user/sven/linux.git/drivers/base, branch v5.4.42

Revert "software node: Simplify software_node_release() function"

2020-05-10T08:31:30Z

commit 7589238a8cf37331607c3222a64ac3140b29532d upstream. This reverts commit 3df85a1ae51f6b256982fe9d17c2dc5bfb4cc402. The reverted commit says "It's possible to release the node ID immediately when fwnode_remove_software_node() is called, no need to wait for software_node_release() with that." However, releasing the node ID before waiting for software_node_release() to be called causes the node ID to be released before the kobject and the underlying sysfs entry; this means there is a period of time where a sysfs entry exists that is associated with an unallocated node ID. Once consequence of this is that there is a race condition where it is possible to call fwnode_create_software_node() with no parent node specified (NULL) and have it fail with -EEXIST because the node ID that was assigned is still associated with a stale sysfs entry that hasn't been cleaned up yet. Although it is difficult to reproduce this race condition under normal conditions, it can be deterministically reproduced with the following minconfig on UML: CONFIG_KUNIT_DRIVER_PE_TEST=y CONFIG_DEBUG_KERNEL=y CONFIG_DEBUG_OBJECTS=y CONFIG_DEBUG_OBJECTS_TIMERS=y CONFIG_DEBUG_KOBJECT_RELEASE=y CONFIG_KUNIT=y Running the tests with this configuration causes the following failure: kobject: 'node0' ((____ptrval____)): kobject_release, parent (____ptrval____) (delayed 400) ok 1 - pe_test_uints sysfs: cannot create duplicate filename '/kernel/software_nodes/node0' CPU: 0 PID: 28 Comm: kunit_try_catch Not tainted 5.6.0-rc3-next-20200227 #14 kobject_add_internal failed for node0 with -EEXIST, don't try to register things with the same name in the same directory. kobject: 'node0' ((____ptrval____)): kobject_release, parent (____ptrval____) (delayed 100) # pe_test_uint_arrays: ASSERTION FAILED at drivers/base/test/property-entry-test.c:123 Expected node is not error, but is: -17 not ok 2 - pe_test_uint_arrays Reported-by: Heidi Fahim Signed-off-by: Brendan Higgins Reviewed-by: Heikki Krogerus Cc: 5.3+ # 5.3+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM: sleep: core: Switch back to async_schedule_dev()

2020-05-02T06:48:53Z

commit 09beebd8f93b3c8bf894e342f0a203a5c612478c upstream. Commit 8b9ec6b73277 ("PM core: Use new async_schedule_dev command") introduced a new function for better performance. However commit f2a424f6c613 ("PM / core: Introduce dpm_async_fn() helper") went back to the non-optimized version, async_schedule(). So switch back to the sync_schedule_dev() to improve performance Fixes: f2a424f6c613 ("PM / core: Introduce dpm_async_fn() helper") Signed-off-by: Kai-Heng Feng Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM: sleep: wakeup: Skip wakeup_source_sysfs_remove() if device is not there

2020-04-17T08:50:12Z

commit 87de6594dc45dbf6819f3e0ef92f9331c5a9444c upstream. Skip wakeup_source_sysfs_remove() to fix a NULL pinter dereference via ws->dev, if the wakeup source is unregistered before registering the wakeup class from device_add(). Fixes: 2ca3d1ecb8c4 ("PM / wakeup: Register wakeup class kobj after device is added") Signed-off-by: Neeraj Upadhyay Cc: 5.4+ # 5.4+ [ rjw: Subject & changelog, white space ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM / Domains: Allow no domain-idle-states DT property in genpd when parsing

2020-04-17T08:50:12Z

commit 56cb26891ea4180121265dc6b596015772c4a4b8 upstream. Commit 2c361684803e ("PM / Domains: Don't treat zero found compatible idle states as an error"), moved of_genpd_parse_idle_states() towards allowing none compatible idle state to be found for the device node, rather than returning an error code. However, it didn't consider that the "domain-idle-states" DT property may be missing as it's optional, which makes of_count_phandle_with_args() to return -ENOENT. Let's fix this to make the behaviour consistent. Fixes: 2c361684803e ("PM / Domains: Don't treat zero found compatible idle states as an error") Reported-by: Benjamin Gaignard Cc: 4.20+ # 4.20+ Reviewed-by: Sudeep Holla Signed-off-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

