user/sven/linux.git/kernel/trace, branch v5.8.8

blktrace: ensure our debugfs dir exists

2020-09-03T09:29:15Z

[ Upstream commit b431ef837e3374da0db8ff6683170359aaa0859c ] We make an assumption that a debugfs directory exists, but since this can fail ensure it exists before allowing blktrace setup to complete. Otherwise we end up stuffing blktrace files on the debugfs root directory. In the worst case scenario this *in theory* can create an eventual panic *iff* in the future a similarly named file is created prior on the debugfs root directory. This theoretical crash can happen due to a recursive removal followed by a specific dentry removal. This doesn't fix any known crash, however I have seen the files go into the main debugfs root directory in cases where the debugfs directory was not created due to other internal bugs with blktrace now fixed. blktrace is also completely useless without this directory, so this ensures to userspace we only setup blktrace if the kernel can stuff files where they are supposed to go into. debugfs directory creations typically aren't checked for, and we have maintainers doing sweep removals of these checks, but since we need this check to ensure proper userspace blktrace functionality we make sure to annotate the justification for the check. Signed-off-by: Luis Chamberlain Reviewed-by: Christoph Hellwig Reviewed-by: Bart Van Assche Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

tracing: Use trace_sched_process_free() instead of exit() for pid tracing

2020-08-21T11:15:00Z

commit afcab636657421f7ebfa0783a91f90256bba0091 upstream. On exit, if a process is preempted after the trace_sched_process_exit() tracepoint but before the process is done exiting, then when it gets scheduled in, the function tracers will not filter it properly against the function tracing pid filters. That is because the function tracing pid filters hooks to the sched_process_exit() tracepoint to remove the exiting task's pid from the filter list. Because the filtering happens at the sched_switch tracepoint, when the exiting task schedules back in to finish up the exit, it will no longer be in the function pid filtering tables. This was noticeable in the notrace self tests on a preemptable kernel, as the tests would fail as it exits and preempted after being taken off the notrace filter table and on scheduling back in it would not be in the notrace list, and then the ending of the exit function would trace. The test detected this and would fail. Cc: stable@vger.kernel.org Cc: Namhyung Kim Fixes: 1e10486ffee0a ("ftrace: Add 'function-fork' trace option") Fixes: c37775d57830a ("tracing: Add infrastructure to allow set_event_pid to follow children" Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

tracing/hwlat: Honor the tracing_cpumask

2020-08-21T11:15:00Z

commit 96b4833b6827a62c295b149213c68b559514c929 upstream. In calculation of the cpu mask for the hwlat kernel thread, the wrong cpu mask is used instead of the tracing_cpumask, this causes the tracing/tracing_cpumask useless for hwlat tracer. Fixes it. Link: https://lkml.kernel.org/r/20200730082318.42584-2-haokexin@gmail.com Cc: Ingo Molnar Cc: stable@vger.kernel.org Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs") Signed-off-by: Kevin Hao Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

ftrace: Setup correct FTRACE_FL_REGS flags for module

2020-08-21T11:14:59Z

commit 8a224ffb3f52b0027f6b7279854c71a31c48fc97 upstream. When module loaded and enabled, we will use __ftrace_replace_code for module if any ftrace_ops referenced it found. But we will get wrong ftrace_addr for module rec in ftrace_get_addr_new, because rec->flags has not been setup correctly. It can cause the callback function of a ftrace_ops has FTRACE_OPS_FL_SAVE_REGS to be called with pt_regs set to NULL. So setup correct FTRACE_FL_REGS flags for rec when we call referenced_filters to find ftrace_ops references it. Link: https://lkml.kernel.org/r/20200728180554.65203-1-zhouchengming@bytedance.com Cc: stable@vger.kernel.org Fixes: 8c4f3c3fa9681 ("ftrace: Check module functions being traced on reload") Signed-off-by: Chengming Zhou Signed-off-by: Muchun Song Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

