lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 27 Nov 2015 05:27:39 +0000 From: Naoya Horiguchi <n-horiguchi@...jp.nec.com> To: Piotr Kwapulinski <kwapulinski.piotr@...il.com> CC: "mhocko@...e.com" <mhocko@...e.com>, "akpm@...ux-foundation.org" <akpm@...ux-foundation.org>, "oleg@...hat.com" <oleg@...hat.com>, "cmetcalf@...hip.com" <cmetcalf@...hip.com>, "mszeredi@...e.cz" <mszeredi@...e.cz>, "viro@...iv.linux.org.uk" <viro@...iv.linux.org.uk>, "dave@...olabs.net" <dave@...olabs.net>, "kirill.shutemov@...ux.intel.com" <kirill.shutemov@...ux.intel.com>, "aarcange@...hat.com" <aarcange@...hat.com>, "iamjoonsoo.kim@....com" <iamjoonsoo.kim@....com>, "jack@...e.cz" <jack@...e.cz>, "xiexiuqi@...wei.com" <xiexiuqi@...wei.com>, "vbabka@...e.cz" <vbabka@...e.cz>, "Vineet.Gupta1@...opsys.com" <Vineet.Gupta1@...opsys.com>, "riel@...hat.com" <riel@...hat.com>, "gang.chen.5i5j@...il.com" <gang.chen.5i5j@...il.com>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, "linux-mm@...ck.org" <linux-mm@...ck.org> Subject: Re: [PATCH v3] mm/mmap.c: remove incorrect MAP_FIXED flag comparison from mmap_region On Mon, Nov 23, 2015 at 06:36:42PM +0100, Piotr Kwapulinski wrote: > The following flag comparison in mmap_region makes no sense: > > if (!(vm_flags & MAP_FIXED)) > return -ENOMEM; > > The condition is always false and thus the above "return -ENOMEM" is never > executed. The vm_flags must not be compared with MAP_FIXED flag. > The vm_flags may only be compared with VM_* flags. > MAP_FIXED has the same value as VM_MAYREAD. > Hitting the rlimit is a slow path and find_vma_intersection should realize > that there is no overlapping VMA for !MAP_FIXED case pretty quickly. > > Remove the code that makes no sense. > > Signed-off-by: Piotr Kwapulinski <kwapulinski.piotr@...il.com> Looks good to me. Thank you. Reviewed-by: Naoya Horiguchi <n-horiguchi@...jp.nec.com> > --- > mm/mmap.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/mm/mmap.c b/mm/mmap.c > index 2ce04a6..42a8259 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -1551,9 +1551,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr, > * MAP_FIXED may remove pages of mappings that intersects with > * requested mapping. Account for the pages it would unmap. > */ > - if (!(vm_flags & MAP_FIXED)) > - return -ENOMEM; > - > nr_pages = count_vma_pages_range(mm, addr, addr + len); > > if (!may_expand_vm(mm, (len >> PAGE_SHIFT) - nr_pages)) > -- > 2.6.2 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists