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From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>,
	Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: [PATCH 08/10] tracing/fprobe: Remove redundant memset in fentry_perf_func()
Date: Mon, 20 Jul 2026 19:44:43 +0900	[thread overview]
Message-ID: <178454428366.296567.16465331441301815980.stgit@devnote2> (raw)
In-Reply-To: <178454420994.296567.10239174745865301350.stgit@devnote2>

From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

fentry_perf_func() calls memset(&entry[1], 0, dsize) prior to calling
store_trace_args(). store_trace_args() populates the entry buffer and
handles dynamic data fields.

Furthermore, passing dsize (the dynamic data byte length) to memset at
&entry[1] (the start of fixed trace arguments) is inaccurate as it zeroes
from the fixed args area rather than the dynamic data region.

Remove this redundant memset call to align with fexit_perf_func() and other
probe perf functions.

Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
 kernel/trace/trace_fprobe.c |    1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c
index 566b64853c61..ec9105fca4a6 100644
--- a/kernel/trace/trace_fprobe.c
+++ b/kernel/trace/trace_fprobe.c
@@ -471,7 +471,6 @@ static int fentry_perf_func(struct trace_fprobe *tf, unsigned long entry_ip,
 	regs = ftrace_fill_perf_regs(fregs, regs);
 
 	entry->ip = entry_ip;
-	memset(&entry[1], 0, dsize);
 	store_trace_args(&entry[1], &tf->tp, fregs, NULL, sizeof(*entry), dsize);
 	perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
 			      head, NULL);


  parent reply	other threads:[~2026-07-20 10:44 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-20 10:43 [PATCH 00/10] tracing/probes: Cleanup probe event code Masami Hiramatsu (Google)
2026-07-20 10:43 ` [PATCH 01/10] tracing/probes: Remove duplicate MAX_ARRAY_LEN macro definition Masami Hiramatsu (Google)
2026-07-20 10:43 ` [PATCH 02/10] tracing/probes: Remove redundant boolean conversion in trace_probe_has_single_file() Masami Hiramatsu (Google)
2026-07-20 10:43 ` [PATCH 03/10] tracing/probes: Remove redundant bounds check in trace_probe_compare_arg_type() Masami Hiramatsu (Google)
2026-07-20 10:44 ` [PATCH 04/10] tracing/probes: Remove unused parameter from parse_probe_var_retval() Masami Hiramatsu (Google)
2026-07-20 10:44 ` [PATCH 05/10] tracing/probes: Cleanup pointer arithmetic in store_trace_entry_data() Masami Hiramatsu (Google)
2026-07-20 10:44 ` [PATCH 06/10] tracing/probes: Simplify BTF_KIND_PTR case in fetch_type_from_btf_type() Masami Hiramatsu (Google)
2026-07-20 10:44 ` [PATCH 07/10] tracing/fprobe: Remove redundant snprintf in trace_fprobe_match_command_head() Masami Hiramatsu (Google)
2026-07-20 10:44 ` Masami Hiramatsu (Google) [this message]
2026-07-20 10:44 ` [PATCH 09/10] tracing/kprobe: Remove redundant memset in kprobe_perf_func() Masami Hiramatsu (Google)
2026-07-20 10:45 ` [PATCH 10/10] tracing/probes: Fix extra whitespace in trace_probe_kernel.h Masami Hiramatsu (Google)

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