ftrace: Fix ftrace_trace_task return value

2020-08-19T06:26:53Z

[ Upstream commit c58b6b0372de0d4cd0536d6585addd1b36b151ae ] I was attempting to use pid filtering with function_graph, but it wasn't allowing anything to make it through. Turns out ftrace_trace_task returns false if ftrace_ignore_pid is not-empty, which isn't correct anymore. We're now setting it to FTRACE_PID_IGNORE if we need to ignore that pid, otherwise it's set to the pid (which is weird considering the name) or to FTRACE_PID_TRACE. Fix the check to check for != FTRACE_PID_IGNORE. With this we can now use function_graph with pid filtering. Link: https://lkml.kernel.org/r/20200725005048.1790-1-josef@toxicpanda.com Fixes: 717e3f5ebc82 ("ftrace: Make function trace pid filtering a bit more exact") Signed-off-by: Josef Bacik Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin

tracing: Move pipe reference to trace array instead of current_tracer

2020-08-19T06:26:29Z

[ Upstream commit 7ef282e05132d56b6f6b71e3873f317664bea78b ] If a process has the trace_pipe open on a trace_array, the current tracer for that trace array should not be changed. This was original enforced by a global lock, but when instances were introduced, it was moved to the current_trace. But this structure is shared by all instances, and a trace_pipe is for a single instance. There's no reason that a process that has trace_pipe open on one instance should prevent another instance from changing its current tracer. Move the reference counter to the trace_array instead. This is marked as "Fixes" but is more of a clean up than a true fix. Backport if you want, but its not critical. Fixes: cf6ab6d9143b1 ("tracing: Add ref count to tracer for when they are being read by pipe") Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin

