From owner-svn-src-stable@freebsd.org Wed May 31 05:10:04 2017 Return-Path: Delivered-To: svn-src-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A42BFA9263C; Wed, 31 May 2017 05:10:04 +0000 (UTC) (envelope-from delphij@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 751AF3646; Wed, 31 May 2017 05:10:04 +0000 (UTC) (envelope-from delphij@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id v4V5A3lK031850; Wed, 31 May 2017 05:10:03 GMT (envelope-from delphij@FreeBSD.org) Received: (from delphij@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id v4V5A3Sx031844; Wed, 31 May 2017 05:10:03 GMT (envelope-from delphij@FreeBSD.org) Message-Id: <201705310510.v4V5A3Sx031844@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: delphij set sender to delphij@FreeBSD.org using -f From: Xin LI Date: Wed, 31 May 2017 05:10:03 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r319277 - in stable/11: lib/libc/sys sys/sys sys/vm X-SVN-Group: stable-11 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-stable@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for all the -stable branches of the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 31 May 2017 05:10:04 -0000 Author: delphij Date: Wed May 31 05:10:03 2017 New Revision: 319277 URL: https://svnweb.freebsd.org/changeset/base/319277 Log: MFC r315272, r315370 r315272: Implement INHERIT_ZERO for minherit(2). INHERIT_ZERO is an OpenBSD feature. When a page is marked as such, it would be zeroed upon fork(). This would be used in new arc4random(3) functions. PR: 182610 Reviewed by: kib (earlier version) Differential Revision: https://reviews.freebsd.org/D427 r315370: The adj_free and max_free values of new_entry will be calculated and assigned by subsequent vm_map_entry_link(), therefore, remove the pointless copying. Submitted by: alc Modified: stable/11/lib/libc/sys/minherit.2 stable/11/sys/sys/mman.h stable/11/sys/vm/vm.h stable/11/sys/vm/vm_map.c Directory Properties: stable/11/ (props changed) Modified: stable/11/lib/libc/sys/minherit.2 ============================================================================== --- stable/11/lib/libc/sys/minherit.2 Wed May 31 05:05:32 2017 (r319276) +++ stable/11/lib/libc/sys/minherit.2 Wed May 31 05:10:03 2017 (r319277) @@ -29,7 +29,7 @@ .\" .\" @(#)minherit.2 8.1 (Berkeley) 6/9/93 .\" -.Dd October 30, 2007 +.Dd March 15, 2017 .Dt MINHERIT 2 .Os .Sh NAME @@ -91,6 +91,11 @@ it will no longer be shared in the parent after the parent forks and there is no way to get the previous shared-backing-store mapping without unmapping and remapping the address space in the parent. +.It Dv INHERIT_ZERO +This option causes the address space in question to be mapped as new +anonymous pages, +which would be initialized to all zero bytes, +in the child process. .El .Sh RETURN VALUES .Rv -std minherit @@ -130,6 +135,13 @@ system call first appeared in .Ox and then in .Fx 2.2 . +.Pp +The +.Dv INHERIT_ZERO +support first appeared in +.Ox 5.6 +and then in +.Fx 12.0 . .Sh BUGS Once you set inheritance to .Dv MAP_PRIVATE Modified: stable/11/sys/sys/mman.h ============================================================================== --- stable/11/sys/sys/mman.h Wed May 31 05:05:32 2017 (r319276) +++ stable/11/sys/sys/mman.h Wed May 31 05:10:03 2017 (r319277) @@ -43,6 +43,7 @@ #define INHERIT_SHARE 0 #define INHERIT_COPY 1 #define INHERIT_NONE 2 +#define INHERIT_ZERO 3 #endif /* Modified: stable/11/sys/vm/vm.h ============================================================================== --- stable/11/sys/vm/vm.h Wed May 31 05:05:32 2017 (r319276) +++ stable/11/sys/vm/vm.h Wed May 31 05:10:03 2017 (r319277) @@ -68,6 +68,7 @@ typedef char vm_inherit_t; /* inheritance codes */ #define VM_INHERIT_SHARE ((vm_inherit_t) 0) #define VM_INHERIT_COPY ((vm_inherit_t) 1) #define VM_INHERIT_NONE ((vm_inherit_t) 2) +#define VM_INHERIT_ZERO ((vm_inherit_t) 3) #define VM_INHERIT_DEFAULT VM_INHERIT_COPY typedef u_char vm_prot_t; /* protection codes */ Modified: stable/11/sys/vm/vm_map.c ============================================================================== --- stable/11/sys/vm/vm_map.c Wed May 31 05:05:32 2017 (r319276) +++ stable/11/sys/vm/vm_map.c Wed May 31 05:10:03 2017 (r319277) @@ -2294,6 +2294,7 @@ vm_map_inherit(vm_map_t map, vm_offset_t start, vm_off case VM_INHERIT_NONE: case VM_INHERIT_COPY: case VM_INHERIT_SHARE: + case VM_INHERIT_ZERO: break; default: return (KERN_INVALID_ARGUMENT); @@ -3451,6 +3452,34 @@ vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_c vmspace_map_entry_forked(vm1, vm2, new_entry); vm_map_copy_entry(old_map, new_map, old_entry, new_entry, fork_charge); + break; + + case VM_INHERIT_ZERO: + /* + * Create a new anonymous mapping entry modelled from + * the old one. + */ + new_entry = vm_map_entry_create(new_map); + memset(new_entry, 0, sizeof(*new_entry)); + + new_entry->start = old_entry->start; + new_entry->end = old_entry->end; + new_entry->avail_ssize = old_entry->avail_ssize; + new_entry->eflags = old_entry->eflags & + ~(MAP_ENTRY_USER_WIRED | MAP_ENTRY_IN_TRANSITION | + MAP_ENTRY_VN_WRITECNT); + new_entry->protection = old_entry->protection; + new_entry->max_protection = old_entry->max_protection; + new_entry->inheritance = VM_INHERIT_ZERO; + + vm_map_entry_link(new_map, new_map->header.prev, + new_entry); + vmspace_map_entry_forked(vm1, vm2, new_entry); + + new_entry->cred = curthread->td_ucred; + crhold(new_entry->cred); + *fork_charge += (new_entry->end - new_entry->start); + break; } old_entry = old_entry->next;