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-rw-r--r--kernel/Makefile3
-rw-r--r--kernel/cgroup.c7
-rw-r--r--kernel/compat.c15
-rw-r--r--kernel/hrtimer.c22
-rw-r--r--kernel/kgdb.c1700
-rw-r--r--kernel/posix-cpu-timers.c30
-rw-r--r--kernel/semaphore.c264
-rw-r--r--kernel/signal.c71
-rw-r--r--kernel/time/clocksource.c30
-rw-r--r--kernel/time/tick-broadcast.c2
-rw-r--r--kernel/time/tick-common.c4
-rw-r--r--kernel/time/tick-oneshot.c2
-rw-r--r--kernel/time/tick-sched.c6
-rw-r--r--kernel/timer.c16
-rw-r--r--kernel/workqueue.c2
15 files changed, 2085 insertions, 89 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index 6c584c55a6e9..6c5f081132a4 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -8,7 +8,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \
8 signal.o sys.o kmod.o workqueue.o pid.o \ 8 signal.o sys.o kmod.o workqueue.o pid.o \
9 rcupdate.o extable.o params.o posix-timers.o \ 9 rcupdate.o extable.o params.o posix-timers.o \
10 kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \ 10 kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \
11 hrtimer.o rwsem.o nsproxy.o srcu.o \ 11 hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
12 notifier.o ksysfs.o pm_qos_params.o 12 notifier.o ksysfs.o pm_qos_params.o
13 13
14obj-$(CONFIG_SYSCTL) += sysctl_check.o 14obj-$(CONFIG_SYSCTL) += sysctl_check.o
@@ -53,6 +53,7 @@ obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
53obj-$(CONFIG_AUDITSYSCALL) += auditsc.o 53obj-$(CONFIG_AUDITSYSCALL) += auditsc.o
54obj-$(CONFIG_AUDIT_TREE) += audit_tree.o 54obj-$(CONFIG_AUDIT_TREE) += audit_tree.o
55obj-$(CONFIG_KPROBES) += kprobes.o 55obj-$(CONFIG_KPROBES) += kprobes.o
56obj-$(CONFIG_KGDB) += kgdb.o
56obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o 57obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o
57obj-$(CONFIG_GENERIC_HARDIRQS) += irq/ 58obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
58obj-$(CONFIG_SECCOMP) += seccomp.o 59obj-$(CONFIG_SECCOMP) += seccomp.o
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 2727f9238359..6d8de051382b 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1722,7 +1722,12 @@ void cgroup_enable_task_cg_lists(void)
1722 use_task_css_set_links = 1; 1722 use_task_css_set_links = 1;
1723 do_each_thread(g, p) { 1723 do_each_thread(g, p) {
1724 task_lock(p); 1724 task_lock(p);
1725 if (list_empty(&p->cg_list)) 1725 /*
1726 * We should check if the process is exiting, otherwise
1727 * it will race with cgroup_exit() in that the list
1728 * entry won't be deleted though the process has exited.
1729 */
1730 if (!(p->flags & PF_EXITING) && list_empty(&p->cg_list))
1726 list_add(&p->cg_list, &p->cgroups->tasks); 1731 list_add(&p->cg_list, &p->cgroups->tasks);
1727 task_unlock(p); 1732 task_unlock(p);
1728 } while_each_thread(g, p); 1733 } while_each_thread(g, p);
diff --git a/kernel/compat.c b/kernel/compat.c
index 5f0e201bcfd3..9c48abfcd4a5 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -47,15 +47,14 @@ static long compat_nanosleep_restart(struct restart_block *restart)
47 mm_segment_t oldfs; 47 mm_segment_t oldfs;
48 long ret; 48 long ret;
49 49
50 rmtp = (struct compat_timespec __user *)(restart->arg1); 50 restart->nanosleep.rmtp = (struct timespec __user *) &rmt;
51 restart->arg1 = (unsigned long)&rmt;
52 oldfs = get_fs(); 51 oldfs = get_fs();
53 set_fs(KERNEL_DS); 52 set_fs(KERNEL_DS);
54 ret = hrtimer_nanosleep_restart(restart); 53 ret = hrtimer_nanosleep_restart(restart);
55 set_fs(oldfs); 54 set_fs(oldfs);
56 55
57 if (ret) { 56 if (ret) {
58 restart->arg1 = (unsigned long)rmtp; 57 rmtp = restart->nanosleep.compat_rmtp;
59 58
60 if (rmtp && put_compat_timespec(&rmt, rmtp)) 59 if (rmtp && put_compat_timespec(&rmt, rmtp))
61 return -EFAULT; 60 return -EFAULT;
@@ -89,7 +88,7 @@ asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
89 = &current_thread_info()->restart_block; 88 = &current_thread_info()->restart_block;
90 89
91 restart->fn = compat_nanosleep_restart; 90 restart->fn = compat_nanosleep_restart;
92 restart->arg1 = (unsigned long)rmtp; 91 restart->nanosleep.compat_rmtp = rmtp;
93 92
94 if (rmtp && put_compat_timespec(&rmt, rmtp)) 93 if (rmtp && put_compat_timespec(&rmt, rmtp))
95 return -EFAULT; 94 return -EFAULT;
@@ -607,9 +606,9 @@ static long compat_clock_nanosleep_restart(struct restart_block *restart)
607 long err; 606 long err;
608 mm_segment_t oldfs; 607 mm_segment_t oldfs;
609 struct timespec tu; 608 struct timespec tu;
610 struct compat_timespec *rmtp = (struct compat_timespec *)(restart->arg1); 609 struct compat_timespec *rmtp = restart->nanosleep.compat_rmtp;
611 610
612 restart->arg1 = (unsigned long) &tu; 611 restart->nanosleep.rmtp = (struct timespec __user *) &tu;
613 oldfs = get_fs(); 612 oldfs = get_fs();
614 set_fs(KERNEL_DS); 613 set_fs(KERNEL_DS);
615 err = clock_nanosleep_restart(restart); 614 err = clock_nanosleep_restart(restart);
@@ -621,7 +620,7 @@ static long compat_clock_nanosleep_restart(struct restart_block *restart)
621 620
622 if (err == -ERESTART_RESTARTBLOCK) { 621 if (err == -ERESTART_RESTARTBLOCK) {
623 restart->fn = compat_clock_nanosleep_restart; 622 restart->fn = compat_clock_nanosleep_restart;
624 restart->arg1 = (unsigned long) rmtp; 623 restart->nanosleep.compat_rmtp = rmtp;
625 } 624 }
626 return err; 625 return err;
627} 626}
@@ -652,7 +651,7 @@ long compat_sys_clock_nanosleep(clockid_t which_clock, int flags,
652 if (err == -ERESTART_RESTARTBLOCK) { 651 if (err == -ERESTART_RESTARTBLOCK) {
653 restart = &current_thread_info()->restart_block; 652 restart = &current_thread_info()->restart_block;
654 restart->fn = compat_clock_nanosleep_restart; 653 restart->fn = compat_clock_nanosleep_restart;
655 restart->arg1 = (unsigned long) rmtp; 654 restart->nanosleep.compat_rmtp = rmtp;
656 } 655 }
657 return err; 656 return err;
658} 657}
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 98bee013f71f..c642ef75069f 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1354,13 +1354,13 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
1354 struct hrtimer_sleeper t; 1354 struct hrtimer_sleeper t;
1355 struct timespec __user *rmtp; 1355 struct timespec __user *rmtp;
1356 1356
1357 hrtimer_init(&t.timer, restart->arg0, HRTIMER_MODE_ABS); 1357 hrtimer_init(&t.timer, restart->nanosleep.index, HRTIMER_MODE_ABS);
1358 t.timer.expires.tv64 = ((u64)restart->arg3 << 32) | (u64) restart->arg2; 1358 t.timer.expires.tv64 = restart->nanosleep.expires;
1359 1359
1360 if (do_nanosleep(&t, HRTIMER_MODE_ABS)) 1360 if (do_nanosleep(&t, HRTIMER_MODE_ABS))
1361 return 0; 1361 return 0;
1362 1362
1363 rmtp = (struct timespec __user *)restart->arg1; 1363 rmtp = restart->nanosleep.rmtp;
1364 if (rmtp) { 1364 if (rmtp) {
1365 int ret = update_rmtp(&t.timer, rmtp); 1365 int ret = update_rmtp(&t.timer, rmtp);
1366 if (ret <= 0) 1366 if (ret <= 0)
@@ -1394,10 +1394,9 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
1394 1394
1395 restart = &current_thread_info()->restart_block; 1395 restart = &current_thread_info()->restart_block;
1396 restart->fn = hrtimer_nanosleep_restart; 1396 restart->fn = hrtimer_nanosleep_restart;
1397 restart->arg0 = (unsigned long) t.timer.base->index; 1397 restart->nanosleep.index = t.timer.base->index;
1398 restart->arg1 = (unsigned long) rmtp; 1398 restart->nanosleep.rmtp = rmtp;
1399 restart->arg2 = t.timer.expires.tv64 & 0xFFFFFFFF; 1399 restart->nanosleep.expires = t.timer.expires.tv64;
1400 restart->arg3 = t.timer.expires.tv64 >> 32;
1401 1400
1402 return -ERESTART_RESTARTBLOCK; 1401 return -ERESTART_RESTARTBLOCK;
1403} 1402}
@@ -1425,7 +1424,6 @@ static void __cpuinit init_hrtimers_cpu(int cpu)
1425 int i; 1424 int i;
1426 1425
1427 spin_lock_init(&cpu_base->lock); 1426 spin_lock_init(&cpu_base->lock);
1428 lockdep_set_class(&cpu_base->lock, &cpu_base->lock_key);
1429 1427
1430 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) 1428 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
1431 cpu_base->clock_base[i].cpu_base = cpu_base; 1429 cpu_base->clock_base[i].cpu_base = cpu_base;
@@ -1466,16 +1464,16 @@ static void migrate_hrtimers(int cpu)
1466 tick_cancel_sched_timer(cpu); 1464 tick_cancel_sched_timer(cpu);
1467 1465
1468 local_irq_disable(); 1466 local_irq_disable();
1469 double_spin_lock(&new_base->lock, &old_base->lock, 1467 spin_lock(&new_base->lock);
1470 smp_processor_id() < cpu); 1468 spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
1471 1469
1472 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { 1470 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1473 migrate_hrtimer_list(&old_base->clock_base[i], 1471 migrate_hrtimer_list(&old_base->clock_base[i],
1474 &new_base->clock_base[i]); 1472 &new_base->clock_base[i]);
1475 } 1473 }
1476 1474
1477 double_spin_unlock(&new_base->lock, &old_base->lock, 1475 spin_unlock(&old_base->lock);
1478 smp_processor_id() < cpu); 1476 spin_unlock(&new_base->lock);
1479 local_irq_enable(); 1477 local_irq_enable();
1480 put_cpu_var(hrtimer_bases); 1478 put_cpu_var(hrtimer_bases);
1481} 1479}
diff --git a/kernel/kgdb.c b/kernel/kgdb.c
new file mode 100644
index 000000000000..1bd0ec1c80b2
--- /dev/null
+++ b/kernel/kgdb.c
@@ -0,0 +1,1700 @@
1/*
2 * KGDB stub.