blktrace: fix debugfs use after free

2020-08-19T06:26:05Z

[ Upstream commit bad8e64fb19d3a0de5e564d9a7271c31bd684369 ] On commit 6ac93117ab00 ("blktrace: use existing disk debugfs directory") merged on v4.12 Omar fixed the original blktrace code for request-based drivers (multiqueue). This however left in place a possible crash, if you happen to abuse blktrace while racing to remove / add a device. We used to use asynchronous removal of the request_queue, and with that the issue was easier to reproduce. Now that we have reverted to synchronous removal of the request_queue, the issue is still possible to reproduce, its however just a bit more difficult. We essentially run two instances of break-blktrace which add/remove a loop device, and setup a blktrace and just never tear the blktrace down. We do this twice in parallel. This is easily reproduced with the script run_0004.sh from break-blktrace [0]. We can end up with two types of panics each reflecting where we race, one a failed blktrace setup: [ 252.426751] debugfs: Directory 'loop0' with parent 'block' already present! [ 252.432265] BUG: kernel NULL pointer dereference, address: 00000000000000a0 [ 252.436592] #PF: supervisor write access in kernel mode [ 252.439822] #PF: error_code(0x0002) - not-present page [ 252.442967] PGD 0 P4D 0 [ 252.444656] Oops: 0002 [#1] SMP NOPTI [ 252.446972] CPU: 10 PID: 1153 Comm: break-blktrace Tainted: G E 5.7.0-rc2-next-20200420+ #164 [ 252.452673] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014 [ 252.456343] RIP: 0010:down_write+0x15/0x40 [ 252.458146] Code: eb ca e8 ae 22 8d ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc 0f 1f 44 00 00 55 48 89 fd e8 52 db ff ff 31 c0 ba 01 00 00 00 48 0f b1 55 00 75 0f 48 8b 04 25 c0 8b 01 00 48 89 45 08 5d [ 252.463638] RSP: 0018:ffffa626415abcc8 EFLAGS: 00010246 [ 252.464950] RAX: 0000000000000000 RBX: ffff958c25f0f5c0 RCX: ffffff8100000000 [ 252.466727] RDX: 0000000000000001 RSI: ffffff8100000000 RDI: 00000000000000a0 [ 252.468482] RBP: 00000000000000a0 R08: 0000000000000000 R09: 0000000000000001 [ 252.470014] R10: 0000000000000000 R11: ffff958d1f9227ff R12: 0000000000000000 [ 252.471473] R13: ffff958c25ea5380 R14: ffffffff8cce15f1 R15: 00000000000000a0 [ 252.473346] FS: 00007f2e69dee540(0000) GS:ffff958c2fc80000(0000) knlGS:0000000000000000 [ 252.475225] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 252.476267] CR2: 00000000000000a0 CR3: 0000000427d10004 CR4: 0000000000360ee0 [ 252.477526] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 252.478776] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 252.479866] Call Trace: [ 252.480322] simple_recursive_removal+0x4e/0x2e0 [ 252.481078] ? debugfs_remove+0x60/0x60 [ 252.481725] ? relay_destroy_buf+0x77/0xb0 [ 252.482662] debugfs_remove+0x40/0x60 [ 252.483518] blk_remove_buf_file_callback+0x5/0x10 [ 252.484328] relay_close_buf+0x2e/0x60 [ 252.484930] relay_open+0x1ce/0x2c0 [ 252.485520] do_blk_trace_setup+0x14f/0x2b0 [ 252.486187] __blk_trace_setup+0x54/0xb0 [ 252.486803] blk_trace_ioctl+0x90/0x140 [ 252.487423] ? do_sys_openat2+0x1ab/0x2d0 [ 252.488053] blkdev_ioctl+0x4d/0x260 [ 252.488636] block_ioctl+0x39/0x40 [ 252.489139] ksys_ioctl+0x87/0xc0 [ 252.489675] __x64_sys_ioctl+0x16/0x20 [ 252.490380] do_syscall_64+0x52/0x180 [ 252.491032] entry_SYSCALL_64_after_hwframe+0x44/0xa9 And the other on the device removal: [ 128.528940] debugfs: Directory 'loop0' with parent 'block' already present! [ 128.615325] BUG: kernel NULL pointer dereference, address: 00000000000000a0 [ 128.619537] #PF: supervisor write access in kernel mode [ 128.622700] #PF: error_code(0x0002) - not-present page [ 128.625842] PGD 0 P4D 0 [ 128.627585] Oops: 0002 [#1] SMP NOPTI [ 128.629871] CPU: 12 PID: 544 Comm: break-blktrace Tainted: G E 5.7.0-rc2-next-20200420+ #164 [ 128.635595] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014 [ 128.640471] RIP: 0010:down_write+0x15/0x40 [ 128.643041] Code: eb ca e8 ae 22 8d ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc 0f 1f 44 00 00 55 48 89 fd e8 52 db ff ff 31 c0 ba 01 00 00 00 48 0f b1 55 00 75 0f 65 48 8b 04 25 c0 8b 01 00 48 89 45 08 5d [ 128.650180] RSP: 0018:ffffa9c3c05ebd78 EFLAGS: 00010246 [ 128.651820] RAX: 0000000000000000 RBX: ffff8ae9a6370240 RCX: ffffff8100000000 [ 128.653942] RDX: 0000000000000001 RSI: ffffff8100000000 RDI: 00000000000000a0 [ 128.655720] RBP: 00000000000000a0 R08: 0000000000000002 R09: ffff8ae9afd2d3d0 [ 128.657400] R10: 0000000000000056 R11: 0000000000000000 R12: 0000000000000000 [ 128.659099] R13: 0000000000000000 R14: 0000000000000003 R15: 00000000000000a0 [ 128.660500] FS: 00007febfd995540(0000) GS:ffff8ae9afd00000(0000) knlGS:0000000000000000 [ 128.662204] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 128.663426] CR2: 00000000000000a0 CR3: 0000000420042003 CR4: 0000000000360ee0 [ 128.664776] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 128.666022] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 128.667282] Call Trace: [ 128.667801] simple_recursive_removal+0x4e/0x2e0 [ 128.668663] ? debugfs_remove+0x60/0x60 [ 128.669368] debugfs_remove+0x40/0x60 [ 128.669985] blk_trace_free+0xd/0x50 [ 128.670593] __blk_trace_remove+0x27/0x40 [ 128.671274] blk_trace_shutdown+0x30/0x40 [ 128.671935] blk_release_queue+0x95/0xf0 [ 128.672589] kobject_put+0xa5/0x1b0 [ 128.673188] disk_release+0xa2/0xc0 [ 128.673786] device_release+0x28/0x80 [ 128.674376] kobject_put+0xa5/0x1b0 [ 128.674915] loop_remove+0x39/0x50 [loop] [ 128.675511] loop_control_ioctl+0x113/0x130 [loop] [ 128.676199] ksys_ioctl+0x87/0xc0 [ 128.676708] __x64_sys_ioctl+0x16/0x20 [ 128.677274] do_syscall_64+0x52/0x180 [ 128.677823] entry_SYSCALL_64_after_hwframe+0x44/0xa9 The common theme here is: debugfs: Directory 'loop0' with parent 'block' already present This crash happens because of how blktrace uses the debugfs directory where it places its files. Upon init we always create the same directory which would be needed by blktrace but we only do this for make_request drivers (multiqueue) block drivers. When you race a removal of these devices with a blktrace setup you end up in a situation where the make_request recursive debugfs removal will sweep away the blktrace files and then later blktrace will also try to remove individual dentries which are already NULL. The inverse is also possible and hence the two types of use after frees. We don't create the block debugfs directory on init for these types of block devices: * request-based block driver block devices * every possible partition * scsi-generic And so, this race should in theory only be possible with make_request drivers. We can fix the UAF by simply re-using the debugfs directory for make_request drivers (multiqueue) and only creating the ephemeral directory for the other type of block devices. The new clarifications on relying on the q->blk_trace_mutex *and* also checking for q->blk_trace *prior* to processing a blktrace ensures the debugfs directories are only created if no possible directory name clashes are possible. This goes tested with: o nvme partitions o ISCSI with tgt, and blktracing against scsi-generic with: o block o tape o cdrom o media changer o blktests This patch is part of the work which disputes the severity of CVE-2019-19770 which shows this issue is not a core debugfs issue, but a misuse of debugfs within blktace. Fixes: 6ac93117ab00 ("blktrace: use existing disk debugfs directory") Reported-by: syzbot+603294af2d01acfdd6da@syzkaller.appspotmail.com Signed-off-by: Luis Chamberlain Reviewed-by: Christoph Hellwig Cc: Bart Van Assche Cc: Omar Sandoval Cc: Hannes Reinecke Cc: Nicolai Stange Cc: Greg Kroah-Hartman Cc: Michal Hocko Cc: "Martin K. Petersen" Cc: "James E.J. Bottomley" Cc: yu kuai Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-06-26T01:27:40Z

