On Tue, 2025-01-07 at 16:56 -0600, Bjorn Helgaas wrote:
> On Tue, Jan 07, 2025 at 09:51:23PM +0800, kingdix10@xxxxxx wrote:
> > From: King Dix <kingdix10@xxxxxx>
> >
> > When using devm_request_mem_region to request a resource, if the
> > passed
> > variable is a stack string variable, it will lead to an oops issue
> > when
> > executing the command cat /proc/iomem.
> >
> > Fix this by replacing outbound_name with the name of the previously
> > requested resource.
>
> Thanks a lot for doing this work!
>
> Add "()" after function names in subject and commit log.
>
Thanks for your review. I will fix the issue right now.
> Please include a couple lines of the oops message to help people
> connect the problem with the fix.
>
This is a potential issue that I found while analyzing the code. I don't
have the conditions to reproduce this issue, but I can write a driver to
reproduce this issue in QEMU and obtain logs for reference.
> I suppose you found this by tripping over it. Can you look through
> the other callers of devm_request_mem_region() and similar
> interfaces,
> at least in drivers/pci, and make sure there are no other similar
> errors?
>
I've already checked that there are only a few calls of
devm_request_mem_region() under the drivers/pci directory, and they
are all correct.
> > Fixes: 2a6d0d63d999 ("PCI: rcar: Add endpoint mode support")
> >
> > Signed-off-by: King Dix <kingdix10@xxxxxx>
> > Reviewed-by: Lad Prabhakar
> > <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > ---
> > Changes in v4:
> > - Add more information to the comment.
> > Changes in v3:
> > - Fix the spelling issue in the comment.
> > Changes in v2:
> > - Fix the code indentation issue.
> > ---
> > drivers/pci/controller/pcie-rcar-ep.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/controller/pcie-rcar-ep.c
> > b/drivers/pci/controller/pcie-rcar-ep.c
> > index 047e2cef5afc..c5e0d025bc43 100644
> > --- a/drivers/pci/controller/pcie-rcar-ep.c
> > +++ b/drivers/pci/controller/pcie-rcar-ep.c
> > @@ -107,7 +107,7 @@ static int
> > rcar_pcie_parse_outbound_ranges(struct rcar_pcie_endpoint *ep,
> > }
> > if (!devm_request_mem_region(&pdev->dev, res->start,
> > resource_size(res),
> > - outbound_name)) {
> > + res->name)) {
> > dev_err(pcie->dev, "Cannot request memory region %s.\n",
> > outbound_name);
> > return -EIO;
> > --
> > 2.43.0
> >
