Re: [PATCH v4 05/17] PCI/DOE: Silence WARN splat with CONFIG_DEBUG_OBJECTS=y

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Tue, 21 Mar 2023 14:42:01 +1100
Alexey Kardashevskiy <aik@amd.com> wrote:

> On 12/3/23 01:40, Lukas Wunner wrote:
> > Gregory Price reports a WARN splat with CONFIG_DEBUG_OBJECTS=y upon CXL
> > probing because pci_doe_submit_task() invokes INIT_WORK() instead of
> > INIT_WORK_ONSTACK() for a work_struct that was allocated on the stack.
> > 
> > All callers of pci_doe_submit_task() allocate the work_struct on the
> > stack, so replace INIT_WORK() with INIT_WORK_ONSTACK() as a backportable
> > short-term fix.
> > 
> > The long-term fix implemented by a subsequent commit is to move to a
> > synchronous API which allocates the work_struct internally in the DOE
> > library.
> > 
> > Stacktrace for posterity:
> > 
> > WARNING: CPU: 0 PID: 23 at lib/debugobjects.c:545 __debug_object_init.cold+0x18/0x183
> > CPU: 0 PID: 23 Comm: kworker/u2:1 Not tainted 6.1.0-0.rc1.20221019gitaae703b02f92.17.fc38.x86_64 #1
> > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
> > Call Trace:
> >   pci_doe_submit_task+0x5d/0xd0
> >   pci_doe_discovery+0xb4/0x100
> >   pcim_doe_create_mb+0x219/0x290
> >   cxl_pci_probe+0x192/0x430
> >   local_pci_probe+0x41/0x80
> >   pci_device_probe+0xb3/0x220
> >   really_probe+0xde/0x380
> >   __driver_probe_device+0x78/0x170
> >   driver_probe_device+0x1f/0x90
> >   __driver_attach_async_helper+0x5c/0xe0
> >   async_run_entry_fn+0x30/0x130
> >   process_one_work+0x294/0x5b0
> > 
> > Fixes: 9d24322e887b ("PCI/DOE: Add DOE mailbox support functions")
> > Link: https://lore.kernel.org/linux-cxl/Y1bOniJliOFszvIK@memverge.com/
> > Reported-by: Gregory Price <gregory.price@memverge.com>
> > Tested-by: Ira Weiny <ira.weiny@intel.com>
> > Tested-by: Gregory Price <gregory.price@memverge.com>
> > Signed-off-by: Lukas Wunner <lukas@wunner.de>
> > Reviewed-by: Ira Weiny <ira.weiny@intel.com>
> > Reviewed-by: Dan Williams <dan.j.williams@intel.com>
> > Reviewed-by: Gregory Price <gregory.price@memverge.com>
> > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huwei.com>  
>                                                    ^^^^^
> 
> huwei? :)
Doh.  I normally type my own name wrong ;)

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Thanks,

Jonathan

> 
>