user/sven/linux.git/drivers/base, branch v5.9.1

mm: don't rely on system state to detect hot-plug operations

2020-09-26T17:33:57Z

In register_mem_sect_under_node() the system_state's value is checked to detect whether the call is made during boot time or during an hot-plug operation. Unfortunately, that check against SYSTEM_BOOTING is wrong because regular memory is registered at SYSTEM_SCHEDULING state. In addition, memory hot-plug operation can be triggered at this system state by the ACPI [1]. So checking against the system state is not enough. The consequence is that on system with interleaved node's ranges like this: Early memory node ranges node 1: [mem 0x0000000000000000-0x000000011fffffff] node 2: [mem 0x0000000120000000-0x000000014fffffff] node 1: [mem 0x0000000150000000-0x00000001ffffffff] node 0: [mem 0x0000000200000000-0x000000048fffffff] node 2: [mem 0x0000000490000000-0x00000007ffffffff] This can be seen on PowerPC LPAR after multiple memory hot-plug and hot-unplug operations are done. At the next reboot the node's memory ranges can be interleaved and since the call to link_mem_sections() is made in topology_init() while the system is in the SYSTEM_SCHEDULING state, the node's id is not checked, and the sections registered to multiple nodes: $ ls -l /sys/devices/system/memory/memory21/node* total 0 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node1 -> ../../node/node1 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node2 -> ../../node/node2 In that case, the system is able to boot but if later one of theses memory blocks is hot-unplugged and then hot-plugged, the sysfs inconsistency is detected and this is triggering a BUG_ON(): kernel BUG at /Users/laurent/src/linux-ppc/mm/memory_hotplug.c:1084! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: rpadlpar_io rpaphp pseries_rng rng_core vmx_crypto gf128mul binfmt_misc ip_tables x_tables xfs libcrc32c crc32c_vpmsum autofs4 CPU: 8 PID: 10256 Comm: drmgr Not tainted 5.9.0-rc1+ #25 Call Trace: add_memory_resource+0x23c/0x340 (unreliable) __add_memory+0x5c/0xf0 dlpar_add_lmb+0x1b4/0x500 dlpar_memory+0x1f8/0xb80 handle_dlpar_errorlog+0xc0/0x190 dlpar_store+0x198/0x4a0 kobj_attr_store+0x30/0x50 sysfs_kf_write+0x64/0x90 kernfs_fop_write+0x1b0/0x290 vfs_write+0xe8/0x290 ksys_write+0xdc/0x130 system_call_exception+0x160/0x270 system_call_common+0xf0/0x27c This patch addresses the root cause by not relying on the system_state value to detect whether the call is due to a hot-plug operation. An extra parameter is added to link_mem_sections() detailing whether the operation is due to a hot-plug operation. [1] According to Oscar Salvador, using this qemu command line, ACPI memory hotplug operations are raised at SYSTEM_SCHEDULING state: $QEMU -enable-kvm -machine pc -smp 4,sockets=4,cores=1,threads=1 -cpu host -monitor pty \ -m size=$MEM,slots=255,maxmem=4294967296k \ -numa node,nodeid=0,cpus=0-3,mem=512 -numa node,nodeid=1,mem=512 \ -object memory-backend-ram,id=memdimm0,size=134217728 -device pc-dimm,node=0,memdev=memdimm0,id=dimm0,slot=0 \ -object memory-backend-ram,id=memdimm1,size=134217728 -device pc-dimm,node=0,memdev=memdimm1,id=dimm1,slot=1 \ -object memory-backend-ram,id=memdimm2,size=134217728 -device pc-dimm,node=0,memdev=memdimm2,id=dimm2,slot=2 \ -object memory-backend-ram,id=memdimm3,size=134217728 -device pc-dimm,node=0,memdev=memdimm3,id=dimm3,slot=3 \ -object memory-backend-ram,id=memdimm4,size=134217728 -device pc-dimm,node=1,memdev=memdimm4,id=dimm4,slot=4 \ -object memory-backend-ram,id=memdimm5,size=134217728 -device pc-dimm,node=1,memdev=memdimm5,id=dimm5,slot=5 \ -object memory-backend-ram,id=memdimm6,size=134217728 -device pc-dimm,node=1,memdev=memdimm6,id=dimm6,slot=6 \ Fixes: 4fbce633910e ("mm/memory_hotplug.c: make register_mem_sect_under_node() a callback of walk_memory_range()") Signed-off-by: Laurent Dufour Signed-off-by: Andrew Morton Reviewed-by: David Hildenbrand Reviewed-by: Oscar Salvador Acked-by: Michal Hocko Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Fenghua Yu Cc: Nathan Lynch Cc: Scott Cheloha Cc: Tony Luck Cc: Link: https://lkml.kernel.org/r/20200915094143.79181-3-ldufour@linux.ibm.com Signed-off-by: Linus Torvalds

