kernel/linux.git/drivers/pps, branch v6.12.80

pps: fix warning in pps_register_cdev when register device fail

2025-10-15T10:00:09+00:00

[ Upstream commit b0531cdba5029f897da5156815e3bdafe1e9b88d ] Similar to previous commit 2a934fdb01db ("media: v4l2-dev: fix error handling in __video_register_device()"), the release hook should be set before device_register(). Otherwise, when device_register() return error and put_device() try to callback the release function, the below warning may happen. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 4760 at drivers/base/core.c:2567 device_release+0x1bd/0x240 drivers/base/core.c:2567 Modules linked in: CPU: 1 UID: 0 PID: 4760 Comm: syz.4.914 Not tainted 6.17.0-rc3+ #1 NONE RIP: 0010:device_release+0x1bd/0x240 drivers/base/core.c:2567 Call Trace: kobject_cleanup+0x136/0x410 lib/kobject.c:689 kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0xe9/0x130 lib/kobject.c:737 put_device+0x24/0x30 drivers/base/core.c:3797 pps_register_cdev+0x2da/0x370 drivers/pps/pps.c:402 pps_register_source+0x2f6/0x480 drivers/pps/kapi.c:108 pps_tty_open+0x190/0x310 drivers/pps/clients/pps-ldisc.c:57 tty_ldisc_open+0xa7/0x120 drivers/tty/tty_ldisc.c:432 tty_set_ldisc+0x333/0x780 drivers/tty/tty_ldisc.c:563 tiocsetd drivers/tty/tty_io.c:2429 [inline] tty_ioctl+0x5d1/0x1700 drivers/tty/tty_io.c:2728 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x194/0x210 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x5f/0x2a0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e Before commit c79a39dc8d06 ("pps: Fix a use-after-free"), pps_register_cdev() call device_create() to create pps->dev, which will init dev->release to device_create_release(). Now the comment is outdated, just remove it. Thanks for the reminder from Calvin Owens, 'kfree_pps' should be removed in pps_register_source() to avoid a double free in the failure case. Link: https://lore.kernel.org/all/20250827065010.3208525-1-wangliang74@huawei.com/ Fixes: c79a39dc8d06 ("pps: Fix a use-after-free") Signed-off-by: Wang Liang Reviewed-By: Calvin Owens Link: https://lore.kernel.org/r/20250830075023.3498174-1-wangliang74@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

pps: clients: gpio: fix interrupt handling order in remove path

2025-08-20T16:30:25+00:00

[ Upstream commit 6bca1e955830808dc90e0506b2951b4256b81bbb ] The interrupt handler in pps_gpio_probe() is registered after calling pps_register_source() using devm_request_irq(). However, in the corresponding remove function, pps_unregister_source() is called before the IRQ is freed, since devm-managed resources are released after the remove function completes. This creates a potential race condition where an interrupt may occur after the PPS source is unregistered but before the handler is removed, possibly leading to a kernel panic. To prevent this, switch from devm-managed IRQ registration to manual management by using request_irq() and calling free_irq() explicitly in the remove path before unregistering the PPS source. This ensures the interrupt handler is safely removed before deactivating the PPS source. Signed-off-by: Eliav Farber Link: https://lore.kernel.org/r/20250527053355.37185-1-farbere@amazon.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

pps: fix poll support

2025-08-15T10:13:35+00:00

[ Upstream commit 12c409aa1ec2592280a2ddcc66ff8f3c7f7bb171 ] Because pps_cdev_poll() returns unconditionally EPOLLIN, a user space program that calls select/poll get always an immediate data ready-to-read response. As a result the intended use to wait until next data becomes ready does not work. User space snippet: struct pollfd pollfd = { .fd = open("/dev/pps0", O_RDONLY), .events = POLLIN|POLLERR, .revents = 0 }; while(1) { poll(&pollfd, 1, 2000/*ms*/); // returns immediate, but should wait if(revents & EPOLLIN) { // always true struct pps_fdata fdata; memset(&fdata, 0, sizeof(memdata)); ioctl(PPS_FETCH, &fdata); // currently fetches data at max speed } } Lets remember the last fetch event counter and compare this value in pps_cdev_poll() with most recent event counter and return 0 if they are equal. Signed-off-by: Denis OSTERLAND-HEIM Co-developed-by: Rodolfo Giometti Signed-off-by: Rodolfo Giometti Fixes: eae9d2ba0cfc ("LinuxPPS: core support") Link: https://lore.kernel.org/all/f6bed779-6d59-4f0f-8a59-b6312bd83b4e@enneenne.com/ Acked-by: Rodolfo Giometti Link: https://lore.kernel.org/r/c3c50ad1eb19ef553eca8a57c17f4c006413ab70.camel@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

