While trying to make sure CONFIG_DEBUG_INFO wasn't set for COMPILE_TEST,
I ordered the choices incorrectly to retain the prior default=n state.
Move DEBUG_INFO_NONE to the top so that the default choice is disabled,
and remove the "if COMPILE_TEST" as it is now redundant.
Reported-by: Nathan Chancellor <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]
Cc: Andrew Morton <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
---
Andrew, this is a fix for kconfigdebug-make-debug_info-selectable-from-a-choice.patch
---
lib/Kconfig.debug | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index a7b657d67318..a1262358d55a 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -234,7 +234,6 @@ config DEBUG_INFO
choice
prompt "Debug information"
depends on DEBUG_KERNEL
- default DEBUG_INFO_NONE if COMPILE_TEST
help
Selecting something other than "None" results in a kernel image
that will include debugging info resulting in a larger kernel image.
@@ -245,6 +244,12 @@ choice
Choose which version of DWARF debug info to emit. If unsure,
select "Toolchain default".
+config DEBUG_INFO_NONE
+ bool "Disable debug information"
+ help
+ Do not build the kernel with debugging information, which will
+ result in a faster and smaller build.
+
config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
bool "Rely on the toolchain's implicit default DWARF version"
select DEBUG_INFO
@@ -283,12 +288,6 @@ config DEBUG_INFO_DWARF5
config if they rely on tooling that has not yet been updated to
support DWARF Version 5.
-config DEBUG_INFO_NONE
- bool "Disable debug information"
- help
- Do not build the kernel with debugging information, which will
- result in a faster and smaller build.
-
endchoice # "Debug information"
if DEBUG_INFO
--
2.30.2
On Fri, Jan 28, 2022 at 01:41:31PM -0800, Kees Cook wrote:
> While trying to make sure CONFIG_DEBUG_INFO wasn't set for COMPILE_TEST,
> I ordered the choices incorrectly to retain the prior default=n state.
> Move DEBUG_INFO_NONE to the top so that the default choice is disabled,
> and remove the "if COMPILE_TEST" as it is now redundant.
>
> Reported-by: Nathan Chancellor <[email protected]>
> Link: https://lore.kernel.org/lkml/[email protected]
> Cc: Andrew Morton <[email protected]>
> Cc: Masahiro Yamada <[email protected]>
> Cc: Nathan Chancellor <[email protected]>
> Cc: Nick Desaulniers <[email protected]>
> Cc: Miguel Ojeda <[email protected]>
> Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Nathan Chancellor <[email protected]>
Another fallout of the original change is that defconfigs that do enable
CONFIG_DEBUG_INFO without any of the DWARF version configs will not have
debug info anymore.
Mainline:
$ make -sj$(nproc) ARCH=arm64 LLVM=1 mrproper defconfig && rg DEBUG_INFO .config
9296:CONFIG_DEBUG_INFO=y
9297:CONFIG_DEBUG_INFO_REDUCED=y
9298:# CONFIG_DEBUG_INFO_COMPRESSED is not set
9299:# CONFIG_DEBUG_INFO_SPLIT is not set
9300:CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y
9301:# CONFIG_DEBUG_INFO_DWARF4 is not set
9302:# CONFIG_DEBUG_INFO_DWARF5 is not set
next-20220128:
$ make -sj$(nproc) ARCH=arm64 LLVM=1 mrproper defconfig && rg DEBUG_INFO .config
9299:CONFIG_DEBUG_INFO=y
9300:CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y
9301:# CONFIG_DEBUG_INFO_DWARF4 is not set
9302:# CONFIG_DEBUG_INFO_DWARF5 is not set
9303:# CONFIG_DEBUG_INFO_NONE is not set
9304:CONFIG_DEBUG_INFO_REDUCED=y
9305:# CONFIG_DEBUG_INFO_COMPRESSED is not set
9306:# CONFIG_DEBUG_INFO_SPLIT is not set
next-20220128 + this patch:
$ make -sj$(nproc) ARCH=arm64 LLVM=1 mrproper defconfig && rg DEBUG_INFO .config
9299:CONFIG_DEBUG_INFO_NONE=y
9300:# CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT is not set
9301:# CONFIG_DEBUG_INFO_DWARF4 is not set
9302:# CONFIG_DEBUG_INFO_DWARF5 is not set
I guess there is not really a way around that other than having people
regenerate their defconfigs (which should really be done each release
anyways) since DEBUG_INFO is no longer a user selectable symbol and it
is probably better to have this choice default to no debug info rather
than debug info. Is there any precedent to updating defconfigs due to a
change like this or some other way to let people know about it?
Cheers,
Nathan
> ---
> Andrew, this is a fix for kconfigdebug-make-debug_info-selectable-from-a-choice.patch
> ---
> lib/Kconfig.debug | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index a7b657d67318..a1262358d55a 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -234,7 +234,6 @@ config DEBUG_INFO
> choice
> prompt "Debug information"
> depends on DEBUG_KERNEL
> - default DEBUG_INFO_NONE if COMPILE_TEST
> help
> Selecting something other than "None" results in a kernel image
> that will include debugging info resulting in a larger kernel image.
> @@ -245,6 +244,12 @@ choice
> Choose which version of DWARF debug info to emit. If unsure,
> select "Toolchain default".
>
> +config DEBUG_INFO_NONE
> + bool "Disable debug information"
> + help
> + Do not build the kernel with debugging information, which will
> + result in a faster and smaller build.
> +
> config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
> bool "Rely on the toolchain's implicit default DWARF version"
> select DEBUG_INFO
> @@ -283,12 +288,6 @@ config DEBUG_INFO_DWARF5
> config if they rely on tooling that has not yet been updated to
> support DWARF Version 5.
>
> -config DEBUG_INFO_NONE
> - bool "Disable debug information"
> - help
> - Do not build the kernel with debugging information, which will
> - result in a faster and smaller build.
> -
> endchoice # "Debug information"
>
> if DEBUG_INFO
> --
> 2.30.2
>