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* nfs41: do not return ENOMEM on LAYOUTUNAVAILABLETigran Mkrtchyan2018-01-181-3/+1
| | | | | | | | | | | | | | | | | | | A pNFS server may return LAYOUTUNAVAILABLE error on LAYOUTGET for files which don't have any layout. In this situation pnfs_update_layout currently returns NULL. As this NULL is converted into ENOMEM, IO requests fails instead of falling back to MDS. Do not return ENOMEM on LAYOUTUNAVAILABLE and let client retry through MDS. Fixes 8d40b0f14846f. I will suggest to backport this fix to affected stable branches. Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de> [trondmy: Use IS_ERR_OR_NULL()] Fixes: 8d40b0f14846 ("NFS filelayout:call GETDEVICEINFO after...") Cc: stable@vger.kernel.org # v4.11+ Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* NFS: commit direct writes even if they fail partiallyJ. Bruce Fields2018-01-161-3/+1
| | | | | | | | | | | | | | | If some of the WRITE calls making up an O_DIRECT write syscall fail, we neglect to commit, even if some of the WRITEs succeed. We also depend on the commit code to free the reference count on the nfs_page taken in the "if (request_commit)" case at the end of nfs_direct_write_completion(). The problem was originally noticed because ENOSPC's encountered partway through a write would result in a closed file being sillyrenamed when it should have been unlinked. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* nfs: remove unused label in nfs_encode_fh()Arnd Bergmann2018-01-161-1/+0
| | | | | | | | | | | | The only reference to the label got removed, so we now get a harmless compiler warning: fs/nfs/export.c: In function 'nfs_encode_fh': fs/nfs/export.c:58:1: error: label 'out' defined but not used [-Werror=unused-label] Fixes: aaa150089465 ("nfs: remove dead code from nfs_encode_fh()") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* SUNRPC: Add explicit rescheduling points in the receive pathTrond Myklebust2018-01-151-2/+19
| | | | | | | When reading the reply from the server, insert an explicit cond_resched() to avoid starving higher priority tasks. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* SUNRPC: Chunk reading of replies from the serverTrond Myklebust2018-01-151-4/+11
| | | | | | | Read the TCP data in chunks of max 2MB so that we do not hog the socket lock. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* SUNRPC: Remove rpc_protocol()Chuck Lever2018-01-152-17/+0
| | | | | | | | Since nfs4_create_referral_server was the only call site of rpc_protocol, rpc_protocol can now be removed. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* nfs: Update server port after referral or migrationChuck Lever2018-01-151-0/+1
| | | | | | | | | | After traversing a referral or recovering from a migration event, ensure that the server port reported in /proc/mounts is updated to the correct port setting for the new submount. Reported-by: Helen Chao <helen.chao@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* nfs: Referrals should use the same proto setting as their parentChuck Lever2018-01-152-5/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | Helen Chao <helen.chao@oracle.com> noticed that when a user traverses a referral on an NFS/RDMA mount, the resulting submount always uses TCP. This behavior does not match the vers= setting when traversing a referral (vers=4.1 is preserved). It also does not match the behavior of crossing from the pseudofs into a real filesystem (proto=rdma is preserved in that case). The Linux NFS client does not currently support the fs_locations_info attribute. The situation is similar for all NFSv4 servers I know of. Therefore until the community has broad support for fs_locations_info, when following a referral: - First try to connect with RPC-over-RDMA. This will fail quickly if the client has no RDMA-capable interfaces. - If connecting with RPC-over-RDMA fails, or the RPC-over-RDMA transport is not available, use TCP. Reported-by: Helen Chao <helen.chao@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* nfs: Define NFS_RDMA_PORTChuck Lever2018-01-151-0/+1
| | | | | | | The NFS/RDMA port assignment is specified in Section 9 of RFC 8267. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* lockd: convert nlm_rqst.a_count from atomic_t to refcount_tElena Reshetova2018-01-153-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable nlm_rqst.a_count is used as pure reference counter. Convert it to refcount_t and fix up the operations. **Important note for maintainers: Some functions from refcount_t API defined in lib/refcount.c have different memory ordering guarantees than their atomic counterparts. The full comparison can be seen in https://lkml.org/lkml/2017/11/15/57 and it is hopefully soon in state to be merged to the documentation tree. Normally the differences should not matter since refcount_t provides enough guarantees to satisfy the refcounting use cases, but in some rare cases it might matter. Please double check that you don't have some undocumented memory guarantees for this variable usage. For the nlm_rqst.a_count it might make a difference in following places: - nlmclnt_release_call() and nlmsvc_release_call(): decrement in refcount_dec_and_test() only provides RELEASE ordering and control dependency on success vs. fully ordered atomic counterpart Suggested-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Windsor <dwindsor@gmail.com> Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* lockd: convert nlm_lockowner.count from atomic_t to refcount_tElena Reshetova2018-01-152-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable nlm_lockowner.count is used as pure reference counter. Convert it to refcount_t and fix up the operations. **Important note for maintainers: Some functions from refcount_t API defined in lib/refcount.c have different memory ordering guarantees than their atomic counterparts. The full comparison can be seen in https://lkml.org/lkml/2017/11/15/57 and it is hopefully soon in state to be merged to the documentation tree. Normally the differences should not matter since refcount_t provides enough guarantees to satisfy the refcounting use cases, but in some rare cases it might matter. Please double check that you don't have some undocumented memory guarantees for this variable usage. For the nlm_lockowner.count it might make a difference in following places: - nlm_put_lockowner(): decrement in refcount_dec_and_lock() only provides RELEASE ordering, control dependency on success and holds a spin lock on success vs. fully ordered atomic counterpart. No changes in spin lock guarantees. Suggested-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Windsor <dwindsor@gmail.com> Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* lockd: convert nsm_handle.sm_count from atomic_t to refcount_tElena Reshetova2018-01-153-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable nsm_handle.sm_count is used as pure reference counter. Convert it to refcount_t and fix up the operations. **Important note for maintainers: Some functions from refcount_t API defined in lib/refcount.c have different memory ordering guarantees than their atomic counterparts. The full comparison can be seen in https://lkml.org/lkml/2017/11/15/57 and it is hopefully soon in state to be merged to the documentation tree. Normally the differences should not matter since refcount_t provides enough guarantees to satisfy the refcounting use cases, but in some rare cases it might matter. Please double check that you don't have some undocumented memory guarantees for this variable usage. For the nsm_handle.sm_count it might make a difference in following places: - nsm_release(): decrement in refcount_dec_and_lock() only provides RELEASE ordering, control dependency on success and holds a spin lock on success vs. fully ordered atomic counterpart. No change for the spin lock guarantees. Suggested-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Windsor <dwindsor@gmail.com> Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* lockd: convert nlm_host.h_count from atomic_t to refcount_tElena Reshetova2018-01-152-8/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable nlm_host.h_count is used as pure reference counter. Convert it to refcount_t and fix up the operations. **Important note for maintainers: Some functions from refcount_t API defined in lib/refcount.c have different memory ordering guarantees than their atomic counterparts. The full comparison can be seen in https://lkml.org/lkml/2017/11/15/57 and it is hopefully soon in state to be merged to the documentation tree. Normally the differences should not matter since refcount_t provides enough guarantees to satisfy the refcounting use cases, but in some rare cases it might matter. Please double check that you don't have some undocumented memory guarantees for this variable usage. For the nlm_host.h_count it might make a difference in following places: - nlmsvc_release_host(): decrement in refcount_dec() provides RELEASE ordering, while original atomic_dec() was fully unordered. Since the change is for better, it should not matter. - nlmclnt_release_host(): decrement in refcount_dec_and_test() only provides RELEASE ordering and control dependency on success vs. fully ordered atomic counterpart. It doesn't seem to matter in this case since object freeing happens under mutex lock anyway. Suggested-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Windsor <dwindsor@gmail.com> Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* nfs/pnfs: fix nfs_direct_req ref leak when i/o falls back to the mdsScott Mayhew2018-01-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently when falling back to doing I/O through the MDS (via pnfs_{read|write}_through_mds), the client frees the nfs_pgio_header without releasing the reference taken on the dreq via pnfs_generic_pg_{read|write}pages -> nfs_pgheader_init -> nfs_direct_pgio_init. It then takes another reference on the dreq via nfs_generic_pg_pgios -> nfs_pgheader_init -> nfs_direct_pgio_init and as a result the requester will become stuck in inode_dio_wait. Once that happens, other processes accessing the inode will become stuck as well. Ensure that pnfs_read_through_mds() and pnfs_write_through_mds() clean up correctly by calling hdr->completion_ops->completion() instead of calling hdr->release() directly. This can be reproduced (sometimes) by performing "storage failover takeover" commands on NetApp filer while doing direct I/O from a client. This can also be reproduced using SystemTap to simulate a failure while doing direct I/O from a client (from Dave Wysochanski <dwysocha@redhat.com>): stap -v -g -e 'probe module("nfs_layout_nfsv41_files").function("nfs4_fl_prepare_ds").return { $return=NULL; exit(); }' Suggested-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Scott Mayhew <smayhew@redhat.com> Fixes: 1ca018d28d ("pNFS: Fix a memory leak when attempted pnfs fails") Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* pnfs/blocklayout: handle transient devicesBenjamin Coddington2018-01-155-12/+82
| | | | | | | | | | | | | | | | | | | | | | | | | | PNFS block/SCSI layouts should gracefully handle cases where block devices are not available when a layout is retrieved, or the block devices are removed while the client holds a layout. While setting up a layout segment, keep a record of an unavailable or un-parsable block device in cache with a flag so that subsequent layouts do not spam the server with GETDEVINFO. We can reuse the current NFS_DEVICEID_UNAVAILABLE handling with one variation: instead of reusing the device, we will discard it and send a fresh GETDEVINFO after the timeout, since the lookup and validation of the device occurs within the GETDEVINFO response handling. A lookup of a layout segment that references an unavailable device will return a segment with the NFS_LSEG_UNAVAILABLE flag set. This will allow the pgio layer to mark the layout with the appropriate fail bit, which forces subsequent IO to the MDS, and prevents spamming the server with LAYOUTGET, LAYOUTRETURN. Finally, when IO to a block device fails, look up the block device(s) referenced by the pgio header, and mark them as unavailable. Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* pnfs/blocklayout: set PNFS_LAYOUTRETURN_ON_ERRORBenjamin Coddington2018-01-152-1/+5
| | | | | | | | | | If there's an error doing I/O to block device, and the client resends the I/O to the MDS, the MDS must recall the layout from the client before processing the I/O. Let's preempt that exchange by returning the layout before falling back to the MDS when there's an error. Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* pnfs/blocklayout: Add module alias for LAYOUT4_SCSIBenjamin Coddington2018-01-151-0/+1
| | | | | | | | | | The blocklayout module contains the client support for both block and SCSI layouts. Add a module alias for the SCSI layout type so that the module will be loaded for SCSI layouts. Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* NFS: remove unused offset arg in nfs_pgio_rpcsetupBenjamin Coddington2018-01-151-4/+4
| | | | | | | | nfs_pgio_rpcsetup() is always called with an offset of 0, so we should be able to drop the arguement altogether. Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* NFSv4: always set NFS_LOCK_LOST when a lock is lost.NeilBrown2018-01-152-5/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | There are 2 comments in the NFSv4 code which suggest that SIGLOST should possibly be sent to a process. In these cases a lock has been lost. The current practice is to set NFS_LOCK_LOST so that read/write returns EIO when a lock is lost. So change these comments to code when sets NFS_LOCK_LOST. One case is when lock recovery after apparent server restart fails with NFS4ERR_DENIED, NFS4ERR_RECLAIM_BAD, or NFS4ERRO_RECLAIM_CONFLICT. The other case is when a lock attempt as part of lease recovery fails with NFS4ERR_DENIED. In an ideal world, these should not happen. However I have a packet trace showing an NFSv4.1 session getting NFS4ERR_BADSESSION after an extended network parition. The NFSv4.1 client treats this like server reboot until/unless it get NFS4ERR_NO_GRACE, in which case it switches over to "nograce" recovery mode. In this network trace, the client attempts to recover a lock and the server (incorrectly) reports NFS4ERR_DENIED rather than NFS4ERR_NO_GRACE. This leads to the ineffective comment and the client then continues to write using the OPEN stateid. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* nfs: remove dead code from nfs_encode_fh()NeilBrown2018-01-151-4/+0
