On Fri, Aug 25, 2023 at 07:44:06AM +0200, Nicolas Schier wrote:

On Thu, Aug 24, 2023 at 03:36:10PM -0700, Kees Cook wrote:

quoted

Doing a "make help" would show only hard-coded Kconfig targets and
depended on the archhelp target to include ".config" targets. There was
nothing showing global kernel/configs/ targets. Solve this by walking
the wildcard list and include them in the output, using the first comment
line as the help text.
[...]

Thanks for that patch!  Several times I found myself searching the tree
to find a specific kconfig fragment; I think you found a nice solution.
Two minor things below.

[...]

quoted

diff --git a/kernel/configs/tiny-base.config b/kernel/configs/tiny-base.config
index 2f0e6bf6db2c..ac4d254abc3f 100644
--- a/kernel/configs/tiny-base.config
+++ b/kernel/configs/tiny-base.config

@@ -1 +1,2 @@
+# Minimal options for tiny systems
 CONFIG_EMBEDDED=y

(just a note: Randy prepared a patch for removing CONFIG_EMBEDDED:
https://lore.kernel.org/linux-kbuild/20230816055010.31534-1-rdunlap@infradead.org/ (local))

Ah yeah, I'll rebase this after the merge window, I guess...

quoted

diff --git a/kernel/configs/tiny.config b/kernel/configs/tiny.config
index 00009f7d0835..ea643e8f7f14 100644
--- a/kernel/configs/tiny.config
+++ b/kernel/configs/tiny.config

@@ -1,3 +1,5 @@
+# Smallest possible kernel image

For this fragment alone (not within 'tinyconfig'), "Size-optimize kernel
image" possibly fits better?

Sounds good to me!

quoted

diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile
index af1c96198f49..c523f24b504a 100644
--- a/scripts/kconfig/Makefile
+++ b/scripts/kconfig/Makefile

@@ -93,11 +93,11 @@ endif
 %_defconfig: $(obj)/conf
 	$(Q)$< $(silent) --defconfig=arch/$(SRCARCH)/configs/$@ $(Kconfig)
 
-configfiles=$(wildcard $(srctree)/kernel/configs/$@ $(srctree)/arch/$(SRCARCH)/configs/$@)
+configfiles=$(wildcard $(srctree)/kernel/configs/$(1) $(srctree)/arch/$(SRCARCH)/configs/$(1))
 
 %.config: $(obj)/conf
-	$(if $(call configfiles),, $(error No configuration exists for this target on this architecture))
-	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh -m .config $(configfiles)
+	$(if $(call configfiles,$@),, $(error No configuration exists for this target on this architecture))
+	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh -m .config $(call configfiles,$@)
 	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
 
 PHONY += tinyconfig

@@ -115,6 +115,7 @@ clean-files += tests/.cache
 
 # Help text used by make help
 help:
+	@echo  'Configuration targets:'
 	@echo  '  config	  - Update current config utilising a line-oriented program'
 	@echo  '  nconfig         - Update current config utilising a ncurses menu based program'
 	@echo  '  menuconfig	  - Update current config utilising a menu based program'

@@ -141,6 +142,12 @@ help:
 	@echo  '                    default value without prompting'
 	@echo  '  tinyconfig	  - Configure the tiniest possible kernel'
 	@echo  '  testconfig	  - Run Kconfig unit tests (requires python3 and pytest)'
+	@echo  ''
+	@echo  'Configuration fragment targets (for enabling various Kconfig items):'
+	@$(foreach c, $(call configfiles,*.config), \
+		printf "  %-20s - %s\\n" \
+			$(shell basename $(c)) \
+			"$(subst # ,,$(shell grep -m1 '^# ' $(c)))";)

Better use '$(notdir $(c))` instead of forking a shell with
'$(shell basename $(c))'.

Ah! Thank you. I *knew* there was a function for this but couldn't find
it for some reason. :)

-- 
Kees Cook