From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4451C60A3808 for ; Tue, 27 Oct 2026 16:45:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=U0/5c308; dkim=pass (1024-bit key, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=UGpMc23Z DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; 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Tue, 27 Oct 2026 09:45:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1793119535; bh=rnhwTZUYMyNC6LhGd7EvjwdU5unqPfJSXAia5nseGlY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UGpMc23ZVSkzbfErHN7Z6gjPhpk5iz/QK3wltY10jtOZwCRtPdr/HxKYmEsipfcbB CNjzr+i4WdRJeAIOwgWPDEAbVJg91iMEk0swBau4nbXuczwWhyUkvFKk3uwBKwEl8m kLp4KuoApUVM5xVs7KKu3F5Bf4L/7bOOfc7gQrfk= Date: Tue, 27 Oct 2026 16:45:27 +0000 From: Catalin Marinas To: Thorsten Blum Cc: Will Deacon , Mark Rutland , Robin Murphy , Oliver Upton , Yureka Lilian , Marc Zyngier , Ard Biesheuvel , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64: idreg-override: Detect trailing "--" in __parse_cmdline() Message-ID: References: <20261015161054.357595-3-blum@kernel.org> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261027_094537_071560_B0D117EC X-CRM114-Status: GOOD ( 26.80 ) X-Spam-Score: -4.4 (----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Tue, Oct 27, 2026 at 03:49:45PM +0100, Thorsten Blum wrote: > On Tue, Oct 27, 2026 at 12:14:07PM +0000, Catalin Marinas wrote: > > On Thu, Oct 15, 2026 at 06:10:54PM +0200, Thorsten Blum wrote: > > > __parse_cmdline() detects "--" only if it is followed by whitespace. > > > However, at the end of the command line, it converts the dashes to > > > underscores and tries to match "__" as an option. > > > > > > Detect trailing "--" directly instead of converting it to "__". > > > > > > Fixes: dc3f5aae0638 ("arm64: idreg-override: Avoid parameq() and parameqn()") > > > Signed-off-by: Thorsten Blum > > > --- > > > arch/arm64/kernel/pi/idreg-override.c | 5 +++-- > > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > > > diff --git a/arch/arm64/kernel/pi/idreg-override.c b/arch/arm64/kernel/pi/idreg-override.c > > > index acaf56234973..38aa28d19650 100644 > > > --- a/arch/arm64/kernel/pi/idreg-override.c > > > +++ b/arch/arm64/kernel/pi/idreg-override.c > > > @@ -352,8 +352,9 @@ static __init void __parse_cmdline(const char *cmdline, bool parse_aliases) > > > > > > cmdline = skip_spaces(cmdline); > > > > > > - /* terminate on "--" appearing on the command line by itself */ > > > - if (cmdline[0] == '-' && cmdline[1] == '-' && isspace(cmdline[2])) > > > + /* Stop at "--" appearing as a separate argument. */ > > > + if (cmdline[0] == '-' && cmdline[1] == '-' && > > > + (!cmdline[2] || isspace(cmdline[2]))) > > > return; > > > > I guess that's more of a cleanup. Does it actually fix anything to > > deserve a Fixes tag? We skip an unnecessary lookup for "__" but there's > > no functional difference. > > Yes, it's a cleanup. > > Functionally, the behavior is equivalent because it also happened to > work before. However, commit dc3f5aae0638 removed the explicit detection > of a trailing "--", so I added the Fixes tag mostly for provenance. Makes sense. We might make it a comment when applying rather than a dedicated Fixes tag. Reviewed-by: Catalin Marinas