February 2025 - Linux-stable-mirror

[PATCH 5.10 1/2] Revert "btrfs: avoid monopolizing a core when activating a swap file"

by Koichiro Den

This reverts commit a1c3a19446a440c68e80e9c34c5f308ff58aac88. The backport for linux-5.10.y, commit a1c3a19446a4 ("btrfs: avoid monopolizing a core when activating a swap file"), inserted cond_resched() in the wrong location. Revert it now; a subsequent commit will re-backport the original patch. Fixes: a1c3a19446a4 ("btrfs: avoid monopolizing a core when activating a swap file") # linux-5.10.y Signed-off-by: Koichiro Den <koichiro.den(a)canonical.com> --- fs/btrfs/inode.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 560c4f2a1833..45c1732a9677 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7127,8 +7127,6 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, ret = -EAGAIN; goto out; } - - cond_resched(); } btrfs_release_path(path); -- 2.45.2

7 months, 1 week

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[PATCH 5.4 1/2] Revert "btrfs: avoid monopolizing a core when activating a swap file"

by Koichiro Den

This reverts commit 3d770d44dd5c6316913b003790998404636ec2a8. The backport for linux-5.4.y, commit 3d770d44dd5c ("btrfs: avoid monopolizing a core when activating a swap file"), inserted cond_resched() in the wrong location. Revert it now; a subsequent commit will re-backport the original patch. Fixes: 3d770d44dd5c ("btrfs: avoid monopolizing a core when activating a swap file") # linux-5.4.y Signed-off-by: Koichiro Den <koichiro.den(a)canonical.com> --- fs/btrfs/inode.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index d9a581f46f13..cd72409ccc94 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7679,8 +7679,6 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, ret = -EAGAIN; goto out; } - - cond_resched(); } btrfs_release_path(path); -- 2.45.2