3 *
4 * Maintainer: Jason Wessel <jason.wessel@windriver.com>
5 *
6 * Copyright (C) 2000-2001 VERITAS Software Corporation.
7 * Copyright (C) 2002-2004 Timesys Corporation
8 * Copyright (C) 2003-2004 Amit S. Kale <amitkale@linsyssoft.com>
9 * Copyright (C) 2004 Pavel Machek <pavel@suse.cz>
10 * Copyright (C) 2004-2006 Tom Rini <trini@kernel.crashing.org>
11 * Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd.
12 * Copyright (C) 2005-2008 Wind River Systems, Inc.
13 * Copyright (C) 2007 MontaVista Software, Inc.
14 * Copyright (C) 2008 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
15 *
16 * Contributors at various stages not listed above:
17 * Jason Wessel ( jason.wessel@windriver.com )
18 * George Anzinger <george@mvista.com>
19 * Anurekh Saxena (anurekh.saxena@timesys.com)
20 * Lake Stevens Instrument Division (Glenn Engel)
21 * Jim Kingdon, Cygnus Support.
22 *
23 * Original KGDB stub: David Grothe <dave@gcom.com>,
24 * Tigran Aivazian <tigran@sco.com>
25 *
26 * This file is licensed under the terms of the GNU General Public License
27 * version 2. This program is licensed "as is" without any warranty of any
28 * kind, whether express or implied.
29 */
30#include <linux/pid_namespace.h>
31#include <linux/clocksource.h>
32#include <linux/interrupt.h>
33#include <linux/spinlock.h>
34#include <linux/console.h>
35#include <linux/threads.h>
36#include <linux/uaccess.h>
37#include <linux/kernel.h>
38#include <linux/module.h>
39#include <linux/ptrace.h>
40#include <linux/reboot.h>
41#include <linux/string.h>
42#include <linux/delay.h>
43#include <linux/sched.h>
44#include <linux/sysrq.h>
45#include <linux/init.h>
46#include <linux/kgdb.h>
47#include <linux/pid.h>
48#include <linux/smp.h>
49#include <linux/mm.h>
50
51#include <asm/cacheflush.h>
52#include <asm/byteorder.h>
53#include <asm/atomic.h>
54#include <asm/system.h>
55
56static int kgdb_break_asap;
57
58struct kgdb_state {
59 int ex_vector;
60 int signo;
61 int err_code;
62 int cpu;
63 int pass_exception;
64 long threadid;
65 long kgdb_usethreadid;
66 struct pt_regs *linux_regs;
67};
68
69static struct debuggerinfo_struct {
70 void *debuggerinfo;
71 struct task_struct *task;
72} kgdb_info[NR_CPUS];
73
74/**
75 * kgdb_connected - Is a host GDB connected to us?
76 */
77int kgdb_connected;
78EXPORT_SYMBOL_GPL(kgdb_connected);
79
80/* All the KGDB handlers are installed */
81static int kgdb_io_module_registered;
82
83/* Guard for recursive entry */
84static int exception_level;
85
86static struct kgdb_io *kgdb_io_ops;
87static DEFINE_SPINLOCK(kgdb_registration_lock);
88
89/* kgdb console driver is loaded */
90static int kgdb_con_registered;
91/* determine if kgdb console output should be used */
92static int kgdb_use_con;
93
94static int __init opt_kgdb_con(char *str)
95{
96 kgdb_use_con = 1;
97 return 0;
98}
99
100early_param("kgdbcon", opt_kgdb_con);
101
102module_param(kgdb_use_con, int, 0644);
103
104/*
105 * Holds information about breakpoints in a kernel. These breakpoints are
106 * added and removed by gdb.
107 */
108static struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = {
109 [0 ... KGDB_MAX_BREAKPOINTS-1] = { .state = BP_UNDEFINED }
110};
111
112/*
113 * The CPU# of the active CPU, or -1 if none:
114 */
115atomic_t kgdb_active = ATOMIC_INIT(-1);
116
117/*
118 * We use NR_CPUs not PERCPU, in case kgdb is used to debug early
119 * bootup code (which might not have percpu set up yet):
120 */
121static atomic_t passive_cpu_wait[NR_CPUS];
122static atomic_t cpu_in_kgdb[NR_CPUS];
123atomic_t kgdb_setting_breakpoint;
124
125struct task_struct *kgdb_usethread;
126struct task_struct *kgdb_contthread;
127
128int kgdb_single_step;
129
130/* Our I/O buffers. */
131static char remcom_in_buffer[BUFMAX];
132static char remcom_out_buffer[BUFMAX];
133
134/* Storage for the registers, in GDB format. */
135static unsigned long gdb_regs[(NUMREGBYTES +
136 sizeof(unsigned long) - 1) /
137 sizeof(unsigned long)];
138
139/* to keep track of the CPU which is doing the single stepping*/
140atomic_t kgdb_cpu_doing_single_step = ATOMIC_INIT(-1);
141
142/*
143 * If you are debugging a problem where roundup (the collection of
144 * all other CPUs) is a problem [this should be extremely rare],
145 * then use the nokgdbroundup option to avoid roundup. In that case
146 * the other CPUs might interfere with your debugging context, so
147 * use this with care:
148 */
149int kgdb_do_roundup = 1;
150
151static int __init opt_nokgdbroundup(char *str)
152{
153 kgdb_do_roundup = 0;
154
155 return 0;
156}
157
158early_param("nokgdbroundup", opt_nokgdbroundup);
159
160/*
161 * Finally, some KGDB code :-)
162 */
163
164/*
165 * Weak aliases for breakpoint management,
166 * can be overriden by architectures when needed:
167 */
168int __weak kgdb_validate_break_address(unsigned long addr)
169{
170 char tmp_variable[BREAK_INSTR_SIZE];
171
172 return probe_kernel_read(tmp_variable, (char *)addr, BREAK_INSTR_SIZE);
173}
174
175int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr)
176{
177 int err;
178
179 err = probe_kernel_read(saved_instr, (char *)addr, BREAK_INSTR_SIZE);
180 if (err)
181 return err;
182
183 return probe_kernel_write((char *)addr, arch_kgdb_ops.gdb_bpt_instr,
184 BREAK_INSTR_SIZE);
185}
186
187int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle)
188{
189 return probe_kernel_write((char *)addr,
190 (char *)bundle, BREAK_INSTR_SIZE);
191}
192
193unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs)
194{
195 return instruction_pointer(regs);
196}
197
198int __weak kgdb_arch_init(void)
199{
200 return 0;
201}
202
203int __weak kgdb_skipexception(int exception, struct pt_regs *regs)
204{
205 return 0;
206}
207
208void __weak
209kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code)
210{
211 return;
212}
213
214/**
215 * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb.
216 * @regs: Current &struct pt_regs.
217 *
218 * This function will be called if the particular architecture must
219 * disable hardware debugging while it is processing gdb packets or
220 * handling exception.
221 */
222void __weak kgdb_disable_hw_debug(struct pt_regs *regs)
223{
224}
225
226/*
227 * GDB remote protocol parser:
228 */
229
230static const char hexchars[] = "0123456789abcdef";
231
232static int hex(char ch)
233{
234 if ((ch >= 'a') && (ch <= 'f'))
235 return ch - 'a' + 10;
236 if ((ch >= '0') && (ch <= '9'))
237 return ch - '0';
238 if ((ch >= 'A') && (ch <= 'F'))
239 return ch - 'A' + 10;
240 return -1;
241}
242
243/* scan for the sequence $<data>#<checksum> */
244static void get_packet(char *buffer)
245{
246 unsigned char checksum;
247 unsigned char xmitcsum;
248 int count;
249 char ch;
250
251 do {
252 /*
253 * Spin and wait around for the start character, ignore all
254 * other characters:
255 */
256 while ((ch = (kgdb_io_ops->read_char())) != '$')
257 /* nothing */;
258
259 kgdb_connected = 1;
260 checksum = 0;
261 xmitcsum = -1;
262
263 count = 0;
264
265 /*
266 * now, read until a # or end of buffer is found:
267 */
268 while (count < (BUFMAX - 1)) {
269 ch = kgdb_io_ops->read_char();
270 if (ch == '#')
271 break;
272 checksum = checksum + ch;
273 buffer[count] = ch;
274 count = count + 1;
275 }
276 buffer[count] = 0;
277
278 if (ch == '#') {
279 xmitcsum = hex(kgdb_io_ops->read_char()) << 4;
280 xmitcsum += hex(kgdb_io_ops->read_char());
281
282 if (checksum != xmitcsum)
283 /* failed checksum */
284 kgdb_io_ops->write_char('-');
285 else
286 /* successful transfer */
287 kgdb_io_ops->write_char('+');
288 if (kgdb_io_ops->flush)
289 kgdb_io_ops->flush();
290 }
291 } while (checksum != xmitcsum);
292}
293
294/*
295 * Send the packet in buffer.
296 * Check for gdb connection if asked for.
297 */
298static void put_packet(char *buffer)
299{
300 unsigned char checksum;
301 int count;
302 char ch;
303
304 /*
305 * $<packet info>#<checksum>.
306 */
307 while (1) {
308 kgdb_io_ops->write_char('$');
309 checksum = 0;
310 count = 0;
311
312 while ((ch = buffer[count])) {
313 kgdb_io_ops->write_char(ch);
314 checksum += ch;
315 count++;
316 }
317
318 kgdb_io_ops->write_char('#');
319 kgdb_io_ops->write_char(hexchars[checksum >> 4]);
320 kgdb_io_ops->write_char(hexchars[checksum & 0xf]);
321 if (kgdb_io_ops->flush)
322 kgdb_io_ops->flush();
323
324 /* Now see what we get in reply. */
325 ch = kgdb_io_ops->read_char();
326
327 if (ch == 3)
328 ch = kgdb_io_ops->read_char();
329
330 /* If we get an ACK, we are done. */
331 if (ch == '+')
332 return;
333
334 /*
335 * If we get the start of another packet, this means
336 * that GDB is attempting to reconnect. We will NAK
337 * the packet being sent, and stop trying to send this
338 * packet.
339 */
340 if (ch == '$') {
341 kgdb_io_ops->write_char('-');
342 if (kgdb_io_ops->flush)
343 kgdb_io_ops->flush();
344 return;
345 }
346 }
347}
348
349static char *pack_hex_byte(char *pkt, u8 byte)
350{
351 *pkt++ = hexchars[byte >> 4];
352 *pkt++ = hexchars[byte & 0xf];
353
354 return pkt;
355}
356
357/*
358 * Convert the memory pointed to by mem into hex, placing result in buf.
359 * Return a pointer to the last char put in buf (null). May return an error.
360 */
361int kgdb_mem2hex(char *mem, char *buf, int count)
362{
363 char *tmp;
364 int err;
365
366 /*
367 * We use the upper half of buf as an intermediate buffer for the
368 * raw memory copy. Hex conversion will work against this one.
