| Message ID | 20240411031903.3050278-3-chengzhihao1@huawei.com |
|---|---|
| State | New |
| Delegated to: | Richard Weinberger |
| Headers | show |
| Series | ubi: Fix serious of resource leaking problems | expand |
On Thu, Apr 11, 2024 at 11:19:01AM +0800, Zhihao Cheng wrote: > The ubiblock_init called by ubi_init will register device number, but > device number is not released in error handling path of ubi_init when > ubi is loaded by inserting module (eg. attaching failure), which leads > to subsequent ubi_init calls failed by running out of device number > (dmesg shows that "__register_blkdev: failed to get major for ubiblock"). > Since ubiblock_init() registers notifier and invokes notification > functions, so we can move it after ubi_init_attach() to fix the problem. > > Fixes: 927c145208b0 ("mtd: ubi: attach from device tree") > Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> > --- > drivers/mtd/ubi/build.c | 51 +++++++++++++++++++++-------------------- > 1 file changed, 26 insertions(+), 25 deletions(-) > > diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c > index 7f95fd7968a8..bc63fbf5e947 100644 > --- a/drivers/mtd/ubi/build.c > +++ b/drivers/mtd/ubi/build.c > @@ -1263,9 +1263,21 @@ static struct mtd_notifier ubi_mtd_notifier = { > .remove = ubi_notify_remove, > }; > > +static void detach_mtd_devs(int count) Missing __init to avoid section missmatch. See also: https://lore.kernel.org/oe-kbuild-all/202404112327.158HJfAw-lkp@intel.com/ > +{ > + int i; > + > + for (i = 0; i < count; i++) > + if (ubi_devices[i]) { > + mutex_lock(&ubi_devices_mutex); > + ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1); > + mutex_unlock(&ubi_devices_mutex); > + } > +} > + > static int __init ubi_init_attach(void) > { > - int err, i, k; > + int err, i; > > /* Attach MTD devices */ > for (i = 0; i < mtd_devs; i++) { > @@ -1317,12 +1329,7 @@ static int __init ubi_init_attach(void) > return 0; > > out_detach: > - for (k = 0; k < i; k++) > - if (ubi_devices[k]) { > - mutex_lock(&ubi_devices_mutex); > - ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1); > - mutex_unlock(&ubi_devices_mutex); > - } > + detach_mtd_devs(i); > return err; > } > #ifndef CONFIG_MTD_UBI_MODULE > @@ -1366,15 +1373,6 @@ static int __init ubi_init(void) > if (err) > goto out_slab; > > - err = ubiblock_init(); > - if (err) { > - pr_err("UBI error: block: cannot initialize, error %d\n", err); > - > - /* See comment above re-ubi_is_module(). */ > - if (ubi_is_module()) > - goto out_debugfs; > - } > - > register_mtd_user(&ubi_mtd_notifier); > > if (ubi_is_module()) { > @@ -1383,11 +1381,21 @@ static int __init ubi_init(void) > goto out_mtd_notifier; > } > > + err = ubiblock_init(); > + if (err) { > + pr_err("UBI error: block: cannot initialize, error %d\n", err); > + > + /* See comment above re-ubi_is_module(). */ > + if (ubi_is_module()) > + goto out_detach; > + } > + > return 0; > > +out_detach: > + detach_mtd_devs(mtd_devs); > out_mtd_notifier: > unregister_mtd_user(&ubi_mtd_notifier); > -out_debugfs: > ubi_debugfs_exit(); > out_slab: > kmem_cache_destroy(ubi_wl_entry_slab); > @@ -1403,17 +1411,10 @@ device_initcall(ubi_init); > > static void __exit ubi_exit(void) > { > - int i; > - > ubiblock_exit(); > unregister_mtd_user(&ubi_mtd_notifier); > > - for (i = 0; i < UBI_MAX_DEVICES; i++) > - if (ubi_devices[i]) { > - mutex_lock(&ubi_devices_mutex); > - ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1); > - mutex_unlock(&ubi_devices_mutex); > - } > + detach_mtd_devs(UBI_MAX_DEVICES); > ubi_debugfs_exit(); > kmem_cache_destroy(ubi_wl_entry_slab); > misc_deregister(&ubi_ctrl_cdev); > -- > 2.39.2 >
… > Since ubiblock_init() registers notifier and invokes notification > functions, so we can move it after ubi_init_attach() to fix the problem. I find this change description improvable. Would an imperative wording be also more desirable here? Regards, Markus
