user/sven/linux.git/include/trace, branch v5.5.5

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 ...

Merge tag 'nfs-for-5.5-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

2019-12-08T00:50:55Z

Pull NFS client updates from Trond Myklebust: "Highlights include: Features: - NFSv4.2 now supports cross device offloaded copy (i.e. offloaded copy of a file from one source server to a different target server). - New RDMA tracepoints for debugging congestion control and Local Invalidate WRs. Bugfixes and cleanups - Drop the NFSv4.1 session slot if nfs4_delegreturn_prepare waits for layoutreturn - Handle bad/dead sessions correctly in nfs41_sequence_process() - Various bugfixes to the delegation return operation. - Various bugfixes pertaining to delegations that have been revoked. - Cleanups to the NFS timespec code to avoid unnecessary conversions between timespec and timespec64. - Fix unstable RDMA connections after a reconnect - Close race between waking an RDMA sender and posting a receive - Wake pending RDMA tasks if connection fails - Fix MR list corruption, and clean up MR usage - Fix another RPCSEC_GSS issue with MIC buffer space" * tag 'nfs-for-5.5-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (79 commits) SUNRPC: Capture completion of all RPC tasks SUNRPC: Fix another issue with MIC buffer space NFS4: Trace lock reclaims NFS4: Trace state recovery operation NFSv4.2 fix memory leak in nfs42_ssc_open NFSv4.2 fix kfree in __nfs42_copy_file_range NFS: remove duplicated include from nfs4file.c NFSv4: Make _nfs42_proc_copy_notify() static NFS: Fallocate should use the nfs4_fattr_bitmap NFS: Return -ETXTBSY when attempting to write to a swapfile fs: nfs: sysfs: Remove NULL check before kfree NFS: remove unneeded semicolon NFSv4: add declaration of current_stateid NFSv4.x: Drop the slot if nfs4_delegreturn_prepare waits for layoutreturn NFSv4.x: Handle bad/dead sessions correctly in nfs41_sequence_process() nfsv4: Move NFSPROC4_CLNT_COPY_NOTIFY to end of list SUNRPC: Avoid RPC delays when exiting suspend NFS: Add a tracepoint in nfs_fh_to_dentry() NFSv4: Don't retry the GETATTR on old stateid in nfs4_delegreturn_done() NFSv4: Handle NFS4ERR_OLD_STATEID in delegreturn ...

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

2019-12-05T03:13:52Z

Pull more tracing updates from Steven Rostedt: "Two fixes and one patch that was missed: Fixes: - Missing __print_hex_dump undef for processing new function in trace events - Stop WARN_ON messages when lockdown disables tracing on boot up Enhancement: - Debug option to inject trace events from userspace (for rasdaemon)" The enhancement has its own config option and is non invasive. It's been discussed for sever months and should have been added to my original push, but I never pulled it into my queue. * tag 'trace-v5.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Do not create directories if lockdown is in affect tracing: Introduce trace event injection tracing: Fix __print_hex_dump scope