aboutsummaryrefslogtreecommitdiffstats
path: root/net/core/dev.c (unfollow)
AgeCommit message (Collapse)AuthorFilesLines
2019-12-20parisc: Fix compiler warnings in debug_core.cHelge Deller1-2/+8
Fix this compiler warning: kernel/debug/debug_core.c: In function ‘kgdb_cpu_enter’: arch/parisc/include/asm/cmpxchg.h:48:3: warning: value computed is not used [-Wunused-value] 48 | ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))) arch/parisc/include/asm/atomic.h:78:30: note: in expansion of macro ‘xchg’ 78 | #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) | ^~~~ kernel/debug/debug_core.c:596:4: note: in expansion of macro ‘atomic_xchg’ 596 | atomic_xchg(&kgdb_active, cpu); | ^~~~~~~~~~~ Signed-off-by: Helge Deller <deller@gmx.de>
2019-12-20block: fix memleak when __blk_rq_map_user_iov() is failedYang Yingliang1-1/+1
When I doing fuzzy test, get the memleak report: BUG: memory leak unreferenced object 0xffff88837af80000 (size 4096): comm "memleak", pid 3557, jiffies 4294817681 (age 112.499s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 20 00 00 00 10 01 00 00 00 00 00 00 01 00 00 00 ............... backtrace: [<000000001c894df8>] bio_alloc_bioset+0x393/0x590 [<000000008b139a3c>] bio_copy_user_iov+0x300/0xcd0 [<00000000a998bd8c>] blk_rq_map_user_iov+0x2f1/0x5f0 [<000000005ceb7f05>] blk_rq_map_user+0xf2/0x160 [<000000006454da92>] sg_common_write.isra.21+0x1094/0x1870 [<00000000064bb208>] sg_write.part.25+0x5d9/0x950 [<000000004fc670f6>] sg_write+0x5f/0x8c [<00000000b0d05c7b>] __vfs_write+0x7c/0x100 [<000000008e177714>] vfs_write+0x1c3/0x500 [<0000000087d23f34>] ksys_write+0xf9/0x200 [<000000002c8dbc9d>] do_syscall_64+0x9f/0x4f0 [<00000000678d8e9a>] entry_SYSCALL_64_after_hwframe+0x49/0xbe If __blk_rq_map_user_iov() is failed in blk_rq_map_user_iov(), the bio(s) which is allocated before this failing will leak. The refcount of the bio(s) is init to 1 and increased to 2 by calling bio_get(), but __blk_rq_unmap_user() only decrease it to 1, so the bio cannot be freed. Fix it by calling blk_rq_unmap_user(). Reviewed-by: Bob Liu <bob.liu@oracle.com> Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-20s390/dasd: fix typo in copyright statementStefan Haberland2-2/+2
coypright -> copyright Reported-by: Kate Stewart <kstewart@linuxfoundation.org> Signed-off-by: Stefan Haberland <sth@linux.ibm.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-20s390/dasd: fix memleak in path handling error caseStefan Haberland1-17/+2
If for whatever reason the dasd_eckd_check_characteristics() function exits after at least some paths have their configuration data allocated those data is never freed again. In the error case the device->private pointer is set to NULL and dasd_eckd_uncheck_device() will exit without freeing the path data because of this NULL pointer. Fix by calling dasd_eckd_clear_conf_data() for error cases. Also use dasd_eckd_clear_conf_data() in dasd_eckd_uncheck_device() to avoid code duplication. Reported-by: Qian Cai <cai@lca.pw> Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com> Signed-off-by: Stefan Haberland <sth@linux.ibm.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-20s390/dasd/cio: Interpret ccw_device_get_mdc return value correctlyJan Höppner2-5/+6
The max data count (mdc) is an unsigned 16-bit integer value as per AR documentation and is received via ccw_device_get_mdc() for a specific path mask from the CIO layer. The function itself also always returns a positive mdc value or 0 in case mdc isn't supported or couldn't be determined. Though, the comment for this function describes a negative return value to indicate failures. As a result, the DASD device driver interprets the return value of ccw_device_get_mdc() incorrectly. The error case is essentially a dead code path. To fix this behaviour, check explicitly for a return value of 0 and change the comment for ccw_device_get_mdc() accordingly. This fix merely enables the error code path in the DASD functions get_fcx_max_data() and verify_fcx_max_data(). The actual functionality stays the same and is still correct. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com> Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com> Reviewed-by: Stefan Haberland <sth@linux.ibm.com> Signed-off-by: Stefan Haberland <sth@linux.ibm.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-20block: Fix a lockdep complaint triggered by request queue flushingBart Van Assche2-0/+6
