tracing: Show kretprobe unknown indicator only for kretprobe_trampoline

ftrace shows "[unknown/kretprobe'd]" indicator all addresses in the kretprobe_trampoline, but the modified address by kretprobe should be only kretprobe_trampoline+0. Link: https://lkml.kernel.org/r/163163056044.489837.794883849706638013.stgit@devnote2 Signed-off-by: Masami Hiramatsu <[email protected]> Acked-by: Steven Rostedt (VMware) <[email protected]> Tested-by: Andrii Nakryiko <[email protected]> Signed-off-by: Steven Rostedt (VMware) <[email protected]>
tadfisher · Oct 1, 2021 · 7da8949 · 7da8949
1 parent 19138af
commit 7da8949
Showing 1 changed file with 4 additions and 13 deletions.
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
@@ -8,6 +8,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/ftrace.h>
+#include <linux/kprobes.h>
 #include <linux/sched/clock.h>
 #include <linux/sched/mm.h>
 
@@ -346,22 +347,12 @@ int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
 }
 EXPORT_SYMBOL_GPL(trace_output_call);
 
-#ifdef CONFIG_KRETPROBES
-static inline const char *kretprobed(const char *name)
+static inline const char *kretprobed(const char *name, unsigned long addr)
 {
-	static const char tramp_name[] = "__kretprobe_trampoline";
-	int size = sizeof(tramp_name);
-
-	if (strncmp(tramp_name, name, size) == 0)
+	if (is_kretprobe_trampoline(addr))
 		return "[unknown/kretprobe'd]";
 	return name;
 }
-#else
-static inline const char *kretprobed(const char *name)
-{
-	return name;
-}
-#endif /* CONFIG_KRETPROBES */
 
 void
 trace_seq_print_sym(struct trace_seq *s, unsigned long address, bool offset)
@@ -374,7 +365,7 @@ trace_seq_print_sym(struct trace_seq *s, unsigned long address, bool offset)
 		sprint_symbol(str, address);
 	else
 		kallsyms_lookup(address, NULL, NULL, NULL, str);
-	name = kretprobed(str);
+	name = kretprobed(str, address);
 
 	if (name && strlen(name)) {
 		trace_seq_puts(s, name);