Pull networking fixes from David Miller: 1) Don't insert ESP trailer twice in IPSEC code, from Huy Nguyen. 2) The default crypto algorithm selection in Kconfig for IPSEC is out of touch with modern reality, fix this up. From Eric Biggers. 3) bpftool is missing an entry for BPF_MAP_TYPE_RINGBUF, from Andrii Nakryiko. 4) Missing init of ->frame_sz in xdp_convert_zc_to_xdp_frame(), from Hangbin Liu. 5) Adjust packet alignment handling in ax88179_178a driver to match what the hardware actually does. From Jeremy Kerr. 6) register_netdevice can leak in the case one of the notifiers fail, from Yang Yingliang. 7) Use after free in ip_tunnel_lookup(), from Taehee Yoo. 8) VLAN checks in sja1105 DSA driver need adjustments, from Vladimir Oltean. 9) tg3 driver can sleep forever when we get enough EEH errors, fix from David Christensen. 10) Missing {READ,WRITE}_ONCE() annotations in various Intel ethernet drivers, from Ciara Loftus. 11) Fix scanning loop break condition in of_mdiobus_register(), from Florian Fainelli. 12) MTU limit is incorrect in ibmveth driver, from Thomas Falcon. 13) Endianness fix in mlxsw, from Ido Schimmel. 14) Use after free in smsc95xx usbnet driver, from Tuomas Tynkkynen. 15) Missing bridge mrp configuration validation, from Horatiu Vultur. 16) Fix circular netns references in wireguard, from Jason A. Donenfeld. 17) PTP initialization on recovery is not done properly in qed driver, from Alexander Lobakin. 18) Endian conversion of L4 ports in filters of cxgb4 driver is wrong, from Rahul Lakkireddy. 19) Don't clear bound device TX queue of socket prematurely otherwise we get problems with ktls hw offloading, from Tariq Toukan. 20) ipset can do atomics on unaligned memory, fix from Russell King. 21) Align ethernet addresses properly in bridging code, from Thomas Martitz. 22) Don't advertise ipv4 addresses on SCTP sockets having ipv6only set, from Marcelo Ricardo Leitner. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (149 commits) rds: transport module should be auto loaded when transport is set sch_cake: fix a few style nits sch_cake: don't call diffserv parsing code when it is not needed sch_cake: don't try to reallocate or unshare skb unconditionally ethtool: fix error handling in linkstate_prepare_data() wil6210: account for napi_gro_receive never returning GRO_DROP hns: do not cast return value of napi_gro_receive to null socionext: account for napi_gro_receive never returning GRO_DROP wireguard: receive: account for napi_gro_receive never returning GRO_DROP vxlan: fix last fdb index during dump of fdb with nhid sctp: Don't advertise IPv4 addresses if ipv6only is set on the socket tc-testing: avoid action cookies with odd length. bpf: tcp: bpf_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTT tcp_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTT net: dsa: sja1105: fix tc-gate schedule with single element net: dsa: sja1105: recalculate gating subschedule after deleting tc-gate rules net: dsa: sja1105: unconditionally free old gating config net: dsa: sja1105: move sja1105_compose_gating_subschedule at the top net: macb: free resources on failure path of at91ether_open() net: macb: call pm_runtime_put_sync on failure path ...

