On Sun, 2017-07-30 at 08:27 -0400, John David Anglin wrote: > On 2017-07-30, at 2:47 AM, Meelis Roos wrote: > > > > > > > > > > > > > > [ 1.940000] [<000000004011b4a4>] > > > > pdc_stable_init+0x2c4/0x458 > > > > > > I don't see this symbol in my build. I see > > > pdc_stable_initialize. > > > > > > Do you have a patch installed? > > > > No, pristine v4.13-rc2-110-g0b5477d9dabd git. > > > James is correct about pdc_stable_init. It is enabled by > CONFIG_PDC_STABLE. > > In the backtrace, > > [ 1.936053] BUG: sleeping function called from invalid context at > mm/slab.h:416 > [ 1.936243] in_atomic(): 1, irqs_disabled(): 0, pid: 1, name: > swapper/0 > [ 1.936601] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.13.0-rc2- > 00110-g0b5477d9dabd #111 > [ 1.936828] Backtrace: > [ 1.936889] [<0000000040217ac8>] show_stack+0x20/0x38 > [ 1.939036] [<00000000406fbbb0>] dump_stack+0xb0/0x128 > [ 1.939174] [<0000000040274090>] ___might_sleep+0x180/0x1b8 > [ 1.940000] [<0000000040274144>] __might_sleep+0x7c/0xe8 > [ 1.940000] [<0000000040373874>] kmem_cache_alloc+0x14c/0x1e0 > [ 1.940000] [<0000000040419514>] __kernfs_new_node+0x84/0x1b8 > [ 1.940000] [<000000004041b09c>] kernfs_new_node+0x3c/0x78 > [ 1.940000] [<000000004041e040>] kernfs_create_link+0x40/0xd8 > [ 1.940000] [<000000004041f320>] > sysfs_do_create_link_sd.isra.0+0xb0/0x130 > [ 1.940000] [<000000004041f3d4>] sysfs_create_link+0x34/0x58 > [ 1.940000] [<000000004011b4a4>] pdc_stable_init+0x2c4/0x458 > > I don't know how we got to sysfs_create_link. It is probably from > here: > > /* Don't forget the root entries */ > error = sysfs_create_group(stable_kobj, &pdcs_attr_group); > > Presumably, this is the sleeping function but it's not clear how the > incorrect context arises. > > Maybe there is an errant spin_lock somewhere. For example, see: > https://lkml.org/lkml/2012/3/29/101 > It might be in a unrelated routine. > > Since this code hasn't changed in a long time, it should be possible > to bisect problem. How about this? There's no need to take the write lock when creating links anyway. James --- diff --git a/drivers/parisc/pdc_stable.c b/drivers/parisc/pdc_stable.c index 7147aa53e9a2..d7c88b1eaf06 100644 --- a/drivers/parisc/pdc_stable.c +++ b/drivers/parisc/pdc_stable.c @@ -331,13 +331,13 @@ pdcspath_hwpath_write(struct pdcspath_entry *entry, const char *buf, size_t coun /* Now, dive in. Write back to the hardware */ pdcspath_store(entry); + write_unlock(&entry->rw_lock); + /* Update the symlink to the real device */ sysfs_remove_link(&entry->kobj, "device"); ret = sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device"); WARN_ON(ret); - write_unlock(&entry->rw_lock); - printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" path to \"%s\"\n", entry->name, buf); -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