pps: Fix a use-after-free

2025-02-08T08:58:16+00:00

commit c79a39dc8d060b9e64e8b0fa9d245d44befeefbe upstream. On a board running ntpd and gpsd, I'm seeing a consistent use-after-free in sys_exit() from gpsd when rebooting: pps pps1: removed ------------[ cut here ]------------ kobject: '(null)' (00000000db4bec24): is not initialized, yet kobject_put() is being called. WARNING: CPU: 2 PID: 440 at lib/kobject.c:734 kobject_put+0x120/0x150 CPU: 2 UID: 299 PID: 440 Comm: gpsd Not tainted 6.11.0-rc6-00308-gb31c44928842 #1 Hardware name: Raspberry Pi 4 Model B Rev 1.1 (DT) pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : kobject_put+0x120/0x150 lr : kobject_put+0x120/0x150 sp : ffffffc0803d3ae0 x29: ffffffc0803d3ae0 x28: ffffff8042dc9738 x27: 0000000000000001 x26: 0000000000000000 x25: ffffff8042dc9040 x24: ffffff8042dc9440 x23: ffffff80402a4620 x22: ffffff8042ef4bd0 x21: ffffff80405cb600 x20: 000000000008001b x19: ffffff8040b3b6e0 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 696e6920746f6e20 x14: 7369203a29343263 x13: 205d303434542020 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: kobject_put+0x120/0x150 cdev_put+0x20/0x3c __fput+0x2c4/0x2d8 ____fput+0x1c/0x38 task_work_run+0x70/0xfc do_exit+0x2a0/0x924 do_group_exit+0x34/0x90 get_signal+0x7fc/0x8c0 do_signal+0x128/0x13b4 do_notify_resume+0xdc/0x160 el0_svc+0xd4/0xf8 el0t_64_sync_handler+0x140/0x14c el0t_64_sync+0x190/0x194 ---[ end trace 0000000000000000 ]--- ...followed by more symptoms of corruption, with similar stacks: refcount_t: underflow; use-after-free. kernel BUG at lib/list_debug.c:62! Kernel panic - not syncing: Oops - BUG: Fatal exception This happens because pps_device_destruct() frees the pps_device with the embedded cdev immediately after calling cdev_del(), but, as the comment above cdev_del() notes, fops for previously opened cdevs are still callable even after cdev_del() returns. I think this bug has always been there: I can't explain why it suddenly started happening every time I reboot this particular board. In commit d953e0e837e6 ("pps: Fix a use-after free bug when unregistering a source."), George Spelvin suggested removing the embedded cdev. That seems like the simplest way to fix this, so I've implemented his suggestion, using __register_chrdev() with pps_idr becoming the source of truth for which minor corresponds to which device. But now that pps_idr defines userspace visibility instead of cdev_add(), we need to be sure the pps->dev refcount can't reach zero while userspace can still find it again. So, the idr_remove() call moves to pps_unregister_cdev(), and pps_idr now holds a reference to pps->dev. pps_core: source serial1 got cdev (251:1) <...> pps pps1: removed pps_core: unregistering pps1 pps_core: deallocating pps1 Fixes: d953e0e837e6 ("pps: Fix a use-after free bug when unregistering a source.") Cc: stable@vger.kernel.org Signed-off-by: Calvin Owens Reviewed-by: Michal Schmidt Link: https://lore.kernel.org/r/a17975fd5ae99385791929e563f72564edbcf28f.1731383727.git.calvin@wbinvd.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