Avoid that running test nvme/012 from the blktests suite triggers the following false positive lockdep complaint: ============================================ WARNING: possible recursive locking detected 5.0.0-rc3-xfstests-00015-g1236f7d60242 #841 Not tainted -------------------------------------------- ksoftirqd/1/16 is trying to acquire lock: 000000000282032e (&(&fq->mq_flush_lock)->rlock){..-.}, at: flush_end_io+0x4e/0x1d0 but task is already holding lock: 00000000cbadcbc2 (&(&fq->mq_flush_lock)->rlock){..-.}, at: flush_end_io+0x4e/0x1d0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&fq->mq_flush_lock)->rlock); lock(&(&fq->mq_flush_lock)->rlock); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by ksoftirqd/1/16: #0: 00000000cbadcbc2 (&(&fq->mq_flush_lock)->rlock){..-.}, at: flush_end_io+0x4e/0x1d0 stack backtrace: CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.0.0-rc3-xfstests-00015-g1236f7d60242 #841 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: dump_stack+0x67/0x90 __lock_acquire.cold.45+0x2b4/0x313 lock_acquire+0x98/0x160 _raw_spin_lock_irqsave+0x3b/0x80 flush_end_io+0x4e/0x1d0 blk_mq_complete_request+0x76/0x110 nvmet_req_complete+0x15/0x110 [nvmet] nvmet_bio_done+0x27/0x50 [nvmet] blk_update_request+0xd7/0x2d0 blk_mq_end_request+0x1a/0x100 blk_flush_complete_seq+0xe5/0x350 flush_end_io+0x12f/0x1d0 blk_done_softirq+0x9f/0xd0 __do_softirq+0xca/0x440 run_ksoftirqd+0x24/0x50 smpboot_thread_fn+0x113/0x1e0 kthread+0x121/0x140 ret_from_fork+0x3a/0x50 Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-20block: Fix the type of 'sts' in bsg_queue_rq()Bart Van Assche1-1/+1
This patch fixes the following sparse warnings: block/bsg-lib.c:269:19: warning: incorrect type in initializer (different base types) block/bsg-lib.c:269:19: expected int sts block/bsg-lib.c:269:19: got restricted blk_status_t [usertype] block/bsg-lib.c:286:16: warning: incorrect type in return expression (different base types) block/bsg-lib.c:286:16: expected restricted blk_status_t block/bsg-lib.c:286:16: got int [assigned] sts Cc: Martin Wilck <mwilck@suse.com> Fixes: d46fe2cb2dce ("block: drop device references in bsg_queue_rq()") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-20parisc: soft_offline_page() now takes the pfnHelge Deller1-2/+1
Switch page deallocation table (pdt) driver to use pfn instead of a page pointer in soft_offline_page(). Fixes: feec24a6139d ("mm, soft-offline: convert parameter to pfn") Signed-off-by: Helge Deller <deller@gmx.de>
2019-12-20arm64: cpu_errata: Add Hisilicon TSV110 to spectre-v2 safe listWei Li1-0/+1
HiSilicon Taishan v110 CPUs didn't implement CSV2 field of the ID_AA64PFR0_EL1, but spectre-v2 is mitigated by hardware, so whitelist the MIDR in the safe list. Signed-off-by: Wei Li <liwei391@huawei.com> [hanjun: re-write the commit log] Signed-off-by: Hanjun Guo <guohanjun@huawei.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-12-20platform/x86: pcengines-apuv2: Spelling fixes in the driverAndy Shevchenko1-20/+20
Mainly does: - capitalize gpio and bios to GPIO and BIOS - capitalize beginning of comments - add periods in multi-line comments Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2019-12-20platform/x86: pcengines-apuv2: detect apuv4 boardEnrico Weigelt, metux IT consult1-0/+27
GPIO stuff on APUv4 seems to be the same as on APUv2, so we just need to match on DMI data. Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2019-12-20platform/x86: pcengines-apuv2: fix simswap GPIO assignmentEnrico Weigelt, metux IT consult1-1/+1
The mapping entry has to hold the GPIO line index instead of controller's register number. Fixes: 5037d4ddda31 ("platform/x86: pcengines-apuv2: wire up simswitch gpio as led") Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2019-12-20platform/x86: pmc_atom: Add Siemens CONNECT X300 to critclk_systems DMI tableMichael Haener1-0/+8
The CONNECT X300 uses the PMC clock for on-board components and gets stuck during boot if the clock is disabled. Therefore, add this device to the critical systems list. Tested on CONNECT X300. Fixes: 648e921888ad ("clk: x86: Stop marking clocks as CLK_IS_CRITICAL") Signed-off-by: Michael Haener <michael.haener@siemens.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2019-12-20platform/x86: hp-wmi: Make buffer for HPWMI_FEATURE2_QUERY 128 bytesHans de Goede1-1/+1
At least on the HP Envy x360 15-cp0xxx model the WMI interface for HPWMI_FEATURE2_QUERY requires an outsize of at least 128 bytes, otherwise it fails with an error code 5 (HPWMI_RET_INVALID_PARAMETERS): Dec 06 00:59:38 kernel: hp_wmi: query 0xd returned error 0x5 We do not care about the contents of the buffer, we just want to know if the HPWMI_FEATURE2_QUERY command is supported. This commits bumps the buffer size, fixing the error. Fixes: 8a1513b4932 ("hp-wmi: limit hotkey enable") Cc: stable@vger.kernel.org BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1520703 Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2019-12-20platform/mellanox: fix the mlx-bootctl sysfsLiming Sun2-6/+6
This is a follow-up commit for the sysfs attributes to change from DRIVER_ATTR to DEVICE_ATTR according to some initial comments. In such case, it's better to point the sysfs path to the device itself instead of the driver. The ABI document is also updated. Fixes: 79e29cb8fbc5 ("platform/mellanox: Add bootctl driver for Mellanox BlueField Soc") Signed-off-by: Liming Sun <lsun@mellanox.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2019-12-20rxrpc: Fix missing security check on incoming callsDavid Howells6-60/+59
Fix rxrpc_new_incoming_call() to check that we have a suitable service key available for the combination of service ID and security class of a new incoming call - and to reject calls for which we don't. This causes an assertion like the following to appear: rxrpc: Assertion failed - 6(0x6) == 12(0xc) is false kernel BUG at net/rxrpc/call_object.c:456! Where call->state is RXRPC_CALL_SERVER_SECURING (6) rather than RXRPC_CALL_COMPLETE (12). Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
