From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 8B2033A5E98; Tue, 18 Nov 2025 17:11:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763485884; cv=none; b=EwqyIx8o1UTAkBHR8M1qwNcjBRFUImprbwVO1TjSXSaVm/+SUjkQVJg2TITjYCCAlQ6vUJc1or7dHD2U8elDI4g0FMkauYqWQeE7w/umPvRrKVaoiouBCrtMugmOWeSQUiZOyl6sZtwBPSa8weY2PHwwuX2G+YhBcdTTiHKJ/Jc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763485884; c=relaxed/simple; bh=rSEsVlgh/sUbgdoQ41V0HN5zUD+TXowim/igLtLGf/c=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=rNUAQF6mdAVVal0s1Z8mvg0vG9uLMNAp1io5cQl6jKS2Uz4RRI09+GfKro/ke7EEp6jEAI8MoTbwc3s9PjDt8fAbqc34LFD7aHXX0kpV/n7SrZKiAaMGXBKcbNJdkfdNxWf4nh6Cz2wzIJC5RfadlxLJxlZF3iH9qjpvFGabx+A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1ED541595; Tue, 18 Nov 2025 09:11:14 -0800 (PST) Received: from [10.57.39.196] (unknown [10.57.39.196]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8977C3F66E; Tue, 18 Nov 2025 09:11:16 -0800 (PST) Message-ID: Date: Tue, 18 Nov 2025 18:11:13 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 04/11] entry: Add syscall_exit_to_user_mode_prepare() helper To: Jinjie Ruan , catalin.marinas@arm.com, will@kernel.org, oleg@redhat.com, tglx@linutronix.de, peterz@infradead.org, luto@kernel.org, shuah@kernel.org, kees@kernel.org, wad@chromium.org, akpm@linux-foundation.org, ldv@strace.io, macro@orcam.me.uk, deller@gmx.de, mark.rutland@arm.com, song@kernel.org, mbenes@suse.cz, ryan.roberts@arm.com, ada.coupriediaz@arm.com, anshuman.khandual@arm.com, broonie@kernel.org, pengcan@kylinos.cn, dvyukov@google.com, kmal@cock.li, lihongbo22@huawei.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org References: <20251117133048.53182-1-ruanjinjie@huawei.com> <20251117133048.53182-5-ruanjinjie@huawei.com> From: Kevin Brodsky Content-Language: en-GB In-Reply-To: <20251117133048.53182-5-ruanjinjie@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 17/11/2025 14:30, Jinjie Ruan wrote: > In the generic entry code, the part before > syscall_exit_to_user_mode_work() calls syscall_exit_work(), which > serves the same purpose as syscall_exit_to_user_mode_prepare() > in arm64. This is really hard to parse, I suppose the point is that the beginning of syscall_exit_to_user_mode_work() can be reused on arm64 and therefore it makes sense to split it? > In preparation for moving arm64 over to the generic entry > code, extract syscall_exit_to_user_mode_prepare() helper from > syscall_exit_to_user_mode_work(). > > No functional changes. > > Signed-off-by: Jinjie Ruan The position of this patch in the series seems a little arbitrary (it has no dependency on other patches), it might make more sense to group it with the other generic patches (i.e. move it to patch 7). Otherwise: Reviewed-by: Kevin Brodsky - Kevin > --- > include/linux/entry-common.h | 35 ++++++++++++++++++++++------------- > 1 file changed, 22 insertions(+), 13 deletions(-) > > diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h > index 7177436f0f9e..cd6dacb2d8bf 100644 > --- a/include/linux/entry-common.h > +++ b/include/linux/entry-common.h > @@ -137,20 +137,11 @@ static __always_inline long syscall_enter_from_user_mode(struct pt_regs *regs, l > */ > void syscall_exit_work(struct pt_regs *regs, unsigned long work); > > -/** > - * syscall_exit_to_user_mode_work - Handle work before returning to user mode > - * @regs: Pointer to currents pt_regs > - * > - * Same as step 1 and 2 of syscall_exit_to_user_mode() but without calling > - * exit_to_user_mode() to perform the final transition to user mode. > - * > - * Calling convention is the same as for syscall_exit_to_user_mode() and it > - * returns with all work handled and interrupts disabled. The caller must > - * invoke exit_to_user_mode() before actually switching to user mode to > - * make the final state transitions. Interrupts must stay disabled between > - * return from this function and the invocation of exit_to_user_mode(). > +/* > + * Syscall specific exit to user mode preparation. Runs with interrupts > + * enabled. > */ > -static __always_inline void syscall_exit_to_user_mode_work(struct pt_regs *regs) > +static __always_inline void syscall_exit_to_user_mode_prepare(struct pt_regs *regs) > { > unsigned long work = READ_ONCE(current_thread_info()->syscall_work); > unsigned long nr = syscall_get_nr(current, regs); > @@ -171,6 +162,24 @@ static __always_inline void syscall_exit_to_user_mode_work(struct pt_regs *regs) > */ > if (unlikely(work & SYSCALL_WORK_EXIT)) > syscall_exit_work(regs, work); > +} > + > +/** > + * syscall_exit_to_user_mode_work - Handle work before returning to user mode > + * @regs: Pointer to currents pt_regs > + * > + * Same as step 1 and 2 of syscall_exit_to_user_mode() but without calling > + * exit_to_user_mode() to perform the final transition to user mode. > + * > + * Calling convention is the same as for syscall_exit_to_user_mode() and it > + * returns with all work handled and interrupts disabled. The caller must > + * invoke exit_to_user_mode() before actually switching to user mode to > + * make the final state transitions. Interrupts must stay disabled between > + * return from this function and the invocation of exit_to_user_mode(). > + */ > +static __always_inline void syscall_exit_to_user_mode_work(struct pt_regs *regs) > +{ > + syscall_exit_to_user_mode_prepare(regs); > local_irq_disable_exit_to_user(); > exit_to_user_mode_prepare(regs); > }