From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3A3F833C1B7; Thu, 21 May 2026 03:09:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779332993; cv=none; b=Xy1W7+08ejc3hHMlFg/TgBK0yTRUrGQHChewlSkhrxY5LeHWbE+b6df2fqGPcIVGwLkAIXKUUFfycDmsHc8IFJMXc1SfYEfJG7lU0W9d0giv18N/Mc0WMHt9Rj0NBmHz0outVrvIZWOakYKeSbMVMyEX9Un2Ixwu3xp9rRQjnjo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779332993; c=relaxed/simple; bh=PyCogTZLqe1oYQBon/CXpNsZwPGKbaLmRJUHRCcKoAc=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=DIVIYqBYgmv6CWz8ZqiD6xkM2/kqkrz3KCPR5Hsig6WkY+SAPP2gah85xkHjb3nC+AoFAqxgRXuOwVSH3nR0jxQ95u/8P0MIGxQSdCXkDJTBKq5TGL0ckqxT4UkuJytU32QEHR/WMpRuzBuSVOUt+atkCSmYuOrhT/4KwzGEb0k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZXpky9JN; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZXpky9JN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AB2B1F000E9; Thu, 21 May 2026 03:09:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779332991; bh=lw7Y3cTnSkm8o3kNd4EremV9Sd2MHFAezFWfaNvBFXs=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=ZXpky9JNK9TTmZzhp7qSFzG7Pv1bOBmChhxIBkv5x8LjiSVubNtyTFIR3M3UjRizt dTQttGJP2LUd9WpMmiaE3DozQmSfexj4FzcOKgVTYL7F68zjy8vKRnfj1giQnKq8EJ AJNpUQ1kH22XOrEGquCoAhw5Uu+kExjF3mrfOUMUx0ZxzYr+OEuTwzQre22pQ+7mUZ 9RHpv1T0ZYXNT/Uwh0JaskklPWR8Ciq1aDdx08sBwoTp+x1vUipE5IV6Ov5EE790js a5UpCE14KCMxN6CGEUS5VbkcgcNvOuLfP4ujrU6cn3945cvO+wp+zYeP/HjgmRC2Mo Mrdj44ERfWPSg== Date: Thu, 21 May 2026 12:09:47 +0900 From: Masami Hiramatsu (Google) To: Rosen Penev Cc: linux-trace-kernel@vger.kernel.org, Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Kees Cook , "Gustavo A. R. Silva" , linux-kernel@vger.kernel.org (open list:TRACING), linux-hardening@vger.kernel.org (open list:KERNEL HARDENING (not covered by other areas):Keyword:\b__counted_by(_le|_be|_ptr)?\b) Subject: Re: [PATCH] tracing: Use flexible array for entry fetch code Message-Id: <20260521120947.08f00bd4d7445bc6abc98ce0@kernel.org> In-Reply-To: <20260520215817.16560-1-rosenp@gmail.com> References: <20260520215817.16560-1-rosenp@gmail.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 20 May 2026 14:58:17 -0700 Rosen Penev wrote: > Store probe entry fetch instructions in the probe_entry_arg > allocation instead of allocating a separate instruction array. > > This keeps the entry fetch code tied to the entry argument lifetime while > leaving regular probe_arg instruction arrays separately allocated and > freed. > Thanks, this looks good to me. > Assisted-by: Codex:GPT-5.5 > Signed-off-by: Rosen Penev > --- > kernel/trace/trace_probe.c | 8 +------- > kernel/trace/trace_probe.h | 2 +- > 2 files changed, 2 insertions(+), 8 deletions(-) > > diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c > index e0d3a0da26af..39f040c863e8 100644 > --- a/kernel/trace/trace_probe.c > +++ b/kernel/trace/trace_probe.c > @@ -838,15 +838,10 @@ static int __store_entry_arg(struct trace_probe *tp, int argnum) > int i, offset, last_offset = 0; > > if (!earg) { > - earg = kzalloc_obj(*tp->entry_arg); > + earg = kzalloc_flex(*earg, code, 2 * tp->nr_args + 1); > if (!earg) > return -ENOMEM; > earg->size = 2 * tp->nr_args + 1; > - earg->code = kzalloc_objs(struct fetch_insn, earg->size); > - if (!earg->code) { > - kfree(earg); > - return -ENOMEM; > - } > /* Fill the code buffer with 'end' to simplify it */ > for (i = 0; i < earg->size; i++) > earg->code[i].op = FETCH_OP_END; > @@ -2051,7 +2046,6 @@ void trace_probe_cleanup(struct trace_probe *tp) > traceprobe_free_probe_arg(&tp->args[i]); > > if (tp->entry_arg) { > - kfree(tp->entry_arg->code); > kfree(tp->entry_arg); > tp->entry_arg = NULL; > } > diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h > index 262d8707a3df..1076f1df347b 100644 > --- a/kernel/trace/trace_probe.h > +++ b/kernel/trace/trace_probe.h > @@ -238,8 +238,8 @@ struct probe_arg { > }; > > struct probe_entry_arg { > - struct fetch_insn *code; > unsigned int size; /* The entry data size */ > + struct fetch_insn code[] __counted_by(size); > }; > > struct trace_uprobe_filter { > -- > 2.54.0 > -- Masami Hiramatsu (Google)