[PATCH v2] powerpc/kexec: Fix build failure from uninitialised variable

[PATCH v2] powerpc/kexec: Fix build failure from uninitialised variable

[Russell Currey]

clang 14 won't build because ret is uninitialised and can be returned if
both prop and fdtprop are NULL.  Drop the ret variable and return an
error in that failure case.

Fixes: b1fc44eaa9ba ("pseries/iommu/ddw: Fix kdump to work in absence of ibm,dma-window")
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Russell Currey <ruscur@russell.cc>
---
v2: adopt Christophe's suggestion, which is better

 arch/powerpc/kexec/file_load_64.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c
index 683462e4556b..349a781cea0b 100644
--- a/arch/powerpc/kexec/file_load_64.c
+++ b/arch/powerpc/kexec/file_load_64.c
@@ -1043,17 +1043,17 @@ static int copy_property(void *fdt, int node_offset, const struct device_node *d
 			 const char *propname)
 {
 	const void *prop, *fdtprop;
-	int len = 0, fdtlen = 0, ret;
+	int len = 0, fdtlen = 0;
 
 	prop = of_get_property(dn, propname, &len);
 	fdtprop = fdt_getprop(fdt, node_offset, propname, &fdtlen);
 
 	if (fdtprop && !prop)
-		ret = fdt_delprop(fdt, node_offset, propname);
+		return fdt_delprop(fdt, node_offset, propname);
 	else if (prop)
-		ret = fdt_setprop(fdt, node_offset, propname, prop, len);
-
-	return ret;
+		return fdt_setprop(fdt, node_offset, propname, prop, len);
+	else
+		return -FDT_ERR_NOTFOUND;
 }
 
 static int update_pci_dma_nodes(void *fdt, const char *dmapropname)
-- 
2.37.1

Re: [PATCH v2] powerpc/kexec: Fix build failure from uninitialised variable

[Nathan Chancellor]

On Wed, Aug 10, 2022 at 03:43:31PM +1000, Russell Currey wrote:
> clang 14 won't build because ret is uninitialised and can be returned if
> both prop and fdtprop are NULL.  Drop the ret variable and return an
> error in that failure case.
> 
> Fixes: b1fc44eaa9ba ("pseries/iommu/ddw: Fix kdump to work in absence of ibm,dma-window")
> Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> Signed-off-by: Russell Currey <ruscur@russell.cc>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

Thanks for the patch!

> ---
> v2: adopt Christophe's suggestion, which is better
> 
>  arch/powerpc/kexec/file_load_64.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c
> index 683462e4556b..349a781cea0b 100644
> --- a/arch/powerpc/kexec/file_load_64.c
> +++ b/arch/powerpc/kexec/file_load_64.c
> @@ -1043,17 +1043,17 @@ static int copy_property(void *fdt, int node_offset, const struct device_node *d
>  			 const char *propname)
>  {
>  	const void *prop, *fdtprop;
> -	int len = 0, fdtlen = 0, ret;
> +	int len = 0, fdtlen = 0;
>  
>  	prop = of_get_property(dn, propname, &len);
>  	fdtprop = fdt_getprop(fdt, node_offset, propname, &fdtlen);
>  
>  	if (fdtprop && !prop)
> -		ret = fdt_delprop(fdt, node_offset, propname);
> +		return fdt_delprop(fdt, node_offset, propname);
>  	else if (prop)
> -		ret = fdt_setprop(fdt, node_offset, propname, prop, len);
> -
> -	return ret;
> +		return fdt_setprop(fdt, node_offset, propname, prop, len);
> +	else
> +		return -FDT_ERR_NOTFOUND;
>  }
>  
>  static int update_pci_dma_nodes(void *fdt, const char *dmapropname)
> -- 
> 2.37.1
> 

Re: [PATCH v2] powerpc/kexec: Fix build failure from uninitialised variable

[Michael Ellerman]

On Wed, 10 Aug 2022 15:43:31 +1000, Russell Currey wrote:
> clang 14 won't build because ret is uninitialised and can be returned if
> both prop and fdtprop are NULL.  Drop the ret variable and return an
> error in that failure case.
> 
> 

Applied to powerpc/fixes.

[1/1] powerpc/kexec: Fix build failure from uninitialised variable
      https://git.kernel.org/powerpc/c/83ee9f23763a432a4077bf20624ee35de87bce99

cheers