From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-x534.google.com (mail-pg1-x534.google.com [IPv6:2607:f8b0:4864:20::534]) by sourceware.org (Postfix) with ESMTPS id 28F4F3858D39 for ; Wed, 10 Apr 2024 01:48:39 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 28F4F3858D39 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 28F4F3858D39 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2607:f8b0:4864:20::534 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1712713721; cv=none; b=Ib8dD2Dh8fsnodxYEDo97o7wn90ndYOWErFud0Z2u8eE2nAcLEOZ6xSUGGZhirQHgXUbjQkQ1DpqhSzzoV5OcMYlzSo5RWjDtd6Oj0CxiTHy2Ot5hgC953VN7jP/4LCnAH8nYl3XBlPEDAk+TKGxA39ZmXfMX/ofwwhKPnbzv9g= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1712713721; c=relaxed/simple; bh=dDwknt3dSnL9TLh/80oWEL+2mXEw1I6DNwTtWJhqJ7Q=; h=DKIM-Signature:Date:Message-ID:From:To:Subject; b=EwmMdtezyPaAhAK2AAXpEQHXoHqoLrxt+qPGAtooynmaz5CZCARmxtOFSFXS2xBy55AOTmlQnT7gBwo/g0WFx8ETg7NTqeB4vIcp85D1q4/3SYoRxFw9K4goqLbUMS+iEOmCPVo0yfpK2kO0TNrBzN2D2Ly1lV+GDbSesfnF+Ac= ARC-Authentication-Results: i=1; server2.sourceware.org Received: by mail-pg1-x534.google.com with SMTP id 41be03b00d2f7-5bdbe2de25fso4992411a12.3 for ; Tue, 09 Apr 2024 18:48:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1712713718; x=1713318518; darn=gcc.gnu.org; h=in-reply-to:subject:to:from:message-id:date:from:to:cc:subject:date :message-id:reply-to; bh=xQyc/BQqkFDsNDvaGYuXIh66MnqBhBZqAMmCzuFyZn0=; b=MxhyCcyYcBAyzM+hQsI844LVAz0bm5ez4EZuUFNTECDf4l2siLjEe2nqa3aL9ZCoEO EA3nadoxeYSCG4bjCK5/Wz6nP8OlXsIBU4Z6BtxORgHHW/ERiJxIuXZ5TXnBcZXYsBvt lLeEGWnDL9xSw1h+o72/UyGcanz66FWydhk4oPZjO3PdW5KJ0gV3CsDrZfU8v7MCPBU6 73lKMYccMp6l2TJR6ylVHhz96UHJkZiiN6qLUHhbJP5A3m8ADheCpp0LsjTMFTDLxlsV YHfjgT/2WiDySNFRruEeWnlLgoVv5hfY7Jj8irwZz+QeCz2xI0V+9lpRO1RAs085nq12 Vd+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1712713718; x=1713318518; h=in-reply-to:subject:to:from:message-id:date:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=xQyc/BQqkFDsNDvaGYuXIh66MnqBhBZqAMmCzuFyZn0=; b=CnAtLZ1BnaIF6LhmMUEyoMx+xKY99s2J9YaqAFs+elToiJJNJRYY6e7orE+R/Ounrk 1mGkZDaYfCnsaUI0OXTptwL2BjVBNg/G7nq45zLPRplts+n6XYMPleTQR4a4ccj4Bj1F BNn5BfqfAHmNNp55qb461LE3P4mU7T4rI0G2awfVwpnmml257BBRxlzYngiaP1h19L+r 5ZcnEbNCyE2PjiCHAOpC35bpWGgnrTvD9uU2Goi3IP8Sr3gbPlsLGKBGfh8T25qBtlqX hvmeeboZ0YP/gfOr9Vz0bCU8V0YWlvDAtg9MCaT4auxAFb1M6G9yyr0KnktTAqa3GrCb eWSw== X-Gm-Message-State: AOJu0YxLORF2UxyvNOgtx/4uDFgYe1zIRtMhQLRKss9lHk4E2tBK5hIb AUsSHW1si37siIwiY3C9P2l47S9wkAbfjgwpQ0k3dLiP1ifSsPcup5acYpoX X-Google-Smtp-Source: AGHT+IFNP2+nLicruroC2DkLniem18dxkYrP0jyOImIiFf7Mgoq0flmN9TqKFZ21dcxQOq1NP6h8/w== X-Received: by 2002:a17:903:1247:b0:1dc:8eba:42c3 with SMTP id u7-20020a170903124700b001dc8eba42c3mr2046666plh.23.1712713717775; Tue, 09 Apr 2024 18:48:37 -0700 (PDT) Received: from localhost ([138.117.155.58]) by smtp.gmail.com with ESMTPSA id im22-20020a170902bb1600b001e3c01dfaf5sm9643168plb.24.2024.04.09.18.48.36 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Apr 2024 18:48:37 -0700 (PDT) Date: Tue, 09 Apr 2024 22:48:37 -0300 Message-ID: From: Matheus Afonso Martins Moreira To: gcc@gcc.gnu.org Subject: [RFC] Linux system call builtins In-Reply-To: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: > Now the question comes is the argument long or some other type? I believe so. Every library I've seen and the kernel itself uses long. Other types just get typecasted to long. I think it's just supposed to mean "register type" since all the arguments must be in registers. > E.g. for some 32bit ABIs built on top of 64bit ISA might always > just pass 32bits or they might allow passing the full 64bits. > (x32 might fall under this and MIPS n32). The registers used are documented here: https://www.man7.org/linux/man-pages/man2/syscall.2.html x32 uses the exact same registers as x86_64, all 64 bit: > x86-64 rdi rsi rdx r10 r8 r9 > x32 rdi rsi rdx r10 r8 r9 MIPS calling conventions work like this: > mips/n32,64 a0 a1 a2 a3 a4 a5 > mips/o32 a0 a1 a2 a3 ... > mips/o32 args5-8 are passed on the stack > Maybe you should warn/error out > if not passed the correct sized argument. Yes. It should be an error if the inputs are not register sized. As far as I know all system call inputs are either register sized values or pointers to C strings, buffers or much larger structures. > Also do you sign or zero extend a 32bit argument for LP64 targets? I'm not sure. System call stubs just declare these register values as signed long so whatever happens in that case seems to be appropriate.