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Biederman" , Adrian Reber , Thomas Gleixner , Jens Axboe , Alexei Starovoitov , "linux-fsdevel@vger.kernel.org" , "linux-kernel@vger.kernel.org" , linux-kselftest@vger.kernel.org, linux-mm@kvack.org, tiozhang , Luis Chamberlain , "Paulo Alcantara (SUSE)" , Sergey Senozhatsky , Frederic Weisbecker , YueHaibing , Paul Moore , Aleksa Sarai , Stefan Roesch , Chao Yu , xu xin , Jeff Layton , Jan Kara , David Hildenbrand , Dave Chinner , Shuah Khan , Zheng Yejian , Elena Reshetova , David Windsor , Mateusz Guzik , Ard Biesheuvel , "Joel Fernandes (Google)" , "Matthew Wilcox (Oracle)" , Hans Liljestrand Subject: Re: [PATCH v14] exec: Fix dead-lock in de_thread with ptrace_attach Message-ID: <20240122134446.GB22901@redhat.com> References: <20240116152210.GA12342@redhat.com> <20240117163739.GA32526@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.8 X-Rspamd-Queue-Id: 951E3180007 X-Rspam-User: X-Stat-Signature: 88bcpd5uh6pciwhf4e9n9bb1y5y6d4rm X-Rspamd-Server: rspam01 X-HE-Tag: 1705931180-109105 X-HE-Meta: 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 FWFDmaUR Ma9OufVD8g/uV8tllUToe7G/VrojggSS5HjD0Uut3PF5Ve+Z+1Jsg+v6MIqAQCaQPHUZ/65GctWU1FkQ= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: I'll try to read your email later, just one note for now... On 01/22, Bernd Edlinger wrote: > > > I didn't say that t is a group leader. I said it can be a zombie sub-thread > > with ->exit_state != 0. > > the condition here is > > (t != tsk->group_leader || !t->exit_state) > > so in other words, if t is a sub-thread, i.e. t != tsk->group_leader > then the t->exit_state does not count, Ah indeed, somehow I misread this check as if you skip the sub-threads with ->exit_state != 0. Sorry for noise. Oleg.