From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/12165 Path: news.gmane.org!.POSTED!not-for-mail From: Szabolcs Nagy Newsgroups: gmane.linux.lib.musl.general Subject: Re: [PATCH] Wasm support patch 2 (static syscalls) Date: Tue, 28 Nov 2017 16:08:06 +0100 Message-ID: <20171128150806.GO15263@port70.net> References: <20171128125948.GK15263@port70.net> <20171128140531.GM15263@port70.net> <20171128143549.GN15263@port70.net> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: blaine.gmane.org 1511881737 21415 195.159.176.226 (28 Nov 2017 15:08:57 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 28 Nov 2017 15:08:57 +0000 (UTC) User-Agent: Mutt/1.6.0 (2016-04-01) To: musl@lists.openwall.com Original-X-From: musl-return-12181-gllmg-musl=m.gmane.org@lists.openwall.com Tue Nov 28 16:08:50 2017 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.84_2) (envelope-from ) id 1eJhUs-0004Ix-MI for gllmg-musl@m.gmane.org; Tue, 28 Nov 2017 16:08:30 +0100 Original-Received: (qmail 10217 invoked by uid 550); 28 Nov 2017 15:08:18 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 10168 invoked from network); 28 Nov 2017 15:08:18 -0000 Mail-Followup-To: musl@lists.openwall.com Content-Disposition: inline In-Reply-To: Xref: news.gmane.org gmane.linux.lib.musl.general:12165 Archived-At: * Nicholas Wilson [2017-11-28 14:53:58 +0000]: > I think LTO would be required - but I might be missing something in your scheme? I'm considering the cases like __setxid and pthread_cancel, where the compiler can't work out which syscall numbers are possible (because the numbers come from another translation unit). In these cases, there's no way to eliminate any of the branches in your switch statement. > > In particular, getuid() is such a common library call that I think we do want to be able to support it on Wasm, without having Musl link in everything. I mean, it's not an obscure piece of functionality, so it's worth a small refactor to make it usable with Wasm. getuid is not affected, only __setxid and cancellable syscalls are. __setxid is not that important and can be worked around in generic code, but i don't see an easy solution for syscall_cp except that wasm probably don't need cancellation at all so it can be just defined to syscall.