PCI/P2PDMA: Fix a sleeping issue in a RCU read section

tititiou36 · Sasha Levin · commit 558d8fedded8 · 2024-03-26T18:17:04.000-04:00
[ Upstream commit 1e5c66a ] It is not allowed to sleep within a RCU read section, so use GFP_ATOMIC instead of GFP_KERNEL here. Link: https://lore.kernel.org/r/02d9ec4a10235def0e764ff1f5be881ba12e16e8.1704397858.git.christophe.jaillet@wanadoo.fr Fixes: ae21f83 ("PCI/P2PDMA: Finish RCU conversion of pdev->p2pdma") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
@@ -661,7 +661,7 @@ calc_map_type_and_dist(struct pci_dev *provider, struct pci_dev *client,
 	p2pdma = rcu_dereference(provider->p2pdma);
 	if (p2pdma)
 		xa_store(&p2pdma->map_types, map_types_idx(client),
-			 xa_mk_value(map_type), GFP_KERNEL);
+			 xa_mk_value(map_type), GFP_ATOMIC);
 	rcu_read_unlock();
 	return map_type;
 }

Original file line number	Diff line number	Diff line change
`@@ -661,7 +661,7 @@ calc_map_type_and_dist(struct pci_dev provider, struct pci_dev client,`
`661`	`661`	`p2pdma = rcu_dereference(provider->p2pdma);`
`662`	`662`	`if (p2pdma)`
`663`	`663`	`xa_store(&p2pdma->map_types, map_types_idx(client),`
`664`		`- xa_mk_value(map_type), GFP_KERNEL);`
	`664`	`+ xa_mk_value(map_type), GFP_ATOMIC);`
`665`	`665`	`rcu_read_unlock();`
`666`	`666`	`return map_type;`
`667`	`667`	`}`