[tree-wide] finally take no_llseek out

2024-09-27T15:18:43+00:00

no_llseek had been defined to NULL two years ago, in commit 868941b14441 ("fs: remove no_llseek") To quote that commit, At -rc1 we'll need do a mechanical removal of no_llseek - git grep -l -w no_llseek | grep -v porting.rst | while read i; do sed -i '/\/d' $i done would do it. Unfortunately, that hadn't been done. Linus, could you do that now, so that we could finally put that thing to rest? All instances are of the form .llseek = no_llseek, so it's obviously safe. Signed-off-by: Al Viro Signed-off-by: Linus Torvalds

pps: add an error check in parport_attach

2024-09-03T10:33:09+00:00

In parport_attach, the return value of ida_alloc is unchecked, witch leads to the use of an invalid index value. To address this issue, index should be checked. When the index value is abnormal, the device should be freed. Found by code review, compile tested only. Cc: stable@vger.kernel.org Fixes: fb56d97df70e ("pps: client: use new parport device model") Signed-off-by: Ma Ke Acked-by: Rodolfo Giometti Link: https://lore.kernel.org/r/20240828131814.3034338-1-make24@iscas.ac.cn Signed-off-by: Greg Kroah-Hartman

Merge tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2024-07-25T17:42:22+00:00

Pull driver core updates from Greg KH: "Here is the big set of driver core changes for 6.11-rc1. Lots of stuff in here, with not a huge diffstat, but apis are evolving which required lots of files to be touched. Highlights of the changes in here are: - platform remove callback api final fixups (Uwe took many releases to get here, finally!) - Rust bindings for basic firmware apis and initial driver-core interactions. It's not all that useful for a "write a whole driver in rust" type of thing, but the firmware bindings do help out the phy rust drivers, and the driver core bindings give a solid base on which others can start their work. There is still a long way to go here before we have a multitude of rust drivers being added, but it's a great first step. - driver core const api changes. This reached across all bus types, and there are some fix-ups for some not-common bus types that linux-next and 0-day testing shook out. This work is being done to help make the rust bindings more safe, as well as the C code, moving toward the end-goal of allowing us to put driver structures into read-only memory. We aren't there yet, but are getting closer. - minor devres cleanups and fixes found by code inspection - arch_topology minor changes - other minor driver core cleanups All of these have been in linux-next for a very long time with no reported problems" * tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits) ARM: sa1100: make match function take a const pointer sysfs/cpu: Make crash_hotplug attribute world-readable dio: Have dio_bus_match() callback take a const * zorro: make match function take a const pointer driver core: module: make module_[add|remove]_driver take a const * driver core: make driver_find_device() take a const * driver core: make driver_[create|remove]_file take a const * firmware_loader: fix soundness issue in `request_internal` firmware_loader: annotate doctests as `no_run` devres: Correct code style for functions that return a pointer type devres: Initialize an uninitialized struct member devres: Fix memory leakage caused by driver API devm_free_percpu() devres: Fix devm_krealloc() wasting memory driver core: platform: Switch to use kmemdup_array() driver core: have match() callback in struct bus_type take a const * MAINTAINERS: add Rust device abstractions to DRIVER CORE device: rust: improve safety comments MAINTAINERS: add Danilo as FIRMWARE LOADER maintainer MAINTAINERS: add Rust FW abstractions to FIRMWARE LOADER firmware: rust: improve safety comments ...

parport: Remove parport_driver.devmodel

2024-07-03T14:44:22+00:00

'devmodel' hasn't actually been used since: 'commit 3275158fa52a ("parport: remove use of devmodel")' and everyone now has it set to true and has been fixed up; remove the flag. (There are still comments all over about it) Signed-off-by: Dr. David Alan Gilbert Acked-by: Sudip Mukherjee Link: https://lore.kernel.org/r/20240502154823.67235-4-linux@treblig.org Signed-off-by: Greg Kroah-Hartman

pps: clients: gpio: Convert to platform remove callback returning void

2024-05-27T08:13:55+00:00

The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Acked-by: Rodolfo Giometti Link: https://lore.kernel.org/r/f4b9402af72e5f285c8b0f068076a76418f653f5.1709886922.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König

pps: remove usage of the deprecated ida_simple_xx() API

2024-04-29T15:20:06+00:00

ida_alloc() and ida_free() should be preferred to the deprecated ida_simple_get() and ida_simple_remove(). This is less verbose. Link: https://lkml.kernel.org/r/9f681747d446b874952a892491387d79ffe565a9.1713089394.git.christophe.jaillet@wanadoo.fr Signed-off-by: Christophe JAILLET Cc: Rodolfo Giometti Cc: Greg Kroah-Hartman Signed-off-by: Andrew Morton