| | | | | | | | | This code can never be used as the IS_AUTOMOUNT(inode) case has already been handled. So remove it to avoid confusion. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* Support statx() mask and query flags parametersTrond Myklebust2018-01-151-13/+39
| | | | | | | | | | | Support the query flags AT_STATX_FORCE_SYNC by forcing an attribute revalidation, and AT_STATX_DONT_SYNC by returning cached attributes only. Use the mask to optimise away server revalidation for attributes that are not being requested by the user. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* NFS: Fix nfsstat breakage due to LOOKUPPTrond Myklebust2018-01-152-30/+46
| | | | | | | | | | | | | The LOOKUPP operation was inserted into the nfs4_procedures array rather than being appended, which put /proc/net/rpc/nfs out of whack, and broke the nfsstat utility. Fix by moving the LOOKUPP operation to the end of the array, and by ensuring that it keeps the same length whether or not NFSV4.1 and NFSv4.2 are compiled in. Fixes: 5b5faaf6df734 ("nfs4: add NFSv4 LOOKUPP handlers") Cc: stable@vger.kernel.org # v4.13+ Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* NFSv4: Convert LOCKU to use nfs4_async_handle_exception()Trond Myklebust2018-01-151-2/+8
| | | | | | | Convert CLOSE so that it specifies the correct stateid and inode for the error handling. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* NFSv4: Convert DELEGRETURN to use nfs4_handle_exception()Trond Myklebust2018-01-151-3/+8
| | | | Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* NFSv4: Convert CLOSE to use nfs4_async_handle_exception()Trond Myklebust2018-01-151-1/+8
| | | | | | | Convert CLOSE so that it specifies the correct stateid, state and inode for the error handling. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* NFS: Add a cond_resched() to nfs_commit_release_pages()Trond Myklebust2018-01-151-0/+2
| | | | | | | | | | The commit list can get very large, and so we need a cond_resched() in nfs_commit_release_pages() in order to ensure we don't hog the CPU for excessive periods of time. Reported-by: Mike Galbraith <efault@gmx.de> Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* Linux 4.15-rc8v4.15-rc8Linus Torvalds2018-01-151-1/+1
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* Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds2018-01-151-2/+0
|\ | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixlet from Thomas Gleixner. Remove a warning about lack of compiler support for retpoline that most people can't do anything about, so it just annoys them needlessly. * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/retpoline: Remove compile time warning
| * x86/retpoline: Remove compile time warningThomas Gleixner2018-01-141-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the compile time warning when CONFIG_RETPOLINE=y and the compiler does not have retpoline support. Linus rationale for this is: It's wrong because it will just make people turn off RETPOLINE, and the asm updates - and return stack clearing - that are independent of the compiler are likely the most important parts because they are likely the ones easiest to target. And it's annoying because most people won't be able to do anything about it. The number of people building their own compiler? Very small. So if their distro hasn't got a compiler yet (and pretty much nobody does), the warning is just annoying crap. It is already properly reported as part of the sysfs interface. The compile-time warning only encourages bad things. Fixes: 76b043848fd2 ("x86/retpoline: Add initial retpoline support") Requested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: gnomes@lxorguk.ukuu.org.uk Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: thomas.lendacky@amd.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Link: https://lkml.kernel.org/r/CA+55aFzWgquv4i6Mab6bASqYXg3ErV3XDFEYf=GEcCDQg5uAtw@mail.gmail.com
* | Merge tag 'powerpc-4.15-7' of ↵Linus Torvalds2018-01-1521-36/+561