tracing/boottime: Fix kprobe multiple events

2020-06-24T01:51:50Z

Fix boottime kprobe events to report and abort after each failure when adding probes. As an example, when we try to set multiprobe kprobe events in bootconfig like this: ftrace.event.kprobes.vfsevents { probes = "vfs_read $arg1 $arg2,, !error! not reported;?", // leads to error "vfs_write $arg1 $arg2" } This will not work as expected. After commit da0f1f4167e3af69e ("tracing/boottime: Fix kprobe event API usage"), the function trace_boot_add_kprobe_event will not produce any error message when adding a probe fails at kprobe_event_gen_cmd_start. Furthermore, we continue to add probes when kprobe_event_gen_cmd_end fails (and kprobe_event_gen_cmd_start did not fail). In this case the function even returns successfully when the last call to kprobe_event_gen_cmd_end is successful. The behaviour of reporting and aborting after failures is not consistent. The function trace_boot_add_kprobe_event now reports each failure and stops adding probes immediately. Link: https://lkml.kernel.org/r/20200618163301.25854-1-sascha.ortmann@stud.uni-hannover.de Cc: stable@vger.kernel.org Cc: linux-kernel@i4.cs.fau.de Co-developed-by: Maximilian Werner Fixes: da0f1f4167e3 ("tracing/boottime: Fix kprobe event API usage") Acked-by: Masami Hiramatsu Signed-off-by: Maximilian Werner Signed-off-by: Sascha Ortmann Signed-off-by: Steven Rostedt (VMware)

tracing: Fix event trigger to accept redundant spaces

2020-06-24T01:51:40Z

Fix the event trigger to accept redundant spaces in the trigger input. For example, these return -EINVAL echo " traceon" > events/ftrace/print/trigger echo "traceon if common_pid == 0" > events/ftrace/print/trigger echo "disable_event:kmem:kmalloc " > events/ftrace/print/trigger But these are hard to find what is wrong. To fix this issue, use skip_spaces() to remove spaces in front of actual tokens, and set NULL if there is no token. Link: http://lkml.kernel.org/r/159262476352.185015.5261566783045364186.stgit@devnote2 Cc: Tom Zanussi Cc: stable@vger.kernel.org Fixes: 85f2b08268c0 ("tracing: Add basic event trigger framework") Reviewed-by: Tom Zanussi Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)