From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8CB34132124; Tue, 22 Oct 2024 02:22:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729563748; cv=none; b=UqaqIgq/WG8bv5PWkvwvali5ejltA1yVAQ7Z2Y5U7+sp/iICnKIgY/G1b78M4JpGox+S9GRVXP1Y3vCkWlaFralCerMOday5mejdPkMCNYxaXAgoGYa0yL7PpLAm8Z2y0tZnn5bhIx3xo7SWcRf8sQO4eWkeYYgduyjviFryMJY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729563748; c=relaxed/simple; bh=cvOmKRaGaYic+n9hOuxtcNdHZWL09dWwyvl2zywQ6YA=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=f+Ocb1HJ7YkU195LIm+OlNhMAPr5RKrO+tEKiKAYQazUYQhJpDozHK7fuvBuI5jx1f5r6rsmUaZg8KTcXlFJXH8hdMyzytT41zDyRW0iPiEGyy/9lspdt2mwGvMquRPvbve230vc9FcVMuekP1jBEYR+u57ur16n+C4kejdmQIw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=vBjvOxRG; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="vBjvOxRG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D5B84C4CEC3; Tue, 22 Oct 2024 02:22:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729563746; bh=cvOmKRaGaYic+n9hOuxtcNdHZWL09dWwyvl2zywQ6YA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=vBjvOxRGdj9JZ0nSM7TA2sy0vRXPjqAC1D6zruQaiuk9dyPya31u1p8bAQmzZk3a3 9x5nFBCwPdGYk4CRPzLkxQ4g8FMfpgm5/44kbrdG3SezFZL9tUN8wnJ+zpzhbEIfoZ EhFIEhRksSf1VbHTjvR7fr+1EHGkD7A3fbN0pTbgsxfWikGhu9a+/wItrxUO57uC29 5j6cUda1NSV3q3sDWWwqCUtquUVqGhU7d2R/VnxYV84o85n3ujbbFAzHtO1Z8AP+nL CWELl1DIrHS379TaS08rbjd3VMdbSS9uIkkEFblzA54ArRR2MLiEUDWJ2lsEw+UIQP Njwqo4GA6PZGg== Date: Tue, 22 Oct 2024 11:22:22 +0900 From: Masami Hiramatsu (Google) To: Oleg Nesterov Cc: Liao Chang , 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, mhiramat@kernel.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH] uprobes: Remove redundant spinlock in uprobe_deny_signal Message-Id: <20241022112222.1edeeac3aee13714a53c217c@kernel.org> In-Reply-To: <20240731141231.GB16718@redhat.com> References: <20240731095017.1560516-1-liaochang1@huawei.com> <20240731141231.GB16718@redhat.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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-Transfer-Encoding: 7bit On Wed, 31 Jul 2024 16:12:32 +0200 Oleg Nesterov wrote: > On 07/31, Liao Chang wrote: > > > > --- a/kernel/events/uprobes.c > > +++ b/kernel/events/uprobes.c > > @@ -1979,9 +1979,7 @@ bool uprobe_deny_signal(void) > > WARN_ON_ONCE(utask->state != UTASK_SSTEP); > > > > if (task_sigpending(t)) { > > - spin_lock_irq(&t->sighand->siglock); > > clear_tsk_thread_flag(t, TIF_SIGPENDING); > > - spin_unlock_irq(&t->sighand->siglock); > > Agreed, in this case ->siglock buys nothing, another signal can come > right after spin_unlock(). > > Acked-by: Oleg Nesterov > > Looks good to me. Acked-by: Masami Hiramatsu (Google) Peter, can you pick this? Thanks, -- Masami Hiramatsu (Google)