2019-12-20rxrpc: Don't take call->user_mutex in rxrpc_new_incoming_call()David Howells1-17/+3
Standard kernel mutexes cannot be used in any way from interrupt or softirq context, so the user_mutex which manages access to a call cannot be a mutex since on a new call the mutex must start off locked and be unlocked within the softirq handler to prevent userspace interfering with a call we're setting up. Commit a0855d24fc22d49cdc25664fb224caee16998683 ("locking/mutex: Complain upon mutex API misuse in IRQ contexts") causes big warnings to be splashed in dmesg for each a new call that comes in from the server. Whilst it *seems* like it should be okay, since the accept path uses trylock, there are issues with PI boosting and marking the wrong task as the owner. Fix this by not taking the mutex in the softirq path at all. It's not obvious that there should be any need for it as the state is set before the first notification is generated for the new call. There's also no particular reason why the link-assessing ping should be triggered inside the mutex. It's not actually transmitted there anyway, but rather it has to be deferred to a workqueue. Further, I don't think that there's any particular reason that the socket notification needs to be done from within rx->incoming_lock, so the amount of time that lock is held can be shortened too and the ping prepared before the new call notification is sent. Fixes: 540b1c48c37a ("rxrpc: Fix deadlock between call creation and sendmsg/recvmsg") Signed-off-by: David Howells <dhowells@redhat.com> cc: Peter Zijlstra (Intel) <peterz@infradead.org> cc: Ingo Molnar <mingo@redhat.com> cc: Will Deacon <will@kernel.org> cc: Davidlohr Bueso <dave@stgolabs.net>
2019-12-20rxrpc: Unlock new call in rxrpc_new_incoming_call() rather than the callerDavid Howells2-26/+28
Move the unlock and the ping transmission for a new incoming call into rxrpc_new_incoming_call() rather than doing it in the caller. This makes it clearer to see what's going on. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> cc: Ingo Molnar <mingo@redhat.com> cc: Will Deacon <will@kernel.org> cc: Davidlohr Bueso <dave@stgolabs.net>
2019-12-20xfs: Make the symbol 'xfs_rtalloc_log_count' staticChen Wandun1-1/+1
Fix the following sparse warning: fs/xfs/libxfs/xfs_trans_resv.c:206:1: warning: symbol 'xfs_rtalloc_log_count' was not declared. Should it be static? Fixes: b1de6fc7520f ("xfs: fix log reservation overflows when allocating large rt extents") Signed-off-by: Chen Wandun <chenwandun@huawei.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-12-20xen/grant-table: remove multiple BUG_ON on gnttab_interfaceAditya Pakki1-4/+0
gnttab_request_version() always sets the gnttab_interface variable and the assertions to check for empty gnttab_interface is unnecessary. The patch eliminates multiple such assertions. Signed-off-by: Aditya Pakki <pakki001@umn.edu> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-12-20xen-blkback: support dynamic unbind/bindPaul Durrant1-18/+38
By simply re-attaching to shared rings during connect_ring() rather than assuming they are freshly allocated (i.e assuming the counters are zero) it is possible for vbd instances to be unbound and re-bound from and to (respectively) a running guest. This has been tested by running: while true; do fio --name=randwrite --ioengine=libaio --iodepth=16 \ --rw=randwrite --bs=4k --direct=1 --size=1G --verify=crc32; done in a PV guest whilst running: while true; do echo vbd-$DOMID-$VBD >unbind; echo unbound; sleep 5; echo vbd-$DOMID-$VBD >bind; echo bound; sleep 3; done in dom0 from /sys/bus/xen-backend/drivers/vbd to continuously unbind and re-bind its system disk image. This is a highly useful feature for a backend module as it allows it to be unloaded and re-loaded (i.e. updated) without requiring domUs to be halted. This was also tested by running: while true; do echo vbd-$DOMID-$VBD >unbind; echo unbound; sleep 5; rmmod xen-blkback; echo unloaded; sleep 1; modprobe xen-blkback; echo bound; cd $(pwd); sleep 3; done in dom0 whilst running the same loop as above in the (single) PV guest. Some (less stressful) testing has also been done using a Windows HVM guest with the latest 9.0 PV drivers installed. Signed-off-by: Paul Durrant <pdurrant@amazon.com> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-12-20xen/interface: re-define FRONT/BACK_RING_ATTACH()Paul Durrant1-20/+9
Currently these macros are defined to re-initialize a front/back ring (respectively) to values read from the shared ring in such a way that any requests/responses that are added to the shared ring whilst the front/back is detached will be skipped over. This, in general, is not a desirable semantic since most frontend implementations will eventually block waiting for a response which would either never appear or never be processed. Since the macros are currently unused, take this opportunity to re-define them to re-initialize a front/back ring using specified values. This also allows FRONT/BACK_RING_INIT() to be re-defined in terms of FRONT/BACK_RING_ATTACH() using a specified value of 0. NOTE: BACK_RING_ATTACH() will be used directly in a subsequent patch. Signed-off-by: Paul Durrant <pdurrant@amazon.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-12-20xenbus: limit when state is forced to closedPaul Durrant2-2/+11
