[PATCH v1] powerpc: Error on assembly warnings

[PATCH v1] powerpc: Error on assembly warnings

[Benjamin Gray]

We currently enable -Werror on the arch/powerpc subtree. However this
only catches C warnings. Assembly warnings are logged, but the make
invocation will still succeed. This can allow incorrect syntax such as

  ori r3, r4, r5

to be compiled without catching that the assembler is treating r5
as the immediate value 5.

To prevent this in assembly files and inline assembly, add the
-fatal-warnings option to assembler invocations.

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
---
 arch/powerpc/Kbuild | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/Kbuild b/arch/powerpc/Kbuild
index 22cd0d55a892..da862e9558bc 100644
--- a/arch/powerpc/Kbuild
+++ b/arch/powerpc/Kbuild
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
-subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
+subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror -Wa,-fatal-warnings
+subdir-asflags-$(CONFIG_PPC_WERROR) := -Wa,-fatal-warnings
 
 obj-y += kernel/
 obj-y += mm/
-- 
2.44.0

Re: [PATCH v1] powerpc: Error on assembly warnings

[Andrew Donnellan]

On Tue, 2024-03-26 at 15:44 +1100, Benjamin Gray wrote:
> We currently enable -Werror on the arch/powerpc subtree. However this
> only catches C warnings. Assembly warnings are logged, but the make
> invocation will still succeed. This can allow incorrect syntax such
> as
> 
>   ori r3, r4, r5
> 
> to be compiled without catching that the assembler is treating r5
> as the immediate value 5.
> 
> To prevent this in assembly files and inline assembly, add the
> -fatal-warnings option to assembler invocations.
> 
> Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>

Seems like a good idea to me!

Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Tested-by: Andrew Donnellan <ajd@linux.ibm.com>

> ---
>  arch/powerpc/Kbuild | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/Kbuild b/arch/powerpc/Kbuild
> index 22cd0d55a892..da862e9558bc 100644
> --- a/arch/powerpc/Kbuild
> +++ b/arch/powerpc/Kbuild
> @@ -1,5 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
> -subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
> +subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror -Wa,-fatal-warnings
> +subdir-asflags-$(CONFIG_PPC_WERROR) := -Wa,-fatal-warnings
>  
>  obj-y += kernel/
>  obj-y += mm/

-- 
Andrew Donnellan    OzLabs, ADL Canberra
ajd@linux.ibm.com   IBM Australia Limited

Re: [PATCH v1] powerpc: Error on assembly warnings

[Michael Ellerman]

On Tue, 26 Mar 2024 15:44:20 +1100, Benjamin Gray wrote:
> We currently enable -Werror on the arch/powerpc subtree. However this
> only catches C warnings. Assembly warnings are logged, but the make
> invocation will still succeed. This can allow incorrect syntax such as
> 
>   ori r3, r4, r5
> 
> to be compiled without catching that the assembler is treating r5
> as the immediate value 5.
> 
> [...]

Applied to powerpc/next.

[1/1] powerpc: Error on assembly warnings
      https://git.kernel.org/powerpc/c/608d4a5ca56302181e669cea0aa571cbec6680eb

cheers