369 */
370 tmp = buf + count;
371
372 err = probe_kernel_read(tmp, mem, count);
373 if (!err) {
374 while (count > 0) {
375 buf = pack_hex_byte(buf, *tmp);
376 tmp++;
377 count--;
378 }
379
380 *buf = 0;
381 }
382
383 return err;
384}
385
386/*
387 * Copy the binary array pointed to by buf into mem. Fix $, #, and
388 * 0x7d escaped with 0x7d. Return a pointer to the character after
389 * the last byte written.
390 */
391static int kgdb_ebin2mem(char *buf, char *mem, int count)
392{
393 int err = 0;
394 char c;
395
396 while (count-- > 0) {
397 c = *buf++;
398 if (c == 0x7d)
399 c = *buf++ ^ 0x20;
400
401 err = probe_kernel_write(mem, &c, 1);
402 if (err)
403 break;
404
405 mem++;
406 }
407
408 return err;
409}
410
411/*
412 * Convert the hex array pointed to by buf into binary to be placed in mem.
413 * Return a pointer to the character AFTER the last byte written.
414 * May return an error.
415 */
416int kgdb_hex2mem(char *buf, char *mem, int count)
417{
418 char *tmp_raw;
419 char *tmp_hex;
420
421 /*
422 * We use the upper half of buf as an intermediate buffer for the
423 * raw memory that is converted from hex.
424 */
425 tmp_raw = buf + count * 2;
426
427 tmp_hex = tmp_raw - 1;
428 while (tmp_hex >= buf) {
429 tmp_raw--;
430 *tmp_raw = hex(*tmp_hex--);
431 *tmp_raw |= hex(*tmp_hex--) << 4;
432 }
433
434 return probe_kernel_write(mem, tmp_raw, count);
435}
436
437/*
438 * While we find nice hex chars, build a long_val.
439 * Return number of chars processed.
440 */
441int kgdb_hex2long(char **ptr, long *long_val)
442{
443 int hex_val;
444 int num = 0;
445
446 *long_val = 0;
447
448 while (**ptr) {
449 hex_val = hex(**ptr);
450 if (hex_val < 0)
451 break;
452
453 *long_val = (*long_val << 4) | hex_val;
454 num++;
455 (*ptr)++;
456 }
457
458 return num;
459}
460
461/* Write memory due to an 'M' or 'X' packet. */
462static int write_mem_msg(int binary)
463{
464 char *ptr = &remcom_in_buffer[1];
465 unsigned long addr;
466 unsigned long length;
467 int err;
468
469 if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' &&
470 kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') {
471 if (binary)
472 err = kgdb_ebin2mem(ptr, (char *)addr, length);
473 else
474 err = kgdb_hex2mem(ptr, (char *)addr, length);
475 if (err)
476 return err;
477 if (CACHE_FLUSH_IS_SAFE)
478 flush_icache_range(addr, addr + length + 1);
479 return 0;
480 }
481
482 return -EINVAL;
483}
484
485static void error_packet(char *pkt, int error)
486{
487 error = -error;
488 pkt[0] = 'E';
489 pkt[1] = hexchars[(error / 10)];
490 pkt[2] = hexchars[(error % 10)];
491 pkt[3] = '\0';
492}
493
494/*
495 * Thread ID accessors. We represent a flat TID space to GDB, where
496 * the per CPU idle threads (which under Linux all have PID 0) are
497 * remapped to negative TIDs.
498 */
499
500#define BUF_THREAD_ID_SIZE 16
501
502static char *pack_threadid(char *pkt, unsigned char *id)
503{
504 char *limit;
505
506 limit = pkt + BUF_THREAD_ID_SIZE;
507 while (pkt < limit)
508 pkt = pack_hex_byte(pkt, *id++);
509
510 return pkt;
511}
512
513static void int_to_threadref(unsigned char *id, int value)
514{
515 unsigned char *scan;
516 int i = 4;
517
518 scan = (unsigned char *)id;
519 while (i--)
520 *scan++ = 0;
521 *scan++ = (value >> 24) & 0xff;
522 *scan++ = (value >> 16) & 0xff;
523 *scan++ = (value >> 8) & 0xff;
524 *scan++ = (value & 0xff);
525}
526
527static struct task_struct *getthread(struct pt_regs *regs, int tid)
528{
529 /*
530 * Non-positive TIDs are remapped idle tasks:
531 */
532 if (tid <= 0)
533 return idle_task(-tid);
534
535 /*
536 * find_task_by_pid_ns() does not take the tasklist lock anymore
537 * but is nicely RCU locked - hence is a pretty resilient
538 * thing to use:
539 */
540 return find_task_by_pid_ns(tid, &init_pid_ns);
541}
542
543/*
544 * CPU debug state control:
545 */
546
547#ifdef CONFIG_SMP
548static void kgdb_wait(struct pt_regs *regs)
549{
550 unsigned long flags;
551 int cpu;
552
553 local_irq_save(flags);
554 cpu = raw_smp_processor_id();
555 kgdb_info[cpu].debuggerinfo = regs;
556 kgdb_info[cpu].task = current;
557 /*
558 * Make sure the above info reaches the primary CPU before
559 * our cpu_in_kgdb[] flag setting does:
560 */
561 smp_wmb();
562 atomic_set(&cpu_in_kgdb[cpu], 1);
563
564 /* Wait till primary CPU is done with debugging */
565 while (atomic_read(&passive_cpu_wait[cpu]))
566 cpu_relax();
567
568 kgdb_info[cpu].debuggerinfo = NULL;
569 kgdb_info[cpu].task = NULL;
570
571 /* fix up hardware debug registers on local cpu */
572 if (arch_kgdb_ops.correct_hw_break)
573 arch_kgdb_ops.correct_hw_break();
574
575 /* Signal the primary CPU that we are done: */
576 atomic_set(&cpu_in_kgdb[cpu], 0);
577 clocksource_touch_watchdog();
578 local_irq_restore(flags);
579}
580#endif
581
582/*
583 * Some architectures need cache flushes when we set/clear a
584 * breakpoint:
585 */
586static void kgdb_flush_swbreak_addr(unsigned long addr)
587{
588 if (!CACHE_FLUSH_IS_SAFE)
589 return;
590
591 if (current->mm && current->mm->mmap_cache) {
592 flush_cache_range(current->mm->mmap_cache,
593 addr, addr + BREAK_INSTR_SIZE);
594 }
595 /* Force flush instruction cache if it was outside the mm */
596 flush_icache_range(addr, addr + BREAK_INSTR_SIZE);
597}
598
599/*
600 * SW breakpoint management:
601 */
602static int kgdb_activate_sw_breakpoints(void)
603{
604 unsigned long addr;
605 int error = 0;
606 int i;
607
608 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
609 if (kgdb_break[i].state != BP_SET)
610 continue;
611
612 addr = kgdb_break[i].bpt_addr;
613 error = kgdb_arch_set_breakpoint(addr,
614 kgdb_break[i].saved_instr);
615 if (error)
616 return error;
617
618 kgdb_flush_swbreak_addr(addr);
619 kgdb_break[i].state = BP_ACTIVE;
620 }
621 return 0;
622}
623
624static int kgdb_set_sw_break(unsigned long addr)
625{
626 int err = kgdb_validate_break_address(addr);
627 int breakno = -1;
628 int i;
629
630 if (err)
631 return err;
632
633 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
634 if ((kgdb_break[i].state == BP_SET) &&
635 (kgdb_break[i].bpt_addr == addr))
636 return -EEXIST;
637 }
638 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
639 if (kgdb_break[i].state == BP_REMOVED &&
640 kgdb_break[i].bpt_addr == addr) {
641 breakno = i;
642 break;
643 }
644 }
645
646 if (breakno == -1) {
647 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
648 if (kgdb_break[i].state == BP_UNDEFINED) {
649 breakno = i;
650 break;
651 }
652 }
653 }
654
655 if (breakno == -1)
656 return -E2BIG;
657
658 kgdb_break[breakno].state = BP_SET;
659 kgdb_break[breakno].type = BP_BREAKPOINT;
660 kgdb_break[breakno].bpt_addr = addr;
661
662 return 0;
663}
664
665static int kgdb_deactivate_sw_breakpoints(void)
666{
667 unsigned long addr;
668 int error = 0;
669 int i;
670
671 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
672 if (kgdb_break[i].state != BP_ACTIVE)
673 continue;
674 addr = kgdb_break[i].bpt_addr;
675 error = kgdb_arch_remove_breakpoint(addr,
676 kgdb_break[i].saved_instr);
677 if (error)
678 return error;
679
680 kgdb_flush_swbreak_addr(addr);
681 kgdb_break[i].state = BP_SET;
682 }
683 return 0;
684}
685
686static int kgdb_remove_sw_break(unsigned long addr)
687{
688 int i;
689
690 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
691 if ((kgdb_break[i].state == BP_SET) &&
692 (kgdb_break[i].bpt_addr == addr)) {
693 kgdb_break[i].state = BP_REMOVED;
694 return 0;
695 }
696 }
697 return -ENOENT;
698}
699
700int kgdb_isremovedbreak(unsigned long addr)
701{
702 int i;
703
704 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
705 if ((kgdb_break[i].state == BP_REMOVED) &&
706 (kgdb_break[i].bpt_addr == addr))
707 return 1;
708 }
709 return 0;
710}
711
712int remove_all_break(void)
713{
714 unsigned long addr;
715 int error;
716 int i;
717
718 /* Clear memory breakpoints. */
719 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
720 if (kgdb_break[i].state != BP_ACTIVE)
721 goto setundefined;
722 addr = kgdb_break[i].bpt_addr;
723 error = kgdb_arch_remove_breakpoint(addr,
724 kgdb_break[i].saved_instr);
725 if (error)
726 printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n",
727 addr);
728setundefined:
729 kgdb_break[i].state = BP_UNDEFINED;
730 }
731
732 /* Clear hardware breakpoints. */
733 if (arch_kgdb_ops.remove_all_hw_break)
734 arch_kgdb_ops.remove_all_hw_break();
735
736 return 0;
737}
738
739/*
740 * Remap normal tasks to their real PID, idle tasks to -1 ... -NR_CPUs:
741 */
742static inline int shadow_pid(int realpid)
743{
744 if (realpid)
745 return realpid;
746
747 return -1-raw_smp_processor_id();
748}
749
750static char gdbmsgbuf[BUFMAX + 1];
751
752static void kgdb_msg_write(const char *s, int len)
753{
754 char *bufptr;
755 int wcount;
756 int i;
757
758 /* 'O'utput */
759 gdbmsgbuf[0] = 'O';
760
761 /* Fill and send buffers... */
762 while (len > 0) {
763 bufptr = gdbmsgbuf + 1;
764
765 /* Calculate how many this time */
766 if ((len << 1) > (BUFMAX - 2))
767 wcount = (BUFMAX - 2) >> 1;
768 else
769 wcount = len;
770
771 /* Pack in hex chars */
772 for (i = 0; i < wcount; i++)
773 bufptr = pack_hex_byte(bufptr, s[i]);
774 *bufptr = '\0';
775
776 /* Move up */
777 s += wcount;
778 len -= wcount;
779
780 /* Write packet */
781 put_packet(gdbmsgbuf);
782 }
783}
784
785/*
786 * Return true if there is a valid kgdb I/O module. Also if no
787 * debugger is attached a message can be printed to the console about
788 * waiting for the debugger to attach.