If a driver probe() fails then leave the xenstore state alone. There is no reason to modify it as the failure may be due to transient resource allocation issues and hence a subsequent probe() may succeed. If the driver supports re-binding then only force state to closed during remove() only in the case when the toolstack may need to clean up. This can be detected by checking whether the state in xenstore has been set to closing prior to device removal. NOTE: Re-bind support is indicated by new boolean in struct xenbus_driver, which defaults to false. Subsequent patches will add support to some backend drivers. Signed-off-by: Paul Durrant <pdurrant@amazon.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-12-20xenbus: move xenbus_dev_shutdown() into frontend code...Paul Durrant4-27/+23
...and make it static xenbus_dev_shutdown() is seemingly intended to cause clean shutdown of PV frontends when a guest is rebooted. Indeed the function waits for a conpletion which is only set by a call to xenbus_frontend_closed(). This patch removes the shutdown() method from backends and moves xenbus_dev_shutdown() from xenbus_probe.c into xenbus_probe_frontend.c, renaming it appropriately and making it static. NOTE: In the case where the backend is running in a driver domain, the toolstack should have already terminated any frontends that may be using it (since Xen does not support re-startable PV driver domains) so xenbus_dev_shutdown() should never be called. Signed-off-by: Paul Durrant <pdurrant@amazon.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-12-20xen/blkfront: Adjust indentation in xlvbd_alloc_gendiskNathan Chancellor1-2/+2
Clang warns: ../drivers/block/xen-blkfront.c:1117:4: warning: misleading indentation; statement is not part of the previous 'if' [-Wmisleading-indentation] nr_parts = PARTS_PER_DISK; ^ ../drivers/block/xen-blkfront.c:1115:3: note: previous statement is here if (err) ^ This is because there is a space at the beginning of this line; remove it so that the indentation is consistent according to the Linux kernel coding style and clang no longer warns. While we are here, the previous line has some trailing whitespace; clean that up as well. Fixes: c80a420995e7 ("xen-blkfront: handle Xen major numbers other than XENVBD") Link: https://github.com/ClangBuiltLinux/linux/issues/791 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Juergen Gross <jgross@suse.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-12-20riscv: move sifive_l2_cache.c to drivers/socChristoph Hellwig8-2/+17
The sifive_l2_cache.c is in no way related to RISC-V architecture memory management. It is a little stub driver working around the fact that the EDAC maintainers prefer their drivers to be structured in a certain way that doesn't fit the SiFive SOCs. Move the file to drivers/soc and add a Kconfig option for it, as well as the whole drivers/soc boilerplate for CONFIG_SOC_SIFIVE. Fixes: a967a289f169 ("RISC-V: sifive_l2_cache: Add L2 cache controller driver for SiFive SoCs") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Borislav Petkov <bp@suse.de> [paul.walmsley@sifive.com: keep the MAINTAINERS change specific to the L2$ controller code] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-12-20riscv: define vmemmap before pfn_to_page callsDavid Abdurachmanov1-17/+21
pfn_to_page & page_to_pfn depend on vmemmap being available before the calls if kernel is configured with CONFIG_SPARSEMEM_VMEMMAP=y. This was caused by NOMMU changes which moved vmemmap definition bellow functions definitions calling pfn_to_page & page_to_pfn. Noticed while compiled 5.5-rc2 kernel for Fedora/RISCV. v2: - Add a comment for vmemmap in source Signed-off-by: David Abdurachmanov <david.abdurachmanov@sifive.com> Fixes: 6bd33e1ece52 ("riscv: add nommu support") Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-12-20riscv: fix scratch register clearing in M-mode.Greentime Hu1-1/+1
This patch fixes that the sscratch register clearing in M-mode. It cleared sscratch register in M-mode, but it should clear mscratch register. That will cause kernel trap if the CPU core doesn't support S-mode when trying to access sscratch. Fixes: 9e80635619b5 ("riscv: clear the instruction cache and all registers when booting") Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-12-20riscv: Fix use of undefined config option CONFIG_CONFIG_MMUAndreas Schwab1-1/+1
In Kconfig files, config options are written without the CONFIG_ prefix. Fixes: 6bd33e1ece52 ("riscv: add nommu support") Signed-off-by: Andreas Schwab <schwab@suse.de> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-12-19tc-testing: initial tdc selftests for cls_u32Davide Caratti2-22/+205
- move test "e9a3 - Add u32 with source match" to u32.json, and change the match pattern to catch all hnodes - add testcases for relevant error paths of cls_u32 module Signed-off-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-19net/sched: cls_u32: fix refcount leak in the error path of u32_change()Davide Caratti1-0/+25
