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authorLinus Torvalds <torvalds@linux-foundation.org>2020-10-01 09:41:02 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-01 09:41:02 -0700
commitaa5ff93523ebc9f4cfd9fb37d021b5204ce14657 (patch)
treefb32c9e5ae708888d9a56066f994975dab68191b
parent60e720931556fc1034d0981460164dcf02697679 (diff)
parentb40341fad6cc2daa195f8090fd3348f18fff640a (diff)
Merge tag 'trace-v5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt: "Two tracing fixes: - Fix temp buffer accounting that caused a WARNING for ftrace_dump_on_opps() - Move the recursion check in one of the function callback helpers to the beginning of the function, as if the rcu_is_watching() gets traced, it will cause a recursive loop that will crash the kernel" * tag 'trace-v5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Move RCU is watching check after recursion check tracing: Fix trace_find_next_entry() accounting of temp buffer size
-rw-r--r--kernel/trace/ftrace.c6
-rw-r--r--kernel/trace/trace.c10
2 files changed, 8 insertions, 8 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 603255f5f085..541453927c82 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -6993,16 +6993,14 @@ static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
{
int bit;
- if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching())
- return;
-
bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
if (bit < 0)
return;
preempt_disable_notrace();
- op->func(ip, parent_ip, op, regs);
+ if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching())
+ op->func(ip, parent_ip, op, regs);
preempt_enable_notrace();
trace_clear_recursion(bit);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2a7c26345e83..d3e5de717df2 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3546,13 +3546,15 @@ struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
if (iter->ent && iter->ent != iter->temp) {
if ((!iter->temp || iter->temp_size < iter->ent_size) &&
!WARN_ON_ONCE(iter->temp == static_temp_buf)) {
- kfree(iter->temp);
- iter->temp = kmalloc(iter->ent_size, GFP_KERNEL);
- if (!iter->temp)
+ void *temp;
+ temp = kmalloc(iter->ent_size, GFP_KERNEL);
+ if (!temp)
return NULL;
+ kfree(iter->temp);
+ iter->temp = temp;
+ iter->temp_size = iter->ent_size;
}
memcpy(iter->temp, iter->ent, iter->ent_size);
- iter->temp_size = iter->ent_size;
iter->ent = iter->temp;
}
entry = __find_next_entry(iter, ent_cpu, NULL, ent_ts);