789 *
790 * The print_wait argument is only to be true when called from inside
791 * the core kgdb_handle_exception, because it will wait for the
792 * debugger to attach.
793 */
794static int kgdb_io_ready(int print_wait)
795{
796 if (!kgdb_io_ops)
797 return 0;
798 if (kgdb_connected)
799 return 1;
800 if (atomic_read(&kgdb_setting_breakpoint))
801 return 1;
802 if (print_wait)
803 printk(KERN_CRIT "KGDB: Waiting for remote debugger\n");
804 return 1;
805}
806
807/*
808 * All the functions that start with gdb_cmd are the various
809 * operations to implement the handlers for the gdbserial protocol
810 * where KGDB is communicating with an external debugger
811 */
812
813/* Handle the '?' status packets */
814static void gdb_cmd_status(struct kgdb_state *ks)
815{
816 /*
817 * We know that this packet is only sent
818 * during initial connect. So to be safe,
819 * we clear out our breakpoints now in case
820 * GDB is reconnecting.
821 */
822 remove_all_break();
823
824 remcom_out_buffer[0] = 'S';
825 pack_hex_byte(&remcom_out_buffer[1], ks->signo);
826}
827
828/* Handle the 'g' get registers request */
829static void gdb_cmd_getregs(struct kgdb_state *ks)
830{
831 struct task_struct *thread;
832 void *local_debuggerinfo;
833 int i;
834
835 thread = kgdb_usethread;
836 if (!thread) {
837 thread = kgdb_info[ks->cpu].task;
838 local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo;
839 } else {
840 local_debuggerinfo = NULL;
841 for (i = 0; i < NR_CPUS; i++) {
842 /*
843 * Try to find the task on some other
844 * or possibly this node if we do not
845 * find the matching task then we try
846 * to approximate the results.
847 */
848 if (thread == kgdb_info[i].task)
849 local_debuggerinfo = kgdb_info[i].debuggerinfo;
850 }
851 }
852
853 /*
854 * All threads that don't have debuggerinfo should be
855 * in __schedule() sleeping, since all other CPUs
856 * are in kgdb_wait, and thus have debuggerinfo.
857 */
858 if (local_debuggerinfo) {
859 pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo);
860 } else {
861 /*
862 * Pull stuff saved during switch_to; nothing
863 * else is accessible (or even particularly
864 * relevant).
865 *
866 * This should be enough for a stack trace.
867 */
868 sleeping_thread_to_gdb_regs(gdb_regs, thread);
869 }
870 kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES);
871}
872
873/* Handle the 'G' set registers request */
874static void gdb_cmd_setregs(struct kgdb_state *ks)
875{
876 kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES);
877
878 if (kgdb_usethread && kgdb_usethread != current) {
879 error_packet(remcom_out_buffer, -EINVAL);
880 } else {
881 gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs);
882 strcpy(remcom_out_buffer, "OK");
883 }
884}
885
886/* Handle the 'm' memory read bytes */
887static void gdb_cmd_memread(struct kgdb_state *ks)
888{
889 char *ptr = &remcom_in_buffer[1];
890 unsigned long length;
891 unsigned long addr;
892 int err;
893
894 if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' &&
895 kgdb_hex2long(&ptr, &length) > 0) {
896 err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length);
897 if (err)
898 error_packet(remcom_out_buffer, err);
899 } else {
900 error_packet(remcom_out_buffer, -EINVAL);
901 }
902}
903
904/* Handle the 'M' memory write bytes */
905static void gdb_cmd_memwrite(struct kgdb_state *ks)
906{
907 int err = write_mem_msg(0);
908
909 if (err)
910 error_packet(remcom_out_buffer, err);
911 else
912 strcpy(remcom_out_buffer, "OK");
913}
914
915/* Handle the 'X' memory binary write bytes */
916static void gdb_cmd_binwrite(struct kgdb_state *ks)
917{
918 int err = write_mem_msg(1);
919
920 if (err)
921 error_packet(remcom_out_buffer, err);
922 else
923 strcpy(remcom_out_buffer, "OK");
924}
925
926/* Handle the 'D' or 'k', detach or kill packets */
927static void gdb_cmd_detachkill(struct kgdb_state *ks)
928{
929 int error;
930
931 /* The detach case */
932 if (remcom_in_buffer[0] == 'D') {
933 error = remove_all_break();
934 if (error < 0) {
935 error_packet(remcom_out_buffer, error);
936 } else {
937 strcpy(remcom_out_buffer, "OK");
938 kgdb_connected = 0;
939 }
940 put_packet(remcom_out_buffer);
941 } else {
942 /*
943 * Assume the kill case, with no exit code checking,
944 * trying to force detach the debugger:
945 */
946 remove_all_break();
947 kgdb_connected = 0;
948 }
949}
950
951/* Handle the 'R' reboot packets */
952static int gdb_cmd_reboot(struct kgdb_state *ks)
953{
954 /* For now, only honor R0 */
955 if (strcmp(remcom_in_buffer, "R0") == 0) {
956 printk(KERN_CRIT "Executing emergency reboot\n");
957 strcpy(remcom_out_buffer, "OK");
958 put_packet(remcom_out_buffer);
959
960 /*
961 * Execution should not return from
962 * machine_emergency_restart()
963 */
964 machine_emergency_restart();
965 kgdb_connected = 0;
966
967 return 1;
968 }
969 return 0;
970}
971
972/* Handle the 'q' query packets */
973static void gdb_cmd_query(struct kgdb_state *ks)
974{
975 struct task_struct *thread;
976 unsigned char thref[8];
977 char *ptr;
978 int i;
979
980 switch (remcom_in_buffer[1]) {
981 case 's':
982 case 'f':
983 if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) {
984 error_packet(remcom_out_buffer, -EINVAL);
985 break;
986 }
987
988 if (remcom_in_buffer[1] == 'f')
989 ks->threadid = 1;
990
991 remcom_out_buffer[0] = 'm';
992 ptr = remcom_out_buffer + 1;
993
994 for (i = 0; i < 17; ks->threadid++) {
995 thread = getthread(ks->linux_regs, ks->threadid);
996 if (thread) {
997 int_to_threadref(thref, ks->threadid);
998 pack_threadid(ptr, thref);
999 ptr += BUF_THREAD_ID_SIZE;
1000 *(ptr++) = ',';
1001 i++;
1002 }
1003 }
1004 *(--ptr) = '\0';
1005 break;
1006
1007 case 'C':
1008 /* Current thread id */
1009 strcpy(remcom_out_buffer, "QC");
1010 ks->threadid = shadow_pid(current->pid);
1011 int_to_threadref(thref, ks->threadid);
1012 pack_threadid(remcom_out_buffer + 2, thref);
1013 break;
1014 case 'T':
1015 if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) {
1016 error_packet(remcom_out_buffer, -EINVAL);
1017 break;
1018 }
1019 ks->threadid = 0;
1020 ptr = remcom_in_buffer + 17;
1021 kgdb_hex2long(&ptr, &ks->threadid);
1022 if (!getthread(ks->linux_regs, ks->threadid)) {
1023 error_packet(remcom_out_buffer, -EINVAL);
1024 break;
1025 }
1026 if (ks->threadid > 0) {
1027 kgdb_mem2hex(getthread(ks->linux_regs,
1028 ks->threadid)->comm,
1029 remcom_out_buffer, 16);
1030 } else {
1031 static char tmpstr[23 + BUF_THREAD_ID_SIZE];
1032
1033 sprintf(tmpstr, "Shadow task %d for pid 0",
1034 (int)(-ks->threadid-1));
1035 kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr));
1036 }
1037 break;
1038 }
1039}
1040
1041/* Handle the 'H' task query packets */
1042static void gdb_cmd_task(struct kgdb_state *ks)
1043{
1044 struct task_struct *thread;
1045 char *ptr;
1046
1047 switch (remcom_in_buffer[1]) {
1048 case 'g':
1049 ptr = &remcom_in_buffer[2];
1050 kgdb_hex2long(&ptr, &ks->threadid);
1051 thread = getthread(ks->linux_regs, ks->threadid);
1052 if (!thread && ks->threadid > 0) {
1053 error_packet(remcom_out_buffer, -EINVAL);
1054 break;
1055 }
1056 kgdb_usethread = thread;
1057 ks->kgdb_usethreadid = ks->threadid;
1058 strcpy(remcom_out_buffer, "OK");
1059 break;
1060 case 'c':
1061 ptr = &remcom_in_buffer[2];
1062 kgdb_hex2long(&ptr, &ks->threadid);
1063 if (!ks->threadid) {
1064 kgdb_contthread = NULL;
1065 } else {
1066 thread = getthread(ks->linux_regs, ks->threadid);
1067 if (!thread && ks->threadid > 0) {
1068 error_packet(remcom_out_buffer, -EINVAL);
1069 break;
1070 }
1071 kgdb_contthread = thread;
1072 }
1073 strcpy(remcom_out_buffer, "OK");
1074 break;
1075 }
1076}
1077
1078/* Handle the 'T' thread query packets */
1079static void gdb_cmd_thread(struct kgdb_state *ks)
1080{
1081 char *ptr = &remcom_in_buffer[1];
1082 struct task_struct *thread;
1083
1084 kgdb_hex2long(&ptr, &ks->threadid);
1085 thread = getthread(ks->linux_regs, ks->threadid);
1086 if (thread)
1087 strcpy(remcom_out_buffer, "OK");
1088 else
1089 error_packet(remcom_out_buffer, -EINVAL);
1090}
1091
1092/* Handle the 'z' or 'Z' breakpoint remove or set packets */
1093static void gdb_cmd_break(struct kgdb_state *ks)
1094{
1095 /*
1096 * Since GDB-5.3, it's been drafted that '0' is a software
1097 * breakpoint, '1' is a hardware breakpoint, so let's do that.
