From patchwork Mon Apr 13 14:25:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "H.J. Lu" X-Patchwork-Id: 38808 Return-Path: X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from mail-pf1-x444.google.com (mail-pf1-x444.google.com [IPv6:2607:f8b0:4864:20::444]) by sourceware.org (Postfix) with ESMTPS id 14C1B3887007 for ; Mon, 13 Apr 2020 14:25:19 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 14C1B3887007 Received: by mail-pf1-x444.google.com with SMTP id k15so4554122pfh.6 for ; Mon, 13 Apr 2020 07:25:19 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ZXWBr1KcAl+7SNLdKxJ4jI9ffG8/3ftn0HbDescWTUk=; b=cnNUOOX+4FLSPZdrC0yBK0CXwI1umyhnjsMD2TxTB9yOcC9SuPC3gbYBwlv+HowuFx K45xKdbAM8VqD+t9z/hRQWbq6eWFYbfQR/Txi8/BUukrLJaREZ7phCdo1G1Fd66iex5t QMTHyaGNKlFGQNkb73DZWw599eo8ypk4spsOf72mZyPV5K4FQ7qc8zE4WR5qnfaeOMdU K6zDP2dketlzNXoIRK6WEv3EwqWMrE6wAzfbRJufwMITEmMprtuUNHwwv+kkpjI1xBQo MMP0ctlmB/Vg4ZhBeN3DJjD6i3Ol9jp7jQUzcFuQQojZ31pk4H1T/ZeddKzSQPPRb6fO QGxg== X-Gm-Message-State: AGi0PuaU233GUSgDRCEq8XtELE4RFBOk2ICImLt2si1dcO2iK9PuHeL5 FzyLvW8uvcxZH5Lnnhoft9A= X-Google-Smtp-Source: APiQypJxkLv/fsZgYmxNtwKlkooVerm4yZTTbk/uTTx72C13iWYeMi10+DUsH4KAFajX1gAeAN64GA== X-Received: by 2002:a63:2c87:: with SMTP id s129mr18456259pgs.406.1586787918142; Mon, 13 Apr 2020 07:25:18 -0700 (PDT) Received: from gnu-cfl-2.localdomain (c-69-181-90-243.hsd1.ca.comcast.net. [69.181.90.243]) by smtp.gmail.com with ESMTPSA id v17sm12144794pjr.1.2020.04.13.07.25.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Apr 2020 07:25:17 -0700 (PDT) Received: from gnu-cfl-2.localdomain (localhost [IPv6:::1]) by gnu-cfl-2.localdomain (Postfix) with ESMTP id 97CBAC0079; Mon, 13 Apr 2020 07:25:16 -0700 (PDT) From: "H.J. Lu" To: libc-alpha@sourceware.org Subject: [PATCH 0/3] x32: Properly pass long to syscall [BZ #25810] Date: Mon, 13 Apr 2020 07:25:12 -0700 Message-Id: <20200413142515.16619-1-hjl.tools@gmail.com> X-Mailer: git-send-email 2.25.2 MIME-Version: 1.0 X-Spam-Status: No, score=-16.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Apr 2020 14:25:20 -0000 X32 has 32-bit long and pointer with 64-bit off_t. Since x32 psABI requires that pointers passed in registers must be zero-extended to 64bit, x32 can share many syscall interfaces with LP64. When a LP64 syscall with long and unsigned long arguments is used for x32, these arguments must be properly extended to 64-bit. Otherwise if the upper 32 bits of the register have undefined value, such a syscall will be rejected by kernel. For syscalls implemented in assembly codes, 'U' is added to syscall signature key letters for unsigned long. SYSCALL_ULONG_ARG_1 and SYSCALL_ULONG_ARG_2 are passed to syscall-template.S for the first and the second unsigned long arguments if PSEUDOS_HAVE_4_ARGS is defined. They are used by x32 to zero-extend 32-bit arguments to 64 bits. For x32 INLINE_SYSCALLs, cast 1. pointer to unsigned long (32 bit). 2. 32-bit unsigned integer to unsigned long long (64 bit). 3. 32-bit integer to long long (64 bit). For void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset); we now generate 0: 41 f7 c1 ff 0f 00 00 test $0xfff,%r9d 7: 75 1f jne 28 <__mmap64+0x28> 9: 48 63 d2 movslq %edx,%rdx c: 89 f6 mov %esi,%esi e: 4d 63 c0 movslq %r8d,%r8 11: 4c 63 d1 movslq %ecx,%r10 14: b8 09 00 00 40 mov $0x40000009,%eax 19: 0f 05 syscall That is 1. addr is unchanged. 2. length is zero-extend to 64 bits. 3. prot is sign-extend to 64 bits. 4. flags is sign-extend to 64 bits. 5. fd is sign-extend to 64 bits. 6. offset is unchanged. For int arguments, since kernel uses only the lower 32 bits and ignores the upper 32 bits in 64-bit registers, these work correctly. Tested on i386, x86-64 and x32 as well as with build-many-glibcs.py. H.J. Lu (3): Add SYSCALL_ULONG_ARG_[12] to pass long to syscall [BZ #25810] x32: Properly pass long to syscall [BZ #25810] Add a syscall test for [BZ #25810] misc/Makefile | 2 +- misc/tst-syscalls.c | 146 ++++++++++++++++++++ sysdeps/unix/make-syscalls.sh | 88 ++++++++++++ sysdeps/unix/syscall-template.S | 43 +++++- sysdeps/unix/syscalls.list | 6 +- sysdeps/unix/sysv/linux/syscalls.list | 14 +- sysdeps/unix/sysv/linux/x86_64/sysdep.h | 80 ++++++++--- sysdeps/unix/sysv/linux/x86_64/x32/sysdep.h | 38 +++++ 8 files changed, 385 insertions(+), 32 deletions(-) create mode 100644 misc/tst-syscalls.c