user/sven/linux.git/include/trace, branch v5.5.14

afs: Fix some tracing details

2020-04-01T09:00:15Z

commit 4636cf184d6d9a92a56c2554681ea520dd4fe49a upstream. Fix a couple of tracelines to indicate the usage count after the atomic op, not the usage count before it to be consistent with other afs and rxrpc trace lines. Change the wording of the afs_call_trace_work trace ID label from "WORK" to "QUEUE" to reflect the fact that it's queueing work, not doing work. Fixes: 341f741f04be ("afs: Refcount the afs_call struct") Signed-off-by: David Howells Signed-off-by: Greg Kroah-Hartman

rcu: Fix data-race due to atomic_t copy-by-value

2020-02-24T07:38:00Z

[ Upstream commit 6cf539a87a61a4fbc43f625267dbcbcf283872ed ] This fixes a data-race where `atomic_t dynticks` is copied by value. The copy is performed non-atomically, resulting in a data-race if `dynticks` is updated concurrently. This data-race was found with KCSAN: ================================================================== BUG: KCSAN: data-race in dyntick_save_progress_counter / rcu_irq_enter write to 0xffff989dbdbe98e0 of 4 bytes by task 10 on cpu 3: atomic_add_return include/asm-generic/atomic-instrumented.h:78 [inline] rcu_dynticks_snap kernel/rcu/tree.c:310 [inline] dyntick_save_progress_counter+0x43/0x1b0 kernel/rcu/tree.c:984 force_qs_rnp+0x183/0x200 kernel/rcu/tree.c:2286 rcu_gp_fqs kernel/rcu/tree.c:1601 [inline] rcu_gp_fqs_loop+0x71/0x880 kernel/rcu/tree.c:1653 rcu_gp_kthread+0x22c/0x3b0 kernel/rcu/tree.c:1799 kthread+0x1b5/0x200 kernel/kthread.c:255 read to 0xffff989dbdbe98e0 of 4 bytes by task 154 on cpu 7: rcu_nmi_enter_common kernel/rcu/tree.c:828 [inline] rcu_irq_enter+0xda/0x240 kernel/rcu/tree.c:870 irq_enter+0x5/0x50 kernel/softirq.c:347 Reported by Kernel Concurrency Sanitizer on: CPU: 7 PID: 154 Comm: kworker/7:1H Not tainted 5.3.0+ #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Workqueue: kblockd blk_mq_run_work_fn ================================================================== Signed-off-by: Marco Elver Cc: Paul E. McKenney Cc: Josh Triplett Cc: Steven Rostedt Cc: Mathieu Desnoyers Cc: Joel Fernandes Cc: Ingo Molnar Cc: Dmitry Vyukov Cc: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Joel Fernandes (Google) Signed-off-by: Paul E. McKenney Signed-off-by: Sasha Levin

memcg: fix a crash in wb_workfn when a device disappears

2020-02-11T12:36:43Z

commit 68f23b89067fdf187763e75a56087550624fdbee upstream. Without memcg, there is a one-to-one mapping between the bdi and bdi_writeback structures. In this world, things are fairly straightforward; the first thing bdi_unregister() does is to shutdown the bdi_writeback structure (or wb), and part of that writeback ensures that no other work queued against the wb, and that the wb is fully drained. With memcg, however, there is a one-to-many relationship between the bdi and bdi_writeback structures; that is, there are multiple wb objects which can all point to a single bdi. There is a refcount which prevents the bdi object from being released (and hence, unregistered). So in theory, the bdi_unregister() *should* only get called once its refcount goes to zero (bdi_put will drop the refcount, and when it is zero, release_bdi gets called, which calls bdi_unregister). Unfortunately, del_gendisk() in block/gen_hd.c never got the memo about the Brave New memcg World, and calls bdi_unregister directly. It does this without informing the file system, or the memcg code, or anything else. This causes the root wb associated with the bdi to be unregistered, but none of the memcg-specific wb's are shutdown. So when one of these wb's are woken up to do delayed work, they try to dereference their wb->bdi->dev to fetch the device name, but unfortunately bdi->dev is now NULL, thanks to the bdi_unregister() called by del_gendisk(). As a result, *boom*. Fortunately, it looks like the rest of the writeback path is perfectly happy with bdi->dev and bdi->owner being NULL, so the simplest fix is to create a bdi_dev_name() function which can handle bdi->dev being NULL. This also allows us to bulletproof the writeback tracepoints to prevent them from dereferencing a NULL pointer and crashing the kernel if one is tracing with memcg's enabled, and an iSCSI device dies or a USB storage stick is pulled. The most common way of triggering this will be hotremoval of a device while writeback with memcg enabled is going on. It was triggering several times a day in a heavily loaded production environment. Google Bug Id: 145475544 Link: https://lore.kernel.org/r/20191227194829.150110-1-tytso@mit.edu Link: http://lkml.kernel.org/r/20191228005211.163952-1-tytso@mit.edu Signed-off-by: Theodore Ts'o Cc: Chris Mason Cc: Tejun Heo Cc: Jens Axboe Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

Merge tag 'trace-v5.5-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2020-01-23T19:23:37Z

