linux-kernel - Re: [PATCH 1/2] tracing: Remove "__attribute_

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250711120322.4ddb9b39@batman.local.home>
Date: Fri, 11 Jul 2025 12:03:22 -0400
From: Steven Rostedt <rostedt@...dmis.org>
To: "Masami Hiramatsu (Google)" <mhiramat@...nel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
 linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] tracing: Remove "__attribute__()" from the type
 field of event format

On Fri, 11 Jul 2025 14:37:03 +0900
Masami Hiramatsu (Google) <mhiramat@...nel.org> wrote:

> I investigated this but it is not possible to use update_event_fields()
> because that function is only used if the 
> CONFIG_TRACE_EVAL_MAP_FILE=y.

That had better *not* be true, otherwise all the TRACE_DEFINE_ENUM() in
include/trace/events/*.h would be useless and those events would not
parse. Note, I usually run without that config enabled, so it would
most definitely break on me if this was true.

In the code we have:

----------------------8<----------------------
#else /* CONFIG_TRACE_EVAL_MAP_FILE */
static inline void trace_create_eval_file(struct dentry *d_tracer) { }
static inline void trace_insert_eval_map_file(struct module *mod,
			      struct trace_eval_map **start, int len) { }
#endif /* !CONFIG_TRACE_EVAL_MAP_FILE */

static void trace_insert_eval_map(struct module *mod,
				  struct trace_eval_map **start, int len)
{
	struct trace_eval_map **map;

	if (len <= 0)
		return;

	map = start;

	trace_event_eval_update(map, len);

	trace_insert_eval_map_file(mod, start, len);
}
---------------------->8----------------------

Notice the "#endif". The trace_insert_eval_map_file() is a nop, but the
trace_event_eval_update() is not. That has the call to
update_event_printk() and update_event_fields().

So it can most definitely be used when that config is not defined. That
config only creates a file to show you *what* was replaced. It doesn't
stop the replacing.

-- Steve