From patchwork Wed Aug 11 16:40:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Samuel Thibault X-Patchwork-Id: 44643 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 040C33985834 for ; Wed, 11 Aug 2021 16:41:08 +0000 (GMT) X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from hera.aquilenet.fr (hera.aquilenet.fr [185.233.100.1]) by sourceware.org (Postfix) with ESMTPS id 4CE8A3985456 for ; Wed, 11 Aug 2021 16:40:36 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 4CE8A3985456 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=ens-lyon.org Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=ens-lyon.org Received: from localhost (localhost [127.0.0.1]) by hera.aquilenet.fr (Postfix) with ESMTP id 40239ACB; Wed, 11 Aug 2021 18:40:35 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at aquilenet.fr Received: from hera.aquilenet.fr ([127.0.0.1]) by localhost (hera.aquilenet.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id LftVeCDWashe; Wed, 11 Aug 2021 18:40:32 +0200 (CEST) Received: from begin (unknown [IPv6:2a01:cb19:956:1b00:de41:a9ff:fe47:ec49]) by hera.aquilenet.fr (Postfix) with ESMTPSA id 8F2982E; Wed, 11 Aug 2021 18:40:32 +0200 (CEST) Received: from samy by begin with local (Exim 4.94.2) (envelope-from ) id 1mDrHL-002Px1-Uh; Wed, 11 Aug 2021 18:40:31 +0200 From: Samuel Thibault To: libc-alpha@sourceware.org Subject: [hurd,commited] hurd mmap: Reduce the requested max vmprot Date: Wed, 11 Aug 2021 18:40:31 +0200 Message-Id: <20210811164031.576368-1-samuel.thibault@ens-lyon.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Spamd-Bar: ++ X-Rspamd-Server: hera Authentication-Results: hera.aquilenet.fr X-Rspamd-Queue-Id: 40239ACB X-Spamd-Result: default: False [2.06 / 15.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; BROKEN_CONTENT_TYPE(1.50)[]; R_MISSING_CHARSET(2.50)[]; RCVD_COUNT_THREE(0.00)[3]; MID_CONTAINS_FROM(1.00)[]; RCVD_NO_TLS_LAST(0.10)[]; FROM_EQ_ENVFROM(0.00)[]; FREEMAIL_CC(0.00)[gmail.com]; BAYES_HAM(-2.94)[99.73%] X-Spam-Status: No, score=-11.7 required=5.0 tests=BAYES_00, GIT_PATCH_0, JMQ_SPF_NEUTRAL, KAM_DMARC_STATUS, SPF_HELO_PASS, SPF_NEUTRAL, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) 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: , Cc: commit-hurd@gnu.org, Sergey Bugaev Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" From: Sergey Bugaev When the memory object is read-only, the kernel would be right in refusing max vmprot containing VM_PROT_WRITE. Reviewed-by: Samuel Thibault --- sysdeps/mach/hurd/mmap.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/sysdeps/mach/hurd/mmap.c b/sysdeps/mach/hurd/mmap.c index 9fa265f752..c7413aff1a 100644 --- a/sysdeps/mach/hurd/mmap.c +++ b/sysdeps/mach/hurd/mmap.c @@ -34,7 +34,7 @@ void * __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset) { error_t err; - vm_prot_t vmprot; + vm_prot_t vmprot, max_vmprot; memory_object_t memobj; vm_address_t mapaddr; boolean_t copy; @@ -62,6 +62,7 @@ __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset) case MAP_ANON: memobj = MACH_PORT_NULL; + max_vmprot = VM_PROT_ALL; break; case MAP_FILE: @@ -84,16 +85,23 @@ __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset) anonymous or not when selecting addresses. */ case PROT_NONE: case PROT_READ: + max_vmprot = VM_PROT_READ|VM_PROT_EXECUTE; + if (wobj == robj) + max_vmprot |= VM_PROT_WRITE; memobj = robj; if (wobj != MACH_PORT_NULL) __mach_port_deallocate (__mach_task_self (), wobj); break; case PROT_WRITE: + max_vmprot = VM_PROT_WRITE; + if (robj == wobj) + max_vmprot |= VM_PROT_READ|VM_PROT_EXECUTE; memobj = wobj; if (robj != MACH_PORT_NULL) __mach_port_deallocate (__mach_task_self (), robj); break; case PROT_READ|PROT_WRITE: + max_vmprot = VM_PROT_ALL; if (robj == wobj) { memobj = wobj; @@ -122,11 +130,14 @@ __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset) /* XXX handle MAP_INHERIT */ + if (copy) + max_vmprot = VM_PROT_ALL; + err = __vm_map (__mach_task_self (), &mapaddr, (vm_size_t) len, (vm_address_t) 0, mapaddr == 0, memobj, (vm_offset_t) offset, - copy, vmprot, VM_PROT_ALL, + copy, vmprot, max_vmprot, copy ? VM_INHERIT_COPY : VM_INHERIT_SHARE); if (flags & MAP_FIXED) @@ -140,7 +151,7 @@ __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset) err = __vm_map (__mach_task_self (), &mapaddr, (vm_size_t) len, (vm_address_t) 0, 0, memobj, (vm_offset_t) offset, - copy, vmprot, VM_PROT_ALL, + copy, vmprot, max_vmprot, copy ? VM_INHERIT_COPY : VM_INHERIT_SHARE); } } @@ -150,13 +161,16 @@ __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset) err = __vm_map (__mach_task_self (), &mapaddr, (vm_size_t) len, (vm_address_t) 0, 1, memobj, (vm_offset_t) offset, - copy, vmprot, VM_PROT_ALL, + copy, vmprot, max_vmprot, copy ? VM_INHERIT_COPY : VM_INHERIT_SHARE); } if (memobj != MACH_PORT_NULL) __mach_port_deallocate (__mach_task_self (), memobj); + if (err == KERN_PROTECTION_FAILURE) + err = EACCES; + if (err) return (void *) (long int) __hurd_fail (err);