1098 */
1099 char *bpt_type = &remcom_in_buffer[1];
1100 char *ptr = &remcom_in_buffer[2];
1101 unsigned long addr;
1102 unsigned long length;
1103 int error = 0;
1104
1105 if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') {
1106 /* Unsupported */
1107 if (*bpt_type > '4')
1108 return;
1109 } else {
1110 if (*bpt_type != '0' && *bpt_type != '1')
1111 /* Unsupported. */
1112 return;
1113 }
1114
1115 /*
1116 * Test if this is a hardware breakpoint, and
1117 * if we support it:
1118 */
1119 if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT))
1120 /* Unsupported. */
1121 return;
1122
1123 if (*(ptr++) != ',') {
1124 error_packet(remcom_out_buffer, -EINVAL);
1125 return;
1126 }
1127 if (!kgdb_hex2long(&ptr, &addr)) {
1128 error_packet(remcom_out_buffer, -EINVAL);
1129 return;
1130 }
1131 if (*(ptr++) != ',' ||
1132 !kgdb_hex2long(&ptr, &length)) {
1133 error_packet(remcom_out_buffer, -EINVAL);
1134 return;
1135 }
1136
1137 if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0')
1138 error = kgdb_set_sw_break(addr);
1139 else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0')
1140 error = kgdb_remove_sw_break(addr);
1141 else if (remcom_in_buffer[0] == 'Z')
1142 error = arch_kgdb_ops.set_hw_breakpoint(addr,
1143 (int)length, *bpt_type - '0');
1144 else if (remcom_in_buffer[0] == 'z')
1145 error = arch_kgdb_ops.remove_hw_breakpoint(addr,
1146 (int) length, *bpt_type - '0');
1147
1148 if (error == 0)
1149 strcpy(remcom_out_buffer, "OK");
1150 else
1151 error_packet(remcom_out_buffer, error);
1152}
1153
1154/* Handle the 'C' signal / exception passing packets */
1155static int gdb_cmd_exception_pass(struct kgdb_state *ks)
1156{
1157 /* C09 == pass exception
1158 * C15 == detach kgdb, pass exception
1159 */
1160 if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') {
1161
1162 ks->pass_exception = 1;
1163 remcom_in_buffer[0] = 'c';
1164
1165 } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') {
1166
1167 ks->pass_exception = 1;
1168 remcom_in_buffer[0] = 'D';
1169 remove_all_break();
1170 kgdb_connected = 0;
1171 return 1;
1172
1173 } else {
1174 error_packet(remcom_out_buffer, -EINVAL);
1175 return 0;
1176 }
1177
1178 /* Indicate fall through */
1179 return -1;
1180}
1181
1182/*
1183 * This function performs all gdbserial command procesing
1184 */
1185static int gdb_serial_stub(struct kgdb_state *ks)
1186{
1187 int error = 0;
1188 int tmp;
1189
1190 /* Clear the out buffer. */
1191 memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
1192
1193 if (kgdb_connected) {
1194 unsigned char thref[8];
1195 char *ptr;
1196
1197 /* Reply to host that an exception has occurred */
1198 ptr = remcom_out_buffer;
1199 *ptr++ = 'T';
1200 ptr = pack_hex_byte(ptr, ks->signo);
1201 ptr += strlen(strcpy(ptr, "thread:"));
1202 int_to_threadref(thref, shadow_pid(current->pid));
1203 ptr = pack_threadid(ptr, thref);
1204 *ptr++ = ';';
1205 put_packet(remcom_out_buffer);
1206 }
1207
1208 kgdb_usethread = kgdb_info[ks->cpu].task;
1209 ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
1210 ks->pass_exception = 0;
1211
1212 while (1) {
1213 error = 0;
1214
1215 /* Clear the out buffer. */
1216 memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
1217
1218 get_packet(remcom_in_buffer);
1219
1220 switch (remcom_in_buffer[0]) {
1221 case '?': /* gdbserial status */
1222 gdb_cmd_status(ks);
1223 break;
1224 case 'g': /* return the value of the CPU registers */
1225 gdb_cmd_getregs(ks);
1226 break;
1227 case 'G': /* set the value of the CPU registers - return OK */
1228 gdb_cmd_setregs(ks);
1229 break;
1230 case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */
1231 gdb_cmd_memread(ks);
1232 break;
1233 case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */
1234 gdb_cmd_memwrite(ks);
1235 break;
1236 case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */
1237 gdb_cmd_binwrite(ks);
1238 break;
1239 /* kill or detach. KGDB should treat this like a
1240 * continue.
1241 */
1242 case 'D': /* Debugger detach */
1243 case 'k': /* Debugger detach via kill */
1244 gdb_cmd_detachkill(ks);
1245 goto default_handle;
1246 case 'R': /* Reboot */
1247 if (gdb_cmd_reboot(ks))
1248 goto default_handle;
1249 break;
1250 case 'q': /* query command */
1251 gdb_cmd_query(ks);
1252 break;
1253 case 'H': /* task related */
1254 gdb_cmd_task(ks);
1255 break;
1256 case 'T': /* Query thread status */
1257 gdb_cmd_thread(ks);
1258 break;
1259 case 'z': /* Break point remove */
1260 case 'Z': /* Break point set */
1261 gdb_cmd_break(ks);
1262 break;
1263 case 'C': /* Exception passing */
1264 tmp = gdb_cmd_exception_pass(ks);
1265 if (tmp > 0)
1266 goto default_handle;
1267 if (tmp == 0)
1268 break;
1269 /* Fall through on tmp < 0 */
1270 case 'c': /* Continue packet */
1271 case 's': /* Single step packet */
1272 if (kgdb_contthread && kgdb_contthread != current) {
1273 /* Can't switch threads in kgdb */
1274 error_packet(remcom_out_buffer, -EINVAL);
1275 break;
1276 }
1277 kgdb_activate_sw_breakpoints();
1278 /* Fall through to default processing */
1279 default:
1280default_handle:
1281 error = kgdb_arch_handle_exception(ks->ex_vector,
1282 ks->signo,
1283 ks->err_code,
1284 remcom_in_buffer,
1285 remcom_out_buffer,
1286 ks->linux_regs);
1287 /*
1288 * Leave cmd processing on error, detach,
1289 * kill, continue, or single step.
1290 */
1291 if (error >= 0 || remcom_in_buffer[0] == 'D' ||
1292 remcom_in_buffer[0] == 'k') {
1293 error = 0;
1294 goto kgdb_exit;
1295 }
1296
1297 }
1298
1299 /* reply to the request */
1300 put_packet(remcom_out_buffer);
1301 }
1302
1303kgdb_exit:
1304 if (ks->pass_exception)
1305 error = 1;
1306 return error;
1307}
1308
1309static int kgdb_reenter_check(struct kgdb_state *ks)
1310{
1311 unsigned long addr;
1312
1313 if (atomic_read(&kgdb_active) != raw_smp_processor_id())
1314 return 0;
1315
1316 /* Panic on recursive debugger calls: */
1317 exception_level++;
1318 addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs);
1319 kgdb_deactivate_sw_breakpoints();
1320
1321 /*
1322 * If the break point removed ok at the place exception
1323 * occurred, try to recover and print a warning to the end
1324 * user because the user planted a breakpoint in a place that
1325 * KGDB needs in order to function.
1326 */
1327 if (kgdb_remove_sw_break(addr) == 0) {
1328 exception_level = 0;
1329 kgdb_skipexception(ks->ex_vector, ks->linux_regs);
1330 kgdb_activate_sw_breakpoints();
1331 printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n",
1332 addr);
1333 WARN_ON_ONCE(1);
1334
1335 return 1;
1336 }
1337 remove_all_break();
1338 kgdb_skipexception(ks->ex_vector, ks->linux_regs);
1339
1340 if (exception_level > 1) {
1341 dump_stack();
1342 panic("Recursive entry to debugger");
1343 }
1344
1345 printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n");
1346 dump_stack();
1347 panic("Recursive entry to debugger");
1348
1349 return 1;
1350}
1351
1352/*
1353 * kgdb_handle_exception() - main entry point from a kernel exception
1354 *
1355 * Locking hierarchy:
1356 * interface locks, if any (begin_session)
1357 * kgdb lock (kgdb_active)
1358 */
1359int
1360kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
1361{
1362 struct kgdb_state kgdb_var;
1363 struct kgdb_state *ks = &kgdb_var;
1364 unsigned long flags;
1365 int error = 0;
1366 int i, cpu;
1367
1368 ks->cpu = raw_smp_processor_id();
1369 ks->ex_vector = evector;
1370 ks->signo = signo;
1371 ks->ex_vector = evector;
1372 ks->err_code = ecode;
1373 ks->kgdb_usethreadid = 0;
1374 ks->linux_regs = regs;
1375
1376 if (kgdb_reenter_check(ks))
1377 return 0; /* Ouch, double exception ! */
1378
1379acquirelock:
1380 /*
1381 * Interrupts will be restored by the 'trap return' code, except when
1382 * single stepping.
1383 */
1384 local_irq_save(flags);
1385
1386 cpu = raw_smp_processor_id();
1387
1388 /*
1389 * Acquire the kgdb_active lock:
1390 */
1391 while (atomic_cmpxchg(&kgdb_active, -1, cpu) != -1)
1392 cpu_relax();
1393
1394 /*
1395 * Do not start the debugger connection on this CPU if the last
1396 * instance of the exception handler wanted to come into the
1397 * debugger on a different CPU via a single step
1398 */
1399 if (atomic_read(&kgdb_cpu_doing_single_step) != -1 &&
1400 atomic_read(&kgdb_cpu_doing_single_step) != cpu) {
1401
1402 atomic_set(&kgdb_active, -1);
1403 clocksource_touch_watchdog();
1404 local_irq_restore(flags);
1405
1406 goto acquirelock;
1407 }
1408
1409 if (!kgdb_io_ready(1)) {
1410 error = 1;
1411 goto kgdb_restore; /* No I/O connection, so resume the system */
1412 }
1413
1414 /*
1415 * Don't enter if we have hit a removed breakpoint.
1416 */
1417 if (kgdb_skipexception(ks->ex_vector, ks->linux_regs))
1418 goto kgdb_restore;
1419
1420 /* Call the I/O driver's pre_exception routine */
1421 if (kgdb_io_ops->pre_exception)
1422 kgdb_io_ops->pre_exception();
1423
1424 kgdb_info[ks->cpu].debuggerinfo = ks->linux_regs;
1425 kgdb_info[ks->cpu].task = current;
1426
1427 kgdb_disable_hw_debug(ks->linux_regs);
1428
1429 /*
1430 * Get the passive CPU lock which will hold all the non-primary
1431 * CPU in a spin state while the debugger is active
1432 */
1433 if (!kgdb_single_step || !kgdb_contthread) {
1434 for (i = 0; i < NR_CPUS; i++)
1435 atomic_set(&passive_cpu_wait[i], 1);
1436 }
1437
1438 /*
1439 * spin_lock code is good enough as a barrier so we don't
1440 * need one here:
1441 */
1442 atomic_set(&cpu_in_kgdb[ks->cpu], 1);
1443
1444#ifdef CONFIG_SMP
1445 /* Signal the other CPUs to enter kgdb_wait() */
1446 if ((!kgdb_single_step || !kgdb_contthread) && kgdb_do_roundup)
1447 kgdb_roundup_cpus(flags);
1448#endif
1449
1450 /*
1451 * Wait for the other CPUs to be notified and be waiting for us:
1452 */
1453 for_each_online_cpu(i) {
1454 while (!atomic_read(&cpu_in_kgdb[i]))
1455 cpu_relax();
1456 }
1457
1458 /*
1459 * At this point the primary processor is completely
1460 * in the debugger and all secondary CPUs are quiescent
1461 */
1462 kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code);
1463 kgdb_deactivate_sw_breakpoints();
1464 kgdb_single_step = 0;
1465 kgdb_contthread = NULL;
1466 exception_level = 0;
1467
1468 /* Talk to debugger with gdbserial protocol */
1469 error = gdb_serial_stub(ks);
1470
1471 /* Call the I/O driver's post_exception routine */
1472 if (kgdb_io_ops->post_exception)
1473 kgdb_io_ops->post_exception();
1474
1475 kgdb_info[ks->cpu].debuggerinfo = NULL;
1476 kgdb_info[ks->cpu].task = NULL;
1477 atomic_set(&cpu_in_kgdb[ks->cpu], 0);
1478
1479 if (!kgdb_single_step || !kgdb_contthread) {
1480 for (i = NR_CPUS-1; i >= 0; i--)
1481 atomic_set(&passive_cpu_wait[i], 0);
1482 /*
1483 * Wait till all the CPUs have quit
1484 * from the debugger.
