Subject: Re: arm64 crash in today's next due to 'blk-mq: fix use of incorrect goto label in blk_mq_init_queue error path'

From: Mike Snitzer <[email-masked]>
Date: Fri, 13 Mar 2015 08:31:15 -0400

On Fri, Mar 13 2015 at  5:40am -0400,
Guenter Roeck <[email-masked]> wrote:

> I see an arm64 crash in today's -next.
> 
> [<ffffffc0002d3214>] blk_mq_freeze_queue_start+0x38/0x54
> [<ffffffc0002d3284>] blk_mq_update_tag_set_depth+0x2c/0xb8
> [<ffffffc0002d39f4>] blk_mq_init_allocated_queue+0x6e4/0x71c
> [<ffffffc0002d3a58>] blk_mq_init_queue+0x2c/0x6c
> [<ffffffc00036b9b8>] loop_add+0xc0/0x24c
> [<ffffffc0006b3af8>] loop_init+0x134/0x190
> [<ffffffc0000828b4>] do_one_initcall+0x88/0x1a8
> [<ffffffc000696ad4>] kernel_init_freeable+0x140/0x1e8
> [<ffffffc0004db960>] kernel_init+0xc/0xdc
> 
> See http://server.roeck-us.net:8010/builders/qemu-arm64-next/builds/132/steps/qemubuildcommand/logs/stdio
> for a complete log.
> 
> Bisect results:
> 
...
> # first bad commit: [c9e8c91f8a279b87eb0d94b037504ea9fc1bef7c] blk-mq: fix use of incorrect goto label in blk_mq_init_queue error path
> 
> Looking into the patch, this is not surprising, since 'q' is now used before it is allocated.

Yes, sorry about this.  Certainly embarrassing, please see:
https://lkml.org/lkml/2015/3/13/299