| Message ID | 20231114055456.2231990-6-yoshihiro.shimoda.uh@renesas.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Krzysztof Wilczyński |
| Headers | show |
| Series | PCI: controllers: tidy code up | expand |
On Tue, Nov 14, 2023 at 6:55 AM Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> wrote: > From: Justin Stitt <justinstitt@google.com> > > When building with clang 18 I see the following warning: > | drivers/pci/controller/pcie-iproc-platform.c:55:15: warning: cast to smaller > | integer type 'enum iproc_pcie_type' from 'const void *' [-Wvoid-pointer-to-enum-cast] > | 55 | pcie->type = (enum iproc_pcie_type) of_device_get_match_data(dev); > > This is due to the fact that `of_device_get_match_data` returns a void* > while `enum iproc_pcie_type` has the size of an int. This leads to > truncation and possible data loss. Note that in this case there is no data loss, as the original value stored is of type enum iproc_pcie_type. > Link: https://github.com/ClangBuiltLinux/linux/issues/1910 > Reported-by: Nathan Chancellor <nathan@kernel.org> > Signed-off-by: Justin Stitt <justinstitt@google.com> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Gr{oetje,eeting}s, Geert
On Tue, Nov 14, 2023 at 02:54:55PM +0900, Yoshihiro Shimoda wrote: > From: Justin Stitt <justinstitt@google.com> > > When building with clang 18 I see the following warning: > | drivers/pci/controller/pcie-iproc-platform.c:55:15: warning: cast to smaller > | integer type 'enum iproc_pcie_type' from 'const void *' [-Wvoid-pointer-to-enum-cast] > | 55 | pcie->type = (enum iproc_pcie_type) of_device_get_match_data(dev); > > This is due to the fact that `of_device_get_match_data` returns a void* > while `enum iproc_pcie_type` has the size of an int. This leads to > truncation and possible data loss. > As Geert noted, this statement is wrong as there is no possible data loss in this driver. Please fix it in next version. > Link: https://github.com/ClangBuiltLinux/linux/issues/1910 > Reported-by: Nathan Chancellor <nathan@kernel.org> > Signed-off-by: Justin Stitt <justinstitt@google.com> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> - Mani > --- > drivers/pci/controller/pcie-iproc-platform.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/pcie-iproc-platform.c b/drivers/pci/controller/pcie-iproc-platform.c > index acdc583d2980..83cbc95f4384 100644 > --- a/drivers/pci/controller/pcie-iproc-platform.c > +++ b/drivers/pci/controller/pcie-iproc-platform.c > @@ -52,7 +52,7 @@ static int iproc_pltfm_pcie_probe(struct platform_device *pdev) > pcie = pci_host_bridge_priv(bridge); > > pcie->dev = dev; > - pcie->type = (enum iproc_pcie_type) of_device_get_match_data(dev); > + pcie->type = (uintptr_t) of_device_get_match_data(dev); > > ret = of_address_to_resource(np, 0, ®); > if (ret < 0) { > -- > 2.34.1 >
Hello Manivannan, > From: Manivannan Sadhasivam, Sent: Friday, November 17, 2023 6:22 PM > > On Tue, Nov 14, 2023 at 02:54:55PM +0900, Yoshihiro Shimoda wrote: > > From: Justin Stitt <justinstitt@google.com> > > > > When building with clang 18 I see the following warning: > > | drivers/pci/controller/pcie-iproc-platform.c:55:15: warning: cast to smaller > > | integer type 'enum iproc_pcie_type' from 'const void *' [-Wvoid-pointer-to-enum-cast] > > | 55 | pcie->type = (enum iproc_pcie_type) of_device_get_match_data(dev); > > > > This is due to the fact that `of_device_get_match_data` returns a void* > > while `enum iproc_pcie_type` has the size of an int. This leads to > > truncation and possible data loss. > > > > As Geert noted, this statement is wrong as there is no possible data loss in > this driver. Please fix it in next version. I got it. I'll drop this statement on v3. > > Link: <snip URL> > > Reported-by: Nathan Chancellor <nathan@kernel.org> > > Signed-off-by: Justin Stitt <justinstitt@google.com> > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> > > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Thank you for your review! Best regards, Yoshihiro Shimoda > - Mani > > > --- > > drivers/pci/controller/pcie-iproc-platform.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/pci/controller/pcie-iproc-platform.c b/drivers/pci/controller/pcie-iproc-platform.c > > index acdc583d2980..83cbc95f4384 100644 > > --- a/drivers/pci/controller/pcie-iproc-platform.c > > +++ b/drivers/pci/controller/pcie-iproc-platform.c > > @@ -52,7 +52,7 @@ static int iproc_pltfm_pcie_probe(struct platform_device *pdev) > > pcie = pci_host_bridge_priv(bridge); > > > > pcie->dev = dev; > > - pcie->type = (enum iproc_pcie_type) of_device_get_match_data(dev); > > + pcie->type = (uintptr_t) of_device_get_match_data(dev); > > > > ret = of_address_to_resource(np, 0, ®); > > if (ret < 0) { > > -- > > 2.34.1 > > > > -- > மணிவண்ணன் சதாசிவம்
diff --git a/drivers/pci/controller/pcie-iproc-platform.c b/drivers/pci/controller/pcie-iproc-platform.c index acdc583d2980..83cbc95f4384 100644 --- a/drivers/pci/controller/pcie-iproc-platform.c +++ b/drivers/pci/controller/pcie-iproc-platform.c @@ -52,7 +52,7 @@ static int iproc_pltfm_pcie_probe(struct platform_device *pdev) pcie = pci_host_bridge_priv(bridge); pcie->dev = dev; - pcie->type = (enum iproc_pcie_type) of_device_get_match_data(dev); + pcie->type = (uintptr_t) of_device_get_match_data(dev); ret = of_address_to_resource(np, 0, ®); if (ret < 0) {