1485 */
1486 for_each_online_cpu(i) {
1487 while (atomic_read(&cpu_in_kgdb[i]))
1488 cpu_relax();
1489 }
1490 }
1491
1492kgdb_restore:
1493 /* Free kgdb_active */
1494 atomic_set(&kgdb_active, -1);
1495 clocksource_touch_watchdog();
1496 local_irq_restore(flags);
1497
1498 return error;
1499}
1500
1501int kgdb_nmicallback(int cpu, void *regs)
1502{
1503#ifdef CONFIG_SMP
1504 if (!atomic_read(&cpu_in_kgdb[cpu]) &&
1505 atomic_read(&kgdb_active) != cpu &&
1506 atomic_read(&cpu_in_kgdb[atomic_read(&kgdb_active)])) {
1507 kgdb_wait((struct pt_regs *)regs);
1508 return 0;
1509 }
1510#endif
1511 return 1;
1512}
1513
1514void kgdb_console_write(struct console *co, const char *s, unsigned count)
1515{
1516 unsigned long flags;
1517
1518 /* If we're debugging, or KGDB has not connected, don't try
1519 * and print. */
1520 if (!kgdb_connected || atomic_read(&kgdb_active) != -1)
1521 return;
1522
1523 local_irq_save(flags);
1524 kgdb_msg_write(s, count);
1525 local_irq_restore(flags);
1526}
1527
1528static struct console kgdbcons = {
1529 .name = "kgdb",
1530 .write = kgdb_console_write,
1531 .flags = CON_PRINTBUFFER | CON_ENABLED,
1532 .index = -1,
1533};
1534
1535#ifdef CONFIG_MAGIC_SYSRQ
1536static void sysrq_handle_gdb(int key, struct tty_struct *tty)
1537{
1538 if (!kgdb_io_ops) {
1539 printk(KERN_CRIT "ERROR: No KGDB I/O module available\n");
1540 return;
1541 }
1542 if (!kgdb_connected)
1543 printk(KERN_CRIT "Entering KGDB\n");
1544
1545 kgdb_breakpoint();
1546}
1547
1548static struct sysrq_key_op sysrq_gdb_op = {
1549 .handler = sysrq_handle_gdb,
1550 .help_msg = "Gdb",
1551 .action_msg = "GDB",
1552};
1553#endif
1554
1555static void kgdb_register_callbacks(void)
1556{
1557 if (!kgdb_io_module_registered) {
1558 kgdb_io_module_registered = 1;
1559 kgdb_arch_init();
1560#ifdef CONFIG_MAGIC_SYSRQ
1561 register_sysrq_key('g', &sysrq_gdb_op);
1562#endif
1563 if (kgdb_use_con && !kgdb_con_registered) {
1564 register_console(&kgdbcons);
1565 kgdb_con_registered = 1;
1566 }
1567 }
1568}
1569
1570static void kgdb_unregister_callbacks(void)
1571{
1572 /*
1573 * When this routine is called KGDB should unregister from the
1574 * panic handler and clean up, making sure it is not handling any
1575 * break exceptions at the time.
1576 */
1577 if (kgdb_io_module_registered) {
1578 kgdb_io_module_registered = 0;
1579 kgdb_arch_exit();
1580#ifdef CONFIG_MAGIC_SYSRQ
1581 unregister_sysrq_key('g', &sysrq_gdb_op);
1582#endif
1583 if (kgdb_con_registered) {
1584 unregister_console(&kgdbcons);
1585 kgdb_con_registered = 0;
1586 }
1587 }
1588}
1589
1590static void kgdb_initial_breakpoint(void)
1591{
1592 kgdb_break_asap = 0;
1593
1594 printk(KERN_CRIT "kgdb: Waiting for connection from remote gdb...\n");
1595 kgdb_breakpoint();
1596}
1597
1598/**
1599 * kgdb_register_io_module - register KGDB IO module
1600 * @new_kgdb_io_ops: the io ops vector
1601 *
1602 * Register it with the KGDB core.
1603 */
1604int kgdb_register_io_module(struct kgdb_io *new_kgdb_io_ops)
1605{
1606 int err;
1607
1608 spin_lock(&kgdb_registration_lock);
1609
1610 if (kgdb_io_ops) {
1611 spin_unlock(&kgdb_registration_lock);
1612
1613 printk(KERN_ERR "kgdb: Another I/O driver is already "
1614 "registered with KGDB.\n");
1615 return -EBUSY;
1616 }
1617
1618 if (new_kgdb_io_ops->init) {
1619 err = new_kgdb_io_ops->init();
1620 if (err) {
1621 spin_unlock(&kgdb_registration_lock);
1622 return err;
1623 }
1624 }
1625
1626 kgdb_io_ops = new_kgdb_io_ops;
1627
1628 spin_unlock(&kgdb_registration_lock);
1629
1630 printk(KERN_INFO "kgdb: Registered I/O driver %s.\n",
1631 new_kgdb_io_ops->name);
1632
1633 /* Arm KGDB now. */
1634 kgdb_register_callbacks();
1635
1636 if (kgdb_break_asap)
1637 kgdb_initial_breakpoint();
1638
1639 return 0;
1640}
1641EXPORT_SYMBOL_GPL(kgdb_register_io_module);
1642
1643/**
1644 * kkgdb_unregister_io_module - unregister KGDB IO module
1645 * @old_kgdb_io_ops: the io ops vector
1646 *
1647 * Unregister it with the KGDB core.
1648 */
1649void kgdb_unregister_io_module(struct kgdb_io *old_kgdb_io_ops)
1650{
1651 BUG_ON(kgdb_connected);
1652
1653 /*
1654 * KGDB is no longer able to communicate out, so
1655 * unregister our callbacks and reset state.
1656 */
1657 kgdb_unregister_callbacks();
1658
1659 spin_lock(&kgdb_registration_lock);
1660
1661 WARN_ON_ONCE(kgdb_io_ops != old_kgdb_io_ops);
1662 kgdb_io_ops = NULL;
1663
1664 spin_unlock(&kgdb_registration_lock);
1665
1666 printk(KERN_INFO
1667 "kgdb: Unregistered I/O driver %s, debugger disabled.\n",
1668 old_kgdb_io_ops->name);
1669}
1670EXPORT_SYMBOL_GPL(kgdb_unregister_io_module);
1671
1672/**
1673 * kgdb_breakpoint - generate breakpoint exception
1674 *
1675 * This function will generate a breakpoint exception. It is used at the
1676 * beginning of a program to sync up with a debugger and can be used
1677 * otherwise as a quick means to stop program execution and "break" into
1678 * the debugger.
1679 */
1680void kgdb_breakpoint(void)
1681{
1682 atomic_set(&kgdb_setting_breakpoint, 1);
1683 wmb(); /* Sync point before breakpoint */
1684 arch_kgdb_breakpoint();
1685 wmb(); /* Sync point after breakpoint */
1686 atomic_set(&kgdb_setting_breakpoint, 0);
1687}
1688EXPORT_SYMBOL_GPL(kgdb_breakpoint);
1689
1690static int __init opt_kgdb_wait(char *str)
1691{
1692 kgdb_break_asap = 1;
1693
1694 if (kgdb_io_module_registered)
1695 kgdb_initial_breakpoint();
1696
1697 return 0;
1698}
1699
1700early_param("kgdbwait", opt_kgdb_wait);
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 2eae91f954ca..ae5c6c147c4b 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -1087,45 +1087,45 @@ static void check_process_timers(struct task_struct *tsk,
1087 maxfire = 20; 1087 maxfire = 20;
1088 prof_expires = cputime_zero; 1088 prof_expires = cputime_zero;
1089 while (!list_empty(timers)) { 1089 while (!list_empty(timers)) {
1090 struct cpu_timer_list *t = list_first_entry(timers, 1090 struct cpu_timer_list *tl = list_first_entry(timers,
1091 struct cpu_timer_list, 1091 struct cpu_timer_list,
1092 entry); 1092 entry);
1093 if (!--maxfire || cputime_lt(ptime, t->expires.cpu)) { 1093 if (!--maxfire || cputime_lt(ptime, tl->expires.cpu)) {
1094 prof_expires = t->expires.cpu; 1094 prof_expires = tl->expires.cpu;
1095 break; 1095 break;
1096 } 1096 }
1097 t->firing = 1; 1097 tl->firing = 1;
1098 list_move_tail(&t->entry, firing); 1098 list_move_tail(&tl->entry, firing);
1099 } 1099 }
1100 1100
1101 ++timers; 1101 ++timers;
1102 maxfire = 20; 1102 maxfire = 20;
1103 virt_expires = cputime_zero; 1103 virt_expires = cputime_zero;
1104 while (!list_empty(timers)) { 1104 while (!list_empty(timers)) {
1105 struct cpu_timer_list *t = list_first_entry(timers, 1105 struct cpu_timer_list *tl = list_first_entry(timers,
1106 struct cpu_timer_list, 1106 struct cpu_timer_list,
1107 entry); 1107 entry);
1108 if (!--maxfire || cputime_lt(utime, t->expires.cpu)) { 1108 if (!--maxfire || cputime_lt(utime, tl->expires.cpu)) {
1109 virt_expires = t->expires.cpu; 1109 virt_expires = tl->expires.cpu;
1110 break; 1110 break;
1111 } 1111 }
1112 t->firing = 1; 1112 tl->firing = 1;
1113 list_move_tail(&t->entry, firing); 1113 list_move_tail(&tl->entry, firing);
1114 } 1114 }
1115 1115
1116 ++timers; 1116 ++timers;
1117 maxfire = 20; 1117 maxfire = 20;
1118 sched_expires = 0; 1118 sched_expires = 0;
1119 while (!list_empty(timers)) { 1119 while (!list_empty(timers)) {
1120 struct cpu_timer_list *t = list_first_entry(timers, 1120 struct cpu_timer_list *tl = list_first_entry(timers,
1121 struct cpu_timer_list, 1121 struct cpu_timer_list,
1122 entry); 1122 entry);
1123 if (!--maxfire || sum_sched_runtime < t->expires.sched) { 1123 if (!--maxfire || sum_sched_runtime < tl->expires.sched) {
1124 sched_expires = t->expires.sched; 1124 sched_expires = tl->expires.sched;
1125 break; 1125 break;
1126 } 1126 }
1127 t->firing = 1; 1127 tl->firing = 1;
1128 list_move_tail(&t->entry, firing); 1128 list_move_tail(&tl->entry, firing);
1129 } 1129 }
1130 1130
1131 /* 1131 /*
diff --git a/kernel/semaphore.c b/kernel/semaphore.c
new file mode 100644
index 000000000000..5c2942e768cd
--- /dev/null
+++ b/kernel/semaphore.c
@@ -0,0 +1,264 @@
1/*
2 * Copyright (c) 2008 Intel Corporation
3 * Author: Matthew Wilcox <willy@linux.intel.com>
4 *
5 * Distributed under the terms of the GNU GPL, version 2
6 *
7 * This file implements counting semaphores.