7 months, 1 week

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FAILED: patch "[PATCH] pps: Fix a use-after-free" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x c79a39dc8d060b9e64e8b0fa9d245d44befeefbe # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025020420-subtly-blaming-0ded@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From c79a39dc8d060b9e64e8b0fa9d245d44befeefbe Mon Sep 17 00:00:00 2001 From: Calvin Owens <calvin(a)wbinvd.org> Date: Mon, 11 Nov 2024 20:13:29 -0800 Subject: [PATCH] pps: Fix a use-after-free 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(a)vger.kernel.org Signed-off-by: Calvin Owens <calvin(a)wbinvd.org> Reviewed-by: Michal Schmidt <mschmidt(a)redhat.com> Link: https://lore.kernel.org/r/a17975fd5ae99385791929e563f72564edbcf28f.17313837… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c index 634c3b2f8c26..f77b19884f05 100644 --- a/drivers/pps/clients/pps-gpio.c +++ b/drivers/pps/clients/pps-gpio.c @@ -214,8 +214,8 @@ static int pps_gpio_probe(struct platform_device *pdev) return -EINVAL; } - dev_info(data->pps->dev, "Registered IRQ %d as PPS source\n", - data->irq); + dev_dbg(&data->pps->dev, "Registered IRQ %d as PPS source\n", + data->irq); return 0; } diff --git a/drivers/pps/clients/pps-ktimer.c b/drivers/pps/clients/pps-ktimer.c index d33106bd7a29..2f465549b843 100644 --- a/drivers/pps/clients/pps-ktimer.c +++ b/drivers/pps/clients/pps-ktimer.c @@ -56,7 +56,7 @@ static struct pps_source_info pps_ktimer_info = { static void __exit pps_ktimer_exit(void) { - dev_info(pps->dev, "ktimer PPS source unregistered\n"); + dev_dbg(&pps->dev, "ktimer PPS source unregistered\n"); del_timer_sync(&ktimer); pps_unregister_source(pps); @@ -74,7 +74,7 @@ static int __init pps_ktimer_init(void) timer_setup(&ktimer, pps_ktimer_event, 0); mod_timer(&ktimer, jiffies + HZ); - dev_info(pps->dev, "ktimer PPS source registered\n"); + dev_dbg(&pps->dev, "ktimer PPS source registered\n"); return 0; } diff --git a/drivers/pps/clients/pps-ldisc.c b/drivers/pps/clients/pps-ldisc.c index 443d6bae19d1..fa5660f3c4b7 100644 --- a/drivers/pps/clients/pps-ldisc.c +++ b/drivers/pps/clients/pps-ldisc.c @@ -32,7 +32,7 @@ static void pps_tty_dcd_change(struct tty_struct *tty, bool active) pps_event(pps, &ts, active ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR, NULL); - dev_dbg(pps->dev, "PPS %s at %lu\n", + dev_dbg(&pps->dev, "PPS %s at %lu\n", active ? "assert" : "clear", jiffies); } @@ -69,7 +69,7 @@ static int pps_tty_open(struct tty_struct *tty) goto err_unregister; } - dev_info(pps->dev, "source \"%s\" added\n", info.path); + dev_dbg(&pps->dev, "source \"%s\" added\n", info.path); return 0; @@ -89,7 +89,7 @@ static void pps_tty_close(struct tty_struct *tty) if (WARN_ON(!pps)) return; - dev_info(pps->dev, "removed\n"); + dev_info(&pps->dev, "removed\n"); pps_unregister_source(pps); } diff --git a/drivers/pps/clients/pps_parport.c b/drivers/pps/clients/pps_parport.c index abaffb4e1c1c..24db06750297 100644 --- a/drivers/pps/clients/pps_parport.c +++ b/drivers/pps/clients/pps_parport.c @@ -81,7 +81,7 @@ static void parport_irq(void *handle) /* check the signal (no signal means the pulse is lost this time) */ if (!signal_is_set(port)) { local_irq_restore(flags); - dev_err(dev->pps->dev, "lost the signal\n"); + dev_err(&dev->pps->dev, "lost the signal\n"); goto out_assert; } @@ -98,7 +98,7 @@ static void parport_irq(void *handle) /* timeout */ dev->cw_err++; if (dev->cw_err >= CLEAR_WAIT_MAX_ERRORS) { - dev_err(dev->pps->dev, "disabled clear edge capture after %d" + dev_err(&dev->pps->dev, "disabled clear edge capture after %d" " timeouts\n", dev->cw_err); dev->cw = 0; dev->cw_err = 0; diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c index d9d566f70ed1..92d1b62ea239 100644 --- a/drivers/pps/kapi.c +++ b/drivers/pps/kapi.c @@ -41,7 +41,7 @@ static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset) static void pps_echo_client_default(struct pps_device *pps, int event, void *data) { - dev_info(pps->dev, "echo %s %s\n", + dev_info(&pps->dev, "echo %s %s\n", event & PPS_CAPTUREASSERT ? "assert" : "", event & PPS_CAPTURECLEAR ? "clear" : ""); } @@ -112,7 +112,7 @@ struct pps_device *pps_register_source(struct pps_source_info *info, goto kfree_pps; } - dev_info(pps->dev, "new PPS source %s\n", info->name); + dev_dbg(&pps->dev, "new PPS source %s\n", info->name); return pps; @@ -166,7 +166,7 @@ void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, /* check event type */ BUG_ON((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0); - dev_dbg(pps->dev, "PPS event at %lld.%09ld\n", + dev_dbg(&pps->dev, "PPS event at %lld.%09ld\n", (s64)ts->ts_real.tv_sec, ts->ts_real.tv_nsec); timespec_to_pps_ktime(&ts_real, ts->ts_real); @@ -188,7 +188,7 @@ void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, /* Save the time stamp */ pps->assert_tu = ts_real; pps->assert_sequence++; - dev_dbg(pps->dev, "capture assert seq #%u\n", + dev_dbg(&pps->dev, "capture assert seq #%u\n", pps->assert_sequence); captured = ~0; @@ -202,7 +202,7 @@ void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, /* Save the time stamp */ pps->clear_tu = ts_real; pps->clear_sequence++; - dev_dbg(pps->dev, "capture clear seq #%u\n", + dev_dbg(&pps->dev, "capture clear seq #%u\n", pps->clear_sequence); captured = ~0; diff --git a/drivers/pps/kc.c b/drivers/pps/kc.c index 50dc59af45be..fbd23295afd7 100644 --- a/drivers/pps/kc.c +++ b/drivers/pps/kc.c @@ -43,11 +43,11 @@ int pps_kc_bind(struct pps_device *pps, struct pps_bind_args *bind_args) pps_kc_hardpps_mode = 0; pps_kc_hardpps_dev = NULL; spin_unlock_irq(&pps_kc_hardpps_lock); - dev_info(pps->dev, "unbound kernel" + dev_info(&pps->dev, "unbound kernel" " consumer\n"); } else { spin_unlock_irq(&pps_kc_hardpps_lock); - dev_err(pps->dev, "selected kernel consumer" + dev_err(&pps->dev, "selected kernel consumer" " is not bound\n"); return -EINVAL; } @@ -57,11 +57,11 @@ int pps_kc_bind(struct pps_device *pps, struct pps_bind_args *bind_args) pps_kc_hardpps_mode = bind_args->edge; pps_kc_hardpps_dev = pps; spin_unlock_irq(&pps_kc_hardpps_lock); - dev_info(pps->dev, "bound kernel consumer: " + dev_info(&pps->dev, "bound kernel consumer: " "edge=0x%x\n", bind_args->edge); } else { spin_unlock_irq(&pps_kc_hardpps_lock); - dev_err(pps->dev, "another kernel consumer" + dev_err(&pps->dev, "another kernel consumer" " is already bound\n"); return -EINVAL; } @@ -83,7 +83,7 @@ void pps_kc_remove(struct pps_device *pps) pps_kc_hardpps_mode = 0; pps_kc_hardpps_dev = NULL; spin_unlock_irq(&pps_kc_hardpps_lock); - dev_info(pps->dev, "unbound kernel consumer" + dev_info(&pps->dev, "unbound kernel consumer" " on device removal\n"); } else spin_unlock_irq(&pps_kc_hardpps_lock); diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c index 25d47907db17..6a02245ea35f 100644 --- a/drivers/pps/pps.c +++ b/drivers/pps/pps.c @@ -25,7 +25,7 @@ * Local variables */ -static dev_t pps_devt; +static int pps_major; static struct class *pps_class; static DEFINE_MUTEX(pps_idr_lock); @@ -62,7 +62,7 @@ static int pps_cdev_pps_fetch(struct pps_device *pps, struct pps_fdata *fdata) else { unsigned long ticks; - dev_dbg(pps->dev, "timeout %lld.%09d\n", + dev_dbg(&pps->dev, "timeout %lld.