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "One fix for an oops at boot if we take a hotplug interrupt before we are ready to handle it. The bulk is patches to implement mitigation for Meltdown, see the change logs for more details. Thanks to: Nicholas Piggin, Michael Neuling, Oliver O'Halloran, Jon Masters, Jose Ricardo Ziviani, David Gibson" * tag 'powerpc-4.15-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/powernv: Check device-tree for RFI flush settings powerpc/pseries: Query hypervisor for RFI flush settings powerpc/64s: Support disabling RFI flush with no_rfi_flush and nopti powerpc/64s: Add support for RFI flush of L1-D cache powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL powerpc/64: Convert fast_exception_return to use RFI_TO_USER/KERNEL powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNEL powerpc/64s: Simple RFI macro conversions powerpc/64: Add macros for annotating the destination of rfid/hrfid powerpc/pseries: Add H_GET_CPU_CHARACTERISTICS flags & wrapper powerpc/pseries: Make RAS IRQ explicitly dependent on DLPAR WQ
| * | powerpc/powernv: Check device-tree for RFI flush settingsOliver O'Halloran2018-01-101-0/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | New device-tree properties are available which tell the hypervisor settings related to the RFI flush. Use them to determine the appropriate flush instruction to use, and whether the flush is required. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | powerpc/pseries: Query hypervisor for RFI flush settingsMichael Neuling2018-01-101-0/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | A new hypervisor call is available which tells the guest settings related to the RFI flush. Use it to query the appropriate flush instruction(s), and whether the flush is required. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | powerpc/64s: Support disabling RFI flush with no_rfi_flush and noptiMichael Ellerman2018-01-101-1/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because there may be some performance overhead of the RFI flush, add kernel command line options to disable it. We add a sensibly named 'no_rfi_flush' option, but we also hijack the x86 option 'nopti'. The RFI flush is not the same as KPTI, but if we see 'nopti' we can guess that the user is trying to avoid any overhead of Meltdown mitigations, and it means we don't have to educate every one about a different command line option. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | powerpc/64s: Add support for RFI flush of L1-D cacheMichael Ellerman2018-01-109-8/+286
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On some CPUs we can prevent the Meltdown vulnerability by flushing the L1-D cache on exit from kernel to user mode, and from hypervisor to guest. This is known to be the case on at least Power7, Power8 and Power9. At this time we do not know the status of the vulnerability on other CPUs such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale CPUs. As more information comes to light we can enable this, or other mechanisms on those CPUs. The vulnerability occurs when the load of an architecturally inaccessible memory region (eg. userspace load of kernel memory) is speculatively executed to the point where its result can influence the address of a subsequent speculatively executed load. In order for that to happen, the first load must hit in the L1, because before the load is sent to the L2 the permission check is performed. Therefore if no kernel addresses hit in the L1 the vulnerability can not occur. We can ensure that is the case by flushing the L1 whenever we return to userspace. Similarly for hypervisor vs guest. In order to flush the L1-D cache on exit, we add a section of nops at each (h)rfi location that returns to a lower privileged context, and patch that with some sequence. Newer firmwares are able to advertise to us that there is a special nop instruction that flushes the L1-D. If we do not see that advertised, we fall back to doing a displacement flush in software. For guest kernels we support migration between some CPU versions, and different CPUs may use different flush instructions. So that we are prepared to migrate to a machine with a different flush instruction activated, we may have to patch more than one flush instruction at boot if the hypervisor tells us to. In the end this patch is mostly the work of Nicholas Piggin and Michael Ellerman. However a cast of thousands contributed to analysis of the issue, earlier versions of the patch, back ports testing etc. Many thanks to all of them. Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNELNicholas Piggin2018-01-091-1/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | In the SLB miss handler we may be returning to user or kernel. We need to add a check early on and save the result in the cr4 register, and then we bifurcate the return path based on that. