diff mbox

[v4,3/3] PCI: endpoint: Fix find_first_zero_bit() usage

Message ID 20171212141634.5985-4-niklas.cassel@axis.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Niklas Cassel Dec. 12, 2017, 2:16 p.m. UTC 
find_first_zero_bit()'s parameter 'size' is defined in bits,
not in bytes.

Calling find_first_zero_bit() with the wrong size unit
will lead to insidious bugs.

Fix this by calling find_first_zero_bit() with size BITS_PER_LONG,
rather than sizeof() and add missing find_first_zero_bit() return
handling.

Fixes: d74679911610 ("PCI: endpoint: Introduce configfs entry for configuring EP functions")
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
 drivers/pci/endpoint/pci-ep-cfs.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Comments

Kishon Vijay Abraham I Dec. 14, 2017, 11:09 a.m. UTC | #1 
On Tuesday 12 December 2017 07:46 PM, Niklas Cassel wrote:
> find_first_zero_bit()'s parameter 'size' is defined in bits,
> not in bytes.
> 
> Calling find_first_zero_bit() with the wrong size unit
> will lead to insidious bugs.
> 
> Fix this by calling find_first_zero_bit() with size BITS_PER_LONG,
> rather than sizeof() and add missing find_first_zero_bit() return
> handling.
> 
> Fixes: d74679911610 ("PCI: endpoint: Introduce configfs entry for configuring EP functions")
> Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

I'll hold Acking this patch, since it is dependent on the previous one.

Thanks
Kishon
diff mbox

Patch

diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c
index e1f5adc9e113..f5ccd1aa2963 100644
--- a/drivers/pci/endpoint/pci-ep-cfs.c
+++ b/drivers/pci/endpoint/pci-ep-cfs.c
@@ -109,7 +109,11 @@  static int pci_epc_epf_link(struct config_item *epc_item,
 		return ret;
 
 	func_no = find_first_zero_bit(&epc_group->function_num_map,
-				      sizeof(epc_group->function_num_map));
+				      BITS_PER_LONG);
+	if (func_no >= BITS_PER_LONG) {
+		ret = -EINVAL;
+		goto err_func_no;
+	}
 	set_bit(func_no, &epc_group->function_num_map);
 	epf->func_no = func_no;
 
@@ -121,6 +125,7 @@  static int pci_epc_epf_link(struct config_item *epc_item,
 
 err_epf_bind:
 	clear_bit(func_no, &epc_group->function_num_map);
+err_func_no:
 	pci_epc_remove_epf(epc, epf);
 
 	return ret;