8 * A counting semaphore may be acquired 'n' times before sleeping.
9 * See mutex.c for single-acquisition sleeping locks which enforce
10 * rules which allow code to be debugged more easily.
11 */
12
13/*
14 * Some notes on the implementation:
15 *
16 * The spinlock controls access to the other members of the semaphore.
17 * down_trylock() and up() can be called from interrupt context, so we
18 * have to disable interrupts when taking the lock. It turns out various
19 * parts of the kernel expect to be able to use down() on a semaphore in
20 * interrupt context when they know it will succeed, so we have to use
21 * irqsave variants for down(), down_interruptible() and down_killable()
22 * too.
23 *
24 * The ->count variable represents how many more tasks can acquire this
25 * semaphore. If it's zero, there may be tasks waiting on the wait_list.
26 */
27
28#include <linux/compiler.h>
29#include <linux/kernel.h>
30#include <linux/module.h>
31#include <linux/sched.h>
32#include <linux/semaphore.h>
33#include <linux/spinlock.h>
34
35static noinline void __down(struct semaphore *sem);
36static noinline int __down_interruptible(struct semaphore *sem);
37static noinline int __down_killable(struct semaphore *sem);
38static noinline int __down_timeout(struct semaphore *sem, long jiffies);
39static noinline void __up(struct semaphore *sem);
40
41/**
42 * down - acquire the semaphore
43 * @sem: the semaphore to be acquired
44 *
45 * Acquires the semaphore. If no more tasks are allowed to acquire the
46 * semaphore, calling this function will put the task to sleep until the
47 * semaphore is released.
48 *
49 * Use of this function is deprecated, please use down_interruptible() or
50 * down_killable() instead.
51 */
52void down(struct semaphore *sem)
53{
54 unsigned long flags;
55
56 spin_lock_irqsave(&sem->lock, flags);
57 if (likely(sem->count > 0))
58 sem->count--;
59 else
60 __down(sem);
61 spin_unlock_irqrestore(&sem->lock, flags);
62}
63EXPORT_SYMBOL(down);
64
65/**
66 * down_interruptible - acquire the semaphore unless interrupted
67 * @sem: the semaphore to be acquired
68 *
69 * Attempts to acquire the semaphore. If no more tasks are allowed to
70 * acquire the semaphore, calling this function will put the task to sleep.
71 * If the sleep is interrupted by a signal, this function will return -EINTR.
72 * If the semaphore is successfully acquired, this function returns 0.
73 */
74int down_interruptible(struct semaphore *sem)
75{
76 unsigned long flags;
77 int result = 0;
78
79 spin_lock_irqsave(&sem->lock, flags);
80 if (likely(sem->count > 0))
81 sem->count--;
82 else
83 result = __down_interruptible(sem);
84 spin_unlock_irqrestore(&sem->lock, flags);
85
86 return result;
87}
88EXPORT_SYMBOL(down_interruptible);
89
90/**
91 * down_killable - acquire the semaphore unless killed
92 * @sem: the semaphore to be acquired
93 *
94 * Attempts to acquire the semaphore. If no more tasks are allowed to
95 * acquire the semaphore, calling this function will put the task to sleep.
96 * If the sleep is interrupted by a fatal signal, this function will return
97 * -EINTR. If the semaphore is successfully acquired, this function returns
98 * 0.
99 */
100int down_killable(struct semaphore *sem)
101{
102 unsigned long flags;
103 int result = 0;
104
105 spin_lock_irqsave(&sem->lock, flags);
106 if (likely(sem->count > 0))
107 sem->count--;
108 else
109 result = __down_killable(sem);
110 spin_unlock_irqrestore(&sem->lock, flags);
111
112 return result;
113}
114EXPORT_SYMBOL(down_killable);
115
116/**
117 * down_trylock - try to acquire the semaphore, without waiting
118 * @sem: the semaphore to be acquired
119 *
120 * Try to acquire the semaphore atomically. Returns 0 if the mutex has
121 * been acquired successfully or 1 if it it cannot be acquired.
122 *
123 * NOTE: This return value is inverted from both spin_trylock and
124 * mutex_trylock! Be careful about this when converting code.
125 *
126 * Unlike mutex_trylock, this function can be used from interrupt context,
127 * and the semaphore can be released by any task or interrupt.
128 */
129int down_trylock(struct semaphore *sem)
130{
131 unsigned long flags;
132 int count;
133
134 spin_lock_irqsave(&sem->lock, flags);
135 count = sem->count - 1;
136 if (likely(count >= 0))
137 sem->count = count;
138 spin_unlock_irqrestore(&sem->lock, flags);
139
140 return (count < 0);
141}
142EXPORT_SYMBOL(down_trylock);
143
144/**
145 * down_timeout - acquire the semaphore within a specified time
146 * @sem: the semaphore to be acquired
147 * @jiffies: how long to wait before failing
148 *
149 * Attempts to acquire the semaphore. If no more tasks are allowed to
150 * acquire the semaphore, calling this function will put the task to sleep.
151 * If the semaphore is not released within the specified number of jiffies,
152 * this function returns -ETIME. It returns 0 if the semaphore was acquired.
153 */
154int down_timeout(struct semaphore *sem, long jiffies)
155{
156 unsigned long flags;
157 int result = 0;
158
159 spin_lock_irqsave(&sem->lock, flags);
160 if (likely(sem->count > 0))
161 sem->count--;
162 else
163 result = __down_timeout(sem, jiffies);
164 spin_unlock_irqrestore(&sem->lock, flags);
165
166 return result;
167}
168EXPORT_SYMBOL(down_timeout);
169
170/**
171 * up - release the semaphore
172 * @sem: the semaphore to release
173 *
174 * Release the semaphore. Unlike mutexes, up() may be called from any
175 * context and even by tasks which have never called down().
176 */
177void up(struct semaphore *sem)
178{
179 unsigned long flags;
180
181 spin_lock_irqsave(&sem->lock, flags);
182 if (likely(list_empty(&sem->wait_list)))
183 sem->count++;
184 else
185 __up(sem);
186 spin_unlock_irqrestore(&sem->lock, flags);
187}
188EXPORT_SYMBOL(up);
189
190/* Functions for the contended case */
191
192struct semaphore_waiter {
193 struct list_head list;
194 struct task_struct *task;
195 int up;
196};
197
198/*
199 * Because this function is inlined, the 'state' parameter will be
200 * constant, and thus optimised away by the compiler. Likewise the
201 * 'timeout' parameter for the cases without timeouts.
202 */
203static inline int __sched __down_common(struct semaphore *sem, long state,
204 long timeout)
205{
206 struct task_struct *task = current;
207 struct semaphore_waiter waiter;
208
209 list_add_tail(&waiter.list, &sem->wait_list);
210 waiter.task = task;
211 waiter.up = 0;
212
213 for (;;) {
214 if (state == TASK_INTERRUPTIBLE && signal_pending(task))
215 goto interrupted;
216 if (state == TASK_KILLABLE && fatal_signal_pending(task))
217 goto interrupted;
218 if (timeout <= 0)
219 goto timed_out;
220 __set_task_state(task, state);
221 spin_unlock_irq(&sem->lock);
222 timeout = schedule_timeout(timeout);
223 spin_lock_irq(&sem->lock);
224 if (waiter.up)
225 return 0;
226 }
227
228 timed_out:
229 list_del(&waiter.list);
230 return -ETIME;
231
232 interrupted:
233 list_del(&waiter.list);
234 return -EINTR;
235}
236
237static noinline void __sched __down(struct semaphore *sem)
238{
239 __down_common(sem, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
240}
241
242static noinline int __sched __down_interruptible(struct semaphore *sem)
243{
244 return __down_common(sem, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
245}
246
247static noinline int __sched __down_killable(struct semaphore *sem)
248{
249 return __down_common(sem, TASK_KILLABLE, MAX_SCHEDULE_TIMEOUT);
250}
251
252static noinline int __sched __down_timeout(struct semaphore *sem, long jiffies)
253{
254 return __down_common(sem, TASK_UNINTERRUPTIBLE, jiffies);
255}
256
257static noinline void __sched __up(struct semaphore *sem)
258{
259 struct semaphore_waiter *waiter = list_first_entry(&sem->wait_list,
260 struct semaphore_waiter, list);
261 list_del(&waiter->list);
262 waiter->up = 1;
263 wake_up_process(waiter->task);
264}
diff --git a/kernel/signal.c b/kernel/signal.c
index 6af1210092c3..cc8303cd093d 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1757,6 +1757,45 @@ static int do_signal_stop(int signr)
1757 return 1; 1757 return 1;
1758} 1758}
1759 1759
1760static int ptrace_signal(int signr, siginfo_t *info,
1761 struct pt_regs *regs, void *cookie)
1762{
1763 if (!(current->ptrace & PT_PTRACED))
1764 return signr;
1765
1766 ptrace_signal_deliver(regs, cookie);
1767
1768 /* Let the debugger run. */
1769 ptrace_stop(signr, 0, info);
1770
1771 /* We're back. Did the debugger cancel the sig? */
1772 signr = current->exit_code;
1773 if (signr == 0)
1774 return signr;
1775
1776 current->exit_code = 0;
1777
1778 /* Update the siginfo structure if the signal has
1779 changed. If the debugger wanted something
1780 specific in the siginfo structure then it should
1781 have updated *info via PTRACE_SETSIGINFO. */
1782 if (signr != info->si_signo) {
1783 info->si_signo = signr;
1784 info->si_errno = 0;
1785 info->si_code = SI_USER;
1786 info->si_pid = task_pid_vnr(current->parent);
1787 info->si_uid = current->parent->uid;
1788 }
1789
1790 /* If the (new) signal is now blocked, requeue it. */
1791 if (sigismember(&current->blocked, signr)) {
1792 specific_send_sig_info(signr, info, current);
1793 signr = 0;
1794 }
1795
1796 return signr;
1797}
1798
1760int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, 1799int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka,
1761 struct pt_regs *regs, void *cookie) 1800 struct pt_regs *regs, void *cookie)
1762{ 1801{
@@ -1785,36 +1824,10 @@ relock:
1785 if (!signr) 1824 if (!signr)
1786 break; /* will return 0 */ 1825 break; /* will return 0 */
1787 1826
1788 if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) { 1827 if (signr != SIGKILL) {
1789 ptrace_signal_deliver(regs, cookie); 1828 signr = ptrace_signal(signr, info, regs, cookie);
1790 1829 if (!signr)
1791 /* Let the debugger run. */
1792 ptrace_stop(signr, 0, info);
1793
1794 /* We're back. Did the debugger cancel the sig? */
1795 signr = current->exit_code;
1796 if (signr == 0)
1797 continue;
1798
1799 current->exit_code = 0;
1800
1801 /* Update the siginfo structure if the signal has
1802 changed. If the debugger wanted something
1803 specific in the siginfo structure then it should
1804 have updated *info via PTRACE_SETSIGINFO. */
1805 if (signr != info->si_signo) {
1806 info->si_signo = signr;
1807 info->si_errno = 0;
1808 info->si_code = SI_USER;
1809 info->si_pid = task_pid_vnr(current->parent);
1810 info->si_uid = current->parent->uid;
1811 }
1812
1813 /* If the (new) signal is now blocked, requeue it. */
1814 if (sigismember(&current->blocked, signr)) {
1815 specific_send_sig_info(signr, info, current);
1816 continue; 1830 continue;
1817 }
1818 } 1831 }
1819 1832
1820 ka = &current->sighand->action[signr-1]; 1833 ka = &current->sighand->action[signr-1];
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 7f60097d443a..73961f35fdc8 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -141,8 +141,16 @@ static void clocksource_watchdog(unsigned long data)
141 } 141 }
142 142
143 if (!list_empty(&watchdog_list)) { 143 if (!list_empty(&watchdog_list)) {
144 __mod_timer(&watchdog_timer, 144 /*
145 watchdog_timer.expires + WATCHDOG_INTERVAL); 145 * Cycle through CPUs to check if the CPUs stay
146 * synchronized to each other.