Merge tag 'regmap-fix-v5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

2020-09-25T22:11:24Z

Pull regmap fixes from Mark Brown: "Two issues here - one is a fix for use after free issues in the case where a regmap overrides its name using something dynamically generated, the other is that we weren't handling access checks non-incrementing I/O on registers within paged register regions correctly resulting in spurious errors. Both of these are quite rare but serious if they occur" * tag 'regmap-fix-v5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap: regmap: fix page selection for noinc writes regmap: fix page selection for noinc reads regmap: debugfs: Add back in erroneously removed initialisation of ret regmap: debugfs: Fix handling of name string for debugfs init delays

regmap: fix page selection for noinc writes

2020-09-21T19:58:02Z

Non-incrementing writes can fail if register + length crosses page border. However for non-incrementing writes we should not check for page border crossing. Fix this by passing additional flag to _regmap_raw_write and passing length to _regmap_select_page basing on the flag. Signed-off-by: Dmitry Baryshkov Fixes: cdf6b11daa77 ("regmap: Add regmap_noinc_write API") Link: https://lore.kernel.org/r/20200917153405.3139200-2-dmitry.baryshkov@linaro.org Signed-off-by: Mark Brown

regmap: fix page selection for noinc reads

2020-09-21T19:58:01Z

Non-incrementing reads can fail if register + length crosses page border. However for non-incrementing reads we should not check for page border crossing. Fix this by passing additional flag to _regmap_raw_read and passing length to _regmap_select_page basing on the flag. Signed-off-by: Dmitry Baryshkov Fixes: 74fe7b551f33 ("regmap: Add regmap_noinc_read API") Link: https://lore.kernel.org/r/20200917153405.3139200-1-dmitry.baryshkov@linaro.org Signed-off-by: Mark Brown

regmap: debugfs: Add back in erroneously removed initialisation of ret

2020-09-18T11:47:37Z

Fixes: 94cc89eb8fa5 ("regmap: debugfs: Fix handling of name string for debugfs init delays") Reported-by: kernel test robot Reported-by: Dan Carpenter Signed-off-by: Charles Keepax Link: https://lore.kernel.org/r/20200918112002.15216-1-ckeepax@opensource.cirrus.com Signed-off-by: Mark Brown

regmap: debugfs: Fix handling of name string for debugfs init delays

2020-09-17T17:54:20Z

In regmap_debugfs_init the initialisation of the debugfs is delayed if the root node isn't ready yet. Most callers of regmap_debugfs_init pass the name from the regmap_config, which is considered temporary ie. may be unallocated after the regmap_init call returns. This leads to a potential use after free, where config->name has been freed by the time it is used in regmap_debugfs_initcall. This situation can be seen on Zynq, where the architecture init_irq callback registers a syscon device, using a local variable for the regmap_config. As init_irq is very early in the platform bring up the regmap debugfs root isn't ready yet. Although this doesn't crash it does result in the debugfs entry not having the correct name. Regmap already sets map->name from config->name on the regmap_init path and the fact that a separate field is used to pass the name to regmap_debugfs_init appears to be an artifact of the debugfs name being added before the map name. As such this patch updates regmap_debugfs_init to use map->name, which is already duplicated from the config avoiding the issue. This does however leave two lose ends, both regmap_attach_dev and regmap_reinit_cache can be called after a regmap is registered and would have had the effect of applying a new name to the debugfs entries. In both of these cases it was chosen to update the map name. In the case of regmap_attach_dev there are 3 users that currently use this function to update the name, thus doing so avoids changes for those users and it seems reasonable that attaching a device would want to set the name of the map. In the case of regmap_reinit_cache the primary use-case appears to be devices that need some register access to identify the device (for example devices in the same family) and then update the cache to match the exact hardware. Whilst no users do currently update the name here, given the use-case it seemed reasonable the name might want to be updated once the device is better identified. Signed-off-by: Charles Keepax Link: https://lore.kernel.org/r/20200917120828.12987-1-ckeepax@opensource.cirrus.com Signed-off-by: Mark Brown