%09d\n", (long long) fdata->timeout.sec, fdata->timeout.nsec); ticks = fdata->timeout.sec * HZ; @@ -80,7 +80,7 @@ static int pps_cdev_pps_fetch(struct pps_device *pps, struct pps_fdata *fdata) /* Check for pending signals */ if (err == -ERESTARTSYS) { - dev_dbg(pps->dev, "pending signal caught\n"); + dev_dbg(&pps->dev, "pending signal caught\n"); return -EINTR; } @@ -98,7 +98,7 @@ static long pps_cdev_ioctl(struct file *file, switch (cmd) { case PPS_GETPARAMS: - dev_dbg(pps->dev, "PPS_GETPARAMS\n"); + dev_dbg(&pps->dev, "PPS_GETPARAMS\n"); spin_lock_irq(&pps->lock); @@ -114,7 +114,7 @@ static long pps_cdev_ioctl(struct file *file, break; case PPS_SETPARAMS: - dev_dbg(pps->dev, "PPS_SETPARAMS\n"); + dev_dbg(&pps->dev, "PPS_SETPARAMS\n"); /* Check the capabilities */ if (!capable(CAP_SYS_TIME)) @@ -124,14 +124,14 @@ static long pps_cdev_ioctl(struct file *file, if (err) return -EFAULT; if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) { - dev_dbg(pps->dev, "capture mode unspecified (%x)\n", + dev_dbg(&pps->dev, "capture mode unspecified (%x)\n", params.mode); return -EINVAL; } /* Check for supported capabilities */ if ((params.mode & ~pps->info.mode) != 0) { - dev_dbg(pps->dev, "unsupported capabilities (%x)\n", + dev_dbg(&pps->dev, "unsupported capabilities (%x)\n", params.mode); return -EINVAL; } @@ -144,7 +144,7 @@ static long pps_cdev_ioctl(struct file *file, /* Restore the read only parameters */ if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) { /* section 3.3 of RFC 2783 interpreted */ - dev_dbg(pps->dev, "time format unspecified (%x)\n", + dev_dbg(&pps->dev, "time format unspecified (%x)\n", params.mode); pps->params.mode |= PPS_TSFMT_TSPEC; } @@ -165,7 +165,7 @@ static long pps_cdev_ioctl(struct file *file, break; case PPS_GETCAP: - dev_dbg(pps->dev, "PPS_GETCAP\n"); + dev_dbg(&pps->dev, "PPS_GETCAP\n"); err = put_user(pps->info.mode, iuarg); if (err) @@ -176,7 +176,7 @@ static long pps_cdev_ioctl(struct file *file, case PPS_FETCH: { struct pps_fdata fdata; - dev_dbg(pps->dev, "PPS_FETCH\n"); + dev_dbg(&pps->dev, "PPS_FETCH\n"); err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata)); if (err) @@ -206,7 +206,7 @@ static long pps_cdev_ioctl(struct file *file, case PPS_KC_BIND: { struct pps_bind_args bind_args; - dev_dbg(pps->dev, "PPS_KC_BIND\n"); + dev_dbg(&pps->dev, "PPS_KC_BIND\n"); /* Check the capabilities */ if (!capable(CAP_SYS_TIME)) @@ -218,7 +218,7 @@ static long pps_cdev_ioctl(struct file *file, /* Check for supported capabilities */ if ((bind_args.edge & ~pps->info.mode) != 0) { - dev_err(pps->dev, "unsupported capabilities (%x)\n", + dev_err(&pps->dev, "unsupported capabilities (%x)\n", bind_args.edge); return -EINVAL; } @@ -227,7 +227,7 @@ static long pps_cdev_ioctl(struct file *file, if (bind_args.tsformat != PPS_TSFMT_TSPEC || (bind_args.edge & ~PPS_CAPTUREBOTH) != 0 || bind_args.consumer != PPS_KC_HARDPPS) { - dev_err(pps->dev, "invalid kernel consumer bind" + dev_err(&pps->dev, "invalid kernel consumer bind" " parameters (%x)\n", bind_args.edge); return -EINVAL; } @@ -259,7 +259,7 @@ static long pps_cdev_compat_ioctl(struct file *file, struct pps_fdata fdata; int err; - dev_dbg(pps->dev, "PPS_FETCH\n"); + dev_dbg(&pps->dev, "PPS_FETCH\n"); err = copy_from_user(&compat, uarg, sizeof(struct pps_fdata_compat)); if (err) @@ -296,20 +296,36 @@ static long pps_cdev_compat_ioctl(struct file *file, #define pps_cdev_compat_ioctl NULL #endif +static struct pps_device *pps_idr_get(unsigned long id) +{ + struct pps_device *pps; + + mutex_lock(&pps_idr_lock); + pps = idr_find(&pps_idr, id); + if (pps) + get_device(&pps->dev); + + mutex_unlock(&pps_idr_lock); + return pps; +} + static int pps_cdev_open(struct inode *inode, struct file *file) { - struct pps_device *pps = container_of(inode->i_cdev, - struct pps_device, cdev); + struct pps_device *pps = pps_idr_get(iminor(inode)); + + if (!pps) + return -ENODEV; + file->private_data = pps; - kobject_get(&pps->dev->kobj); return 0; } static int pps_cdev_release(struct inode *inode, struct file *file) { - struct pps_device *pps = container_of(inode->i_cdev, - struct pps_device, cdev); - kobject_put(&pps->dev->kobj); + struct pps_device *pps = file->private_data; + + WARN_ON(pps->id != iminor(inode)); + put_device(&pps->dev); return 0; } @@ -331,22 +347,13 @@ static void pps_device_destruct(struct device *dev) { struct pps_device *pps = dev_get_drvdata(dev); - cdev_del(&pps->cdev); - - /* Now we can release the ID for re-use */ pr_debug("deallocating pps%d\n", pps->id); - mutex_lock(&pps_idr_lock); - idr_remove(&pps_idr, pps->id); - mutex_unlock(&pps_idr_lock); - - kfree(dev); kfree(pps); } int pps_register_cdev(struct pps_device *pps) { int err; - dev_t devt; mutex_lock(&pps_idr_lock); /* @@ -363,40 +370,29 @@ int pps_register_cdev(struct pps_device *pps) goto out_unlock; } pps->id = err; - mutex_unlock(&pps_idr_lock); - devt = MKDEV(MAJOR(pps_devt), pps->id); - - cdev_init(&pps->cdev, &pps_cdev_fops); - pps->cdev.owner = pps->info.owner; - - err = cdev_add(&pps->cdev, devt, 1); - if (err) { - pr_err("%s: failed to add char device %d:%d\n", - pps->info.name, MAJOR(pps_devt), pps->id); + pps->dev.class = pps_class; + pps->dev.parent = pps->info.dev; + pps->dev.devt = MKDEV(pps_major, pps->id); + dev_set_drvdata(&pps->dev, pps); + dev_set_name(&pps->dev, "pps%d", pps->id); + err = device_register(&pps->dev); + if (err) goto free_idr; - } - pps->dev = device_create(pps_class, pps->info.dev, devt, pps, - "pps%d", pps->id); - if (IS_ERR(pps->dev)) { - err = PTR_ERR(pps->dev); - goto del_cdev; - } /* Override the release function with our own */ - pps->dev->release = pps_device_destruct; + pps->dev.release = pps_device_destruct; - pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, - MAJOR(pps_devt), pps->id); + pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, pps_major, + pps->id); + get_device(&pps->dev); + mutex_unlock(&pps_idr_lock); return 0; -del_cdev: - cdev_del(&pps->cdev); - free_idr: - mutex_lock(&pps_idr_lock); idr_remove(&pps_idr, pps->id); + put_device(&pps->dev); out_unlock: mutex_unlock(&pps_idr_lock); return err; @@ -406,7 +402,13 @@ void pps_unregister_cdev(struct pps_device *pps) { pr_debug("unregistering pps%d\n", pps->id); pps->lookup_cookie = NULL; - device_destroy(pps_class, pps->dev->devt); + device_destroy(pps_class, pps->dev.devt); + + /* Now we can release the ID for re-use */ + mutex_lock(&pps_idr_lock); + idr_remove(&pps_idr, pps->id); + put_device(&pps->dev); + mutex_unlock(&pps_idr_lock); } /* @@ -426,6 +428,11 @@ void pps_unregister_cdev(struct pps_device *pps) * so that it will not be used again, even if the pps device cannot * be removed from the idr due to pending references holding the minor * number in use. + * + * Since pps_idr holds a reference to the device, the returned + * pps_device is guaranteed to be valid until pps_unregister_cdev() is + * called on it. But after calling pps_unregister_cdev(), it may be + * freed at any time. */ struct pps_device *pps_lookup_dev(void const *cookie) { @@ -448,13 +455,11 @@ EXPORT_SYMBOL(pps_lookup_dev); static void __exit pps_exit(void) { class_destroy(pps_class); - unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES); + __unregister_chrdev(pps_major, 0, PPS_MAX_SOURCES, "pps"); } static int __init pps_init(void) { - int err; - pps_class = class_create("pps"); if (IS_ERR(pps_class)) { pr_err("failed to allocate class\n"); @@ -462,8 +467,9 @@ static int __init pps_init(void) } pps_class->dev_groups = pps_groups; - err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps"); - if (err < 0) { + pps_major = __register_chrdev(0, 0, PPS_MAX_SOURCES, "pps", + &pps_cdev_fops); + if (pps_major < 0) { pr_err("failed to allocate char device region\n"); goto remove_class; } @@ -476,8 +482,7 @@ static int __init pps_init(void) remove_class: class_destroy(pps_class); - - return err; + return pps_major; } subsys_initcall(pps_init); diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c index 5feecaadde8e..120db96d9e95 100644 --- a/drivers/ptp/ptp_ocp.c +++ b/drivers/ptp/ptp_ocp.c @@ -4420,7 +4420,7 @@ ptp_ocp_complete(struct ptp_ocp *bp) pps = pps_lookup_dev(bp->ptp); if (pps) - ptp_ocp_symlink(bp, pps->dev, "pps"); + ptp_ocp_symlink(bp, &pps->dev, "pps"); ptp_ocp_debugfs_add_device(bp); diff --git a/include/linux/pps_kernel.h b/include/linux/pps_kernel.h index 78c8ac4951b5..c7abce28ed29 100644 --- a/include/linux/pps_kernel.h +++ b/include/linux/pps_kernel.h @@ -56,8 +56,7 @@ struct pps_device { unsigned int id; /* PPS source unique ID */ void const *lookup_cookie; /* For pps_lookup_dev() only */ - struct cdev cdev; - struct device *dev; + struct device dev; struct fasync_struct *async_queue; /* fasync method */ spinlock_t lock; };

