linux-kernel - Re: thread leader death under strace (was Re: [PATCH 03/10] ptrace: implement PTRACE

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]

Date:	Thu, 2 Jun 2011 18:36:54 +0200
From:	Oleg Nesterov <oleg@...hat.com>
To:	Denys Vlasenko <vda.linux@...glemail.com>
Cc:	Tejun Heo <tj@...nel.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>, indan@....nu,
	bdonlan@...il.com, linux-kernel@...r.kernel.org,
	jan.kratochvil@...hat.com, akpm@...ux-foundation.org
Subject: Re: thread leader death under strace (was Re: [PATCH 03/10]
	ptrace: implement PTRACE_SEIZE)

On 06/02, Denys Vlasenko wrote:
>
> The problem is that right now it seems that if tracer doesn't catch
> EVENT_EXIT and detach tracee when it sees it, really weird things
> happen.

The test-case is wrong afaics...

Perhaps this should be considered as a bug in glibc, I dunno.

> thread1(void *unused)
> {
> //	usleep(100*1000);
> //	VERBOSE("WINCH\n");
> //	raise(SIGWINCH);
>
> 	usleep(100*1000);
> 	VERBOSE("DYING\n");
> 	raise(SIGUSR1);

This doesn't send a signal. This does tgkill(tgid, 0, SIGUSR1) which
fails correctly with -EINVAL.

> static int
> thread_leader(void *unused)
> {
> 	/* malloc gives sufficiently aligned buffer.
> 	 * long buf[] does not! (on ia64).
> 	 */
> 	clone2(thread1, malloc(16 * 1024), 16 * 1024, 0

Probably because of this clone2.

Could you test with pthread_create? Or s/raise/tkill/ ?

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/