From db5e228611b118cf7b1f8084063feda5c037f4a7 Mon Sep 17 00:00:00 2001
From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Date: Wed, 26 Feb 2025 15:19:02 +0900
Subject: [PATCH] tracing: fprobe-events: Log error for exceeding the number of
entry args
Add error message when the number of entry argument exceeds the
maximum size of entry data.
This is currently checked when registering fprobe, but in this case
no error message is shown in the error_log file.
Link: https://lore.kernel.org/all/174055074269.4079315.17809232650360988538.stgit@mhiramat.tok.corp.google.com/
Fixes: 25f00e40ce79 ("tracing/probes: Support $argN in return probe (kprobe and fprobe)")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/trace/trace_fprobe.c | 5 +++++
kernel/trace/trace_probe.h | 3 ++-
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c
index 85f037dc14623..e27305d31fc57 100644
--- a/kernel/trace/trace_fprobe.c
+++ b/kernel/trace/trace_fprobe.c
@@ -1230,6 +1230,11 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
if (is_return && tf->tp.entry_arg) {
tf->fp.entry_handler = trace_fprobe_entry_handler;
tf->fp.entry_data_size = traceprobe_get_entry_data_size(&tf->tp);
+ if (ALIGN(tf->fp.entry_data_size, sizeof(long)) > MAX_FPROBE_DATA_SIZE) {
+ trace_probe_log_set_index(2);
+ trace_probe_log_err(0, TOO_MANY_EARGS);
+ return -E2BIG;
+ }
}
ret = traceprobe_set_print_fmt(&tf->tp,
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index fba3ede870541..c47ca002347a7 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -545,7 +545,8 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
C(NO_BTF_FIELD, "This field is not found."), \
C(BAD_BTF_TID, "Failed to get BTF type info."),\
C(BAD_TYPE4STR, "This type does not fit for string."),\
- C(NEED_STRING_TYPE, "$comm and immediate-string only accepts string type"),
+ C(NEED_STRING_TYPE, "$comm and immediate-string only accepts string type"),\
+ C(TOO_MANY_EARGS, "Too many entry arguments specified"),
#undef C
#define C(a, b) TP_ERR_##a
--
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