From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.4 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 12808 invoked from network); 13 Apr 2022 10:58:09 -0000 Received: from mother.openwall.net (195.42.179.200) by inbox.vuxu.org with ESMTPUTF8; 13 Apr 2022 10:58:09 -0000 Received: (qmail 13403 invoked by uid 550); 13 Apr 2022 10:58:03 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 32617 invoked from network); 13 Apr 2022 07:26:27 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649834775; bh=A/EAxHZf/1dLHEaneenB2i6FlHCXxPiTlaeS/xafuqM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IqqJq/5yVFg67KxdN+da5yi/D6DhhW48JBe0Kq43AGnj9kRcmnpWV9Jmkv6JkOcak cuaTlJlshe17kREo6FBI0AT714lFJRVchE/Je6dzVmu/UPEvltpnbNLQurISBQzW1R k6C4LgXphcauvB6oB4bRpbG83KgQd/Id2hOGb2nSlzB3nf88/YNJ2yJnWEM9OCMi32 2z9o3WLJj13+cpcTgj8Is14we/7KYdsuIGeg+LlBAH0u66xtPPgoD4/qAo8CkvGZqH Pj52Zfb/UMpf2yZH6OSfH80FUi9fi8kvPubv6mBKF7GS6dSA/0b1sgBST3kFfsJd24 CyCXUgUp2HcEw== Date: Wed, 13 Apr 2022 09:26:06 +0200 From: Christian Brauner To: Arnd Bergmann Cc: musl@lists.openwall.com Message-ID: <20220413072606.44wwkk64xshn5mmm@wittgenstein> References: <1fec7c01-ea91-aa7c-d6d5-474c00d9347c@loongson.cn> <20220406160042.GB8499@voyager> <8dfcd620-4143-7450-8429-a89ed2264620@loongson.cn> <20220409131939.GK7074@brightrain.aerifal.cx> <20220409133044.GL7074@brightrain.aerifal.cx> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Subject: Re: [musl] Re: add loongarch64 port On Sun, Apr 10, 2022 at 12:30:59PM +0200, Arnd Bergmann wrote: > On Sat, Apr 9, 2022 at 3:31 PM Rich Felker wrote: > > > > Actually, if there aren't yet archs lacking SYS_clone, this API > > regression may be a good argument not to drop SYS_clone on new archs > > yet until there's a way for new archs to get the same behavior > > (unspecified stack size). > > That is a good point, but it also appears that the behavior of > clone3() is unintentional > here, I'm fairly sure it was meant to be a drop-in replacement for clone() with > additional features. Mostly but not in all ways. We did decide it's ok to make API improvements that might break compatibility with legacy clone(). > > Not sure what the best fix for this is, as the check for size==0 was clearly > intentional, but seems to prevent this from working. A special flag to ignore > the size, or a magic size value like -1ull might work, but neither of them > is a great interface. Can someone explain the use-case in a bit more detail, please? If it is a legitimate use-case that callers need to be able to pass a stack and have no way of also passing a size then we should just remove the size == 0 check for all architectures that don't have a hard requirement on passing a size together with the stack pointer. Wdyt, Arnd?