[PATCH v3 02/17] ARM: add self test for runtime patch mechanism

On 9/21/2012 1:40 PM, Nicolas Pitre wrote:

On Tue, 11 Sep 2012, Cyril Chemparathy wrote:

quoted

This patch adds basic sanity tests to ensure that the instruction patching
results in valid instruction encodings.  This is done by verifying the output
of the patch process against a vector of assembler generated instructions at
init time.

Signed-off-by: Cyril Chemparathy <redacted>
---
  arch/arm/Kconfig                |   12 +++++++
  arch/arm/kernel/runtime-patch.c |   75 +++++++++++++++++++++++++++++++++++++++
  2 files changed, 87 insertions(+)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 36de4ea..bfcd29d 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig

@@ -207,6 +207,18 @@ config ARM_PATCH_PHYS_VIRT
  	  this feature (eg, building a kernel for a single machine) and
  	  you need to shrink the kernel to the minimal size.

+config ARM_RUNTIME_PATCH_TEST
+	bool "Self test runtime patching mechanism" if ARM_RUNTIME_PATCH
+	default y

Here you probably want this instead:

	bool "Self test runtime patching mechanism"
	default y
	depends on ARM_RUNTIME_PATCH

Otherwise ARM_RUNTIME_PATCH_TEST will be forced to y whenever
ARM_RUNTIME_PATCH is unset.  That doesn't currently affect the build
since the containing .c file is only compiled when ARM_RUNTIME_PATCH is
set but that is still not strictly right.

Indeed.  Excellent.  Thanks.

[...]

quoted

@@ -189,5 +261,8 @@ void __init runtime_patch_kernel(void)
  	const void *start = &__runtime_patch_table_begin;
  	const void *end   = &__runtime_patch_table_end;

+#ifdef CONFIG_ARM_RUNTIME_PATCH_TEST
+	runtime_patch_test();
+#endif
  	BUG_ON(runtime_patch(start, end - start));

I think you shoulld have runtime_patch_test() return a possible error
code and use BUG_ON() with it as well.

Sure.  Will do in v4.

With those minor changes you can add...

Reviewed-by: Nicolas Pitre <redacted>

Thanks.

-- 
- Cyril