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | powerpc/64: Convert fast_exception_return to use RFI_TO_USER/KERNELNicholas Piggin2018-01-091-2/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Similar to the syscall return path, in fast_exception_return we may be returning to user or kernel context. We already have a test for that, because we conditionally restore r13. So use that existing test and branch, and bifurcate the return based on that. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNELNicholas Piggin2018-01-091-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the syscall exit path we may be returning to user or kernel context. We already have a test for that, because we conditionally restore r13. So use that existing test and branch, and bifurcate the return based on that. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | powerpc/64s: Simple RFI macro conversionsNicholas Piggin2018-01-096-28/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit does simple conversions of rfi/rfid to the new macros that include the expected destination context. By simple we mean cases where there is a single well known destination context, and it's simply a matter of substituting the instruction for the appropriate macro. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | powerpc/64: Add macros for annotating the destination of rfid/hrfidNicholas Piggin2018-01-092-0/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The rfid/hrfid ((Hypervisor) Return From Interrupt) instruction is used for switching from the kernel to userspace, and from the hypervisor to the guest kernel. However it can and is also used for other transitions, eg. from real mode kernel code to virtual mode kernel code, and it's not always clear from the code what the destination context is. To make it clearer when reading the code, add macros which encode the expected destination context. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | Merge branch 'topic/ppc-kvm' into fixesMichael Ellerman2018-01-092-0/+31
| |\ \ | | | | | | | | | | | | | | | | | | | | Merge the topic branch with share with the kvm-ppc tree. In this case we need to share the definition of a new hypervisor call and associated flags.
| | * | powerpc/pseries: Add H_GET_CPU_CHARACTERISTICS flags & wrapperMichael Neuling2018-01-092-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A new hypervisor call has been defined to communicate various characteristics of the CPU to guests. Add definitions for the hcall number, flags and a wrapper function. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | powerpc/pseries: Make RAS IRQ explicitly dependent on DLPAR WQMichael Ellerman2018-01-083-4/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The hotplug code uses its own workqueue to handle IRQ requests (pseries_hp_wq), however that workqueue is initialized after init_ras_IRQ(). That can lead to a kernel panic if any hotplug interrupts fire after init_ras_IRQ() but before pseries_hp_wq is initialised. eg: UDP-Lite hash table entries: 2048 (order: 0, 65536 bytes) NET: Registered protocol family 1 Unpacking initramfs... (qemu) object_add memory-backend-ram,id=mem1,size=10G (qemu) device_add pc-dimm,id=dimm1,memdev=mem1 Unable to handle kernel paging request for data at address 0xf94d03007c421378 Faulting instruction address: 0xc00000000012d744 Oops: Kernel access of bad area, sig: 11 [#1] LE SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc2-ziviani+ #26 task: (ptrval) task.stack: (ptrval) NIP: c00000000012d744 LR: c00000000012d744 CTR: 0000000000000000 REGS: (ptrval) TRAP: 0380 Not tainted (4.15.0-rc2-ziviani+) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 28088042 XER: 20040000 CFAR: c00000000012d3c4 SOFTE: 0 ... NIP [c00000000012d744] __queue_work+0xd4/0x5c0 LR [c00000000012d744] __queue_work+0xd4/0x5c0 Call Trace: [c0000000fffefb90] [c00000000012d744] __queue_work+0xd4/0x5c0 (unreliable) [c0000000fffefc70] [c00000000012dce4] queue_work_on+0xb4/0xf0 This commit makes the RAS IRQ registration explicitly dependent on the creation of the pseries_hp_wq. Reported-by: Min Deng <mdeng@redhat.com> Reported-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com> Tested-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* | | | Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds2018-01-141-0/+1
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull NVMe fix from Jens Axboe: "Just a single fix for nvme over fabrics that should go into 4.15" * 'for-linus' of git://git.kernel.dk/linux-block: nvme-fabrics: initialize default host->id in nvmf_host_default()
| * \ \ \ Merge branch 'nvme-4.15' of git://git.infradead.org/nvme into for-linusJens Axboe2018-01-121-0/+1
| |\ \ \ \ | | | | | | | | | | | | | | | | | | Pull a single NVMe fix from Christoph for 4.15.
