| Message ID | 20230815-void-drivers-net-ethernet-ni-nixge-v1-1-f096a6e43038@google.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: nixge: fix -Wvoid-pointer-to-enum-cast warning | expand |
On Tue, Aug 15, 2023 at 08:50:13PM +0000, Justin Stitt wrote: > When building with clang 18 I see the following warning: > | drivers/net/ethernet/ni/nixge.c:1273:12: warning: cast to smaller integer > | type 'enum nixge_version' from 'const void *' [-Wvoid-pointer-to-enum-cast] > | 1273 | version = (enum nixge_version)of_id->data; > > This is due to the fact that `of_id->data` is a void* while `enum nixge_version` > has the size of an int. This leads to truncation and possible data loss. > > Link: https://github.com/ClangBuiltLinux/linux/issues/1910 > Reported-by: Nathan Chancellor <nathan@kernel.org> > Signed-off-by: Justin Stitt <justinstitt@google.com> > --- > Note: There is likely no data loss occurring here since `enum nixge_version` > has only a few fields which aren't nearly large enough to cause data > loss. However, this patch still works towards the goal of enabling this > warning for more builds by reducing noise. This information might be better placed in the patch description, above the scissors (---) and tags ("Link:", ...) And, although I did make an error in this area myself as recently as yesterday, this patch should probably be tagged as being for net-next. It's probably not necessary to repost for this. Subject: [PATCH net-next] ... The above notwithstanding, Reviewed-by: Simon Horman <horms@kernel.org> Tested-by: Simon Horman <horms@kernel.org> # build-tested
diff --git a/drivers/net/ethernet/ni/nixge.c b/drivers/net/ethernet/ni/nixge.c index 0fd156286d4d..105977804e6a 100644 --- a/drivers/net/ethernet/ni/nixge.c +++ b/drivers/net/ethernet/ni/nixge.c @@ -1270,7 +1270,7 @@ static int nixge_of_get_resources(struct platform_device *pdev) if (!of_id) return -ENODEV; - version = (enum nixge_version)of_id->data; + version = (uintptr_t)of_id->data; if (version <= NIXGE_V2) priv->dma_regs = devm_platform_get_and_ioremap_resource(pdev, 0, NULL); else
When building with clang 18 I see the following warning: | drivers/net/ethernet/ni/nixge.c:1273:12: warning: cast to smaller integer | type 'enum nixge_version' from 'const void *' [-Wvoid-pointer-to-enum-cast] | 1273 | version = (enum nixge_version)of_id->data; This is due to the fact that `of_id->data` is a void* while `enum nixge_version` has the size of an int. This leads to truncation and possible data loss. Link: https://github.com/ClangBuiltLinux/linux/issues/1910 Reported-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Justin Stitt <justinstitt@google.com> --- Note: There is likely no data loss occurring here since `enum nixge_version` has only a few fields which aren't nearly large enough to cause data loss. However, this patch still works towards the goal of enabling this warning for more builds by reducing noise. --- drivers/net/ethernet/ni/nixge.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- base-commit: 2ccdd1b13c591d306f0401d98dedc4bdcd02b421 change-id: 20230815-void-drivers-net-ethernet-ni-nixge-37b465831af0 Best regards, -- Justin Stitt <justinstitt@google.com>