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authorThomas Gleixner <tglx@linutronix.de>2009-07-25 17:50:36 +0200
committerIngo Molnar <mingo@elte.hu>2011-09-13 11:11:54 +0200
commit07354eb1a74d1e1ece29f8bafe0b46e8c77a95ef (patch)
tree4e2370ce5a6eb5eccc20d89dcfca44cc0dafbfa6
parent5389f6fad27019f2ba78f1b332f719ec05f12a42 (diff)
locking, printk: Annotate logbuf_lock as raw
The logbuf_lock lock can be taken in atomic context and therefore cannot be preempted on -rt - annotate it. In mainline this change documents the low level nature of the lock - otherwise there's no functional difference. Lockdep and Sparse checking will work as usual. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ merged and fixed it ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--include/linux/ratelimit.h6
-rw-r--r--kernel/printk.c46
-rw-r--r--lib/ratelimit.c4
3 files changed, 28 insertions, 28 deletions
diff --git a/include/linux/ratelimit.h b/include/linux/ratelimit.h
index 2f007157fab9..e11ccb4cf48d 100644
--- a/include/linux/ratelimit.h
+++ b/include/linux/ratelimit.h
@@ -8,7 +8,7 @@
#define DEFAULT_RATELIMIT_BURST 10
struct ratelimit_state {
- spinlock_t lock; /* protect the state */
+ raw_spinlock_t lock; /* protect the state */
int interval;
int burst;
@@ -20,7 +20,7 @@ struct ratelimit_state {
#define DEFINE_RATELIMIT_STATE(name, interval_init, burst_init) \
\
struct ratelimit_state name = { \
- .lock = __SPIN_LOCK_UNLOCKED(name.lock), \
+ .lock = __RAW_SPIN_LOCK_UNLOCKED(name.lock), \
.interval = interval_init, \
.burst = burst_init, \
}
@@ -28,7 +28,7 @@ struct ratelimit_state {
static inline void ratelimit_state_init(struct ratelimit_state *rs,
int interval, int burst)
{
- spin_lock_init(&rs->lock);
+ raw_spin_lock_init(&rs->lock);
rs->interval = interval;
rs->burst = burst;
rs->printed = 0;
diff --git a/kernel/printk.c b/kernel/printk.c
index 28a40d8171b8..b7da18391c38 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -100,7 +100,7 @@ static int console_locked, console_suspended;
* It is also used in interesting ways to provide interlocking in
* console_unlock();.
*/
-static DEFINE_SPINLOCK(logbuf_lock);
+static DEFINE_RAW_SPINLOCK(logbuf_lock);
#define LOG_BUF_MASK (log_buf_len-1)
#define LOG_BUF(idx) (log_buf[(idx) & LOG_BUF_MASK])
@@ -212,7 +212,7 @@ void __init setup_log_buf(int early)
return;
}
- spin_lock_irqsave(&logbuf_lock, flags);
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
log_buf_len = new_log_buf_len;
log_buf = new_log_buf;
new_log_buf_len = 0;
@@ -230,7 +230,7 @@ void __init setup_log_buf(int early)
log_start -= offset;
con_start -= offset;
log_end -= offset;
- spin_unlock_irqrestore(&logbuf_lock, flags);
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
pr_info("log_buf_len: %d\n", log_buf_len);
pr_info("early log buf free: %d(%d%%)\n",
@@ -365,18 +365,18 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
if (error)
goto out;
i = 0;
- spin_lock_irq(&logbuf_lock);
+ raw_spin_lock_irq(&logbuf_lock);
while (!error && (log_start != log_end) && i < len) {
c = LOG_BUF(log_start);
log_start++;
- spin_unlock_irq(&logbuf_lock);
+ raw_spin_unlock_irq(&logbuf_lock);
error = __put_user(c,buf);
buf++;
i++;
cond_resched();
- spin_lock_irq(&logbuf_lock);
+ raw_spin_lock_irq(&logbuf_lock);
}
- spin_unlock_irq(&logbuf_lock);
+ raw_spin_unlock_irq(&logbuf_lock);
if (!error)
error = i;
break;
@@ -399,7 +399,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
count = len;
if (count > log_buf_len)
count = log_buf_len;
- spin_lock_irq(&logbuf_lock);
+ raw_spin_lock_irq(&logbuf_lock);
if (count > logged_chars)
count = logged_chars;
if (do_clear)
@@ -416,12 +416,12 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
if (j + log_buf_len < log_end)
break;
c = LOG_BUF(j);