7 months, 1 week

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FAILED: patch "[PATCH] pps: Fix a use-after-free" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x c79a39dc8d060b9e64e8b0fa9d245d44befeefbe # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025020424-bloated-undecided-1814@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From c79a39dc8d060b9e64e8b0fa9d245d44befeefbe Mon Sep 17 00:00:00 2001 From: Calvin Owens <calvin(a)wbinvd.org> Date: Mon, 11 Nov 2024 20:13:29 -0800 Subject: [PATCH] pps: Fix a use-after-free 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(a)vger.kernel.org Signed-off-by: Calvin Owens <calvin(a)wbinvd.org> Reviewed-by: Michal Schmidt <mschmidt(a)redhat.com> Link: https://lore.kernel.org/r/a17975fd5ae99385791929e563f72564edbcf28f.17313837… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c index 634c3b2f8c26..f77b19884f05 100644 --- a/drivers/pps/clients/pps-gpio.c +++ b/drivers/pps/clients/pps-gpio.c @@ -214,8 +214,8 @@ static int pps_gpio_probe(struct platform_device *pdev) return -EINVAL; } - dev_info(data->pps->dev, "Registered IRQ %d as PPS source\n", - data->irq); + dev_dbg(&data->pps->dev, "Registered IRQ %d as PPS source\n", + data->irq); return 0; } diff --git a/drivers/pps/clients/pps-ktimer.c b/drivers/pps/clients/pps-ktimer.c index d33106bd7a29..2f465549b843 100644 --- a/drivers/pps/clients/pps-ktimer.c +++ b/drivers/pps/clients/pps-ktimer.c @@ -56,7 +56,7 @@ static struct pps_source_info pps_ktimer_info = { static void __exit pps_ktimer_exit(void) { - dev_info(pps->dev, "ktimer PPS source unregistered\n"); + dev_dbg(&pps->dev, "ktimer PPS source unregistered\n"); del_timer_sync(&ktimer); pps_unregister_source(pps); @@ -74,7 +74,7 @@ static int __init pps_ktimer_init(void) timer_setup(&ktimer, pps_ktimer_event, 0); mod_timer(&ktimer, jiffies + HZ); - dev_info(pps->dev, "ktimer PPS source registered\n"); + dev_dbg(&pps->dev, "ktimer PPS source registered\n"); return 0; } diff --git a/drivers/pps/clients/pps-ldisc.c b/drivers/pps/clients/pps-ldisc.c index 443d6bae19d1..fa5660f3c4b7 100644 --- a/drivers/pps/clients/pps-ldisc.c +++ b/drivers/pps/clients/pps-ldisc.c @@ -32,7 +32,7 @@ static void pps_tty_dcd_change(struct tty_struct *tty, bool active) pps_event(pps, &ts, active ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR, NULL); - dev_dbg(pps->dev, "PPS %s at %lu\n", + dev_dbg(&pps->dev, "PPS %s at %lu\n", active ? "assert" : "clear", jiffies); } @@ -69,7 +69,7 @@ static int pps_tty_open(struct tty_struct *tty) goto err_unregister; } - dev_info(pps->dev, "source \"%s\" added\n", info.path); + dev_dbg(&pps->dev, "source \"%s\" added\n", info.path); return 0; @@ -89,7 +89,7 @@ static void pps_tty_close(struct tty_struct *tty) if (WARN_ON(!pps)) return; - dev_info(pps->dev, "removed\n"); + dev_info(&pps->dev, "removed\n"); pps_unregister_source(pps); } diff --git a/drivers/pps/clients/pps_parport.c b/drivers/pps/clients/pps_parport.c index abaffb4e1c1c..24db06750297 100644 --- a/drivers/pps/clients/pps_parport.c +++ b/drivers/pps/clients/pps_parport.c @@ -81,7 +81,7 @@ static void parport_irq(void *handle) /* check the signal (no signal means the pulse is lost this time) */ if (!signal_is_set(port)) { local_irq_restore(flags); - dev_err(dev->pps->dev, "lost the signal\n"); + dev_err(&dev->pps->dev, "lost the signal\n"); goto out_assert; } @@ -98,7 +98,7 @@ static void parport_irq(void *handle) /* timeout */ dev->cw_err++; if (dev->cw_err >= CLEAR_WAIT_MAX_ERRORS) { - dev_err(dev->pps->dev, "disabled clear edge capture after %d" + dev_err(&dev->pps->dev, "disabled clear edge capture after %d" " timeouts\n", dev->cw_err); dev->cw = 0; dev->cw_err = 0; diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c index d9d566f70ed1..92d1b62ea239 100644 --- a/drivers/pps/kapi.c +++ b/drivers/pps/kapi.c @@ -41,7 +41,7 @@ static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset) static void pps_echo_client_default(struct pps_device *pps, int event, void *data) { - dev_info(pps->dev, "echo %s %s\n", + dev_info(&pps->dev, "echo %s %s\n", event & PPS_CAPTUREASSERT ? "assert" : "", event & PPS_CAPTURECLEAR ? "clear" : ""); } @@ -112,7 +112,7 @@ struct pps_device *pps_register_source(struct pps_source_info *info, goto kfree_pps; } - dev_info(pps->dev, "new PPS source %s\n", info->name); + dev_dbg(&pps->dev, "new PPS source %s\n", info->name); return pps; @@ -166,7 +166,7 @@ void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, /* check event type */ BUG_ON((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0); - dev_dbg(pps->dev, "PPS event at %lld.%09ld\n", + dev_dbg(&pps->dev, "PPS event at %lld.%09ld\n", (s64)ts->ts_real.tv_sec, ts->ts_real.tv_nsec); timespec_to_pps_ktime(&ts_real, ts->ts_real); @@ -188,7 +188,7 @@ void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, /* Save the time stamp */ pps->assert_tu = ts_real; pps->assert_sequence++; - dev_dbg(pps->dev, "capture assert seq #%u\n", + dev_dbg(&pps->dev, "capture assert seq #%u\n", pps->assert_sequence); captured = ~0; @@ -202,7 +202,7 @@ void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, /* Save the time stamp */ pps->clear_tu = ts_real; pps->clear_sequence++; - dev_dbg(pps->dev, "capture clear seq #%u\n", + dev_dbg(&pps->dev, "capture clear seq #%u\n", pps->clear_sequence); captured = ~0; diff --git a/drivers/pps/kc.c b/drivers/pps/kc.c index 50dc59af45be..fbd23295afd7 100644 --- a/drivers/pps/kc.c +++ b/drivers/pps/kc.c @@ -43,11 +43,11 @@ int pps_kc_bind(struct pps_device *pps, struct pps_bind_args *bind_args) pps_kc_hardpps_mode = 0; pps_kc_hardpps_dev = NULL; spin_unlock_irq(&pps_kc_hardpps_lock); - dev_info(pps->dev, "unbound kernel" + dev_info(&pps->dev, "unbound kernel" " consumer\n"); } else { spin_unlock_irq(&pps_kc_hardpps_lock); - dev_err(pps->dev, "selected kernel consumer" + dev_err(&pps->dev, "selected kernel consumer" " is not bound\n"); return -EINVAL; } @@ -57,11 +57,11 @@ int pps_kc_bind(struct pps_device *pps, struct pps_bind_args *bind_args) pps_kc_hardpps_mode = bind_args->edge; pps_kc_hardpps_dev = pps; spin_unlock_irq(&pps_kc_hardpps_lock); - dev_info(pps->dev, "bound kernel consumer: " + dev_info(&pps->dev, "bound kernel consumer: " "edge=0x%x\n", bind_args->edge); } else { spin_unlock_irq(&pps_kc_hardpps_lock); - dev_err(pps->dev, "another kernel consumer" + dev_err(&pps->dev, "another kernel consumer" " is already bound\n"); return -EINVAL; } @@ -83,7 +83,7 @@ void pps_kc_remove(struct pps_device *pps) pps_kc_hardpps_mode = 0; pps_kc_hardpps_dev = NULL; spin_unlock_irq(&pps_kc_hardpps_lock); - dev_info(pps->dev, "unbound kernel consumer" + dev_info(&pps->dev, "unbound kernel consumer" " on device removal\n"); } else spin_unlock_irq(&pps_kc_hardpps_lock); diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c index 25d47907db17..6a02245ea35f 100644 --- a/drivers/pps/pps.c +++ b/drivers/pps/pps.c @@ -25,7 +25,7 @@ * Local variables */ -static dev_t pps_devt; +static int pps_major; static struct class *pps_class; static DEFINE_MUTEX(pps_idr_lock); @@ -62,7 +62,7 @@ static int pps_cdev_pps_fetch(struct pps_device *pps, struct pps_fdata *fdata) else { unsigned long ticks; - dev_dbg(pps->dev, "timeout %lld.%09d\n", + dev_dbg(&pps->dev, "timeout %lld.%09d\n", (long long) fdata->timeout.sec, fdata->timeout.nsec); ticks = fdata->timeout.sec * HZ; @@ -80,7 +80,7 @@ static int pps_cdev_pps_fetch(struct pps_device *pps, struct pps_fdata *fdata) /* Check for pending signals */ if (err == -ERESTARTSYS) { - dev_dbg(pps->dev, "pending signal caught\n"); + dev_dbg(&pps->dev, "pending signal caught\n"); return -EINTR; } @@ -98,7 +98,7 @@ static long pps_cdev_ioctl(struct file *file, switch (cmd) { case PPS_GETPARAMS: - dev_dbg(pps->dev, "PPS_GETPARAMS\n"); + dev_dbg(&pps->dev, "PPS_GETPARAMS\n"); spin_lock_irq(&pps->lock); @@ -114,7 +114,7 @@ static long pps_cdev_ioctl(struct file *file, break; case PPS_SETPARAMS: - dev_dbg(pps->dev, "PPS_SETPARAMS\n"); + dev_dbg(&pps->dev, "PPS_SETPARAMS\n"); /* Check the capabilities */ if (!capable(CAP_SYS_TIME)) @@ -124,14 +124,14 @@ static long pps_cdev_ioctl(struct file *file, if (err) return -EFAULT; if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) { - dev_dbg(pps->dev, "capture mode unspecified (%x)\n", + dev_dbg(&pps->dev, "capture mode unspecified (%x)\n", params.mode); return -EINVAL; } /* Check for supported capabilities */ if ((params.mode & ~pps->info.mode) != 0) { - dev_dbg(pps->dev, "unsupported capabilities (%x)\n", + dev_dbg(&pps->dev, "unsupported capabilities (%x)\n", params.mode); return -EINVAL; } @@ -144,7 +144,7 @@ static long pps_cdev_ioctl(struct file *file, /* Restore the read only parameters */ if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) { /* section 3.3 of RFC 2783 interpreted */ - dev_dbg(pps->dev, "time format unspecified (%x)\n", + dev_dbg(&pps->dev, "time format unspecified (%x)\n", params.mode); pps->params.mode |= PPS_TSFMT_TSPEC; } @@ -165,7 +165,7 @@ static long pps_cdev_ioctl(struct file *file, break; case PPS_GETCAP: - dev_dbg(pps->dev, "PPS_GETCAP\n"); + dev_dbg(&pps->dev, "PPS_GETCAP\n"); err = put_user(pps->info.mode, iuarg); if (err) @@ -176,7 +176,7 @@ static long pps_cdev_ioctl(struct file *file, case PPS_FETCH: { struct pps_fdata fdata; - dev_dbg(pps->dev, "PPS_FETCH\n"); + dev_dbg(&pps->dev, "PPS_FETCH\n"); err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata)); if (err) @@ -206,7 +206,7 @@ static long pps_cdev_ioctl(struct file *file, case PPS_KC_BIND: { struct pps_bind_args bind_args; - dev_dbg(pps->dev, "PPS_KC_BIND\n"); + dev_dbg(&pps->dev, "PPS_KC_BIND\n"); /* Check the capabilities */ if (!capable(CAP_SYS_TIME)) @@ -218,7 +218,7 @@ static long pps_cdev_ioctl(struct file *file, /* Check for supported capabilities */ if ((bind_args.edge & ~pps->info.mode) != 0) { - dev_err(pps->dev, "unsupported capabilities (%x)\n", + dev_err(&pps->dev, "unsupported capabilities (%x)\n", bind_args.edge); return -EINVAL; } @@ -227,7 +227,7 @@ static long pps_cdev_ioctl(struct file *file, if (bind_args.tsformat != PPS_TSFMT_TSPEC || (bind_args.edge & ~PPS_CAPTUREBOTH) != 0 || bind_args.consumer != PPS_KC_HARDPPS) { - dev_err(pps->dev, "invalid kernel consumer bind" + dev_err(&pps->dev, "invalid kernel consumer bind" " parameters (%x)\n", bind_args.edge); return -EINVAL; } @@ -259,7 +259,7 @@ static long pps_cdev_compat_ioctl(struct file *file, struct pps_fdata fdata; int err; - dev_dbg(pps->dev, "PPS_FETCH\n"); + dev_dbg(&pps->dev, "PPS_FETCH\n"); err = copy_from_user(&compat, uarg, sizeof(struct pps_fdata_compat)); if (err) @@ -296,20 +296,36 @@ static long pps_cdev_compat_ioctl(struct file *file, #define pps_cdev_compat_ioctl NULL #endif +static struct pps_device *pps_idr_get(unsigned long id) +{ + struct pps_device *pps; + + mutex_lock(&pps_idr_lock); + pps = idr_find(&pps_idr, id); + if (pps) + get_device(&pps->dev); + + mutex_unlock(&pps_idr_lock); + return pps; +} + static int pps_cdev_open(struct inode *inode, struct file *file) { - struct pps_device *pps = container_of(inode->i_cdev, - struct pps_device, cdev); + struct pps_device *pps = pps_idr_get(iminor(inode)); + + if (!pps) + return -ENODEV; + file->private_data = pps; - kobject_get(&pps->dev->kobj); return 0; } static int pps_cdev_release(struct inode *inode, struct file *file) { - struct pps_device *pps = container_of(inode->i_cdev, - struct pps_device, cdev); - kobject_put(&pps->dev->kobj); + struct pps_device *pps = file->private_data; + + WARN_ON(pps->id != iminor(inode)); + put_device(&pps->dev); return 0; } @@ -331,22 +347,13 @@ static void pps_device_destruct(struct device *dev) { struct pps_device *pps = dev_get_drvdata(dev); - cdev_del(&pps->cdev); - - /* Now we can release the ID for re-use */ pr_debug("deallocating pps%d\n", pps->id); - mutex_lock(&pps_idr_lock); - idr_remove(&pps_idr, pps->id); - mutex_unlock(&pps_idr_lock); - - kfree(dev); kfree(pps); } int pps_register_cdev(struct pps_device *pps) { int err; - dev_t devt; mutex_lock(&pps_idr_lock); /* @@ -363,40 +370,29 @@ int pps_register_cdev(struct pps_device *pps) goto out_unlock; } pps->id = err; - mutex_unlock(&pps_idr_lock); - devt = MKDEV(MAJOR(pps_devt), pps->id); - - cdev_init(&pps->cdev, &pps_cdev_fops); - pps->cdev.owner = pps->info.owner; - - err = cdev_add(&pps->cdev, devt, 1); - if (err) { - pr_err("%s: failed to add char device %d:%d\n", - pps->info.name, MAJOR(pps_devt), pps->id); + pps->dev.class = pps_class; + pps->dev.parent = pps->info.dev; + pps->dev.devt = MKDEV(pps_major, pps->id); + dev_set_drvdata(&pps->dev, pps); + dev_set_name(&pps->dev, "pps%d", pps->id); + err = device_register(&pps->dev); + if (err) goto free_idr; - } - pps->dev = device_create(pps_class, pps->info.dev, devt, pps, - "pps%d", pps->id); - if (IS_ERR(pps->dev)) { - err = PTR_ERR(pps->dev); - goto del_cdev; - } /* Override the release function with our own */ - pps->dev->release = pps_device_destruct; + pps->dev.release = pps_device_destruct; - pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, - MAJOR(pps_devt), pps->id); + pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, pps_major, + pps->id); + get_device(&pps->dev); + mutex_unlock(&pps_idr_lock); return 0; -del_cdev: - cdev_del(&pps->cdev); - free_idr: - mutex_lock(&pps_idr_lock); idr_remove(&pps_idr, pps->id); + put_device(&pps->dev); out_unlock: mutex_unlock(&pps_idr_lock); return err; @@ -406,7 +402,13 @@ void pps_unregister_cdev(struct pps_device *pps) { pr_debug("unregistering pps%d\n", pps->id); pps->lookup_cookie = NULL; - device_destroy(pps_class, pps->dev->devt); + device_destroy(pps_class, pps->dev.devt); + + /* Now we can release the ID for re-use */ + mutex_lock(&pps_idr_lock); + idr_remove(&pps_idr, pps->id); + put_device(&pps->dev); + mutex_unlock(&pps_idr_lock); } /* @@ -426,6 +428,11 @@ void pps_unregister_cdev(struct pps_device *pps) * so that it will not be used again, even if the pps device cannot * be removed from the idr due to pending references holding the minor * number in use. + * + * Since pps_idr holds a reference to the device, the returned + * pps_device is guaranteed to be valid until pps_unregister_cdev() is + * called on it. But after calling pps_unregister_cdev(), it may be + * freed at any time. */ struct pps_device *pps_lookup_dev(void const *cookie) { @@ -448,13 +455,11 @@ EXPORT_SYMBOL(pps_lookup_dev); static void __exit pps_exit(void) { class_destroy(pps_class); - unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES); + __unregister_chrdev(pps_major, 0, PPS_MAX_SOURCES, "pps"); } static int __init pps_init(void) { - int err; - pps_class = class_create("pps"); if (IS_ERR(pps_class)) { pr_err("failed to allocate class\n"); @@ -462,8 +467,9 @@ static int __init pps_init(void) } pps_class->dev_groups = pps_groups; - err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps"); - if (err < 0) { + pps_major = __register_chrdev(0, 0, PPS_MAX_SOURCES, "pps", + &pps_cdev_fops); + if (pps_major < 0) { pr_err("failed to allocate char device region\n"); goto remove_class; } @@ -476,8 +482,7 @@ static int __init pps_init(void) remove_class: class_destroy(pps_class); - - return err; + return pps_major; } subsys_initcall(pps_init); diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c index 5feecaadde8e..120db96d9e95 100644 --- a/drivers/ptp/ptp_ocp.c +++ b/drivers/ptp/ptp_ocp.c @@ -4420,7 +4420,7 @@ ptp_ocp_complete(struct ptp_ocp *bp) pps = pps_lookup_dev(bp->ptp); if (pps) - ptp_ocp_symlink(bp, pps->dev, "pps"); + ptp_ocp_symlink(bp, &pps->dev, "pps"); ptp_ocp_debugfs_add_device(bp); diff --git a/include/linux/pps_kernel.h b/include/linux/pps_kernel.h index 78c8ac4951b5..c7abce28ed29 100644 --- a/include/linux/pps_kernel.h +++ b/include/linux/pps_kernel.h @@ -56,8 +56,7 @@ struct pps_device { unsigned int id; /* PPS source unique ID */ void const *lookup_cookie; /* For pps_lookup_dev() only */ - struct cdev cdev; - struct device *dev; + struct device dev; struct fasync_struct *async_queue; /* fasync method */ spinlock_t lock; };