147 */
148 int next_cpu = next_cpu(raw_smp_processor_id(), cpu_online_map);
149
150 if (next_cpu >= NR_CPUS)
151 next_cpu = first_cpu(cpu_online_map);
152 watchdog_timer.expires += WATCHDOG_INTERVAL;
153 add_timer_on(&watchdog_timer, next_cpu);
146 } 154 }
147 spin_unlock(&watchdog_lock); 155 spin_unlock(&watchdog_lock);
148} 156}
@@ -164,7 +172,8 @@ static void clocksource_check_watchdog(struct clocksource *cs)
164 if (!started && watchdog) { 172 if (!started && watchdog) {
165 watchdog_last = watchdog->read(); 173 watchdog_last = watchdog->read();
166 watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL; 174 watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
167 add_timer(&watchdog_timer); 175 add_timer_on(&watchdog_timer,
176 first_cpu(cpu_online_map));
168 } 177 }
169 } else { 178 } else {
170 if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) 179 if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
@@ -185,7 +194,8 @@ static void clocksource_check_watchdog(struct clocksource *cs)
185 watchdog_last = watchdog->read(); 194 watchdog_last = watchdog->read();
186 watchdog_timer.expires = 195 watchdog_timer.expires =
187 jiffies + WATCHDOG_INTERVAL; 196 jiffies + WATCHDOG_INTERVAL;
188 add_timer(&watchdog_timer); 197 add_timer_on(&watchdog_timer,
198 first_cpu(cpu_online_map));
189 } 199 }
190 } 200 }
191 } 201 }
@@ -222,6 +232,18 @@ void clocksource_resume(void)
222} 232}
223 233
224/** 234/**
235 * clocksource_touch_watchdog - Update watchdog
236 *
237 * Update the watchdog after exception contexts such as kgdb so as not
238 * to incorrectly trip the watchdog.
239 *
240 */
241void clocksource_touch_watchdog(void)
242{
243 clocksource_resume_watchdog();
244}
245
246/**
225 * clocksource_get_next - Returns the selected clocksource 247 * clocksource_get_next - Returns the selected clocksource
226 * 248 *
227 */ 249 */
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index e1bd50cbbf5d..fdfa0c745bb6 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -14,7 +14,7 @@
14#include <linux/cpu.h> 14#include <linux/cpu.h>
15#include <linux/err.h> 15#include <linux/err.h>
16#include <linux/hrtimer.h> 16#include <linux/hrtimer.h>
17#include <linux/irq.h> 17#include <linux/interrupt.h>
18#include <linux/percpu.h> 18#include <linux/percpu.h>
19#include <linux/profile.h> 19#include <linux/profile.h>
20#include <linux/sched.h> 20#include <linux/sched.h>
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 1bea399a9ef0..4f3886562b8c 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -14,12 +14,14 @@
14#include <linux/cpu.h> 14#include <linux/cpu.h>
15#include <linux/err.h> 15#include <linux/err.h>
16#include <linux/hrtimer.h> 16#include <linux/hrtimer.h>
17#include <linux/irq.h> 17#include <linux/interrupt.h>
18#include <linux/percpu.h> 18#include <linux/percpu.h>
19#include <linux/profile.h> 19#include <linux/profile.h>
20#include <linux/sched.h> 20#include <linux/sched.h>
21#include <linux/tick.h> 21#include <linux/tick.h>
22 22
23#include <asm/irq_regs.h>
24
23#include "tick-internal.h" 25#include "tick-internal.h"
24 26
25/* 27/*
diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c
index 0258d3115d54..450c04935b66 100644
--- a/kernel/time/tick-oneshot.c
+++ b/kernel/time/tick-oneshot.c
@@ -14,7 +14,7 @@
14#include <linux/cpu.h> 14#include <linux/cpu.h>
15#include <linux/err.h> 15#include <linux/err.h>
16#include <linux/hrtimer.h> 16#include <linux/hrtimer.h>
17#include <linux/irq.h> 17#include <linux/interrupt.h>
18#include <linux/percpu.h> 18#include <linux/percpu.h>
19#include <linux/profile.h> 19#include <linux/profile.h>
20#include <linux/sched.h> 20#include <linux/sched.h>
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 686da821d376..69dba0c71727 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -158,9 +158,8 @@ void tick_nohz_stop_idle(int cpu)
158 } 158 }
159} 159}
160 160
161static ktime_t tick_nohz_start_idle(int cpu) 161static ktime_t tick_nohz_start_idle(struct tick_sched *ts)
162{ 162{
163 struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
164 ktime_t now, delta; 163 ktime_t now, delta;
165 164
166 now = ktime_get(); 165 now = ktime_get();
@@ -201,8 +200,8 @@ void tick_nohz_stop_sched_tick(void)
201 local_irq_save(flags); 200 local_irq_save(flags);
202 201
203 cpu = smp_processor_id(); 202 cpu = smp_processor_id();
204 now = tick_nohz_start_idle(cpu);
205 ts = &per_cpu(tick_cpu_sched, cpu); 203 ts = &per_cpu(tick_cpu_sched, cpu);
204 now = tick_nohz_start_idle(ts);
206 205
207 /* 206 /*
208 * If this cpu is offline and it is the one which updates 207 * If this cpu is offline and it is the one which updates
@@ -222,7 +221,6 @@ void tick_nohz_stop_sched_tick(void)
222 if (need_resched()) 221 if (need_resched())
223 goto end; 222 goto end;
224 223
225 cpu = smp_processor_id();
226 if (unlikely(local_softirq_pending())) { 224 if (unlikely(local_softirq_pending())) {
227 static int ratelimit; 225 static int ratelimit;
228 226
diff --git a/kernel/timer.c b/kernel/timer.c
index b024106daa70..f3d35d4ea42e 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1228,13 +1228,6 @@ asmlinkage long sys_sysinfo(struct sysinfo __user *info)
1228 return 0; 1228 return 0;
1229} 1229}
1230 1230
1231/*
1232 * lockdep: we want to track each per-CPU base as a separate lock-class,
1233 * but timer-bases are kmalloc()-ed, so we need to attach separate
1234 * keys to them:
1235 */
1236static struct lock_class_key base_lock_keys[NR_CPUS];
1237
1238static int __cpuinit init_timers_cpu(int cpu) 1231static int __cpuinit init_timers_cpu(int cpu)
1239{ 1232{
1240 int j; 1233 int j;
@@ -1277,7 +1270,6 @@ static int __cpuinit init_timers_cpu(int cpu)
1277 } 1270 }
1278 1271
1279 spin_lock_init(&base->lock); 1272 spin_lock_init(&base->lock);
1280 lockdep_set_class(&base->lock, base_lock_keys + cpu);
1281 1273
1282 for (j = 0; j < TVN_SIZE; j++) { 1274 for (j = 0; j < TVN_SIZE; j++) {
1283 INIT_LIST_HEAD(base->tv5.vec + j); 1275 INIT_LIST_HEAD(base->tv5.vec + j);
@@ -1316,8 +1308,8 @@ static void __cpuinit migrate_timers(int cpu)
1316 new_base = get_cpu_var(tvec_bases); 1308 new_base = get_cpu_var(tvec_bases);
1317 1309
1318 local_irq_disable(); 1310 local_irq_disable();
1319 double_spin_lock(&new_base->lock, &old_base->lock, 1311 spin_lock(&new_base->lock);
1320 smp_processor_id() < cpu); 1312 spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
1321 1313
1322 BUG_ON(old_base->running_timer); 1314 BUG_ON(old_base->running_timer);
1323 1315
@@ -1330,8 +1322,8 @@ static void __cpuinit migrate_timers(int cpu)
1330 migrate_timer_list(new_base, old_base->tv5.vec + i); 1322 migrate_timer_list(new_base, old_base->tv5.vec + i);
1331 } 1323 }
1332 1324
1333 double_spin_unlock(&new_base->lock, &old_base->lock, 1325 spin_unlock(&old_base->lock);
1334 smp_processor_id() < cpu); 1326 spin_unlock(&new_base->lock);
1335 local_irq_enable(); 1327 local_irq_enable();
1336 put_cpu_var(tvec_bases); 1328 put_cpu_var(tvec_bases);
1337} 1329}
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index ff06611655af..00ff4d08e370 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -219,6 +219,7 @@ int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
219 struct timer_list *timer = &dwork->timer; 219 struct timer_list *timer = &dwork->timer;
220 struct work_struct *work = &dwork->work; 220 struct work_struct *work = &dwork->work;
221 221
222 timer_stats_timer_set_start_info(&dwork->timer);
222 if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) { 223 if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) {
223 BUG_ON(timer_pending(timer)); 224 BUG_ON(timer_pending(timer));
224 BUG_ON(!list_empty(&work->entry)); 225 BUG_ON(!list_empty(&work->entry));
@@ -580,6 +581,7 @@ EXPORT_SYMBOL(schedule_delayed_work);
580int schedule_delayed_work_on(int cpu, 581int schedule_delayed_work_on(int cpu,
581 struct delayed_work *dwork, unsigned long delay) 582 struct delayed_work *dwork, unsigned long delay)
582{ 583{
584 timer_stats_timer_set_start_info(&dwork->timer);
583 return queue_delayed_work_on(cpu, keventd_wq, dwork, delay); 585 return queue_delayed_work_on(cpu, keventd_wq, dwork, delay);
584} 586}
585EXPORT_SYMBOL(schedule_delayed_work_on); 587EXPORT_SYMBOL(schedule_delayed_work_on);
generated by cgit v1.2.2 (git 2.25.0) at 2025-12-28 09:42:22 -0500