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Biederman) To: LKML Cc: Oleg Nesterov , Linus Torvalds , Thomas Gleixner References: <20200419141057.621356-1-gladkov.alexey@gmail.com> <87ftcv1nqe.fsf@x220.int.ebiederm.org> <87wo66vvnm.fsf_-_@x220.int.ebiederm.org> <20200424173927.GB26802@redhat.com> <87mu6ymkea.fsf_-_@x220.int.ebiederm.org> <875zdmmj4y.fsf_-_@x220.int.ebiederm.org> <878sihgfzh.fsf@x220.int.ebiederm.org> <87sggnajpv.fsf_-_@x220.int.ebiederm.org> <20200428180540.GB29960@redhat.com> <87mu6v70in.fsf_-_@x220.int.ebiederm.org> Date: Tue, 28 Apr 2020 16:53:31 -0500 In-Reply-To: <87mu6v70in.fsf_-_@x220.int.ebiederm.org> (Eric W. Biederman's message of "Tue, 28 Apr 2020 16:39:44 -0500") Message-ID: <87zhav5lb8.fsf_-_@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1jTYDd-0003Kw-J2;;;mid=<87zhav5lb8.fsf_-_@x220.int.ebiederm.org>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1/9SFOGLrwqMnM+GMHpEChkArNfTp8VniM= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on sa02.xmission.com X-Spam-Level: * X-Spam-Status: No, score=1.8 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,TR_Symld_Words,T_TooManySym_01,T_TooManySym_02, T_TooManySym_03,XMGappySubj_01 autolearn=disabled version=3.4.2 X-Spam-Virus: No X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5000] * 1.5 TR_Symld_Words too many words that have symbols inside * 0.5 XMGappySubj_01 Very gappy subject * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa02 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 T_TooManySym_02 5+ unique symbols in subject * 0.0 T_TooManySym_03 6+ unique symbols in subject X-Spam-DCC: XMission; sa02 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: *;LKML X-Spam-Relay-Country: X-Spam-Timing: total 259 ms - load_scoreonly_sql: 0.03 (0.0%), signal_user_changed: 3.9 (1.5%), b_tie_ro: 2.7 (1.1%), parse: 0.71 (0.3%), extract_message_metadata: 8 (3.3%), get_uri_detail_list: 0.70 (0.3%), tests_pri_-1000: 11 (4.2%), tests_pri_-950: 1.00 (0.4%), tests_pri_-900: 0.79 (0.3%), tests_pri_-90: 90 (34.8%), check_bayes: 89 (34.4%), b_tokenize: 3.9 (1.5%), b_tok_get_all: 5 (2.1%), b_comp_prob: 1.17 (0.5%), b_tok_touch_all: 76 (29.3%), b_finish: 0.70 (0.3%), tests_pri_0: 134 (51.6%), check_dkim_signature: 0.37 (0.1%), check_dkim_adsp: 2.2 (0.8%), poll_dns_idle: 0.87 (0.3%), tests_pri_10: 1.76 (0.7%), tests_pri_500: 5 (2.1%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH v1 3/4] exec: Remove BUG_ON(has_group_leader_pid) X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With the introduction of exchange_tids thread_group_leader and has_group_leader_pid have become equivalent. Further at this point in the code a thread group has exactly two threads, the previous thread_group_leader that is waiting to be reaped and tsk. So we know it is impossible for tsk to be the thread_group_leader. This is also the last user of has_group_leader_pid so removing this check will allow has_group_leader_pid to be removed. So remove the "BUG_ON(has_group_leader_pid)" that will never fire. Signed-off-by: "Eric W. Biederman" --- fs/exec.c | 1 - 1 file changed, 1 deletion(-) diff --git a/fs/exec.c b/fs/exec.c index 9b60f927afd7..6ab1c19d84fa 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1176,7 +1176,6 @@ static int de_thread(struct task_struct *tsk) tsk->start_boottime = leader->start_boottime; BUG_ON(!same_thread_group(leader, tsk)); - BUG_ON(has_group_leader_pid(tsk)); /* * An exec() starts a new thread group with the * TGID of the previous thread group. Rehash the -- 2.20.1