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| author | Amol Grover <frextrite@gmail.com> | 2020-02-01 12:57:04 +0530 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-02-05 17:14:26 -0500 |
| commit | 24a9729f831462b1d9d61dc85ecc91c59037243f (patch) | |
| tree | 5dba5453c90b039bac3afe99f4d2d25fd6f4200a /kernel | |
| parent | 7495e0926fdf302cb9e62a49f7c22198815624cd (diff) | |
| download | lwn-24a9729f831462b1d9d61dc85ecc91c59037243f.tar.gz lwn-24a9729f831462b1d9d61dc85ecc91c59037243f.zip | |
tracing: Annotate ftrace_graph_hash pointer with __rcu
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
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ftrace.c | 2 | ||||
| -rw-r--r-- | 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 |