在 2024/4/11 23:48, Daniel Golle 写道: > On Thu, Apr 11, 2024 at 11:19:01AM +0800, Zhihao Cheng wrote: >> The ubiblock_init called by ubi_init will register device number, but >> device number is not released in error handling path of ubi_init when >> ubi is loaded by inserting module (eg. attaching failure), which leads >> to subsequent ubi_init calls failed by running out of device number >> (dmesg shows that "__register_blkdev: failed to get major for ubiblock"). >> Since ubiblock_init() registers notifier and invokes notification >> functions, so we can move it after ubi_init_attach() to fix the problem. >> >> Fixes: 927c145208b0 ("mtd: ubi: attach from device tree") >> Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> >> --- >> drivers/mtd/ubi/build.c | 51 +++++++++++++++++++++-------------------- >> 1 file changed, 26 insertions(+), 25 deletions(-) >> >> diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c >> index 7f95fd7968a8..bc63fbf5e947 100644 >> --- a/drivers/mtd/ubi/build.c >> +++ b/drivers/mtd/ubi/build.c >> @@ -1263,9 +1263,21 @@ static struct mtd_notifier ubi_mtd_notifier = { >> .remove = ubi_notify_remove, >> }; >> >> +static void detach_mtd_devs(int count) > > Missing __init to avoid section missmatch. > > See also: https://lore.kernel.org/oe-kbuild-all/202404112327.158HJfAw-lkp@intel.com/ I think function without '__init' attributes can be called in ubi_init, for example misc_register, kmem_cache_create, and I verify it by make W=1 in local machine. And above warning(in your link) is only detected in my v1 series. After investigating the '__init' and '__exit', I understand that there are two independent text section for these functions, for example, __init text section will be removed from memory after it is finished, so we cannot call __exit function in __init function. > >> +{ >> + int i; >> + >> + for (i = 0; i < count; i++) >> + if (ubi_devices[i]) { >> + mutex_lock(&ubi_devices_mutex); >> + ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1); >> + mutex_unlock(&ubi_devices_mutex); >> + } >> +}
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index 7f95fd7968a8..bc63fbf5e947 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -1263,9 +1263,21 @@ static struct mtd_notifier ubi_mtd_notifier = { .remove = ubi_notify_remove, }; +static void detach_mtd_devs(int count) +{ + int i; + + for (i = 0; i < count; i++) + if (ubi_devices[i]) { + mutex_lock(&ubi_devices_mutex); + ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1); + mutex_unlock(&ubi_devices_mutex); + } +} + static int __init ubi_init_attach(void) { - int err, i, k; + int err, i; /* Attach MTD devices */ for (i = 0; i < mtd_devs; i++) { @@ -1317,12 +1329,7 @@ static int __init ubi_init_attach(void) return 0; out_detach: - for (k = 0; k < i; k++) - if (ubi_devices[k]) { - mutex_lock(&ubi_devices_mutex); - ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1); - mutex_unlock(&ubi_devices_mutex); - } + detach_mtd_devs(i); return err; } #ifndef CONFIG_MTD_UBI_MODULE @@ -1366,15 +1373,6 @@ static int __init ubi_init(void) if (err) goto out_slab; - err = ubiblock_init(); - if (err) { - pr_err("UBI error: block: cannot initialize, error %d\n", err); - - /* See comment above re-ubi_is_module(). */ - if (ubi_is_module()) - goto out_debugfs; - } - register_mtd_user(&ubi_mtd_notifier); if (ubi_is_module()) { @@ -1383,11 +1381,21 @@ static int __init ubi_init(void) goto out_mtd_notifier; } + err = ubiblock_init(); + if (err) { + pr_err("UBI error: block: cannot initialize, error %d\n", err); + + /* See comment above re-ubi_is_module(). */ + if (ubi_is_module()) + goto out_detach; + } + return 0; +out_detach: + detach_mtd_devs(mtd_devs); out_mtd_notifier: unregister_mtd_user(&ubi_mtd_notifier); -out_debugfs: ubi_debugfs_exit(); out_slab: kmem_cache_destroy(ubi_wl_entry_slab); @@ -1403,17 +1411,10 @@ device_initcall(ubi_init); static void __exit ubi_exit(void) { - int i; - ubiblock_exit(); unregister_mtd_user(&ubi_mtd_notifier); - for (i = 0; i < UBI_MAX_DEVICES; i++) - if (ubi_devices[i]) { - mutex_lock(&ubi_devices_mutex); - ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1); - mutex_unlock(&ubi_devices_mutex); - } + detach_mtd_devs(UBI_MAX_DEVICES); ubi_debugfs_exit(); kmem_cache_destroy(ubi_wl_entry_slab); misc_deregister(&ubi_ctrl_cdev);
The ubiblock_init called by ubi_init will register device number, but device number is not released in error handling path of ubi_init when ubi is loaded by inserting module (eg. attaching failure), which leads to subsequent ubi_init calls failed by running out of device number (dmesg shows that "__register_blkdev: failed to get major for ubiblock"). Since ubiblock_init() registers notifier and invokes notification functions, so we can move it after ubi_init_attach() to fix the problem. Fixes: 927c145208b0 ("mtd: ubi: attach from device tree") Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> --- drivers/mtd/ubi/build.c | 51 +++++++++++++++++++++-------------------- 1 file changed, 26 insertions(+), 25 deletions(-)