- spin_unlock_irq(&logbuf_lock);
+ raw_spin_unlock_irq(&logbuf_lock);
error = __put_user(c,&buf[count-1-i]);
cond_resched();
- spin_lock_irq(&logbuf_lock);
+ raw_spin_lock_irq(&logbuf_lock);
}
- spin_unlock_irq(&logbuf_lock);
+ raw_spin_unlock_irq(&logbuf_lock);
if (error)
break;
error = i;
@@ -689,7 +689,7 @@ static void zap_locks(void)
oops_timestamp = jiffies;
/* If a crash is occurring, make sure we can't deadlock */
- spin_lock_init(&logbuf_lock);
+ raw_spin_lock_init(&logbuf_lock);
/* And make sure that we print immediately */
sema_init(&console_sem, 1);
}
@@ -802,9 +802,9 @@ static int console_trylock_for_printk(unsigned int cpu)
}
}
printk_cpu = UINT_MAX;
- spin_unlock(&logbuf_lock);
if (wake)
up(&console_sem);
+ raw_spin_unlock(&logbuf_lock);
return retval;
}
static const char recursion_bug_msg [] =
@@ -864,7 +864,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
}
lockdep_off();
- spin_lock(&logbuf_lock);
+ raw_spin_lock(&logbuf_lock);
printk_cpu = this_cpu;
if (recursion_bug) {
@@ -1257,14 +1257,14 @@ void console_unlock(void)
again:
for ( ; ; ) {
- spin_lock_irqsave(&logbuf_lock, flags);
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
wake_klogd |= log_start - log_end;
if (con_start == log_end)
break; /* Nothing to print */
_con_start = con_start;
_log_end = log_end;
con_start = log_end; /* Flush */
- spin_unlock(&logbuf_lock);
+ raw_spin_unlock(&logbuf_lock);
stop_critical_timings(); /* don't trace print latency */
call_console_drivers(_con_start, _log_end);
start_critical_timings();
@@ -1276,7 +1276,7 @@ again:
if (unlikely(exclusive_console))
exclusive_console = NULL;
- spin_unlock(&logbuf_lock);
+ raw_spin_unlock(&logbuf_lock);
up(&console_sem);
@@ -1286,13 +1286,13 @@ again:
* there's a new owner and the console_unlock() from them will do the
* flush, no worries.
*/
- spin_lock(&logbuf_lock);
+ raw_spin_lock(&logbuf_lock);
if (con_start != log_end)
retry = 1;
- spin_unlock_irqrestore(&logbuf_lock, flags);
if (retry && console_trylock())
goto again;
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
if (wake_klogd)
wake_up_klogd();
}
@@ -1522,9 +1522,9 @@ void register_console(struct console *newcon)
* console_unlock(); will print out the buffered messages
* for us.
*/
- spin_lock_irqsave(&logbuf_lock, flags);
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
con_start = log_start;
- spin_unlock_irqrestore(&logbuf_lock, flags);
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
/*
* We're about to replay the log buffer. Only do this to the
* just-registered console to avoid excessive message spam to
@@ -1731,10 +1731,10 @@ void kmsg_dump(enum kmsg_dump_reason reason)
/* Theoretically, the log could move on after we do this, but
there's not a lot we can do about that. The new messages
will overwrite the start of what we dump. */
- spin_lock_irqsave(&logbuf_lock, flags);
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
end = log_end & LOG_BUF_MASK;
chars = logged_chars;
- spin_unlock_irqrestore(&logbuf_lock, flags);
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
if (chars > end) {
s1 = log_buf + log_buf_len - chars + end;
diff --git a/lib/ratelimit.c b/lib/ratelimit.c
index 027a03f4c56d..c96d500577de 100644
--- a/lib/ratelimit.c
+++ b/lib/ratelimit.c
@@ -39,7 +39,7 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func)
* in addition to the one that will be printed by
* the entity that is holding the lock already:
*/
- if (!spin_trylock_irqsave(&rs->lock, flags))
+ if (!raw_spin_trylock_irqsave(&rs->lock, flags))
return 0;
if (!rs->begin)
@@ -60,7 +60,7 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func)
rs->missed++;
ret = 0;
}
- spin_unlock_irqrestore(&rs->lock, flags);
+ raw_spin_unlock_irqrestore(&rs->lock, flags);
return ret;
}