diff options
| author | Atsushi Nemoto <anemo@mba.ocn.ne.jp> | 2007-01-26 00:56:54 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-01-26 13:50:58 -0800 |
| commit | 1e9a51dca19dc1d8807c63cb3bd4413d3f95aaf5 (patch) | |
| tree | 941d5039c0dfb5aeb8a499e9cbebda0a1e80d8a8 /drivers/spi | |
| parent | 863c47028eb469c9e6c4e4287b01bea2bbf78766 (diff) | |
[PATCH] SPI: alternative fix for spi_busnum_to_master
If a SPI master device exists, udev (udevtrigger) causes kernel crash, due
to wrong kobj pointer in kobject_uevent_env(). This problem was not in
2.6.19.
The backtrace (on MIPS) was:
[<8024db6c>] kobject_uevent_env+0x54c/0x5e8
[<802a8264>] store_uevent+0x1c/0x3c (in drivers/class.c)
[<801cb14c>] subsys_attr_store+0x2c/0x50
[<801cb80c>] flush_write_buffer+0x38/0x5c
[<801cb900>] sysfs_write_file+0xd0/0x190
[<80181444>] vfs_write+0xc4/0x1a0
[<80181cdc>] sys_write+0x54/0xa0
[<8010dae4>] stack_done+0x20/0x3c
flush_write_buffer() passes kobject of spi_master_class.subsys to
subsys_addr_store(), then subsys_addr_store() passes a pointer to a struct
subsystem to store_uevent() which expects a pointer to a struct
class_device. The problem seems subsys_attr_store() called instead of
class_device_attr_store().
This mismatch was caused by commit
3bd0f6943520e459659d10f3282285e43d3990f1, which overrides kset of master
class. This made spi_master_class.subsys.kset.ktype NULL so
subsys_sysfs_ops is used instead of class_dev_sysfs_ops.
The commit was to fix spi_busnum_to_master(). Here is a patch fixes
this function in other way, just searching children list of
class_device.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi.c | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 270e6211c2e3..6307428d2c94 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -366,7 +366,6 @@ spi_alloc_master(struct device *dev, unsigned size) class_device_initialize(&master->cdev); master->cdev.class = &spi_master_class; - kobj_set_kset_s(&master->cdev, spi_master_class.subsys); master->cdev.dev = get_device(dev); spi_master_set_devdata(master, &master[1]); @@ -466,14 +465,20 @@ EXPORT_SYMBOL_GPL(spi_unregister_master); */ struct spi_master *spi_busnum_to_master(u16 bus_num) { - char name[9]; - struct kobject *bus; - - snprintf(name, sizeof name, "spi%u", bus_num); - bus = kset_find_obj(&spi_master_class.subsys.kset, name); - if (bus) - return container_of(bus, struct spi_master, cdev.kobj); - return NULL; + struct class_device *cdev; + struct spi_master *master = NULL; + struct spi_master *m; + + down(&spi_master_class.sem); + list_for_each_entry(cdev, &spi_master_class.children, node) { + m = container_of(cdev, struct spi_master, cdev); + if (m->bus_num == bus_num) { + master = spi_master_get(m); + break; + } + } + up(&spi_master_class.sem); + return master; } EXPORT_SYMBOL_GPL(spi_busnum_to_master); |