when users replace cls_u32 filters with new ones having wrong parameters, so that u32_change() fails to validate them, the kernel doesn't roll-back correctly, and leaves semi-configured rules. Fix this in u32_walk(), avoiding a call to the walker function on filters that don't have a match rule connected. The side effect is, these "empty" filters are not even dumped when present; but that shouldn't be a problem as long as we are restoring the original behaviour, where semi-configured filters were not even added in the error path of u32_change(). Fixes: 6676d5e416ee ("net: sched: set dedicated tcf_walker flag when tp is empty") Signed-off-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-19nfc: s3fwrn5: replace the assertion with a WARN_ONAditya Pakki1-1/+4
In s3fwrn5_fw_recv_frame, if fw_info->rsp is not empty, the current code causes a crash via BUG_ON. However, s3fwrn5_fw_send_msg does not crash in such a scenario. The patch replaces the BUG_ON by returning the error to the callers and frees up skb. Signed-off-by: Aditya Pakki <pakki001@umn.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-19net: macb: fix probing of PHY not described in the dtAntoine Tenart1-4/+23
This patch fixes the case where the PHY isn't described in the device tree. This is due to the way the MDIO bus is registered in the driver: whether the PHY is described in the device tree or not, the bus is registered through of_mdiobus_register. The function masks all the PHYs and only allow probing the ones described in the device tree. Prior to the Phylink conversion this was also done but later on in the driver the MDIO bus was manually scanned to circumvent the fact that the PHY wasn't described. This patch fixes it in a proper way, by registering the MDIO bus based on if the PHY attached to a given interface is described in the device tree or not. Fixes: 7897b071ac3b ("net: macb: convert to phylink") Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-19of: mdio: export of_mdiobus_child_is_phyAntoine Tenart2-1/+8
This patch exports of_mdiobus_child_is_phy, allowing to check if a child node is a network PHY. Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-19tracing: Have the histogram compare functions convert to u64 firstSteven Rostedt (VMware)1-2/+2
The compare functions of the histogram code would be specific for the size of the value being compared (byte, short, int, long long). It would reference the value from the array via the type of the compare, but the value was stored in a 64 bit number. This is fine for little endian machines, but for big endian machines, it would end up comparing zeros or all ones (depending on the sign) for anything but 64 bit numbers. To fix this, first derference the value as a u64 then convert it to the type being compared. Link: http://lkml.kernel.org/r/20191211103557.7bed6928@gandalf.local.home Cc: stable@vger.kernel.org Fixes: 08d43a5fa063e ("tracing: Add lock-free tracing_map") Acked-by: Tom Zanussi <zanussi@kernel.org> Reported-by: Sven Schnelle <svens@stackframe.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-12-19tracing: Avoid memory leak in process_system_preds()Keita Suzuki1-1/+1
When failing in the allocation of filter_item, process_system_preds() goes to fail_mem, where the allocated filter is freed. However, this leads to memory leak of filter->filter_string and filter->prog, which is allocated before and in process_preds(). This bug has been detected by kmemleak as well. Fix this by changing kfree to __free_fiter. unreferenced object 0xffff8880658007c0 (size 32): comm "bash", pid 579, jiffies 4295096372 (age 17.752s) hex dump (first 32 bytes): 63 6f 6d 6d 6f 6e 5f 70 69 64 20 20 3e 20 31 30 common_pid > 10 00 00 00 00 00 00 00 00 65 73 00 00 00 00 00 00 ........es...... backtrace: [<0000000067441602>] kstrdup+0x2d/0x60 [<00000000141cf7b7>] apply_subsystem_event_filter+0x378/0x932 [<000000009ca32334>] subsystem_filter_write+0x5a/0x90 [<0000000072da2bee>] vfs_write+0xe1/0x240 [<000000004f14f473>] ksys_write+0xb4/0x150 [<00000000a968b4a0>] do_syscall_64+0x6d/0x1e0 [<000000001a189f40>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 unreferenced object 0xffff888060c22d00 (size 64): comm "bash", pid 579, jiffies 4295096372 (age 17.752s) hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 00 e8 d7 41 80 88 ff ff ...........A.... 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000b8c1b109>] process_preds+0x243/0x1820 [<000000003972c7f0>] apply_subsystem_event_filter+0x3be/0x932 [<000000009ca32334>] subsystem_filter_write+0x5a/0x90 [<0000000072da2bee>] vfs_write+0xe1/0x240 [<000000004f14f473>] ksys_write+0xb4/0x150 [<00000000a968b4a0>] do_syscall_64+0x6d/0x1e0 [<000000001a189f40>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 unreferenced object 0xffff888041d7e800 (size 512): comm "bash", pid 579, jiffies 4295096372 (age 17.752s) hex dump (first 32 bytes): 70 bc 85 97 ff ff ff ff 0a 00 00 00 00 00 00 00 p............... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<000000001e04af34>] process_preds+0x71a/0x1820 [<000000003972c7f0>] apply_subsystem_event_filter+0x3be/0x932 [<000000009ca32334>] subsystem_filter_write+0x5a/0x90 [<0000000072da2bee>] vfs_write+0xe1/0x240 [<000000004f14f473>] ksys_write+0xb4/0x150 [<00000000a968b4a0>] do_syscall_64+0x6d/0x1e0 [<000000001a189f40>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Link: http://lkml.kernel.org/r/20191211091258.11310-1-keitasuzuki.park@sslab.ics.keio.ac.jp Cc: Ingo Molnar <mingo@redhat.com> Cc: stable@vger.kernel.org Fixes: 404a3add43c9c ("tracing: Only add filter list when needed") Signed-off-by: Keita Suzuki <keitasuzuki.park@sslab.ics.keio.ac.jp> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-12-19bpf: Add further test_verifier cases for record_func_keyDaniel Borkmann3-24/+176
