Re: [PATCH] Makefile: use -gdwarf-{4|5} for assembler for DEBUG_INFO_DWARF{4|5}

[Greg Kroah-Hartman]

On Wed, Mar 15, 2023 at 02:40:59PM -0700, Nick Desaulniers wrote:
> This is _not_ an upstream commit and just for 5.15.y only. It is based
> on upstream
> commit 32ef9e5054ec ("Makefile.debug: re-enable debug info for .S files").
> 
> When the user has chosen not to use their compiler's implicit default
> DWARF version (which changes over time) via selecting
> - CONFIG_DEBUG_INFO_DWARF4 or
> - CONFIG_DEBUG_INFO_DWARF5
> we need to tell the compiler this for Asm sources as well as C sources.
> (We use the compiler to drive assembler jobs in kbuild, since most asm
> needs to be preprocessed first).  Otherwise, we will get object files
> built from Asm sources with the compiler's implicit default DWARF
> version.
> 
> For example, selecting CONFIG_DEBUG_INFO_DWARF4 would produce a DWARFv5
> vmlinux, since it was a mix of DWARFv4 object files from C sources and
> DWARFv5 object files from Asm sources when using Clang as the assembler
> (ex. `make LLVM=1`).
> 
> Fixes: 0ee2f0567a56 ("Makefile.debug: re-enable debug info for .S files")
> Reported-by: Lecopzer Chen <lecopzer.chen@xxxxxxxxxxxx>
> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> ---
>  Makefile | 1 +
>  1 file changed, 1 insertion(+)

Now queued up, thanks,

greg k-h