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authorJean Delvare <khali@linux-fr.org>2009-11-26 09:22:33 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2009-12-08 10:22:39 -0800
commit95c2fff142fd3d44ba55cd6b3d9758c3215b52ca (patch)
treecf035a5051317048d2d7c224419b7139cab7e45a
parentd02b2ced79e2a22b38d6a4fdc758d070ff807d2b (diff)
i2c: Fix userspace_device list corruption
commit bbd2d9c9198c6efd449e9d395b3eaf2d03aa3bba upstream. Fix userspace_device list corruption. The corruption was caused by clients not being removed when adapters with such clients were themselves removed. Something like the following would trigger it (assuming i2c-stub gets adapter number 3): # modprobe i2c-stub chip_addr=0x50 # echo 24c08 0x50 > /sys/bus/i2c/devices/i2c-3/new_device # rmmod i2c-stub # modprobe i2c-stub chip_addr=0x50 # echo 24c08 0x50 > /sys/bus/i2c/devices/i2c-3/new_device For the records, the stack trace in the kernel logs look like this: kernel: WARNING: at lib/list_debug.c:30 __list_add+0x8b/0x90() kernel: Hardware name: (...) kernel: list_add corruption. prev->next should be next (c137fc84), but was (null). (prev=f57111b8). kernel: Modules linked in: (...) kernel: Pid: 4669, comm: bash Not tainted 2.6.32-rc8 #259 kernel: Call Trace: kernel: [<c111eb8b>] ? __list_add+0x8b/0x90 kernel: [<c111eb8b>] ? __list_add+0x8b/0x90 kernel: [<c103265c>] warn_slowpath_common+0x6c/0xc0 kernel: [<c111eb8b>] ? __list_add+0x8b/0x90 kernel: [<c10326f6>] warn_slowpath_fmt+0x26/0x30 kernel: [<c111eb8b>] __list_add+0x8b/0x90 kernel: [<c11ba165>] i2c_sysfs_new_device+0x1c5/0x250 kernel: [<c10861be>] ? might_fault+0x2e/0x80 kernel: [<c11b9fa0>] ? i2c_sysfs_new_device+0x0/0x250 kernel: [<c118c625>] dev_attr_store+0x25/0x30 kernel: [<c10e305c>] sysfs_write_file+0x9c/0xf0 kernel: [<c109d35c>] vfs_write+0x9c/0x160 kernel: [<c10e2fc0>] ? sysfs_write_file+0x0/0xf0 kernel: [<c109d4dd>] sys_write+0x3d/0x70 kernel: [<c1002ed8>] sysenter_do_call+0x12/0x36 Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/i2c/i2c-core.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 0e45c296d3d2..529d82ce5a4c 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -718,6 +718,7 @@ int i2c_del_adapter(struct i2c_adapter *adap)
{
int res = 0;
struct i2c_adapter *found;
+ struct i2c_client *client, *next;
/* First make sure that this adapter was ever added */
mutex_lock(&core_lock);
@@ -737,6 +738,16 @@ int i2c_del_adapter(struct i2c_adapter *adap)
if (res)
return res;
+ /* Remove devices instantiated from sysfs */
+ list_for_each_entry_safe(client, next, &userspace_devices, detected) {
+ if (client->adapter == adap) {
+ dev_dbg(&adap->dev, "Removing %s at 0x%x\n",
+ client->name, client->addr);
+ list_del(&client->detected);
+ i2c_unregister_device(client);
+ }
+ }
+
/* Detach any active clients. This can't fail, thus we do not
checking the returned value. */
res = device_for_each_child(&adap->dev, NULL, __unregister_client);