From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932507Ab3LTNlI (ORCPT ); Fri, 20 Dec 2013 08:41:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:30024 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932292Ab3LTNlE (ORCPT ); Fri, 20 Dec 2013 08:41:04 -0500 Date: Fri, 20 Dec 2013 08:40:49 -0500 From: "Frank Ch. Eigler" To: Ingo Molnar Cc: Masami Hiramatsu , linux-arch@vger.kernel.org, Ananth N Mavinakayanahalli , Sandeepa Prabhu , x86@kernel.org, lkml , "Steven Rostedt (Red Hat)" , systemtap@sourceware.org, "David S. Miller" Subject: Re: [PATCH -tip v6 00/22] kprobes: introduce NOKPROBE_SYMBOL(), cleanup and fixes crash bugs Message-ID: <20131220134049.GC30373@redhat.com> References: <20131219090353.14309.15496.stgit@kbuild-fedora.novalocal> <52B3C5E6.2040802@hitachi.com> <20131220082056.GA15934@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131220082056.GA15934@gmail.com> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi - mingo wrote: > [...] > For example a hash table (hashed by probe address) could be used in > addition to the list, to speed up basic operations. In the past, when this sort of behavior popped up, it was due to machine-wide halt/sync operations being done too eagerly. At one point, the kprobes-unregistration interface grew a mass-unregister API to batch them (and save the machine sync's between operations). Maybe with the new checks/logic, a similar batching API may be needed for the registration side. I'll try to get more perf data once the VM comes back up; after a couple of hours of the test getting started, it died (for possibly unrelated reasons). [ 133.073670] stap_bc6054113aa63134d411836da0afefc3_123_1261: module verification failed: signature and/or required key missing - tainting kernel [ 404.357210] stap_4c53547addc9f25dd87ac4afa0407ed6_36_1948: systemtap: 2.5/0.157, base: ffffffffa0201000, memory: 15882data/24text/1ctx/2058net/4625alloc kb, probes: 34692 [ 1655.745075] hrtimer: interrupt took 1225946 ns [ 3969.175039] [sched_delayed] sched: RT throttling activated [10812.665534] kernel tried to execute NX-protected page - exploit attempt? (uid: 0) [10812.665534] BUG: unable to handle kernel paging request at ffff88007902f038 [10812.665534] IP: [] 0xffff88007902f038 [10812.665534] PGD 2d90067 PUD 2d93067 PMD 80000000790001e3 [10812.665534] Oops: 0010 [#1] SMP [10812.665534] Modules linked in: stap_4c53547addc9f25dd87ac4afa0407ed6_36_1948(OF) rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd sunrpc fscache ppdev microcode parport_pc parport i2c_piix4 virtio_balloon i2c_core serio_raw virtio_net virtio_pci ata_generic virtio_ring pata_acpi virtio [last unloaded: stap_89fcd2b984e11a30dd08d141e6b47e13_123_1681] [10812.665534] CPU: 1 PID: -30720 Comm: x Tainted: GF O 3.13.0-rc4-01828-g8b349c29efae #1 [10812.665534] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [10812.665534] BUG: unable to handle kernel paging request at 000000008f896e09 [10812.665534] IP: [] do_raw_spin_trylock+0x5/0x60 [10812.665534] PGD 0 [10812.665534] Thread overran stack, or stack corrupted [10812.665534] Oops: 0000 [#2] SMP [10812.665534] Modules linked in: stap_4c53547addc9f25dd87ac4afa0407ed6_36_1948(OF) rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd sunrpc fscache ppdev microcode parport_pc parport i2c_piix4 virtio_balloon i2c_core serio_raw virtio_net virtio_pci ata_generic virtio_ring pata_acpi virtio [last unloaded: stap_89fcd2b984e11a30dd08d141e6b47e13_123_1681] [10812.665534] CPU: 1 PID: -30720 Comm: x Tainted: GF O 3.13.0-rc4-01828-g8b349c29efae #1 [10812.665534] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [10812.665534] BUG: unable to handle kernel paging request at 000000008f896e09 [10812.665534] IP: [] do_raw_spin_trylock+0x5/0x60 [10812.665534] PGD 0 [10812.665534] Thread overran stack, or stack corrupted [10812.665534] Oops: 0000 [#3] SMP [10812.665534] Modules linked in: stap_4c53547addc9f25dd87ac4afa0407ed6_36_1948(OF) rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd sunrpc fscache ppdev microcode parport_pc parport i2c_piix4 virtio_balloon i2c_core serio_raw virtio_net virtio_pci ata_generic virtio_ring pata_acpi virtio [last unloaded: stap_89fcd2b984e11a30dd08d141e6b47e13_123_1681] [10812.665534] CPU: 1 PID: -30720 Comm: x Tainted: GF O 3.13.0-rc4-01828-g8b349c29efae #1 [10812.665534] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [10812.665534] BUG: unable to handle kernel paging request at 000000008f896e09 [10812.665534] IP: [] do_raw_spin_trylock+0x5/0x60 [10812.665534] PGD 0 [10812.665534] Thread overran stack, or stack corrupted [10812.665534] Oops: 0000 [#4] SMP [10812.665534] Modules linked in: stap_4c53547addc9f25dd87ac4afa0407ed6_36_1948(OF) rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd sunrpc fscache ppdev microcode parport_pc parport i2c_piix4 virtio_balloon i2c_core serio_raw virtio_net virtio_pci ata_generic virtio_ring pata_acpi virtio [last unloaded: stap_89fcd2b984e11a30dd08d141e6b47e13_123_1681] [10812.665534] CPU: 1 PID: -30720 Comm: x Tainted: GF O 3.13.0-rc4-01828-g8b349c29efae #1 [10812.665534] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [10812.665534] BUG: unable to handle kernel paging request at 000000008f896e09 [10812.665534] IP: [] do_raw_spin_trylock+0x5/0x60 [10812.665534] PGD 0 [10812.665534] Thread overran stack, or stack corrupted [10812.665042] ------------[ cut here ]------------ [10812.665042] WARNING: CPU: 0 PID: 1948 at arch/x86/kernel/kprobes/core.c:600 reenter_kprobe+0x3c/0xd0() [10812.665042] Modules linked in: stap_4c53547addc9f25dd87ac4afa0407ed6_36_1948(OF) rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd sunrpc fscache ppdev microcode parport_pc parport i2c_piix4 virtio_balloon i2c_core serio_raw virtio_net virtio_pci ata_generic virtio_ring pata_acpi virtio [last unloaded: stap_89fcd2b984e11a30dd08d141e6b47e13_123_1681] - FChE