| | * | | | nvme-fabrics: initialize default host->id in nvmf_host_default()Ewan D. Milne2018-01-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The field was uninitialized before use. Signed-off-by: Ewan D. Milne <emilne@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
* | | | | | Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds2018-01-1444-100/+1525
|\ \ \ \ \ \ | | |_|_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 pti updates from Thomas Gleixner: "This contains: - a PTI bugfix to avoid setting reserved CR3 bits when PCID is disabled. This seems to cause issues on a virtual machine at least and is incorrect according to the AMD manual. - a PTI bugfix which disables the perf BTS facility if PTI is enabled. The BTS AUX buffer is not globally visible and causes the CPU to fault when the mapping disappears on switching CR3 to user space. A full fix which restores BTS on PTI is non trivial and will be worked on. - PTI bugfixes for EFI and trusted boot which make sure that the user space visible page table entries have the NX bit cleared - removal of dead code in the PTI pagetable setup functions - add PTI documentation - add a selftest for vsyscall to verify that the kernel actually implements what it advertises. - a sysfs interface to expose vulnerability and mitigation information so there is a coherent way for users to retrieve the status. - the initial spectre_v2 mitigations, aka retpoline: + The necessary ASM thunk and compiler support + The ASM variants of retpoline and the conversion of affected ASM code + Make LFENCE serializing on AMD so it can be used as speculation trap + The RSB fill after vmexit - initial objtool support for retpoline As I said in the status mail this is the most of the set of patches which should go into 4.15 except two straight forward patches still on hold: - the retpoline add on of LFENCE which waits for ACKs - the RSB fill after context switch Both should be ready to go early next week and with that we'll have covered the major holes of spectre_v2 and go back to normality" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (28 commits) x86,perf: Disable intel_bts when PTI security/Kconfig: Correct the Documentation reference for PTI x86/pti: Fix !PCID and sanitize defines selftests/x86: Add test_vsyscall x86/retpoline: Fill return stack buffer on vmexit x86/retpoline/irq32: Convert assembler indirect jumps x86/retpoline/checksum32: Convert assembler indirect jumps x86/retpoline/xen: Convert Xen hypercall indirect jumps x86/retpoline/hyperv: Convert assembler indirect jumps x86/retpoline/ftrace: Convert ftrace assembler indirect jumps x86/retpoline/entry: Convert entry assembler indirect jumps x86/retpoline/crypto: Convert crypto assembler indirect jumps x86/spectre: Add boot time option to select Spectre v2 mitigation x86/retpoline: Add initial retpoline support objtool: Allow alternatives to be ignored objtool: Detect jumps to retpoline thunks x86/pti: Make unpoison of pgd for trusted boot work for real x86/alternatives: Fix optimize_nops() checking sysfs/cpu: Fix typos in vulnerability documentation x86/cpu/AMD: Use LFENCE_RDTSC in preference to MFENCE_RDTSC ...
