From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?KOI8-R?B?98HTyczJyiDuz9fJy8/X?= Subject: fanotify coredump issue Date: Mon, 27 Dec 2010 19:52:08 +0300 Message-ID: Mime-Version: 1.0 Content-Type: multipart/mixed; boundary=0016e64f458813ec3704986728c6 Cc: malware-list@dmesg.printk.net, "linux-fsdevel@vger.kernel.org" , vasily.novikov@kaspersky.com To: "eparis@redhat.com" Return-path: Received: from mail-qy0-f174.google.com ([209.85.216.174]:61859 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753693Ab0L0QwJ (ORCPT ); Mon, 27 Dec 2010 11:52:09 -0500 Received: by qyj19 with SMTP id 19so10431514qyj.19 for ; Mon, 27 Dec 2010 08:52:08 -0800 (PST) Sender: linux-fsdevel-owner@vger.kernel.org List-ID: --0016e64f458813ec3704986728c6 Content-Type: text/plain; charset=ISO-8859-1 Hi Eric, I tested fanotify in 2.6.37-rc7 and faced the following issue: when a fanotify server process (started with open_perm set) segfaults the kernel tries to open core dump file and here it is forced to wait a permission result because fanotify server receives notifications on file operations initiated by itself. Since fanotify server has crashed the permission will never be granted. So the whole system hangs. I don't see the point in receiving notifications on file operations initiated by fanotify server process so I created a patch that disables that and solves the issue at least in case of one fanotify server. Best regards, Vasily --0016e64f458813ec3704986728c6 Content-Type: text/x-patch; charset=US-ASCII; name="fanotify_core.patch" Content-Disposition: attachment; filename="fanotify_core.patch" Content-Transfer-Encoding: base64 X-Attachment-Id: f_gi7lnzfu0 L3Vzci9zcmMvbGludXgKLS0tIC4vZnMvbm90aWZ5L2Zhbm90aWZ5L2Zhbm90aWZ5LmMub3JpZwky MDEwLTEyLTI0IDEyOjUwOjMzLjY1MzAyOTAwMSAtMDUwMAorKysgLi9mcy9ub3RpZnkvZmFub3Rp ZnkvZmFub3RpZnkuYwkyMDEwLTEyLTI0IDEzOjI4OjE5LjU2MTAyOTAwNSAtMDUwMApAQCAtOTIs NiArOTIsOSBAQCBzdGF0aWMgaW50IGZhbm90aWZ5X2dldF9yZXNwb25zZV9mcm9tX2FjCiAKIAlw cl9kZWJ1ZygiJXM6IGdyb3VwPSVwIGV2ZW50PSVwXG4iLCBfX2Z1bmNfXywgZ3JvdXAsIGV2ZW50 KTsKIAorCWlmKGdyb3VwLT5mYW5vdGlmeV9kYXRhLnRnaWQgPT0gdGFza190Z2lkKGN1cnJlbnQp