| 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
| ||
|
Message-ID: <CAOJe8K3zN+fFWumKaGx3Tmv5JRZu10_FZ6R3Tjjc+nc-KVB0hg@mail.gmail.com> Date: Fri, 13 Jun 2014 11:12:08 +0400 From: Denis Kirjanov <kda@...ux-powerpc.org> To: Catalin Marinas <catalin.marinas@....com> Cc: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, "linux-mm@...ck.org" <linux-mm@...ck.org>, Naoya Horiguchi <n-horiguchi@...jp.nec.com> Subject: Re: kmemleak: Unable to handle kernel paging request On 6/12/14, Catalin Marinas <catalin.marinas@....com> wrote: > On Thu, Jun 12, 2014 at 01:00:57PM +0100, Denis Kirjanov wrote: >> On 6/12/14, Denis Kirjanov <kda@...ux-powerpc.org> wrote: >> > On 6/12/14, Catalin Marinas <catalin.marinas@....com> wrote: >> >> On 11 Jun 2014, at 21:04, Denis Kirjanov <kda@...ux-powerpc.org> >> >> wrote: >> >>> On 6/11/14, Catalin Marinas <catalin.marinas@....com> wrote: >> >>>> On Wed, Jun 11, 2014 at 04:13:07PM +0400, Denis Kirjanov wrote: >> >>>>> I got a trace while running 3.15.0-08556-gdfb9454: >> >>>>> >> >>>>> [ 104.534026] Unable to handle kernel paging request for data at >> >>>>> address 0xc00000007f000000 >> >>>> >> >>>> Were there any kmemleak messages prior to this, like "kmemleak >> >>>> disabled"? There could be a race when kmemleak is disabled because >> >>>> of >> >>>> some fatal (for kmemleak) error while the scanning is taking place >> >>>> (which needs some more thinking to fix properly). >> >>> >> >>> No. I checked for the similar problem and didn't find anything >> >>> relevant. >> >>> I'll try to bisect it. >> >> >> >> Does this happen soon after boot? I guess it’s the first scan >> >> (scheduled at around 1min after boot). Something seems to be telling >> >> kmemleak that there is a valid memory block at 0xc00000007f000000. >> > >> > Yeah, it happens after a while with a booted system so that's the >> > first kmemleak scan. >> > >> >> I've bisected to this commit: d4c54919ed86302094c0ca7d48a8cbd4ee753e92 >> "mm: add !pte_present() check on existing hugetlb_entry callbacks". >> Reverting the commit fixes the issue > > I can't figure how this causes the problem but I have more questions. Is > 0xc00000007f000000 address always the same in all crashes? If yes, you > could comment out start_scan_thread() in kmemleak_late_init() to avoid > the scanning thread starting. Once booted, you can run: > > echo dump=0xc00000007f000000 > /sys/kernel/debug/kmemleak > > and check the dmesg for what kmemleak knows about that address, when it > was allocated and whether it should be mapped or not. The address is always the same. [ 179.466239] kmemleak: Object 0xc00000007f000000 (size 16777216): [ 179.466503] kmemleak: comm "swapper/0", pid 0, jiffies 4294892300 [ 179.466508] kmemleak: min_count = 0 [ 179.466512] kmemleak: count = 0 [ 179.466517] kmemleak: flags = 0x1 [ 179.466522] kmemleak: checksum = 0 [ 179.466526] kmemleak: backtrace: [ 179.466531] [<c000000000afc3dc>] .memblock_alloc_range_nid+0x68/0x88 [ 179.466544] [<c000000000afc444>] .memblock_alloc_base+0x20/0x58 [ 179.466553] [<c000000000ae96cc>] .alloc_dart_table+0x5c/0xb0 [ 179.466561] [<c000000000aea300>] .pmac_probe+0x38/0xa0 [ 179.466569] [<000000000002166c>] 0x2166c [ 179.466579] [<0000000000ae0e68>] 0xae0e68 [ 179.466587] [<0000000000009bc4>] 0x9bc4 > -- > Catalin > -- 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