Expand dummy prog generation such that we can easily check on return codes and add few more test cases to make sure we keep on tracking pruning behavior. # ./test_verifier [...] #1066/p XDP pkt read, pkt_data <= pkt_meta', bad access 1 OK #1067/p XDP pkt read, pkt_data <= pkt_meta', bad access 2 OK Summary: 1580 PASSED, 0 SKIPPED, 0 FAILED Also verified that JIT dump of added test cases looks good. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/df7200b6021444fd369376d227de917357285b65.1576789878.git.daniel@iogearbox.net
2019-12-19bpf: Fix record_func_key to perform backtracking on r3Daniel Borkmann1-1/+7
While testing Cilium with /unreleased/ Linus' tree under BPF-based NodePort implementation, I noticed a strange BPF SNAT engine behavior from time to time. In some cases it would do the correct SNAT/DNAT service translation, but at a random point in time it would just stop and perform an unexpected translation after SYN, SYN/ACK and stack would send a RST back. While initially assuming that there is some sort of a race condition in BPF code, adding trace_printk()s for debugging purposes at some point seemed to have resolved the issue auto-magically. Digging deeper on this Heisenbug and reducing the trace_printk() calls to an absolute minimum, it turns out that a single call would suffice to trigger / not trigger the seen RST issue, even though the logic of the program itself remains unchanged. Turns out the single call changed verifier pruning behavior to get everything to work. Reconstructing a minimal test case, the incorrect JIT dump looked as follows: # bpftool p d j i 11346 0xffffffffc0cba96c: [...] 21: movzbq 0x30(%rdi),%rax 26: cmp $0xd,%rax 2a: je 0x000000000000003a 2c: xor %edx,%edx 2e: movabs $0xffff89cc74e85800,%rsi 38: jmp 0x0000000000000049 3a: mov $0x2,%edx 3f: movabs $0xffff89cc74e85800,%rsi 49: mov -0x224(%rbp),%eax 4f: cmp $0x20,%eax 52: ja 0x0000000000000062 54: add $0x1,%eax 57: mov %eax,-0x224(%rbp) 5d: jmpq 0xffffffffffff6911 62: mov $0x1,%eax [...] Hence, unexpectedly, JIT emitted a direct jump even though retpoline based one would have been needed since in line 2c and 3a we have different slot keys in BPF reg r3. Verifier log of the test case reveals what happened: 0: (b7) r0 = 14 1: (73) *(u8 *)(r1 +48) = r0 2: (71) r0 = *(u8 *)(r1 +48) 3: (15) if r0 == 0xd goto pc+4 R0_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff)) R1=ctx(id=0,off=0,imm=0) R10=fp0 4: (b7) r3 = 0 5: (18) r2 = 0xffff89cc74d54a00 7: (05) goto pc+3 11: (85) call bpf_tail_call#12 12: (b7) r0 = 1 13: (95) exit from 3 to 8: R0_w=inv13 R1=ctx(id=0,off=0,imm=0) R10=fp0 8: (b7) r3 = 2 9: (18) r2 = 0xffff89cc74d54a00 11: safe processed 13 insns (limit 1000000) [...] Second branch is pruned by verifier since considered safe, but issue is that record_func_key() couldn't have seen the index in line 3a and therefore decided that emitting a direct jump at this location was okay. Fix this by reusing our backtracking logic for precise scalar verification in order to prevent pruning on the slot key. This means verifier will track content of r3 all the way backwards and only prune if both scalars were unknown in state equivalence check and therefore poisoned in the first place in record_func_key(). The range is [x,x] in record_func_key() case since the slot always would have to be constant immediate. Correct verification after fix: 0: (b7) r0 = 14 1: (73) *(u8 *)(r1 +48) = r0 2: (71) r0 = *(u8 *)(r1 +48) 3: (15) if r0 == 0xd goto pc+4 R0_w=invP(id=0,umax_value=255,var_off=(0x0; 0xff)) R1=ctx(id=0,off=0,imm=0) R10=fp0 4: (b7) r3 = 0 5: (18) r2 = 0x0 7: (05) goto pc+3 11: (85) call bpf_tail_call#12 12: (b7) r0 = 1 13: (95) exit from 3 to 8: R0_w=invP13 R1=ctx(id=0,off=0,imm=0) R10=fp0 8: (b7) r3 = 2 9: (18) r2 = 0x0 11: (85) call bpf_tail_call#12 12: (b7) r0 = 1 13: (95) exit processed 15 insns (limit 1000000) [...] And correct corresponding JIT dump: # bpftool p d j i 11 0xffffffffc0dc34c4: [...] 