Re: [PATCH] PCI: hv: Use struct_size() helper
From: Lorenzo Pieralisi <hidden>
Date: 2020-05-28 14:41:17
Also in:
linux-pci, lkml
On Mon, May 25, 2020 at 11:43:19AM -0500, Gustavo A. R. Silva wrote:
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct hv_dr_state {
...
struct hv_pcidev_description func[];
};
struct pci_bus_relations {
...
struct pci_function_description func[];
} __packed;
Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.
So, replace the following forms:
offsetof(struct hv_dr_state, func) +
(sizeof(struct hv_pcidev_description) *
(relations->device_count))
offsetof(struct pci_bus_relations, func) +
(sizeof(struct pci_function_description) *
(bus_rel->device_count))
with:
struct_size(dr, func, relations->device_count)
and
struct_size(bus_rel, func, bus_rel->device_count)
respectively.
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
drivers/pci/controller/pci-hyperv.c | 22 ++++++++--------------
1 file changed, 8 insertions(+), 14 deletions(-)Applied to pci/hv, thanks. Lorenzo
quoted hunk ↗ jump to hunk
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c index 892f3a742117a..bf40ff09c99d6 100644 --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c@@ -2213,10 +2213,8 @@ static void hv_pci_devices_present(struct hv_pcibus_device *hbus, struct hv_dr_state *dr; int i; - dr = kzalloc(offsetof(struct hv_dr_state, func) + - (sizeof(struct hv_pcidev_description) * - (relations->device_count)), GFP_NOWAIT); - + dr = kzalloc(struct_size(dr, func, relations->device_count), + GFP_NOWAIT); if (!dr) return;@@ -2250,10 +2248,8 @@ static void hv_pci_devices_present2(struct hv_pcibus_device *hbus, struct hv_dr_state *dr; int i; - dr = kzalloc(offsetof(struct hv_dr_state, func) + - (sizeof(struct hv_pcidev_description) * - (relations->device_count)), GFP_NOWAIT); - + dr = kzalloc(struct_size(dr, func, relations->device_count), + GFP_NOWAIT); if (!dr) return;@@ -2447,9 +2443,8 @@ static void hv_pci_onchannelcallback(void *context) bus_rel = (struct pci_bus_relations *)buffer; if (bytes_recvd < - offsetof(struct pci_bus_relations, func) + - (sizeof(struct pci_function_description) * - (bus_rel->device_count))) { + struct_size(bus_rel, func, + bus_rel->device_count)) { dev_err(&hbus->hdev->device, "bus relations too small\n"); break;@@ -2462,9 +2457,8 @@ static void hv_pci_onchannelcallback(void *context) bus_rel2 = (struct pci_bus_relations2 *)buffer; if (bytes_recvd < - offsetof(struct pci_bus_relations2, func) + - (sizeof(struct pci_function_description2) * - (bus_rel2->device_count))) { + struct_size(bus_rel2, func, + bus_rel2->device_count)) { dev_err(&hbus->hdev->device, "bus relations v2 too small\n"); break;-- 2.26.2