Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933547Ab3FRURV (ORCPT ); Tue, 18 Jun 2013 16:17:21 -0400 Received: from longford.logfs.org ([213.229.74.203]:59568 "EHLO longford.logfs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933453Ab3FRURT (ORCPT ); Tue, 18 Jun 2013 16:17:19 -0400 From: Joern Engel To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Andrew Morton , Joern Engel Subject: [PATCH 2/2] mmap: allow MAP_HUGETLB for hugetlbfs files Date: Tue, 18 Jun 2013 14:47:05 -0400 Message-Id: <1371581225-27535-3-git-send-email-joern@logfs.org> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1371581225-27535-1-git-send-email-joern@logfs.org> References: <1371581225-27535-1-git-send-email-joern@logfs.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1924 Lines: 64 It is counterintuitive at best that mmap'ing a hugetlbfs file with MAP_HUGETLB fails, while mmap'ing it without will a) succeed and b) return huge pages. Signed-off-by: Joern Engel --- mm/mmap.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 2a594246..76eb6df 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include @@ -1313,6 +1314,11 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr, return addr; } +static inline int is_hugetlb_file(struct file *file) +{ + return file->f_inode->i_sb->s_magic == HUGETLBFS_MAGIC; +} + SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, unsigned long, prot, unsigned long, flags, unsigned long, fd, unsigned long, pgoff) @@ -1322,11 +1328,12 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, if (!(flags & MAP_ANONYMOUS)) { audit_mmap_fd(fd, flags); - if (unlikely(flags & MAP_HUGETLB)) - return -EINVAL; file = fget(fd); if (!file) goto out; + retval = -EINVAL; + if (unlikely(flags & MAP_HUGETLB && !is_hugetlb_file(file))) + goto out_fput; } else if (flags & MAP_HUGETLB) { struct user_struct *user = NULL; /* @@ -1346,6 +1353,7 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); +out_fput: if (file) fput(file); out: -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/