cxl/memdev: Hold memdev lock during memdev poison injection/clear

cxl_dpa_to_region() assumes that it is running a context where it is not
racing changes to "cxlmd->dev.driver". Acquire the memdev device lock in
the debugfs entry points to preclude debugfs usage racing cxl_mem driver
detach.

Suggested-by: Dan Williams <djbw@kernel.org>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dan Williams <djbw@kernel.org>
Signed-off-by: Li Ming <ming.li@zohomail.com>
Link: https://patch.msgid.link/20260423111949.177399-1-ming.li@zohomail.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index fcffe24dcb42f80510ccf79511af8f0d97813dc2..ab88eaa31d1dbf98d93f4cc946be079b114006f1 100644 (file)
--- 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);
 }