Pull tracing fixes from Steven Rostedt: "Various tracing fixes: - Fix a function comparison warning for a xen trace event macro - Fix a double perf_event linking to a trace_uprobe_filter for multiple events - Fix suspicious RCU warnings in trace event code for using list_for_each_entry_rcu() when the "_rcu" portion wasn't needed. - Fix a bug in the histogram code when using the same variable - Fix a NULL pointer dereference when tracefs lockdown enabled and calling trace_set_default_clock() - A fix to a bug found with the double perf_event linking patch" * tag 'trace-v5.5-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing/uprobe: Fix to make trace_uprobe_filter alignment safe tracing: Do not set trace clock if tracefs lockdown is in effect tracing: Fix histogram code when expression has same var as value tracing: trigger: Replace unneeded RCU-list traversals tracing/uprobe: Fix double perf_event linking on multiprobe uprobe tracing: xen: Ordered comparison of function pointers

tracing: xen: Ordered comparison of function pointers

2020-01-14T20:55:57Z

Just as commit 0566e40ce7 ("tracing: initcall: Ordered comparison of function pointers"), this patch fixes another remaining one in xen.h found by clang-9. In file included from arch/x86/xen/trace.c:21: In file included from ./include/trace/events/xen.h:475: In file included from ./include/trace/define_trace.h:102: In file included from ./include/trace/trace_events.h:473: ./include/trace/events/xen.h:69:7: warning: ordered comparison of function \ pointers ('xen_mc_callback_fn_t' (aka 'void (*)(void *)') and 'xen_mc_callback_fn_t') [-Wordered-compare-function-pointers] __field(xen_mc_callback_fn_t, fn) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ./include/trace/trace_events.h:421:29: note: expanded from macro '__field' ^ ./include/trace/trace_events.h:407:6: note: expanded from macro '__field_ext' is_signed_type(type), filter_type); \ ^ ./include/linux/trace_events.h:554:44: note: expanded from macro 'is_signed_type' ^ Fixes: c796f213a6934 ("xen/trace: add multicall tracing") Signed-off-by: Changbin Du Signed-off-by: Steven Rostedt (VMware)

Merge branch 'dhowells' (patches from DavidH)

2020-01-14T17:56:31Z

Merge misc fixes from David Howells. Two afs fixes and a key refcounting fix. * dhowells: afs: Fix afs_lookup() to not clobber the version on a new dentry afs: Fix use-after-loss-of-ref keys: Fix request_key() cache

afs: Fix use-after-loss-of-ref

2020-01-14T17:40:06Z

afs_lookup() has a tracepoint to indicate the outcome of d_splice_alias(), passing it the inode to retrieve the fid from. However, the function gave up its ref on that inode when it called d_splice_alias(), which may have failed and dropped the inode. Fix this by caching the fid. Fixes: 80548b03991f ("afs: Add more tracepoints") Reported-by: Al Viro Signed-off-by: David Howells Signed-off-by: Linus Torvalds

mm: khugepaged: add trace status description for SCAN_PAGE_HAS_PRIVATE

2020-01-14T02:19:02Z

Commit 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS") introduced a new khugepaged scan result: SCAN_PAGE_HAS_PRIVATE, but the corresponding description for trace events were not added. Link: http://lkml.kernel.org/r/1574793844-2914-1-git-send-email-yang.shi@linux.alibaba.com Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS") Signed-off-by: Yang Shi Cc: Song Liu Cc: Kirill A. Shutemov Cc: Anshuman Khandual Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

tracing: Change offset type to s32 in preempt/irq tracepoints

2020-01-03T16:34:37Z

Discussion in the below link reported that symbols in modules can appear to be before _stext on ARM architecture, causing wrapping with the offsets of this tracepoint. Change the offset type to s32 to fix this. Link: http://lore.kernel.org/r/20191127154428.191095-1-antonio.borneo@st.com Link: http://lkml.kernel.org/r/20200102194625.226436-1-joel@joelfernandes.org Cc: Bjorn Helgaas Cc: David Sterba Cc: Ingo Molnar Cc: Mike Rapoport Cc: "Rafael J. Wysocki" Cc: Sakari Ailus Cc: Antonio Borneo Cc: stable@vger.kernel.org Fixes: d59158162e032 ("tracing: Add support for preempt and irq enable/disable events") Signed-off-by: Joel Fernandes (Google) Signed-off-by: Steven Rostedt (VMware)

Merge tag 'nfsd-5.5' of git://linux-nfs.org/~bfields/linux

2019-12-08T00:56:00Z

Pull nfsd updates from Bruce Fields: "This is a relatively quiet cycle for nfsd, mainly various bugfixes. Possibly most interesting is Trond's fixes for some callback races that were due to my incomplete understanding of rpc client shutdown. Unfortunately at the last minute I've started noticing a new intermittent failure to send callbacks. As the logic seems basically correct, I'm leaving Trond's patches in for now, and hope to find a fix in the next week so I don't have to revert those patches" * tag 'nfsd-5.5' of git://linux-nfs.org/~bfields/linux: (24 commits) nfsd: depend on CRYPTO_MD5 for legacy client tracking NFSD fixing possible null pointer derefering in copy offload nfsd: check for EBUSY from vfs_rmdir/vfs_unink. nfsd: Ensure CLONE persists data and metadata changes to the target file SUNRPC: Fix backchannel latency metrics nfsd: restore NFSv3 ACL support nfsd: v4 support requires CRYPTO_SHA256 nfsd: Fix cld_net->cn_tfm initialization lockd: remove __KERNEL__ ifdefs sunrpc: remove __KERNEL__ ifdefs race in exportfs_decode_fh() nfsd: Drop LIST_HEAD where the variable it declares is never used. nfsd: document callback_wq serialization of callback code nfsd: mark cb path down on unknown errors nfsd: Fix races between nfsd4_cb_release() and nfsd4_shutdown_callback() nfsd: minor 4.1 callback cleanup SUNRPC: Fix svcauth_gss_proxy_init() SUNRPC: Trace gssproxy upcall results sunrpc: fix crash when cache_head become valid before update nfsd: remove private bin2hex implementation ...