21: movzbq 0x30(%rdi),%rax 26: cmp $0xd,%rax 2a: je 0x000000000000003a 2c: xor %edx,%edx 2e: movabs $0xffff9928b4c02200,%rsi 38: jmp 0x0000000000000049 3a: mov $0x2,%edx 3f: movabs $0xffff9928b4c02200,%rsi 49: cmp $0x4,%rdx 4d: jae 0x0000000000000093 4f: and $0x3,%edx 52: mov %edx,%edx 54: cmp %edx,0x24(%rsi) 57: jbe 0x0000000000000093 59: mov -0x224(%rbp),%eax 5f: cmp $0x20,%eax 62: ja 0x0000000000000093 64: add $0x1,%eax 67: mov %eax,-0x224(%rbp) 6d: mov 0x110(%rsi,%rdx,8),%rax 75: test %rax,%rax 78: je 0x0000000000000093 7a: mov 0x30(%rax),%rax 7e: add $0x19,%rax 82: callq 0x000000000000008e 87: pause 89: lfence 8c: jmp 0x0000000000000087 8e: mov %rax,(%rsp) 92: retq 93: mov $0x1,%eax [...] Also explicitly adding explicit env->allow_ptr_leaks to fixup_bpf_calls() since backtracking is enabled under former (direct jumps as well, but use different test). In case of only tracking different map pointers as in c93552c443eb ("bpf: properly enforce index mask to prevent out-of-bounds speculation"), pruning cannot make such short-cuts, neither if there are paths with scalar and non-scalar types as r3. mark_chain_precision() is only needed after we know that register_is_const(). If it was not the case, we already poison the key on first path and non-const key in later paths are not matching the scalar range in regsafe() either. Cilium NodePort testing passes fine as well now. Note, released kernels not affected. Fixes: d2e4c1e6c294 ("bpf: Constant map key tracking for prog array pokes") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/ac43ffdeb7386c5bd688761ed266f3722bb39823.1576789878.git.daniel@iogearbox.net
2019-12-19net, sysctl: Fix compiler warning when only cBPF is presentAlexander Lobakin1-0/+2
proc_dointvec_minmax_bpf_restricted() has been firstly introduced in commit 2e4a30983b0f ("bpf: restrict access to core bpf sysctls") under CONFIG_HAVE_EBPF_JIT. Then, this ifdef has been removed in ede95a63b5e8 ("bpf: add bpf_jit_limit knob to restrict unpriv allocations"), because a new sysctl, bpf_jit_limit, made use of it. Finally, this parameter has become long instead of integer with fdadd04931c2 ("bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64K") and thus, a new proc_dolongvec_minmax_bpf_restricted() has been added. With this last change, we got back to that proc_dointvec_minmax_bpf_restricted() is used only under CONFIG_HAVE_EBPF_JIT, but the corresponding ifdef has not been brought back. So, in configurations like CONFIG_BPF_JIT=y && CONFIG_HAVE_EBPF_JIT=n since v4.20 we have: CC net/core/sysctl_net_core.o net/core/sysctl_net_core.c:292:1: warning: ‘proc_dointvec_minmax_bpf_restricted’ defined but not used [-Wunused-function] 292 | proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Suppress this by guarding it with CONFIG_HAVE_EBPF_JIT again. Fixes: fdadd04931c2 ("bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64K") Signed-off-by: Alexander Lobakin <alobakin@dlink.ru> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191218091821.7080-1-alobakin@dlink.ru
2019-12-19xfs: don't commit sunit/swidth updates to disk if that would cause repair failuresDarrick J. Wong4-1/+130
Alex Lyakas reported[1] that mounting an xfs filesystem with new sunit and swidth values could cause xfs_repair to fail loudly. The problem here is that repair calculates the where mkfs should have allocated the root inode, based on the superblock geometry. The allocation decisions depend on sunit, which means that we really can't go updating sunit if it would lead to a subsequent repair failure on an otherwise correct filesystem. Port from xfs_repair some code that computes the location of the root inode and teach mount to skip the ondisk update if it would cause problems for repair. Along the way we'll update the documentation, provide a function for computing the minimum AGFL size instead of open-coding it, and cut down some indenting in the mount code. Note that we allow the mount to proceed (and new allocations will reflect this new geometry) because we've never screened this kind of thing before. We'll have to wait for a new future incompat feature to enforce correct behavior, alas. Note that the geometry reporting always uses the superblock values, not the incore ones, so that is what xfs_info and xfs_growfs will report. [1] https://lore.kernel.org/linux-xfs/20191125130744.GA44777@bfoster/T/#m00f9594b511e076e2fcdd489d78bc30216d72a7d Reported-by: Alex Lyakas <alex@zadara.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
2019-12-19xfs: split the sunit parameter update into two partsDarrick J. Wong1-51/+72
If the administrator provided a sunit= mount option, we need to validate the raw parameter, convert the mount option units (512b blocks) into the internal unit (fs blocks), and then validate that the (now cooked) parameter doesn't screw anything up on disk. The incore inode geometry computation can depend on the new sunit option, but a subsequent patch will make validating the cooked value depends on the computed inode geometry, so break the sunit update into two steps. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
2019-12-19xfs: refactor agfl length computation functionDarrick J. Wong1-5/+13
Refactor xfs_alloc_min_freelist to accept a NULL @pag argument, in which case it returns the largest possible minimum length. This will be used in an upcoming patch to compute the length of the AGFL at mkfs time. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
2019-12-19libxfs: resync with the userspace libxfsDarrick J. Wong4-24/+34
Prepare to resync the userspace libxfs with the kernel libxfs. There were a few things I missed -- a couple of static inline directory functions that have to be exported for xfs_repair; a couple of directory naming functions that make porting much easier if they're /not/ static inline; and a u16 usage that should have been uint16_t. None of these things are bugs in their own right; this just makes porting xfsprogs easier. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2019-12-19xfs: use bitops interface for buf log item AIL flag checkBrian Foster1-1/+1