KQorCQlyZXR1cm4gMDsKKwogCXdhaXRfZXZlbnQoZ3JvdXAtPmZhbm90aWZ5X2RhdGEuYWNjZXNz X3dhaXRxLCBldmVudC0+cmVzcG9uc2UgfHwKIAkJCQlhdG9taWNfcmVhZCgmZ3JvdXAtPmZhbm90 aWZ5X2RhdGEuYnlwYXNzX3Blcm0pKTsKIApAQCAtMjE3LDYgKzIyMCw3IEBAIHN0YXRpYyB2b2lk IGZhbm90aWZ5X2ZyZWVfZ3JvdXBfcHJpdihzdHIKIAl1c2VyID0gZ3JvdXAtPmZhbm90aWZ5X2Rh dGEudXNlcjsKIAlhdG9taWNfZGVjKCZ1c2VyLT5mYW5vdGlmeV9saXN0ZW5lcnMpOwogCWZyZWVf dWlkKHVzZXIpOworCXB1dF9waWQoZ3JvdXAtPmZhbm90aWZ5X2RhdGEudGdpZCk7CiB9CiAKIGNv bnN0IHN0cnVjdCBmc25vdGlmeV9vcHMgZmFub3RpZnlfZnNub3RpZnlfb3BzID0gewotLS0gLi9m cy9ub3RpZnkvZmFub3RpZnkvZmFub3RpZnlfdXNlci5jLm9yaWcJMjAxMC0xMi0yNCAxMjoxMjow Ny41OTMwMjkwMDEgLTA1MDAKKysrIC4vZnMvbm90aWZ5L2Zhbm90aWZ5L2Zhbm90aWZ5X3VzZXIu YwkyMDEwLTEyLTI3IDA5OjI2OjE1LjI1OTk1NjAwMSAtMDUwMApAQCAtMzM3LDYgKzMzNywxMCBA QCBzdGF0aWMgc3NpemVfdCBmYW5vdGlmeV9yZWFkKHN0cnVjdCBmaWxlCiAJCQlyZXQgPSBQVFJf RVJSKGtldmVudCk7CiAJCQlpZiAoSVNfRVJSKGtldmVudCkpCiAJCQkJYnJlYWs7CisJCQlpZihr ZXZlbnQtPnRnaWQgPT0gZ3JvdXAtPmZhbm90aWZ5X2RhdGEudGdpZCkgeworCQkJCWZzbm90aWZ5 X3B1dF9ldmVudChrZXZlbnQpOworCQkJCWNvbnRpbnVlOworCQkJfQogCQkJcmV0ID0gY29weV9l dmVudF90b191c2VyKGdyb3VwLCBrZXZlbnQsIGJ1Zik7CiAJCQlmc25vdGlmeV9wdXRfZXZlbnQo a2V2ZW50KTsKIAkJCWlmIChyZXQgPCAwKQpAQCAtNzE4LDYgKzcyMiw3IEBAIFNZU0NBTExfREVG SU5FMihmYW5vdGlmeV9pbml0LCB1bnNpZ25lZAogCUlOSVRfTElTVF9IRUFEKCZncm91cC0+ZmFu b3RpZnlfZGF0YS5hY2Nlc3NfbGlzdCk7CiAJYXRvbWljX3NldCgmZ3JvdXAtPmZhbm90aWZ5X2Rh dGEuYnlwYXNzX3Blcm0sIDApOwogI2VuZGlmCisJZ3JvdXAtPmZhbm90aWZ5X2RhdGEudGdpZCA9 IGdldF9waWQodGFza190Z2lkKGN1cnJlbnQpKTsKIAlzd2l0Y2ggKGZsYWdzICYgRkFOX0FMTF9D TEFTU19CSVRTKSB7CiAJY2FzZSBGQU5fQ0xBU1NfTk9USUY6CiAJCWdyb3VwLT5wcmlvcml0eSA9 IEZTX1BSSU9fMDsKLS0tIC4vaW5jbHVkZS9saW51eC9mc25vdGlmeV9iYWNrZW5kLmgub3JpZwky MDEwLTEyLTI0IDEyOjA4OjU5Ljk2NTAyOTAwMiAtMDUwMAorKysgLi9pbmNsdWRlL2xpbnV4L2Zz bm90aWZ5X2JhY2tlbmQuaAkyMDEwLTEyLTI3IDEzOjA1OjM0LjczODYzNjAwMSAtMDUwMApAQCAt MTcxLDYgKzE3MSw3IEBAIHN0cnVjdCBmc25vdGlmeV9ncm91cCB7CiAJCQlpbnQgZl9mbGFnczsK IAkJCXVuc2lnbmVkIGludCBtYXhfbWFya3M7CiAJCQlzdHJ1Y3QgdXNlcl9zdHJ1Y3QgKnVzZXI7 CisJCQlzdHJ1Y3QgcGlkICp0Z2lkOwogCQl9IGZhbm90aWZ5X2RhdGE7CiAjZW5kaWYgLyogQ09O RklHX0ZBTk9USUZZICovCiAJfTsK --0016e64f458813ec3704986728c6--