linux-kernel - Re: [PATCH 1/2] hung_task: Show the blocker task if the task is hung on mutex

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: <20250219185810.57561c69@gandalf.local.home>
Date: Wed, 19 Feb 2025 18:58:10 -0500
From: Steven Rostedt <rostedt@...dmis.org>
To: "Masami Hiramatsu (Google)" <mhiramat@...nel.org>
Cc: Waiman Long <llong@...hat.com>, Peter Zijlstra <peterz@...radead.org>,
 Ingo Molnar <mingo@...hat.com>, Will Deacon <will@...nel.org>, Andrew
 Morton <akpm@...ux-foundation.org>, Boqun Feng <boqun.feng@...il.com>, Joel
 Granados <joel.granados@...nel.org>, Anna Schumaker
 <anna.schumaker@...cle.com>, Lance Yang <ioworker0@...il.com>, Kent
 Overstreet <kent.overstreet@...ux.dev>, Yongliang Gao
 <leonylgao@...cent.com>, Tomasz Figa <tfiga@...omium.org>, Sergey
 Senozhatsky <senozhatsky@...omium.org>, linux-kernel@...r.kernel.org, Linux
 Memory Management List <linux-mm@...ck.org>
Subject: Re: [PATCH 1/2] hung_task: Show the blocker task if the task is
 hung on mutex

On Thu, 20 Feb 2025 08:09:08 +0900
Masami Hiramatsu (Google) <mhiramat@...nel.org> wrote:

> So something like this?
> 
> unsigned int	block_flags;
> union {
> 	struct mutex	*mutex;
> 	struct rwsem	+rwsem;
> 	struct rtmutex	*rtmutex;
> } blocked_on;
> 
> enum {
> 	BLOCKED_ON_MUTEX;
> 	BLOCKED_ON_RWSEM;
> 	BLOCKED_ON_RTMUTEX;
> 	BLOCKED_ON_IO;
> } block_reason;
> 
> For the safety, we may anyway lock the task anyway, but that is the
> same as stacktrace.

Why not make it into a single entity?

struct blocked_on {
	unsigned int	flags;
	union {
		struct mutex	*mutex;
		struct rwsem	*rwsem;
		struct rtmutex	*rtmutex;
	} blocked_on;
};

-- Steve