[PATCH -tip v5 12/12] tracing: Show kretprobe unknown indicator only for kretprobe_trampoline

[Masami Hiramatsu]

ftrace shows "[unknown/kretprobe'd]" indicator all addresses in the
kretprobe_trampoline, but the modified address by kretprobe should
be only kretprobe_trampoline+0.

Signed-off-by: Masami Hiramatsu <mhira...@kernel.org>
Acked-by: Steven Rostedt (VMware) <rost...@goodmis.org>
---
 kernel/trace/trace_output.c |   17 ++++-------------
 1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 61255bad7e01..e12437388686 100644
--- 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);