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Biederman" To: Oleg Nesterov Cc: Avi Weiss , Christian Brauner , Andrew Morton , linux-kernel@vger.kernel.org In-Reply-To: (Oleg Nesterov's message of "Fri, 23 Oct 2026 12:50:38 +0200") References: <20261022061015.3737924-1-thnkslprpt@gmail.com> Date: Fri, 23 Oct 2026 16:46:32 +0000 Message-ID: <87qzhgmkk7.fsf@email.froward.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1xKIPc-00HC6e-Kj;;;mid=<87qzhgmkk7.fsf@email.froward.int.ebiederm.org>;;;hst=in02.mta.xmission.com;;;ip=72.198.196.98;;;frm=ebiederm@xmission.com;;;sPfnum=0;;;sPf=pass X-XM-AID: U2FsdGVkX1+dR77xV5flOxQgDF48qQKcbD/Kx8U+KYI= X-Spam-Level: X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.1 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5001] * 0.7 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa07 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_03 6+ unique symbols in subject * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 T_TooManySym_02 5+ unique symbols in subject X-Spam-DCC: XMission; sa07 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Oleg Nesterov X-Spam-Relay-Country: X-Spam-Timing: total 357 ms - load_scoreonly_sql: 0.04 (0.0%), signal_user_changed: 11 (3.1%), b_tie_ro: 10 (2.7%), parse: 0.71 (0.2%), extract_message_metadata: 10 (2.8%), get_uri_detail_list: 1.15 (0.3%), tests_pri_-2000: 10 (2.9%), tests_pri_-1000: 1.84 (0.5%), tests_pri_-950: 0.88 (0.2%), tests_pri_-900: 0.66 (0.2%), tests_pri_-90: 132 (37.1%), check_bayes: 130 (36.4%), b_tokenize: 4.6 (1.3%), b_tok_get_all: 4.9 (1.4%), b_comp_prob: 2.1 (0.6%), b_tok_touch_all: 114 (31.8%), b_finish: 1.25 (0.3%), tests_pri_0: 174 (48.8%), check_dkim_signature: 0.46 (0.1%), check_dkim_adsp: 2.5 (0.7%), poll_dns_idle: 0.49 (0.1%), tests_pri_10: 1.97 (0.6%), tests_pri_500: 9 (2.7%), rewrite_mail: 0.00 (0.0%) Subject: Re: [PATCH] signal: cleanup the .si_signo checks in dequeue_synchronous_signal() X-SA-Exim-Connect-IP: 166.70.13.52 X-SA-Exim-Rcpt-To: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, brauner@kernel.org, thnkslprpt@gmail.com, oleg@redhat.com X-SA-Exim-Mail-From: ebiederm@xmission.com X-SA-Exim-Scanned: No (on out01.mta.xmission.com); SAEximRunCond expanded to false Oleg Nesterov writes: > Christian, > > This is on top of Avi's > [PATCH v2] signal: respect the blocked mask in dequeue_synchronous_signal() > > If you are going to update your tree and take V2 + my cleanup, I will not > mind if you fold my patch into the fix from Avi. > > And! I just noticed the sashiko's review of Avi's patch: > https://sashiko.dev/#/patchset/20261022061015.3737924-1-thnkslprpt%40gmail.com > > It noticed the problem with UB too. But, unlike me, it noticed another problem > with the "still_pending" logic. The described scenario is not possible after my > change, but we have the same problem with posix timers. > > This needs another change. I'll try to think a bit to avoid a "brute > force" fix. One thing we can reasonably do is to disallow sending signals that are "from the kernel" to ourselves if the signal number is a real time signal. Since the kernel won't generate any of those there is no need to restore them, or test them. So allowing them is unnecessary and leads to bugs in the code. I don't know how useful that would be but it is an option. Eric