firmware: fix a double abort case with fw_load_sysfs_fallback

2020-04-17T08:50:05Z

[ Upstream commit bcfbd3523f3c6eea51a74d217a8ebc5463bcb7f4 ] fw_sysfs_wait_timeout may return err with -ENOENT at fw_load_sysfs_fallback and firmware is already in abort status, no need to abort again, so skip it. This issue is caused by concurrent situation like below: when thread 1# wait firmware loading, thread 2# may write -1 to abort loading and wakeup thread 1# before it timeout. so wait_for_completion_killable_timeout of thread 1# would return remaining time which is != 0 with fw_st->status FW_STATUS_ABORTED.And the results would be converted into err -ENOENT in __fw_state_wait_common and transfered to fw_load_sysfs_fallback in thread 1#. The -ENOENT means firmware status is already at ABORTED, so fw_load_sysfs_fallback no need to get mutex to abort again. ----------------------------- thread 1#,wait for loading fw_load_sysfs_fallback ->fw_sysfs_wait_timeout ->__fw_state_wait_common ->wait_for_completion_killable_timeout in __fw_state_wait_common, ... 93 ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout); 94 if (ret != 0 && fw_st->status == FW_STATUS_ABORTED) 95 return -ENOENT; 96 if (!ret) 97 return -ETIMEDOUT; 98 99 return ret < 0 ? ret : 0; ----------------------------- thread 2#, write -1 to abort loading firmware_loading_store ->fw_load_abort ->__fw_load_abort ->fw_state_aborted ->__fw_state_set ->complete_all in __fw_state_set, ... 111 if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED) 112 complete_all(&fw_st->completion); ------------------------------------------- BTW,the double abort issue would not cause kernel panic or create an issue, but slow down it sometimes.The change is just a minor optimization. Signed-off-by: Junyong Sun Acked-by: Luis Chamberlain Link: https://lore.kernel.org/r/1583202968-28792-1-git-send-email-sunjunyong@xiaomi.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

drivers/base/memory.c: indicate all memory blocks as removable

2020-04-01T09:02:02Z

commit 53cdc1cb29e87ce5a61de5bb393eb08925d14ede upstream. We see multiple issues with the implementation/interface to compute whether a memory block can be offlined (exposed via /sys/devices/system/memory/memoryX/removable) and would like to simplify it (remove the implementation). 1. It runs basically lockless. While this might be good for performance, we see possible races with memory offlining that will require at least some sort of locking to fix. 2. Nowadays, more false positives are possible. No arch-specific checks are performed that validate if memory offlining will not be denied right away (and such check will require locking). For example, arm64 won't allow to offline any memory block that was added during boot - which will imply a very high error rate. Other archs have other constraints. 3. The interface is inherently racy. E.g., if a memory block is detected to be removable (and was not a false positive at that time), there is still no guarantee that offlining will actually succeed. So any caller already has to deal with false positives. 4. It is unclear which performance benefit this interface actually provides. The introducing commit 5c755e9fd813 ("memory-hotplug: add sysfs removable attribute for hotplug memory remove") mentioned "A user-level agent must be able to identify which sections of memory are likely to be removable before attempting the potentially expensive operation." However, no actual performance comparison was included. Known users: - lsmem: Will group memory blocks based on the "removable" property. [1] - chmem: Indirect user. It has a RANGE mode where one can specify removable ranges identified via lsmem to be offlined. However, it also has a "SIZE" mode, which allows a sysadmin to skip the manual "identify removable blocks" step. [2] - powerpc-utils: Uses the "removable" attribute to skip some memory blocks right away when trying to find some to offline+remove. However, with ballooning enabled, it already skips this information completely (because it once resulted in many false negatives). Therefore, the implementation can deal with false positives properly already. [3] According to Nathan Fontenot, DLPAR on powerpc is nowadays no longer driven from userspace via the drmgr command (powerpc-utils). Nowadays it's managed in the kernel - including onlining/offlining of memory blocks - triggered by drmgr writing to /sys/kernel/dlpar. So the affected legacy userspace handling is only active on old kernels. Only very old versions of drmgr on a new kernel (unlikely) might execute slower - totally acceptable. With CONFIG_MEMORY_HOTREMOVE, always indicating "removable" should not break any user space tool. We implement a very bad heuristic now. Without CONFIG_MEMORY_HOTREMOVE we cannot offline anything, so report "not removable" as before. Original discussion can be found in [4] ("[PATCH RFC v1] mm: is_mem_section_removable() overhaul"). Other users of is_mem_section_removable() will be removed next, so that we can remove is_mem_section_removable() completely. [1] http://man7.org/linux/man-pages/man1/lsmem.1.html [2] http://man7.org/linux/man-pages/man8/chmem.8.html [3] https://github.com/ibm-power-utilities/powerpc-utils [4] https://lkml.kernel.org/r/20200117105759.27905-1-david@redhat.com Also, this patch probably fixes a crash reported by Steve. http://lkml.kernel.org/r/CAPcyv4jpdaNvJ67SkjyUJLBnBnXXQv686BiVW042g03FUmWLXw@mail.gmail.com Reported-by: "Scargall, Steve" Suggested-by: Michal Hocko Signed-off-by: David Hildenbrand Signed-off-by: Andrew Morton Reviewed-by: Nathan Fontenot Acked-by: Michal Hocko Cc: Dan Williams Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Badari Pulavarty Cc: Robert Jennings Cc: Heiko Carstens Cc: Karel Zak Cc: Link: http://lkml.kernel.org/r/20200128093542.6908-1-david@redhat.com Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

