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authorDave Young <hidave.darkstar@gmail.com>2008-07-25 01:45:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-25 10:53:29 -0700
commit717115e1a5856b57af0f71e1df7149108294fc10 (patch)
tree9528a992245c2fb993a0cf0bc8221dc7dea5d259 /kernel
parent2711b793eb62a5873a0ba583a69252040aef176e (diff)
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printk ratelimiting rewrite
All ratelimit user use same jiffies and burst params, so some messages (callbacks) will be lost. For example: a call printk_ratelimit(5 * HZ, 1) b call printk_ratelimit(5 * HZ, 1) before the 5*HZ timeout of a, then b will will be supressed. - rewrite __ratelimit, and use a ratelimit_state as parameter. Thanks for hints from andrew. - Add WARN_ON_RATELIMIT, update rcupreempt.h - remove __printk_ratelimit - use __ratelimit in net_ratelimit Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/printk.c17
-rw-r--r--kernel/sysctl.c4
2 files changed, 5 insertions, 16 deletions
diff --git a/kernel/printk.c b/kernel/printk.c
index 3f7a2a9..a7f7559 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1308,6 +1308,8 @@ void tty_write_message(struct tty_struct *tty, char *msg)
}
#if defined CONFIG_PRINTK
+
+DEFINE_RATELIMIT_STATE(printk_ratelimit_state, 5 * HZ, 10);
/*
* printk rate limiting, lifted from the networking subsystem.
*
@@ -1315,22 +1317,9 @@ void tty_write_message(struct tty_struct *tty, char *msg)
* every printk_ratelimit_jiffies to make a denial-of-service
* attack impossible.
*/
-int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst)
-{
- return __ratelimit(ratelimit_jiffies, ratelimit_burst);
-}
-EXPORT_SYMBOL(__printk_ratelimit);
-
-/* minimum time in jiffies between messages */
-int printk_ratelimit_jiffies = 5 * HZ;
-
-/* number of messages we send before ratelimiting */
-int printk_ratelimit_burst = 10;
-
int printk_ratelimit(void)
{
- return __printk_ratelimit(printk_ratelimit_jiffies,
- printk_ratelimit_burst);
+ return __ratelimit(&printk_ratelimit_state);
}
EXPORT_SYMBOL(printk_ratelimit);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 1a8299d..35a50db 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -624,7 +624,7 @@ static struct ctl_table kern_table[] = {
{
.ctl_name = KERN_PRINTK_RATELIMIT,
.procname = "printk_ratelimit",
- .data = &printk_ratelimit_jiffies,
+ .data = &printk_ratelimit_state.interval,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec_jiffies,
@@ -633,7 +633,7 @@ static struct ctl_table kern_table[] = {
{
.ctl_name = KERN_PRINTK_RATELIMIT_BURST,
.procname = "printk_ratelimit_burst",
- .data = &printk_ratelimit_burst,
+ .data = &printk_ratelimit_state.burst,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
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