| * | | | | x86,perf: Disable intel_bts when PTIPeter Zijlstra2018-01-141-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The intel_bts driver does not use the 'normal' BTS buffer which is exposed through the cpu_entry_area but instead uses the memory allocated for the perf AUX buffer. This obviously comes apart when using PTI because then the kernel mapping; which includes that AUX buffer memory; disappears. Fixing this requires to expose a mapping which is visible in all context and that's not trivial. As a quick fix disable this driver when PTI is enabled to prevent malfunction. Fixes: 385ce0ea4c07 ("x86/mm/pti: Add Kconfig") Reported-by: Vince Weaver <vincent.weaver@maine.edu> Reported-by: Robert Święcki <robert@swiecki.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: greg@kroah.com Cc: hughd@google.com Cc: luto@amacapital.net Cc: Vince Weaver <vince@deater.net> Cc: torvalds@linux-foundation.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180114102713.GB6166@worktop.programming.kicks-ass.net
| * | | | | security/Kconfig: Correct the Documentation reference for PTIW. Trevor King2018-01-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the config option for PTI was added a reference to documentation was added as well. But the documentation did not exist at that point. The final documentation has a different file name. Fix it up to point to the proper file. Fixes: 385ce0ea ("x86/mm/pti: Add Kconfig") Signed-off-by: W. Trevor King <wking@tremily.us> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-mm@kvack.org Cc: linux-security-module@vger.kernel.org Cc: James Morris <james.l.morris@oracle.com> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/3009cc8ccbddcd897ec1e0cb6dda524929de0d14.1515799398.git.wking@tremily.us
| * | | | | x86/pti: Fix !PCID and sanitize definesThomas Gleixner2018-01-143-21/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The switch to the user space page tables in the low level ASM code sets unconditionally bit 12 and bit 11 of CR3. Bit 12 is switching the base address of the page directory to the user part, bit 11 is switching the PCID to the PCID associated with the user page tables. This fails on a machine which lacks PCID support because bit 11 is set in CR3. Bit 11 is reserved when PCID is inactive. While the Intel SDM claims that the reserved bits are ignored when PCID is disabled, the AMD APM states that they should be cleared. This went unnoticed as the AMD APM was not checked when the code was developed and reviewed and test systems with Intel CPUs never failed to boot. The report is against a Centos 6 host where the guest fails to boot, so it's not yet clear whether this is a virt issue or can happen on real hardware too, but thats irrelevant as the AMD APM clearly ask for clearing the reserved bits. Make sure that on non PCID machines bit 11 is not set by the page table switching code. Andy suggested to rename the related bits and masks so they are clearly describing what they should be used for, which is done as well for clarity. That split could have been done with alternatives but the macro hell is horrible and ugly. This can be done on top if someone cares to remove the extra orq. For now it's a straight forward fix. Fixes: 6fd166aae78c ("x86/mm: Use/Fix PCID to optimize user/kernel switches") Reported-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable <stable@vger.kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Willy Tarreau <w@1wt.eu> Cc: David Woodhouse <dwmw@amazon.co.uk> Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801140009150.2371@nanos
| * | | | | selftests/x86: Add test_vsyscallAndy Lutomirski2018-01-132-1/+501
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This tests that the vsyscall entries do what they're expected to do. It also confirms that attempts to read the vsyscall page behave as expected. If changes are made to the vsyscall code or its memory map handling, running this test in all three of vsyscall=none, vsyscall=emulate, and vsyscall=native are helpful. (Because it's easy, this also compares the vsyscall results to their vDSO equivalents.) Note to KAISER backporters: please test this under all three vsyscall modes. Also, in the emulate and native modes, make sure that test_vsyscall_64 agrees with the command line or config option as to which mode you're in. It's quite easy to mess up the kernel such that native mode accidentally emulates or vice versa. Greg, etc: please backport this to all your Meltdown-patched kernels. It'll help make sure the patches didn't regress vsyscalls. CSigned-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/2b9c5a174c1d60fd7774461d518aa75598b1d8fd.1515719552.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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