driver code: clarify and fix platform device DMA mask allocation

2020-03-18T06:17:56Z

commit e3a36eb6dfaeea8175c05d5915dcf0b939be6dab upstream. This does three inter-related things to clarify the usage of the platform device dma_mask field. In the process, fix the bug introduced by cdfee5623290 ("driver core: initialize a default DMA mask for platform device") that caused Artem Tashkinov's laptop to not boot with newer Fedora kernels. This does: - First off, rename the field to "platform_dma_mask" to make it greppable. We have way too many different random fields called "dma_mask" in various data structures, where some of them are actual masks, and some of them are just pointers to the mask. And the structures all have pointers to each other, or embed each other inside themselves, and "pdev" sometimes means "platform device" and sometimes it means "PCI device". So to make it clear in the code when you actually use this new field, give it a unique name (it really should be something even more unique like "platform_device_dma_mask", since it's per platform device, not per platform, but that gets old really fast, and this is unique enough in context). To further clarify when the field gets used, initialize it when we actually start using it with the default value. - Then, use this field instead of the random one-off allocation in platform_device_register_full() that is now unnecessary since we now already have a perfectly fine allocation for it in the platform device structure. - The above then allows us to fix the actual bug, where the error path of platform_device_register_full() would unconditionally free the platform device DMA allocation with 'kfree()'. That kfree() was dont regardless of whether the allocation had been done earlier with the (now removed) kmalloc, or whether setup_pdev_dma_masks() had already been used and the dma_mask pointer pointed to the mask that was part of the platform device. It seems most people never triggered the error path, or only triggered it from a call chain that set an explicit pdevinfo->dma_mask value (and thus caused the unnecessary allocation that was "cleaned up" in the error path) before calling platform_device_register_full(). Robin Murphy points out that in Artem's case the wdat_wdt driver failed in platform_device_add(), and that was the one that had called platform_device_register_full() with pdevinfo.dma_mask = 0, and would have caused that kfree() of pdev.dma_mask corrupting the heap. A later unrelated kmalloc() then oopsed due to the heap corruption. Fixes: cdfee5623290 ("driver core: initialize a default DMA mask for platform device") Reported-bisected-and-tested-by: Artem S. Tashkinov Reviewed-by: Robin Murphy Cc: Greg Kroah-Hartman Signed-off-by: Christoph Hellwig Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

driver core: platform: fix u32 greater or equal to zero comparison

2020-02-24T07:36:55Z

[ Upstream commit 0707cfa5c3ef58effb143db9db6d6e20503f9dec ] Currently the check that a u32 variable i is >= 0 is always true because the unsigned variable will never be negative, causing the loop to run forever. Fix this by changing the pre-decrement check to a zero check on i followed by a decrement of i. Addresses-Coverity: ("Unsigned compared against 0") Fixes: 39cc539f90d0 ("driver core: platform: Prevent resouce overflow from causing infinite loops") Signed-off-by: Colin Ian King Reviewed-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20200116175758.88396-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

driver core: Print device when resources present in really_probe()

2020-02-24T07:36:47Z

[ Upstream commit 7c35e699c88bd60734277b26962783c60e04b494 ] If a device already has devres items attached before probing, a warning backtrace is printed. However, this backtrace does not reveal the offending device, leaving the user uninformed. Furthermore, using WARN_ON() causes systems with panic-on-warn to reboot. Fix this by replacing the WARN_ON() by a dev_crit() message. Abort probing the device, to prevent doing more damage to the device's resources. Signed-off-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20191206132219.28908-1-geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

driver core: platform: Prevent resouce overflow from causing infinite loops

2020-02-24T07:36:47Z

[ Upstream commit 39cc539f90d035a293240c9443af50be55ee81b8 ] num_resources in the platform_device struct is declared as a u32. The for loops that iterate over num_resources use an int as the counter, which can cause infinite loops on architectures with smaller ints. Change the loop counters to u32. Signed-off-by: Simon Schwartz Link: https://lore.kernel.org/r/2201ce63a2a171ffd2ed14e867875316efcf71db.camel@theschwartz.xyz Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin