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

[Cyril Chemparathy]

On 9/21/2012 1:40 PM, Nicolas Pitre wrote:
> On Tue, 11 Sep 2012, Cyril Chemparathy wrote:
>
> > 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 <cyril@xxxxxx>
> > ---
> >   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.

> [...]
> > @@ -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 <nico@xxxxxxxxxx>

Thanks.

--
- Cyril
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/