On Tue, 30 Aug 2011, Tixy wrote:

On Mon, 2011-08-29 at 14:44 -0400, Nicolas Pitre wrote:

quoted

On Mon, 29 Aug 2011, Tixy wrote:

quoted

From: Jon Medhurst <redacted>

Signed-off-by: Jon Medhurst <redacted>
---
 arch/arm/Kconfig.debug |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 81cbe40..8f95417 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug

@@ -129,4 +129,14 @@ config DEBUG_S3C_UART
 	  The uncompressor code port configuration is now handled
 	  by CONFIG_S3C_LOWLEVEL_UART_PORT.
 
+config ARM_KPROBES_TESTS
+	bool
+
+config ARM_KPROBES_TEST_MODULE
+	tristate "Kprobes test module"
+	depends on KPROBES && MODULES
+	select ARM_KPROBES_TESTS
+	help
+	  "Perform tests of kprobes API and instruction set simulation"
+

Why do you need two config symbols here? Isn't ARM_KPROBES_TEST_MODULE 
redundant?

When ARM_KPROBES_TEST_MODULE is configured for a stand-alone module,
rather than built-in, then

#ifdef CONFIG_ARM_KPROBES_TEST_MODULE

is false.

OK... It seems that, when you have a tristate config symbol FOOBAR, if 
CONFIG_FOOBAR=y then the CONFIG_FOOBAR preprocessor symbol is defined.  
If you have CONFIG_FOOBAR=m then the CONFIG_FOOBAR_MODULE preprocessor 
symbol is defined.

In your example above you would end up with 
CONFIG_ARM_KPROBES_TEST_MODULE_MODULE being defined.

I found other examples where people seemed to have gotten around this 
by selecting a second config symbol and copied that. E.g. 
FTRACE_STARTUP_TEST selects FTRACE_SELFTEST which is then used in 
#ifdef statements.

Is there a better way? If not, I should explain this anyway in the
changelog.

What I'd suggest is that you have:

config ARM_KPROBES_TEST
	tristate ...

And then you may use this in the code:

#ifdef CONFIG_ARM_KPROBES_TEST_MODULE
EXPORT_SYMBOL_GPL(...);
#endif

so those symbols are only exported when necessary.


Nicolas