The xfs_log_item flags were converted to atomic bitops as of commit 22525c17ed ("xfs: log item flags are racy"). The assert check for AIL presence in xfs_buf_item_relse() still uses the old value based check. This likely went unnoticed as XFS_LI_IN_AIL evaluates to 0 and causes the assert to unconditionally pass. Fix up the check. Signed-off-by: Brian Foster <bfoster@redhat.com> Fixes: 22525c17ed ("xfs: log item flags are racy") Reviewed-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-12-19net/ixgbe: Fix concurrency issues between config flow and XSKMaxim Mikityanskiy2-3/+12
Use synchronize_rcu to wait until the XSK wakeup function finishes before destroying the resources it uses: 1. ixgbe_down already calls synchronize_rcu after setting __IXGBE_DOWN. 2. After switching the XDP program, call synchronize_rcu to let ixgbe_xsk_wakeup exit before the XDP program is freed. 3. Changing the number of channels brings the interface down. 4. Disabling UMEM sets __IXGBE_TX_DISABLED before closing hardware resources and resetting xsk_umem. Check that bit in ixgbe_xsk_wakeup to avoid using the XDP ring when it's already destroyed. synchronize_rcu is called from ixgbe_txrx_ring_disable. Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191217162023.16011-5-maximmi@mellanox.com
2019-12-19net/i40e: Fix concurrency issues between config flow and XSKMaxim Mikityanskiy3-4/+12
Use synchronize_rcu to wait until the XSK wakeup function finishes before destroying the resources it uses: 1. i40e_down already calls synchronize_rcu. On i40e_down either __I40E_VSI_DOWN or __I40E_CONFIG_BUSY is set. Check the latter in i40e_xsk_wakeup (the former is already checked there). 2. After switching the XDP program, call synchronize_rcu to let i40e_xsk_wakeup exit before the XDP program is freed. 3. Changing the number of channels brings the interface down (see i40e_prep_for_reset and i40e_pf_quiesce_all_vsi). 4. Disabling UMEM sets __I40E_CONFIG_BUSY, too. Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191217162023.16011-4-maximmi@mellanox.com
2019-12-19net/mlx5e: Fix concurrency issues between config flow and XSKMaxim Mikityanskiy5-33/+13
After disabling resources necessary for XSK (the XDP program, channels, XSK queues), use synchronize_rcu to wait until the XSK wakeup function finishes, before freeing the resources. Suspend XSK wakeups during switching channels. If the XDP program is being removed, synchronize_rcu before closing the old channels to allow XSK wakeup to complete. Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191217162023.16011-3-maximmi@mellanox.com
2019-12-19xsk: Add rcu_read_lock around the XSK wakeupMaxim Mikityanskiy1-8/+14
The XSK wakeup callback in drivers makes some sanity checks before triggering NAPI. However, some configuration changes may occur during this function that affect the result of those checks. For example, the interface can go down, and all the resources will be destroyed after the checks in the wakeup function, but before it attempts to use these resources. Wrap this callback in rcu_read_lock to allow driver to synchronize_rcu before actually destroying the resources. xsk_wakeup is a new function that encapsulates calling ndo_xsk_wakeup wrapped into the RCU lock. After this commit, xsk_poll starts using xsk_wakeup and checks xs->zc instead of ndo_xsk_wakeup != NULL to decide ndo_xsk_wakeup should be called. It also fixes a bug introduced with the need_wakeup feature: a non-zero-copy socket may be used with a driver supporting zero-copy, and in this case ndo_xsk_wakeup should not be called, so the xs->zc check is the correct one. Fixes: 77cd0d7b3f25 ("xsk: add support for need_wakeup flag in AF_XDP rings") Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191217162023.16011-2-maximmi@mellanox.com
2019-12-19mmc: sdhci-of-esdhc: re-implement erratum A-009204 workaroundYangbo Lu1-0/+10
The erratum A-009204 workaround patch was reverted because of incorrect implementation. 8b6dc6b mmc: sdhci-of-esdhc: Revert "mmc: sdhci-of-esdhc: add erratum A-009204 support" This patch is to re-implement the workaround (add a 5 ms delay before setting SYSCTL[RSTD] to make sure all the DMA transfers are finished). Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Link: https://lore.kernel.org/r/20191219032335.26528-1-yangbo.lu@nxp.com Fixes: 5dd195522562 ("mmc: sdhci-of-esdhc: add erratum A-009204 support") Cc: stable@vger.kernel.org Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2019-12-18clk: qcom: Avoid SMMU/cx gdsc corner casesJeffrey Hugo1-0/+2
Mark the msm8998 cpu CX gdsc as votable and use the hw control to avoid corner cases with SMMU per hardware documentation. Fixes: 3f7df5baa259 ("clk: qcom: Add MSM8998 GPU Clock Controller (GPUCC) driver") Signed-off-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com> Link: https://lkml.kernel.org/r/20191217171905.5619-1-jeffrey.l.hugo@gmail.com Signed-off-by: Stephen Boyd <sboyd@kernel.org>