From: =?UTF-8?B?VG9yYWxmIEbDtnJzdGVy?= Subject: Re: [uml-devel] fuzz tested 32 bit user mode linux image hangs in radix_tree_next_chunk() Date: Sat, 09 Nov 2013 20:07:22 +0100 Message-ID: <527E87EA.8080700@gmx.de> References: <526696BF.6050909@gmx.de> <5266A698.10400@gmx.de> <5266B60A.1000005@nod.at> <52715AD1.7000703@gmx.de> <527AB23D.2060305@gmx.de> <527AB51B.1020005@nod.at> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: Konstantin Khlebnikov , Linux Kernel , linux-fsdevel , "linux-mm@kvack.org" , UML devel To: Richard Weinberger Return-path: In-Reply-To: <527AB51B.1020005@nod.at> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org On 11/06/2013 10:31 PM, Richard Weinberger wrote: > Am 06.11.2013 22:18, schrieb Toralf F=C3=B6rster: >> On 11/06/2013 05:06 PM, Konstantin Khlebnikov wrote: >>> In this case it must stop after scanning whole tree in line: >>> /* Overflow after ~0UL */ >>> if (!index) >>> return NULL; >>> >> >> A fresh current example with latest git tree shows that lines 769 and = 770 do alternate : >=20 > Can you please ask gdb for the value of offset? >=20 > Thanks, > //richard >=20 Still trying to get those values. One attempt to do that was to replace -= O2 with -O0 in the Makefile, but that resulted into this error : LD kernel/built-in.o CC mm/memory.o In function =E2=80=98zap_pmd_range=E2=80=99, inlined from =E2=80=98zap_pud_range=E2=80=99 at mm/memory.c:1265:8, inlined from =E2=80=98unmap_page_range=E2=80=99 at mm/memory.c:1290:8= : mm/memory.c:1220:23: error: call to =E2=80=98__compiletime_assert_1220=E2= =80=99 declared with attribute error: BUILD_BUG failed mm/memory.c: In function =E2=80=98follow_page_mask=E2=80=99: mm/memory.c:1530:18: error: call to =E2=80=98__compiletime_assert_1530=E2= =80=99 declared with attribute error: BUILD_BUG failed make[1]: *** [mm/memory.o] Error 1 make: *** [mm] Error 2 With -O1 it compiled at least. >> >> tfoerste@n22 ~/devel/linux $ sudo gdb /usr/local/bin/linux-v3.12-48-gb= e408cd 16619 -n -batch -ex bt >> 0x08296a8c in radix_tree_next_chunk (root=3D0x25, iter=3D0x462e7c64, f= lags=3D12) at lib/radix-tree.c:770 >> 770 if (node->slots[offset= ]) >> #0 0x08296a8c in radix_tree_next_chunk (root=3D0x25, iter=3D0x462e7c6= 4, flags=3D12) at lib/radix-tree.c:770 >> #1 0x080cc1fe in find_get_pages (mapping=3D0x462ad470, start=3D0, nr_= pages=3D14, pages=3D0xc) at mm/filemap.c:844 >> #2 0x080d5d6a in pagevec_lookup (pvec=3D0x462e7cc8, mapping=3D0x25, s= tart=3D37, nr_pages=3D37) at mm/swap.c:914 >> #3 0x080d615a in truncate_inode_pages_range (mapping=3D0x462ad470, ls= tart=3D0, lend=3D-1) at mm/truncate.c:241 >> #4 0x080d64ff in truncate_inode_pages (mapping=3D0x25, lstart=3D51539= 607589) at mm/truncate.c:358 >> >> >> >> >> tfoerste@n22 ~/devel/linux $ sudo gdb /usr/local/bin/linux-v3.12-48-gb= e408cd 16619 -n -batch -ex bt >> radix_tree_next_chunk (root=3D0x28, iter=3D0x462e7c64, flags=3D18) at = lib/radix-tree.c:769 >> 769 while (++offset < RADIX_TREE_M= AP_SIZE) { >> #0 radix_tree_next_chunk (root=3D0x28, iter=3D0x462e7c64, flags=3D18)= at lib/radix-tree.c:769 >> #1 0x080cc1fe in find_get_pages (mapping=3D0x462ad470, start=3D0, nr_= pages=3D14, pages=3D0x12) at mm/filemap.c:844 >> #2 0x080d5d6a in pagevec_lookup (pvec=3D0x462e7cc8, mapping=3D0x28, s= tart=3D40, nr_pages=3D40) at mm/swap.c:914 >> #3 0x080d615a in truncate_inode_pages_range (mapping=3D0x462ad470, ls= tart=3D0, lend=3D-1) at mm/truncate.c:241 >> #4 0x080d64ff in truncate_inode_pages (mapping=3D0x28, lstart=3D77309= 411368) at mm/truncate.c:358 >> #5 0x0825e388 in hostfs_evict_inode (inode=3D0x462ad3b8) at fs/hostfs= /hostfs_kern.c:242 >> #6 0x0811a8df in evict (inode=3D0x462ad3b8) at fs/inode.c:549 >> >> >=20 >=20 --=20 MfG/Sincerely Toralf F=C3=B6rster pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org