7 months, 1 week

3
2
0 0

[PATCH 6.6 1/2] Revert "btrfs: avoid monopolizing a core when activating a swap file"

by Koichiro Den

This reverts commit 6e1a8225930719a9f352d56320214e33e2dde0a6. The backport for linux-6.6.y, commit 6e1a82259307 ("btrfs: avoid monopolizing a core when activating a swap file"), inserted cond_resched() in the wrong location. Revert it now; a subsequent commit will re-backport the original patch. Fixes: 6e1a82259307 ("btrfs: avoid monopolizing a core when activating a swap file") # linux-6.6.y Signed-off-by: Koichiro Den <koichiro.den(a)canonical.com> --- fs/btrfs/inode.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index eb9319d856f2..49c927e8a807 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7153,8 +7153,6 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, ret = -EAGAIN; goto out; } - - cond_resched(); } if (orig_start) -- 2.45.2

7 months, 1 week

2
2
0 0

[PATCH 5.4~6.13] MIPS: ftrace: Declare ftrace_get_parent_ra_addr() as static

by WangYuli

commit ddd068d81445b17ac0bed084dfeb9e58b4df3ddd upstream. Declare ftrace_get_parent_ra_addr() as static to suppress clang compiler warning that 'no previous prototype'. This function is not intended to be called from other parts. Fix follow error with clang-19: arch/mips/kernel/ftrace.c:251:15: error: no previous prototype for function 'ftrace_get_parent_ra_addr' [-Werror,-Wmissing-prototypes] 251 | unsigned long ftrace_get_parent_ra_addr(unsigned long self_ra, unsigned long | ^ arch/mips/kernel/ftrace.c:251:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 251 | unsigned long ftrace_get_parent_ra_addr(unsigned long self_ra, unsigned long | ^ | static 1 error generated. Signed-off-by: WangYuli <wangyuli(a)uniontech.com> Acked-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org> Reviewed-by: Philippe Mathieu-Daudé <philmd(a)linaro.org> Signed-off-by: Thomas Bogendoerfer <tsbogend(a)alpha.franken.de> Signed-off-by: WangYuli <wangyuli(a)uniontech.com> --- arch/mips/kernel/ftrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c index 8c401e42301c..f39e85fd58fa 100644 --- a/arch/mips/kernel/ftrace.c +++ b/arch/mips/kernel/ftrace.c @@ -248,7 +248,7 @@ int ftrace_disable_ftrace_graph_caller(void) #define S_R_SP (0xafb0 << 16) /* s{d,w} R, offset(sp) */ #define OFFSET_MASK 0xffff /* stack offset range: 0 ~ PT_SIZE */ -unsigned long ftrace_get_parent_ra_addr(unsigned long self_ra, unsigned long +static unsigned long ftrace_get_parent_ra_addr(unsigned long self_ra, unsigned long old_parent_ra, unsigned long parent_ra_addr, unsigned long fp) { unsigned long sp, ip, tmp; -- 2.47.2

7 months, 1 week

2
1
0 0

[PATCH] Documentation/no_hz: Remove description that states boot CPU cannot be nohz_full

by Krishanth Jagaduri via B4 Relay

From: Oleg Nesterov <oleg(a)redhat.com> [ Upstream commit 5097cbcb38e6e0d2627c9dde1985e91d2c9f880e ] Documentation/timers/no_hz.rst states that the "nohz_full=" mask must not include the boot CPU, which is no longer true after: commit 08ae95f4fd3b ("nohz_full: Allow the boot CPU to be nohz_full"). Apply changes only to Documentation/timers/no_hz.rst in stable kernels. Signed-off-by: Oleg Nesterov <oleg(a)redhat.com> Cc: stable(a)vger.kernel.org # 5.4+ Signed-off-by: Krishanth Jagaduri <Krishanth.Jagaduri(a)sony.com> --- Hi, Before kernel 6.9, Documentation/timers/no_hz.rst states that "nohz_full=" mask must not include the boot CPU, which is no longer true after commit 08ae95f4fd3b ("nohz_full: Allow the boot CPU to be nohz_full"). This was fixed upstream by commit 5097cbcb38e6 ("sched/isolation: Prevent boot crash when the boot CPU is nohz_full"). While it fixes the document description, it also fixes issue introduced by another commit aae17ebb53cd ("workqueue: Avoid using isolated cpus' timers on queue_delayed_work"). It is unlikely that it will be backported to stable kernels which does not contain the commit that introduced the issue. Could Documentation/timers/no_hz.rst be fixed in stable kernels 5.4+? --- Documentation/timers/no_hz.rst | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/Documentation/timers/no_hz.rst b/Documentation/timers/no_hz.rst index 065db217cb04fc252bbf6a05991296e7f1d3a4c5..16bda468423e88090c0dc467ca7a5c7f3fd2bf02 100644 --- a/Documentation/timers/no_hz.rst +++ b/Documentation/timers/no_hz.rst @@ -129,11 +129,8 @@ adaptive-tick CPUs: At least one non-adaptive-tick CPU must remain online to handle timekeeping tasks in order to ensure that system calls like gettimeofday() returns accurate values on adaptive-tick CPUs. (This is not an issue for CONFIG_NO_HZ_IDLE=y because there are no running -user processes to observe slight drifts in clock rate.) Therefore, the -boot CPU is prohibited from entering adaptive-ticks mode. Specifying a -"nohz_full=" mask that includes the boot CPU will result in a boot-time -error message, and the boot CPU will be removed from the mask. Note that -this means that your system must have at least two CPUs in order for +user processes to observe slight drifts in clock rate.) Note that this +means that your system must have at least two CPUs in order for CONFIG_NO_HZ_FULL=y to do anything for you. Finally, adaptive-ticks CPUs must have their RCU callbacks offloaded. --- base-commit: 219d54332a09e8d8741c1e1982f5eae56099de85 change-id: 20250129-send-oss-20250129-3c42dcf463eb Best regards, -- Krishanth Jagaduri <Krishanth.Jagaduri(a)sony.com>

