From: Steven Rostedt <rost...@goodmis.org>

Add a helper function called handle_dereference_arg() to replace the logic
that is identical in two locations of test_event_printk().

Signed-off-by: Steven Rostedt (Google) <rost...@goodmis.org>
---
Changes since v1: 
https://lore.kernel.org/20250424151021.44b68...@gandalf.local.home

- Fixed order of parameters in handle_dereference_arg() as len and
  string_flags were reversed, causing it to fail on pretty much all events!
  I did post v1 because it was sitting in my repo and I needed to do more
  work on other things in that repo, but I obviously never tested it!

 kernel/trace/trace_events.c | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 069e92856bda..13cb899ba4fc 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -400,6 +400,20 @@ static bool process_string(const char *fmt, int len, 
struct trace_event_call *ca
        return true;
 }
 
+static void handle_dereference_arg(const char *arg_str, u64 string_flags, int 
len,
+                                  u64 *dereference_flags, int arg,
+                                  struct trace_event_call *call)
+{
+       if (string_flags & (1ULL << arg)) {
+               if (process_string(arg_str, len, call))
+                       *dereference_flags &= ~(1ULL << arg);
+       } else if (process_pointer(arg_str, len, call))
+               *dereference_flags &= ~(1ULL << arg);
+       else
+               pr_warn("TRACE EVENT ERROR: Bad dereference argument: '%.*s'\n",
+                       len, arg_str);
+}
+
 /*
  * Examine the print fmt of the event looking for unsafe dereference
  * pointers using %p* that could be recorded in the trace event and
@@ -563,11 +577,9 @@ static void test_event_printk(struct trace_event_call 
*call)
                        }
 
                        if (dereference_flags & (1ULL << arg)) {
-                               if (string_flags & (1ULL << arg)) {
-                                       if (process_string(fmt + start_arg, e - 
start_arg, call))
-                                               dereference_flags &= ~(1ULL << 
arg);
-                               } else if (process_pointer(fmt + start_arg, e - 
start_arg, call))
-                                       dereference_flags &= ~(1ULL << arg);
+                               handle_dereference_arg(fmt + start_arg, 
string_flags,
+                                                      e - start_arg,
+                                                      &dereference_flags, arg, 
call);
                        }
 
                        start_arg = i;
@@ -578,11 +590,9 @@ static void test_event_printk(struct trace_event_call 
*call)
        }
 
        if (dereference_flags & (1ULL << arg)) {
-               if (string_flags & (1ULL << arg)) {
-                       if (process_string(fmt + start_arg, i - start_arg, 
call))
-                               dereference_flags &= ~(1ULL << arg);
-               } else if (process_pointer(fmt + start_arg, i - start_arg, 
call))
-                       dereference_flags &= ~(1ULL << arg);
+               handle_dereference_arg(fmt + start_arg, string_flags,
+                                      i - start_arg,
+                                      &dereference_flags, arg, call);
        }
 
        /*
-- 
2.47.2


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