Merge tag 'driver-core-5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2020-09-13T16:02:59Z

Pull driver core fixes from Greg KH: "Here are some small driver core and debugfs fixes for 5.9-rc5 Included in here are: - firmware loader memory leak fix - firmware loader testing fixes for non-EFI systems - device link locking fixes found by lockdep - kobject_del() bugfix that has been affecting some callers - debugfs minor fix All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: test_firmware: Test platform fw loading on non-EFI systems PM: : fix @em_pd kernel-doc warning kobject: Drop unneeded conditional in __kobject_del() driver core: Fix device_pm_lock() locking for device links MAINTAINERS: Add the security document to SECURITY CONTACT driver code: print symbolic error code debugfs: Fix module state check condition kobject: Restore old behaviour of kobject_del(NULL) firmware_loader: fix memory leak for paged buffer

driver core: Fix device_pm_lock() locking for device links

2020-09-04T16:21:35Z

This commit fixes two issues: 1. The lockdep warning reported by Dong Aisheng [1]. It is a warning about a cycle (dpm_list_mtx --> kn->active#3 --> fw_lock) that was introduced when device-link devices were added to expose device link information in sysfs. The patch that "introduced" this cycle can't be reverted because it's fixes a real SRCU issue and also ensures that the device-link device is deleted as soon as the device-link is deleted. This is important to avoid sysfs name collisions if the device-link is create again immediately (this can happen a lot with deferred probing). 2. Inconsistency in grabbing device_pm_lock() during device link deletion Some device link deletion code paths grab device_pm_lock(), while others don't. The device_pm_lock() is grabbed during device_link_add() because it checks if the supplier is in the dpm_list and also reorders the dpm_list. However, when a device link is deleted, it does not do either of those and therefore device_pm_lock() is not necessary. Dropping the device_pm_lock() in all the device link deletion paths removes the inconsistency in locking. Thanks to Stephen Boyd for helping me understand the lockdep splat. Fixes: 843e600b8a2b ("driver core: Fix sleeping in invalid context during device link deletion") [1] - https://lore.kernel.org/lkml/CAA+hA=S4eAreb7vo69LAXSk2t5=DEKNxHaiY1wSpk4xTp9urLg@mail.gmail.com/ Reported-by: Dong Aisheng Signed-off-by: Saravana Kannan Tested-by: Peng Fan Link: https://lore.kernel.org/r/20200901184445.1736658-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

driver code: print symbolic error code

2020-09-04T16:14:52Z

dev_err_probe() prepends the message with an error code. Let's make it more readable by translating the code to a more recognisable symbol. Fixes: a787e5400a1c ("driver core: add device probe log helper") Signed-off-by: Michał Mirosław Link: https://lore.kernel.org/r/ea3f973e4708919573026fdce52c264db147626d.1598630856.git.mirq-linux@rere.qmqm.pl Signed-off-by: Greg Kroah-Hartman

Merge tag 'devprop-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2020-08-28T20:23:31Z

Pull device properties framework fix from Rafael Wysocki: "Prevent the promotion of the secondary firmware node of a device to the primary one from leaking a pointer (Heikki Krogerus)" * tag 'devprop-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: device property: Fix the secondary firmware node handling in set_primary_fwnode()