7 months, 1 week

4
3
0 0

FAILED: patch "[PATCH] pps: Fix a use-after-free" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x c79a39dc8d060b9e64e8b0fa9d245d44befeefbe # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025020422-tragedy-splashing-50db@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From c79a39dc8d060b9e64e8b0fa9d245d44befeefbe Mon Sep 17 00:00:00 2001 From: Calvin Owens <calvin(a)wbinvd.org> Date: Mon, 11 Nov 2024 20:13:29 -0800 Subject: [PATCH] pps: Fix a use-after-free 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(a)vger.kernel.org Signed-off-by: Calvin Owens <calvin(a)wbinvd.org> Reviewed-by: Michal Schmidt <mschmidt(a)redhat.com> Link: https://lore.kernel.org/r/a17975fd5ae99385791929e563f72564edbcf28f.17313837… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c index 634c3b2f8c26..f77b19884f05 100644 --- a/drivers/pps/clients/pps-gpio.c +++ b/drivers/pps/clients/pps-gpio.c @@ -214,8 +214,8 @@ static int pps_gpio_probe(struct platform_device *pdev) return -EINVAL; } - dev_info(data->pps->dev, "Registered IRQ %d as PPS source\n", - data->irq); + dev_dbg(&data->pps->dev, "Registered IRQ %d as PPS source\n", + data->irq); return 0; } diff --git a/drivers/pps/clients/pps-ktimer.c b/drivers/pps/clients/pps-ktimer.c index d33106bd7a29..2f465549b843 100644 --- a/drivers/pps/clients/pps-ktimer.c +++ b/drivers/pps/clients/pps-ktimer.c @@ -56,7 +56,7 @@ static struct pps_source_info pps_ktimer_info = { static void __exit pps_ktimer_exit(void) { - dev_info(pps->dev, "ktimer PPS source unregistered\n"); + dev_dbg(&pps->dev, "ktimer PPS source unregistered\n"); del_timer_sync(&ktimer); pps_unregister_source(pps); @@ -74,7 +74,7 @@ static int __init pps_ktimer_init(void) timer_setup(&ktimer, pps_ktimer_event, 0); mod_timer(&ktimer, jiffies + HZ); - dev_info(pps->dev, "ktimer PPS source registered\n"); + dev_dbg(&pps->dev, "ktimer PPS source registered\n"); return 0; } diff --git a/drivers/pps/clients/pps-ldisc.c b/drivers/pps/clients/pps-ldisc.c index 443d6bae19d1..fa5660f3c4b7 100644 --- a/drivers/pps/clients/pps-ldisc.c +++ b/drivers/pps/clients/pps-ldisc.c @@ -32,7 +32,7 @@ static void pps_tty_dcd_change(struct tty_struct *tty, bool active) pps_event(pps, &ts, active ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR, NULL); - dev_dbg(pps->dev, "PPS %s at %lu\n", + dev_dbg(&pps->dev, "PPS %s at %lu\n", active ? "assert" : "clear", jiffies); } @@ -69,7 +69,7 @@ static int pps_tty_open(struct tty_struct *tty) goto err_unregister; } - dev_info(pps->dev, "source \"%s\" added\n", info.path); + dev_dbg(&pps->dev, "source \"%s\" added\n", info.path); return 0; @@ -89,7 +89,7 @@ static void pps_tty_close(struct tty_struct *tty) if (WARN_ON(!pps)) return; - dev_info(pps->dev, "removed\n"); + dev_info(&pps->dev, "removed\n"); pps_unregister_source(pps); } diff --git a/drivers/pps/clients/pps_parport.c b/drivers/pps/clients/pps_parport.c index abaffb4e1c1c..24db06750297 100644 --- a/drivers/pps/clients/pps_parport.c +++ b/drivers/pps/clients/pps_parport.c @@ -81,7 +81,7 @@ static void parport_irq(void *handle) /* check the signal (no signal means the pulse is lost this time) */ if (!signal_is_set(port)) { local_irq_restore(flags); - dev_err(dev->pps->dev, "lost the signal\n"); + dev_err(&dev->pps->dev, "lost the signal\n"); goto out_assert; } @@ -98,7 +98,7 @@ static void parport_irq(void *handle) /* timeout */ dev->cw_err++; if (dev->cw_err >= CLEAR_WAIT_MAX_ERRORS) { - dev_err(dev->pps->dev, "disabled clear edge capture after %d" + dev_err(&dev->pps->dev, "disabled clear edge capture after %d" " timeouts\n", dev->cw_err); dev->cw = 0; dev->cw_err = 0; diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c index d9d566f70ed1..92d1b62ea239 100644 --- a/drivers/pps/kapi.c +++ b/drivers/pps/kapi.c @@ -41,7 +41,7 @@ static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset) static void pps_echo_client_default(struct pps_device *pps, int event, void *data) { - dev_info(pps->dev, "echo %s %s\n", + dev_info(&pps->dev, "echo %s %s\n", event & PPS_CAPTUREASSERT ? "assert" : "", event & PPS_CAPTURECLEAR ? "clear" : ""); } @@ -112,7 +112,7 @@ struct pps_device *pps_register_source(struct pps_source_info *info, goto kfree_pps; } - dev_info(pps->dev, "new PPS source %s\n", info->name); + dev_dbg(&pps->dev, "new PPS source %s\n", info->name); return pps; @@ -166,7 +166,7 @@ void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, /* check event type */ BUG_ON((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0); - dev_dbg(pps->dev, "PPS event at %lld.%09ld\n", + dev_dbg(&pps->dev, "PPS event at %lld.%09ld\n", (s64)ts->ts_real.tv_sec, ts->ts_real.tv_nsec); timespec_to_pps_ktime(&ts_real, ts->ts_real); @@ -188,7 +188,7 @@ void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, /* Save the time stamp */ pps->assert_tu = ts_real; pps->assert_sequence++; - dev_dbg(pps->dev, "capture assert seq #%u\n", + dev_dbg(&pps->dev, "capture assert seq #%u\n", pps->assert_sequence); captured = ~0; @@ -202,7 +202,7 @@ void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, /* Save the time stamp */ pps->clear_tu = ts_real; pps->clear_sequence++; - dev_dbg(pps->dev, "capture clear seq #%u\n", + dev_dbg(&pps->dev, "capture clear seq #%u\n", pps->clear_sequence); captured = ~0; diff --git a/drivers/pps/kc.c b/drivers/pps/kc.c index 50dc59af45be..fbd23295afd7 100644 --- a/drivers/pps/kc.c +++ b/drivers/pps/kc.c @@ -43,11 +43,11 @@ int pps_kc_bind(struct pps_device *pps, struct pps_bind_args *bind_args) pps_kc_hardpps_mode = 0; pps_kc_hardpps_dev = NULL; spin_unlock_irq(&pps_kc_hardpps_lock); - dev_info(pps->dev, "unbound kernel" + dev_info(&pps->dev, "unbound kernel" " consumer\n"); } else { spin_unlock_irq(&pps_kc_hardpps_lock); - dev_err(pps->dev, "selected kernel consumer" + dev_err(&pps->dev, "selected kernel consumer" " is not bound\n"); return -EINVAL; } @@ -57,11 +57,11 @@ int pps_kc_bind(struct pps_device *pps, struct pps_bind_args *bind_args) pps_kc_hardpps_mode = bind_args->edge; pps_kc_hardpps_dev = pps; spin_unlock_irq(&pps_kc_hardpps_lock); - dev_info(pps->dev, "bound kernel consumer: " + dev_info(&pps->dev, "bound kernel consumer: " "edge=0x%x\n", bind_args->edge); } else { spin_unlock_irq(&pps_kc_hardpps_lock); - dev_err(pps->dev, "another kernel consumer" + dev_err(&pps->dev, "another kernel consumer" " is already bound\n"); return -EINVAL; } @@ -83,7 +83,7 @@ void pps_kc_remove(struct pps_device *pps) pps_kc_hardpps_mode = 0; pps_kc_hardpps_dev = NULL; spin_unlock_irq(&pps_kc_hardpps_lock); - dev_info(pps->dev, "unbound kernel consumer" + dev_info(&pps->dev, "unbound kernel consumer" " on device removal\n"); } else spin_unlock_irq(&pps_kc_hardpps_lock); diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c index 25d47907db17..6a02245ea35f 100644 --- a/drivers/pps/pps.c +++ b/drivers/pps/pps.c @@ -25,7 +25,7 @@ * Local variables */ -static dev_t pps_devt; +static int pps_major; static struct class *pps_class; static DEFINE_MUTEX(pps_idr_lock); @@ -62,7 +62,7 @@ static int pps_cdev_pps_fetch(struct pps_device *pps, struct pps_fdata *fdata) else { unsigned long ticks; - dev_dbg(pps->dev, "timeout %lld.%09d\n", + dev_dbg(&pps->dev, "timeout %lld.