From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 139CF19923D for ; Tue, 13 Aug 2024 12:47:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723553276; cv=none; b=p/niAI2f5fbJme5HDZPOmyFJuVl+t8O4CLPHdhmIhBwA0GoLiSWlEfsZqsBXcHhxo9oqcJnjxHfrOZ7nkQiTdXYt1e4NWn9KCjHYj9tnEtRDyKlIh2F7AtR/bexrOSkFRv31x0e6zPAjaVmulsCv9LcIWMVUE8d7iCEJw48H8A0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723553276; c=relaxed/simple; bh=0KWhrcU0YHbJiksdyGvlsjytVHRYOXJJLdmQ+/bgpig=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=k2is0/Rw1yv3zRQ9o0+JPkDG1tZzBPhnQ72qi5uGaEu1neQfu7g2j8mnnPqrQxEP+xA7QJkF25zR3K59ELv2wcHh4rcrHxsv5xrAJZhuuXTkIKoskXZ51ZFw+Z1hwkB64aaGL3iiyULbu2yxMwmgC/0aO3yhtflUOlx0BYjQ9X8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=CT0Dulfu; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="CT0Dulfu" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1723553274; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=1XjhAxPmiM++L3njaRU1wOJhxoxtQOjrtQvzpozAwi8=; b=CT0DulfuxgFB9gGQBdfwM9QY3QRKaDIUW2nfDQcuYDRNzYH/W1hS4ngTddquhKcXoJ2Kyf f7pNUErxPw1hQlv1OG0eq/hCYktbpXj4lKbQgnnb/cJu/wX4ziKec38aoeiLDUcD5UWkSR /r3T2zPcCbIc9u6W9tecftHjUEquesw= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-302-9cj9z-qYMRa2lP7hsRm5jg-1; Tue, 13 Aug 2024 08:47:51 -0400 X-MC-Unique: 9cj9z-qYMRa2lP7hsRm5jg-1 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 329EF1953957; Tue, 13 Aug 2024 12:47:48 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.225.159]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id CB21F1955F66; Tue, 13 Aug 2024 12:47:41 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Tue, 13 Aug 2024 14:47:45 +0200 (CEST) Date: Tue, 13 Aug 2024 14:47:37 +0200 From: Oleg Nesterov To: "Liao, Chang" Cc: mhiramat@kernel.org, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, namhyung@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, kan.liang@linux.intel.com, andrii@kernel.org, rostedt@goodmis.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH v2 1/2] uprobes: Remove redundant spinlock in uprobe_deny_signal() Message-ID: <20240813124737.GA31977@redhat.com> References: <20240809061004.2112369-1-liaochang1@huawei.com> <20240809061004.2112369-2-liaochang1@huawei.com> <20240812120738.GC11656@redhat.com> <2971107e-75e7-8438-c858-b95202d7b5ea@huawei.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2971107e-75e7-8438-c858-b95202d7b5ea@huawei.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 On 08/13, Liao, Chang wrote: > > > Oleg, your explaination is more accurate. So I will reword the commit log and > quote some of your note like this: Oh, please don't. I just tried to explain the history of this spin_lock(siglock). > Since we already have the lockless user of clear_thread_flag(TIF_SIGPENDING). > And for uprobe singlestep case, it doesn't break the rule of "the state of > TIF_SIGPENDING of every thread is stable with sighand->siglock held". It obviously does break the rule above. Please keep your changelog as is. Oleg.