linux/drivers/base/core.c, branch v2.6.34

driver-core: document ERR_PTR() return values

2010-03-19T14:12:21Z

A number of functions in the driver core return ERR_PTR() values on error. Document this in the kernel-doc of the functions. Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman

driver core: Use sysfs_rename_link in device_rename

2010-03-08T01:04:52Z

Don't open code the renaming of symlinks in sysfs instead use the new helper function sysfs_rename_link Acked-by: Tejun Heo Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman Signed-off-by: Greg Kroah-Hartman

Driver core: Constify struct sysfs_ops in struct kobj_type

2010-03-08T01:04:49Z

Constify struct sysfs_ops. This is part of the ops structure constification effort started by Arjan van de Ven et al. Benefits of this constification: * prevents modification of data that is shared (referenced) by many other structure instances at runtime * detects/prevents accidental (but not intentional) modification attempts on archs that enforce read-only kernel data at runtime * potentially better optimized code as the compiler can assume that the const data cannot be changed * the compiler/linker move const data into .rodata and therefore exclude them from false sharing Signed-off-by: Emese Revfy Acked-by: David Teigland Acked-by: Matt Domsch Acked-by: Maciej Sosnowski Acked-by: Hans J. Koch Acked-by: Pekka Enberg Acked-by: Jens Axboe Acked-by: Stephen Hemminger Signed-off-by: Greg Kroah-Hartman

kobject: Constify struct kset_uevent_ops

2010-03-08T01:04:49Z

Constify struct kset_uevent_ops. This is part of the ops structure constification effort started by Arjan van de Ven et al. Benefits of this constification: * prevents modification of data that is shared (referenced) by many other structure instances at runtime * detects/prevents accidental (but not intentional) modification attempts on archs that enforce read-only kernel data at runtime * potentially better optimized code as the compiler can assume that the const data cannot be changed * the compiler/linker move const data into .rodata and therefore exclude them from false sharing Signed-off-by: Emese Revfy Signed-off-by: Greg Kroah-Hartman

Driver-Core: require valid action string in uevent trigger

2010-03-08T01:04:48Z

No longer fall back to "add" and warn, but always require a valid action-string written to the "uevent" file. Signed-off-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman

driver-core: fix race condition in get_device_parent()

2010-03-08T01:04:46Z

sysfs is creating several devices in cuse class concurrently and with CONFIG_SYSFS_DEPRECATED turned off, it triggers the following oops. BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 IP: [] sysfs_addrm_start+0x4a/0xf0 PGD 75bb067 PUD 75be067 PMD 0 Oops: 0000 [#1] PREEMPT SMP last sysfs file: /sys/devices/system/cpu/cpu7/topology/core_siblings CPU 1 Modules linked in: cuse fuse Pid: 4737, comm: osspd Not tainted 2.6.31-work #77 RIP: 0010:[] [] sysfs_addrm_start+0x4a/0xf0 RSP: 0018:ffff88000042f8f8 EFLAGS: 00010296 RAX: ffff88000042ffd8 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff880007eef660 RDI: 0000000000000001 RBP: ffff88000042f918 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: ffffffff81158b0a R12: ffff88000042f928 R13: 00000000fffffff4 R14: 0000000000000000 R15: ffff88000042f9a0 FS: 00007fe93905a950(0000) GS:ffff880008600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000038 CR3: 00000000077c9000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process osspd (pid: 4737, threadinfo ffff88000042e000, task ffff880007eef040) Stack: ffff880005da10e8 0000000011cc8d6e ffff88000042f928 ffff880003d28a28 <0> ffff88000042f988 ffffffff811592d7 0000000000000000 0000000000000000 <0> 0000000000000000 0000000000000000 ffff88000042f958 0000000011cc8d6e Call Trace: [] create_dir+0x67/0xe0 [] sysfs_create_dir+0x58/0xb0 [] ? kobject_add_internal+0xcc/0x220 [] ? vsnprintf+0x3c1/0xb90 [] kobject_add_internal+0x107/0x220 [] kobject_add_varg+0x47/0x80 [] kobject_add+0x53/0x90 [] device_add+0xd4/0x690 [] ? dev_set_name+0x4b/0x70 [] cuse_process_init_reply+0x2b4/0x420 [cuse] ... The problem is that kobject_add_internal() first adds a kobject to the kset and then try to create sysfs directory for it. If the creation fails, it remove the kobject from the kset. get_device_parent() accesses class_dirs kset while only holding class_dirs.list_lock to see whether the cuse class dir exists. But when it exists, it may not have finished initialization yet or may fail and get removed soon. In the above case, the former happened so the second one ends up trying to create subdirectory under NULL sysfs_dirent. Fix it by grabbing a mutex in get_device_parent(). Signed-off-by: Tejun Heo Reported-by: Colin Guthrie Cc: stable Signed-off-by: Greg Kroah-Hartman

Driver-core: Fix bogus 0 error return in device_add()

2009-12-23T19:23:44Z

If device_add() is called with a device which does not have dev->p set up, then device_private_init() is called. If that succeeds, then the error variable is set to 0. Now if the dev_name(dev) check further down fails, then device_add() correctly terminates, but returns 0. That of course lets the driver progress. If later another driver uses this half set up device as parent then device_add() of the child device explodes and renders sysfs completely unusable. Set the error to -EINVAL if dev_name() check fails. Signed-off-by: Thomas Gleixner Cc: Kay Sievers Cc: "Hans J. Koch" Signed-off-by: Greg Kroah-Hartman

Driver core: bin_attribute parameters can often be const*

2009-12-23T19:23:43Z

Many struct bin_attribute descriptors are purely read-only structures, and there's no need to change them. Therefore make the promise not to, which will let those descriptors be put in a ro section. Signed-off-by: Phil Carmody Signed-off-by: Greg Kroah-Hartman

Driver core: device_attribute parameters can often be const*

2009-12-23T19:23:43Z

Most device_attributes are const, and are begging to be put in a ro section. However, the create and remove file interfaces were failing to propagate the const promise which the only functions they call offer. Signed-off-by: Phil Carmody Signed-off-by: Greg Kroah-Hartman

Driver core: fix race in dev_driver_string

2009-12-11T19:24:55Z

This patch (as1310) works around a race in dev_driver_string(). If the device is unbound while the function is running, dev->driver might become NULL after we test it and before we dereference it. Signed-off-by: Alan Stern Cc: stable Cc: Oliver Neukum Signed-off-by: Greg Kroah-Hartman