { |
204 | if (cputime_gt(nval, cputime_zero)) |
205 | nval = cputime_add(nval, |
206 | jiffies_to_cputime(1)); |
207 | set_process_cpu_timer(tsk, CPUCLOCK_PROF, |
208 | &nval, &cval); |
209 | } |
210 | tsk->signal->it_prof_expires = nval; |
211 | tsk->signal->it_prof_incr = ninterval; |
212 | spin_unlock_irq(&tsk->sighand->siglock); |
213 | read_unlock(&tasklist_lock); |
214 | if (ovalue) { |
215 | cputime_to_timeval(cval, &ovalue->it_value); |
216 | cputime_to_timeval(cinterval, &ovalue->it_interval); |
217 | } |
218 | break; |
219 | default: |
220 | return -EINVAL; |
221 | } |
222 | return 0; |
223 | } |
224 | |
225 | asmlinkage long sys_setitimer(int which, |
226 | struct itimerval __user *value, |
227 | struct itimerval __user *ovalue) |
228 | { |
229 | struct itimerval set_buffer, get_buffer; |
230 | int error; |
231 | |
232 | if (value) { |
233 | if(copy_from_user(&set_buffer, value, sizeof(set_buffer))) |
234 | return -EFAULT; |
235 | } else |
236 | memset((char *) &set_buffer, 0, sizeof(set_buffer)); |
237 | |
238 | error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL); |
239 | if (error || !ovalue) |
240 | return error; |
241 | |
242 | if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer))) |
243 | return -EFAULT; |
244 | return 0; |
245 | } |