%09d\n", (long long) fdata->timeout.sec, fdata->timeout.nsec); ticks = fdata->timeout.sec * HZ; @@ -80,7 +80,7 @@ static int pps_cdev_pps_fetch(struct pps_device *pps, struct pps_fdata *fdata) /* Check for pending signals */ if (err == -ERESTARTSYS) { - dev_dbg(pps->dev, "pending signal caught\n"); + dev_dbg(&pps->dev, "pending signal caught\n"); return -EINTR; } @@ -98,7 +98,7 @@ static long pps_cdev_ioctl(struct file *file, switch (cmd) { case PPS_GETPARAMS: - dev_dbg(pps->dev, "PPS_GETPARAMS\n"); + dev_dbg(&pps->dev, "PPS_GETPARAMS\n"); spin_lock_irq(&pps->lock); @@ -114,7 +114,7 @@ static long pps_cdev_ioctl(struct file *file, break; case PPS_SETPARAMS: - dev_dbg(pps->dev, "PPS_SETPARAMS\n"); + dev_dbg(&pps->dev, "PPS_SETPARAMS\n"); /* Check the capabilities */ if (!capable(CAP_SYS_TIME)) @@ -124,14 +124,14 @@ static long pps_cdev_ioctl(struct file *file, if (err) return -EFAULT; if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) { - dev_dbg(pps->dev, "capture mode unspecified (%x)\n", + dev_dbg(&pps->dev, "capture mode unspecified (%x)\n", params.mode); return -EINVAL; } /* Check for supported capabilities */ if ((params.mode & ~pps->info.mode) != 0) { - dev_dbg(pps->dev, "unsupported capabilities (%x)\n", + dev_dbg(&pps->dev, "unsupported capabilities (%x)\n", params.mode); return -EINVAL; } @@ -144,7 +144,7 @@ static long pps_cdev_ioctl(struct file *file, /* Restore the read only parameters */ if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) { /* section 3.3 of RFC 2783 interpreted */ - dev_dbg(pps->dev, "time format unspecified (%x)\n", + dev_dbg(&pps->dev, "time format unspecified (%x)\n", params.mode); pps->params.mode |= PPS_TSFMT_TSPEC; } @@ -165,7 +165,7 @@ static long pps_cdev_ioctl(struct file *file, break; case PPS_GETCAP: - dev_dbg(pps->dev, "PPS_GETCAP\n"); + dev_dbg(&pps->dev, "PPS_GETCAP\n"); err = put_user(pps->info.mode, iuarg); if (err) @@ -176,7 +176,7 @@ static long pps_cdev_ioctl(struct file *file, case PPS_FETCH: { struct pps_fdata fdata; - dev_dbg(pps->dev, "PPS_FETCH\n"); + dev_dbg(&pps->dev, "PPS_FETCH\n"); err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata)); if (err) @@ -206,7 +206,7 @@ static long pps_cdev_ioctl(struct file *file, case PPS_KC_BIND: { struct pps_bind_args bind_args; - dev_dbg(pps->dev, "PPS_KC_BIND\n"); + dev_dbg(&pps->dev, "PPS_KC_BIND\n"); /* Check the capabilities */ if (!capable(CAP_SYS_TIME)) @@ -218,7 +218,7 @@ static long pps_cdev_ioctl(struct file *file, /* Check for supported capabilities */ if ((bind_args.edge & ~pps->info.mode) != 0) { - dev_err(pps->dev, "unsupported capabilities (%x)\n", + dev_err(&pps->dev, "unsupported capabilities (%x)\n", bind_args.edge); return -EINVAL; } @@ -227,7 +227,7 @@ static long pps_cdev_ioctl(struct file *file, if (bind_args.tsformat != PPS_TSFMT_TSPEC || (bind_args.edge & ~PPS_CAPTUREBOTH) != 0 || bind_args.consumer != PPS_KC_HARDPPS) { - dev_err(pps->dev, "invalid kernel consumer bind" + dev_err(&pps->dev, "invalid kernel consumer bind" " parameters (%x)\n", bind_args.edge); return -EINVAL; } @@ -259,7 +259,7 @@ static long pps_cdev_compat_ioctl(struct file *file, struct pps_fdata fdata; int err; - dev_dbg(pps->dev, "PPS_FETCH\n"); + dev_dbg(&pps->dev, "PPS_FETCH\n"); err = copy_from_user(&compat, uarg, sizeof(struct pps_fdata_compat)); if (err) @@ -296,20 +296,36 @@ static long pps_cdev_compat_ioctl(struct file *file, #define pps_cdev_compat_ioctl NULL #endif +static struct pps_device *pps_idr_get(unsigned long id) +{ + struct pps_device *pps; + + mutex_lock(&pps_idr_lock); + pps = idr_find(&pps_idr, id); + if (pps) + get_device(&pps->dev); + + mutex_unlock(&pps_idr_lock); + return pps; +} + static int pps_cdev_open(struct inode *inode, struct file *file) { - struct pps_device *pps = container_of(inode->i_cdev, - struct pps_device, cdev); + struct pps_device *pps = pps_idr_get(iminor(inode)); + + if (!pps) + return -ENODEV; + file->private_data = pps; - kobject_get(&pps->dev->kobj); return 0; } static int pps_cdev_release(struct inode *inode, struct file *file) { - struct pps_device *pps = container_of(inode->i_cdev, - struct pps_device, cdev); - kobject_put(&pps->dev->kobj); + struct pps_device *pps = file->private_data; + + WARN_ON(pps->id != iminor(inode)); + put_device(&pps->dev); return 0; } @@ -331,22 +347,13 @@ static void pps_device_destruct(struct device *dev) { struct pps_device *pps = dev_get_drvdata(dev); - cdev_del(&pps->cdev); - - /* Now we can release the ID for re-use */ pr_debug("deallocating pps%d\n", pps->id); - mutex_lock(&pps_idr_lock); - idr_remove(&pps_idr, pps->id); - mutex_unlock(&pps_idr_lock); - - kfree(dev); kfree(pps); } int pps_register_cdev(struct pps_device *pps) { int err; - dev_t devt; mutex_lock(&pps_idr_lock); /* @@ -363,40 +370,29 @@ int pps_register_cdev(struct pps_device *pps) goto out_unlock; } pps->id = err; - mutex_unlock(&pps_idr_lock); - devt = MKDEV(MAJOR(pps_devt), pps->id); - - cdev_init(&pps->cdev, &pps_cdev_fops); - pps->cdev.owner = pps->info.owner; - - err = cdev_add(&pps->cdev, devt, 1); - if (err) { - pr_err("%s: failed to add char device %d:%d\n", - pps->info.name, MAJOR(pps_devt), pps->id); + pps->dev.class = pps_class; + pps->dev.parent = pps->info.dev; + pps->dev.devt = MKDEV(pps_major, pps->id); + dev_set_drvdata(&pps->dev, pps); + dev_set_name(&pps->dev, "pps%d", pps->id); + err = device_register(&pps->dev); + if (err) goto free_idr; - } - pps->dev = device_create(pps_class, pps->info.dev, devt, pps, - "pps%d", pps->id); - if (IS_ERR(pps->dev)) { - err = PTR_ERR(pps->dev); - goto del_cdev; - } /* Override the release function with our own */ - pps->dev->release = pps_device_destruct; + pps->dev.release = pps_device_destruct; - pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, - MAJOR(pps_devt), pps->id); + pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, pps_major, + pps->id); + get_device(&pps->dev); + mutex_unlock(&pps_idr_lock); return 0; -del_cdev: - cdev_del(&pps->cdev); - free_idr: - mutex_lock(&pps_idr_lock); idr_remove(&pps_idr, pps->id); + put_device(&pps->dev); out_unlock: mutex_unlock(&pps_idr_lock); return err; @@ -406,7 +402,13 @@ void pps_unregister_cdev(struct pps_device *pps) { pr_debug("unregistering pps%d\n", pps->id); pps->lookup_cookie = NULL; - device_destroy(pps_class, pps->dev->devt); + device_destroy(pps_class, pps->dev.devt); + + /* Now we can release the ID for re-use */ + mutex_lock(&pps_idr_lock); + idr_remove(&pps_idr, pps->id); + put_device(&pps->dev); + mutex_unlock(&pps_idr_lock); } /* @@ -426,6 +428,11 @@ void pps_unregister_cdev(struct pps_device *pps) * so that it will not be used again, even if the pps device cannot * be removed from the idr due to pending references holding the minor * number in use. + * + * Since pps_idr holds a reference to the device, the returned + * pps_device is guaranteed to be valid until pps_unregister_cdev() is + * called on it. But after calling pps_unregister_cdev(), it may be + * freed at any time. */ struct pps_device *pps_lookup_dev(void const *cookie) { @@ -448,13 +455,11 @@ EXPORT_SYMBOL(pps_lookup_dev); static void __exit pps_exit(void) { class_destroy(pps_class); - unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES); + __unregister_chrdev(pps_major, 0, PPS_MAX_SOURCES, "pps"); } static int __init pps_init(void) { - int err; - pps_class = class_create("pps"); if (IS_ERR(pps_class)) { pr_err("failed to allocate class\n"); @@ -462,8 +467,9 @@ static int __init pps_init(void) } pps_class->dev_groups = pps_groups; - err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps"); - if (err < 0) { + pps_major = __register_chrdev(0, 0, PPS_MAX_SOURCES, "pps", + &pps_cdev_fops); + if (pps_major < 0) { pr_err("failed to allocate char device region\n"); goto remove_class; } @@ -476,8 +482,7 @@ static int __init pps_init(void) remove_class: class_destroy(pps_class); - - return err; + return pps_major; } subsys_initcall(pps_init); diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c index 5feecaadde8e..120db96d9e95 100644 --- a/drivers/ptp/ptp_ocp.c +++ b/drivers/ptp/ptp_ocp.c @@ -4420,7 +4420,7 @@ ptp_ocp_complete(struct ptp_ocp *bp) pps = pps_lookup_dev(bp->ptp); if (pps) - ptp_ocp_symlink(bp, pps->dev, "pps"); + ptp_ocp_symlink(bp, &pps->dev, "pps"); ptp_ocp_debugfs_add_device(bp); diff --git a/include/linux/pps_kernel.h b/include/linux/pps_kernel.h index 78c8ac4951b5..c7abce28ed29 100644 --- a/include/linux/pps_kernel.h +++ b/include/linux/pps_kernel.h @@ -56,8 +56,7 @@ struct pps_device { unsigned int id; /* PPS source unique ID */ void const *lookup_cookie; /* For pps_lookup_dev() only */ - struct cdev cdev; - struct device *dev; + struct device dev; struct fasync_struct *async_queue; /* fasync method */ spinlock_t lock; };

