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authorSteven Rostedt (VMware) <rostedt@goodmis.org>2020-11-05 21:32:45 -0500
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2020-11-06 08:42:12 -0500
commita25d036d939a30623ff73ecad9c8b9116b02e823 (patch)
tree075bcf99e35bd7448936c5370c3a31c9bd9eba9c /kernel/trace/ftrace.c
parentperf/ftrace: Check for rcu_is_watching() in callback function (diff)
downloadlinux-dev-a25d036d939a30623ff73ecad9c8b9116b02e823.tar.xz
linux-dev-a25d036d939a30623ff73ecad9c8b9116b02e823.zip
ftrace: Reverse what the RECURSION flag means in the ftrace_ops
Now that all callbacks are recursion safe, reverse the meaning of the RECURSION flag and rename it from RECURSION_SAFE to simply RECURSION. Now only callbacks that request to have recursion protecting it will have the added trampoline to do so. Also remove the outdated comment about "PER_CPU" when determining to use the ftrace_ops_assist_func. Link: https://lkml.kernel.org/r/20201028115613.742454631@goodmis.org Link: https://lkml.kernel.org/r/20201106023547.904270143@goodmis.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Cc: Petr Mladek <pmladek@suse.com> Cc: linux-doc@vger.kernel.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r--kernel/trace/ftrace.c20
1 files changed, 9 insertions, 11 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8185f7240095..39f2bba89b76 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -80,7 +80,7 @@ enum {
struct ftrace_ops ftrace_list_end __read_mostly = {
.func = ftrace_stub,
- .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
+ .flags = FTRACE_OPS_FL_STUB,
INIT_OPS_HASH(ftrace_list_end)
};
@@ -866,7 +866,7 @@ static void unregister_ftrace_profiler(void)
#else
static struct ftrace_ops ftrace_profile_ops __read_mostly = {
.func = function_profile_call,
- .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
+ .flags = FTRACE_OPS_FL_INITIALIZED,
INIT_OPS_HASH(ftrace_profile_ops)
};
@@ -1040,8 +1040,7 @@ struct ftrace_ops global_ops = {
.local_hash.notrace_hash = EMPTY_HASH,
.local_hash.filter_hash = EMPTY_HASH,
INIT_OPS_HASH(global_ops)
- .flags = FTRACE_OPS_FL_RECURSION_SAFE |
- FTRACE_OPS_FL_INITIALIZED |
+ .flags = FTRACE_OPS_FL_INITIALIZED |
FTRACE_OPS_FL_PID,
};
@@ -2382,7 +2381,7 @@ static void call_direct_funcs(unsigned long ip, unsigned long pip,
struct ftrace_ops direct_ops = {
.func = call_direct_funcs,
- .flags = FTRACE_OPS_FL_IPMODIFY | FTRACE_OPS_FL_RECURSION_SAFE
+ .flags = FTRACE_OPS_FL_IPMODIFY
| FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS
| FTRACE_OPS_FL_PERMANENT,
/*
@@ -6864,8 +6863,7 @@ void ftrace_init_trace_array(struct trace_array *tr)
struct ftrace_ops global_ops = {
.func = ftrace_stub,
- .flags = FTRACE_OPS_FL_RECURSION_SAFE |
- FTRACE_OPS_FL_INITIALIZED |
+ .flags = FTRACE_OPS_FL_INITIALIZED |
FTRACE_OPS_FL_PID,
};
@@ -7023,11 +7021,11 @@ NOKPROBE_SYMBOL(ftrace_ops_assist_func);
ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
{
/*
- * If the function does not handle recursion, needs to be RCU safe,
- * or does per cpu logic, then we need to call the assist handler.
+ * If the function does not handle recursion or needs to be RCU safe,
+ * then we need to call the assist handler.
*/
- if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) ||
- ops->flags & FTRACE_OPS_FL_RCU)
+ if (ops->flags & (FTRACE_OPS_FL_RECURSION |
+ FTRACE_OPS_FL_RCU))
return ftrace_ops_assist_func;
return ops->func;