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authorAbhishek Sagar <sagar.abhishek@gmail.com>2008-05-24 23:45:02 +0530
committerThomas Gleixner <tglx@linutronix.de>2008-05-26 22:52:04 +0200
commitffdaa3582b6b39d625d585d07e329ffdc925e971 (patch)
tree2e75b26ea065d6e11eeb17b8ea77bcd2f16853c6
parentccbfac2923c9febaeaf07a50054027a92b502718 (diff)
ftrace: safe traversal of ftrace_hash hlist
Hi Steven, I noticed that concurrent instances of ftrace_record_ip() have a race between ftrace_hash list traversal during ftrace_ip_in_hash() (before acquiring ftrace_shutdown_lock) and ftrace_add_hash(). If it's so then this should fix it. Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com> Cc: rostedt@goodmis.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--kernel/trace/ftrace.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2552454609cf..9b7c54f8a62f 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -201,7 +201,7 @@ ftrace_ip_in_hash(unsigned long ip, unsigned long key)
struct hlist_node *t;
int found = 0;
- hlist_for_each_entry(p, t, &ftrace_hash[key], node) {
+ hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) {
if (p->ip == ip) {
found = 1;
break;
@@ -214,7 +214,7 @@ ftrace_ip_in_hash(unsigned long ip, unsigned long key)
static inline void
ftrace_add_hash(struct dyn_ftrace *node, unsigned long key)
{
- hlist_add_head(&node->node, &ftrace_hash[key]);
+ hlist_add_head_rcu(&node->node, &ftrace_hash[key]);
}
static void ftrace_free_rec(struct dyn_ftrace *rec)