From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Wei Liu <wei.liu@kernel.org>, Rob Herring <robh@kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>,
linux-hyperv@vger.kernel.org, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH] PCI: hv: Use struct_size() helper
Date: Thu, 28 May 2020 15:41:07 +0100 [thread overview]
Message-ID: <20200528144107.GB28290@e121166-lin.cambridge.arm.com> (raw)
In-Reply-To: <20200525164319.GA13596@embeddedor>
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
> 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
>
prev parent reply other threads:[~2020-05-28 14:41 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-25 16:43 [PATCH] PCI: hv: Use struct_size() helper Gustavo A. R. Silva
2020-05-26 9:38 ` Wei Liu
2020-05-28 14:41 ` Lorenzo Pieralisi [this message]
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