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.wang@xxxxxxxxxxxxxxxx> --- 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); } -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
