We found the upstream fix, sorry for the noise... Regards, Michael Wang
On 04/11/2017 12:14 PM, Michael Wang wrote: > > sysfs_kf_read() expect the show() callback return the dumped > length, while rdev_attr_show() can return the error which lead > into overflow: > > BUG: unable to handle kernel paging request at ffff88040b084000 > IP: [<ffffffff812fe8f4>] __memmove+0x24/0x1a0 > PGD 1edb067 PUD 1ede067 PMD 406b9a063 PTE 800000040b084161 > Oops: 0003 [#1] SMP > [snip] > Call Trace: > [<ffffffff81208c30>] ? sysfs_kf_read+0x80/0xb0 > [<ffffffff81207e0b>] kernfs_fop_read+0xab/0x160 > [<ffffffff81190be8>] __vfs_read+0x28/0xd0 > [<ffffffff811911f6>] vfs_read+0x86/0x130 > [<ffffffff81191fa6>] SyS_read+0x46/0xa0 > [<ffffffff8158bc97>] entry_SYSCALL_64_fastpath+0x12/0x6a > > Simply return 0 in case of error solved the problem. > > Signed-off-by: Michael Wang <yun.w...@profitbricks.com> > --- > drivers/md/md.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/drivers/md/md.c b/drivers/md/md.c > index 1db88d7..d46d714 100644 > --- a/drivers/md/md.c > +++ b/drivers/md/md.c > @@ -3271,10 +3271,9 @@ rdev_attr_show(struct kobject *kobj, struct attribute > *attr, char *page) > struct rdev_sysfs_entry *entry = container_of(attr, struct > rdev_sysfs_entry, attr); > struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj); > > - if (!entry->show) > - return -EIO; > - if (!rdev->mddev) > - return -EBUSY; > + if (!entry->show || !rdev->mddev) > + return 0; > + > return entry->show(rdev, page); > } > >
