Re: [PATCH v2 2/4] cxl/memdev: Hold memdev lock during memdev poison injection/clear

[Li Ming]

在 2026/3/17 23:00, Dave Jiang 写道:
> On 3/14/26 12:06 AM, Li Ming wrote:
> > CXL memdev poison injection/clearing debugfs interfaces are visible
> > before the CXL memdev endpoint initialization, If user accesses the
> > interfaces before cxlmd->endpoint updated, it is possible to access an
> > invalid endpoint in cxl_dpa_to_region().
> >
> > Hold CXL memdev lock at the beginning of the interfaces, this blocks the
> > interfaces until CXL memdev probing completed.
> >
> > The following patch will check the given endpoint validity in
> > cxl_dpa_to_region().
> >
> > Suggested-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> > Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
> > Reviewed-by: Alison Schofield <alison.schofield@xxxxxxxxx>
> > Signed-off-by: Li Ming <ming.li@xxxxxxxxxxxx>
> Hi Ming, I dropped this patch with Dan's comments [1] and updated cxl/next. Please check and make sure everything looks ok to you. Thanks!
>
> [1]: https://lore.kernel.org/linux-cxl/69b8b81621e16_452b100e@dwillia2-mobl4.notmuch/

Hi Dave,

I think there is no change needed in this patch, just need a independent 
patch for holding memdev lock in cxl_region_debugfs_poison_inject/clear.

Or you want to review this patch again?


Ming

> > ---
> >   drivers/cxl/mem.c | 10 ++++++++++
> >   1 file changed, 10 insertions(+)
> >
> > diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
> > index fcffe24dcb42..ab88eaa31d1d 100644
> > --- a/drivers/cxl/mem.c
> > +++ b/drivers/cxl/mem.c
> > @@ -48,6 +48,11 @@ static int cxl_mem_dpa_show(struct seq_file *file, void *data)
> >   static int cxl_debugfs_poison_inject(void *data, u64 dpa)
> >   {
> >   	struct cxl_memdev *cxlmd = data;
> > +	int rc;
> > +
> > +	ACQUIRE(device_intr, devlock)(&cxlmd->dev);
> > +	if ((rc = ACQUIRE_ERR(device_intr, &devlock)))
> > +		return rc;
> >   
> >   	return cxl_inject_poison(cxlmd, dpa);
> >   }
> > @@ -58,6 +63,11 @@ DEFINE_DEBUGFS_ATTRIBUTE(cxl_poison_inject_fops, NULL,
> >   static int cxl_debugfs_poison_clear(void *data, u64 dpa)
> >   {
> >   	struct cxl_memdev *cxlmd = data;
> > +	int rc;
> > +
> > +	ACQUIRE(device_intr, devlock)(&cxlmd->dev);
> > +	if ((rc = ACQUIRE_ERR(device_intr, &devlock)))
> > +		return rc;
> >   
> >   	return cxl_clear_poison(cxlmd, dpa);
> >   }