From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Amol Grover <frextrite@gmail.com>
Subject: [for-next][PATCH 2/4] tracing: Annotate ftrace_graph_hash pointer with __rcu
Date: Wed, 05 Feb 2020 05:49:31 -0500 [thread overview]
Message-ID: <20200205105113.004907028@goodmis.org> (raw)
In-Reply-To: 20200205104929.313040579@goodmis.org
From: Amol Grover <frextrite@gmail.com>
Fix following instances of sparse error
kernel/trace/ftrace.c:5664:29: error: incompatible types in comparison
kernel/trace/ftrace.c:5785:21: error: incompatible types in comparison
kernel/trace/ftrace.c:5864:36: error: incompatible types in comparison
kernel/trace/ftrace.c:5866:25: error: incompatible types in comparison
Use rcu_dereference_protected to access the __rcu annotated pointer.
Link: http://lkml.kernel.org/r/20200201072703.17330-1-frextrite@gmail.com
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/ftrace.c | 2 +-
kernel/trace/trace.h | 9 ++++++---
2 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 0e9612c30995..01d2ecd66161 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5591,7 +5591,7 @@ static const struct file_operations ftrace_notrace_fops = {
static DEFINE_MUTEX(graph_lock);
-struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH;
+struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH;
struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH;
enum graph_filter_type {
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index f5480a2aa334..18ceab59a5ba 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -964,22 +964,25 @@ extern void __trace_graph_return(struct trace_array *tr,
unsigned long flags, int pc);
#ifdef CONFIG_DYNAMIC_FTRACE
-extern struct ftrace_hash *ftrace_graph_hash;
+extern struct ftrace_hash __rcu *ftrace_graph_hash;
extern struct ftrace_hash *ftrace_graph_notrace_hash;
static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
{
unsigned long addr = trace->func;
int ret = 0;
+ struct ftrace_hash *hash;
preempt_disable_notrace();
- if (ftrace_hash_empty(ftrace_graph_hash)) {
+ hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
+
+ if (ftrace_hash_empty(hash)) {
ret = 1;
goto out;
}
- if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
+ if (ftrace_lookup_ip(hash, addr)) {
/*
* This needs to be cleared on the return functions
--
2.24.1
next prev parent reply other threads:[~2020-02-05 10:51 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-05 10:49 [for-next][PATCH 0/4] tracing: Hopefully last update for 5.6 Steven Rostedt
2020-02-05 10:49 ` [for-next][PATCH 1/4] bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline Steven Rostedt
2020-02-05 10:49 ` Steven Rostedt [this message]
2020-02-05 10:49 ` [for-next][PATCH 3/4] tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu Steven Rostedt
2020-02-05 10:49 ` [for-next][PATCH 4/4] ftrace: Add comment to why rcu_dereference_sched() is open coded Steven Rostedt
2020-02-05 11:33 ` Steven Rostedt
2020-02-05 14:19 ` Joel Fernandes
2020-02-05 14:28 ` Steven Rostedt
2020-02-05 15:42 ` Joel Fernandes
2020-02-05 15:49 ` Steven Rostedt
2020-02-05 16:08 ` Joel Fernandes
2020-02-05 21:54 ` Joel Fernandes
2020-02-05 21:59 ` Joel Fernandes
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