7 months, 1 week

3
2
0 0

[PATCH 6.1 1/2] Revert "btrfs: avoid monopolizing a core when activating a swap file"

by Koichiro Den

This reverts commit bb8e287f596b62fac18ed84cc03a9f1752f6b3b8. The backport for linux-6.1.y, commit bb8e287f596b ("btrfs: avoid monopolizing a core when activating a swap file"), inserted cond_resched() in the wrong location. Revert it now; a subsequent commit will re-backport the original patch. Fixes: bb8e287f596b ("btrfs: avoid monopolizing a core when activating a swap file") # linux-6.1.y Signed-off-by: Koichiro Den <koichiro.den(a)canonical.com> --- fs/btrfs/inode.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index b2cded5bf69c..f4a754d62bf4 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7387,8 +7387,6 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, ret = -EAGAIN; goto out; } - - cond_resched(); } if (orig_start) -- 2.45.2

7 months, 1 week

2
2
0 0

[PATCH 5.15 1/2] Revert "btrfs: avoid monopolizing a core when activating a swap file"

by Koichiro Den

This reverts commit 214d92f0a465f93eea15e702e743f2c63823b1fd. The backport for linux-5.15.y, commit 214d92f0a465 ("btrfs: avoid monopolizing a core when activating a swap file"), inserted cond_resched() in the wrong location. Revert it now; a subsequent commit will re-backport the original patch. Fixes: 214d92f0a465 ("btrfs: avoid monopolizing a core when activating a swap file") # linux-5.15.y Signed-off-by: Koichiro Den <koichiro.den(a)canonical.com> --- fs/btrfs/inode.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index a6b1dd834060..8f048e517e65 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7698,8 +7698,6 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, ret = -EAGAIN; goto out; } - - cond_resched(); } btrfs_release_path(path); -- 2.45.2

7 months, 1 week

2
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