From mboxrd@z Thu Jan 1 00:00:00 1970 From: Palmer Dabbelt Subject: [PATCH 04/13] Always expose MAP_UNINITIALIZED to userspace Date: Tue, 3 Nov 2015 11:46:25 -0800 Message-ID: <1446579994-9937-5-git-send-email-palmer@dabbelt.com> References: <1442271047-4908-1-git-send-email-palmer@dabbelt.com> <1446579994-9937-1-git-send-email-palmer@dabbelt.com> Cc: viro@zeniv.linux.org.uk Return-path: Received: from mail-pa0-f41.google.com ([209.85.220.41]:34977 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932236AbbKCTqv (ORCPT ); Tue, 3 Nov 2015 14:46:51 -0500 Received: by pasz6 with SMTP id z6so27436824pas.2 for ; Tue, 03 Nov 2015 11:46:51 -0800 (PST) To: arnd@arndb.de To: dhowells@redhat.com Cc: ast@plumgrid.com Cc: aishchuk@linux.vnet.ibm.com Cc: aarcange@redhat.com Cc: akpm@linux-foundation.org Cc: luto@kernel.org Cc: acme@kernel.org Cc: bhe@redhat.com Cc: 3chas3@gmail.com Cc: chris@zankel.net Cc: dave@sr71.net Cc: dyoung@redhat.com Cc: drysdale@google.com Cc: davem@davemloft.net Cc: ebiederm@xmission.com Cc: geoff@infradead.org Cc: gregkh@linuxfoundation.org Cc: hpa@zytor.com Cc: mingo@kernel.org Cc: iulia.manda21@gmail.com Cc: plagnioj@jcrosoft.com Cc: jikos@kernel.org Cc: josh@joshtriplett.org Cc: kexec@lists.infradead.org Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-xtensa@linux-xtensa.org Cc: mathieu.desnoyers@efficios.com Cc: jcmvbkbc@gmail.com Cc: paulmck@linux.vnet.ibm.com Cc: a.p.zijlstra@chello.nl Cc: tglx@linutronix.de Cc: tomi.valkeinen@ti.com Cc: vgoyal@redhat.com Cc: x86@kernel.org Cc: Palmer Dabbelt In-Reply-To: <1446579994-9937-1-git-send-email-palmer@dabbelt.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: This used to be hidden behind CONFIG_MMAP_ALLOW_UNINITIALIZED, so userspace wouldn't actually ever see it be non-zero. While I had originally hoped to avoid hiding it, it looks like this conflicts with MAP_HUGE_SHIFT so I think it's safer to just keep this 0. Architectures that want to define this can still override it. In fact, the Xtensa port already overrides it in a very similar manner to the previously broken one (but due to lots of conflicting opinions on how to solve this correctly, I'm just taking the easy way out and letting their arch maintainers deal with it -- sorry). Signed-off-by: Palmer Dabbelt Reviewed-by: Andrew Waterman Reviewed-by: Albert Ou --- include/uapi/asm-generic/mman-common.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h index ddc3b36..0ce2a13 100644 --- a/include/uapi/asm-generic/mman-common.h +++ b/include/uapi/asm-generic/mman-common.h @@ -19,9 +19,7 @@ #define MAP_TYPE 0x0f /* Mask for type of mapping */ #define MAP_FIXED 0x10 /* Interpret addr exactly */ #define MAP_ANONYMOUS 0x20 /* don't use a file */ -#ifdef CONFIG_MMAP_ALLOW_UNINITIALIZED -# define MAP_UNINITIALIZED 0x4000000 /* For anonymous mmap, memory could be uninitialized */ -#else +#ifndef MAP_UNINITIALIZED # define MAP_UNINITIALIZED 0x0 /* Don't support this flag */ #endif -- 2.4.10