[PATCH v7 24/28] powerpc: Test prefixed code patching

[Alistair Popple]

Reviewed-by: Alistair Popple <alistair at popple.id.au>

On Friday, 1 May 2020 1:42:16 PM AEST Jordan Niethe wrote:
> Expand the code-patching self-tests to includes tests for patching
> prefixed instructions.
> 
> Signed-off-by: Jordan Niethe <jniethe5 at gmail.com>
> ---
> v6: New to series
> ---
>  arch/powerpc/lib/Makefile             |  2 +-
>  arch/powerpc/lib/code-patching.c      | 21 +++++++++++++++++++++
>  arch/powerpc/lib/test_code-patching.S | 19 +++++++++++++++++++
>  3 files changed, 41 insertions(+), 1 deletion(-)
>  create mode 100644 arch/powerpc/lib/test_code-patching.S
> 
> diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
> index 546591848219..5e994cda8e40 100644
> --- a/arch/powerpc/lib/Makefile
> +++ b/arch/powerpc/lib/Makefile
> @@ -16,7 +16,7 @@ CFLAGS_code-patching.o += -DDISABLE_BRANCH_PROFILING
>  CFLAGS_feature-fixups.o += -DDISABLE_BRANCH_PROFILING
>  endif
> 
> -obj-y += alloc.o code-patching.o feature-fixups.o pmem.o inst.o
> +obj-y += alloc.o code-patching.o feature-fixups.o pmem.o inst.o
> test_code-patching.o
> 
>  ifndef CONFIG_KASAN
>  obj-y	+=	string.o memcmp_$(BITS).o
> diff --git a/arch/powerpc/lib/code-patching.c
> b/arch/powerpc/lib/code-patching.c index b32fa707725e..7107c6d01261 100644
> --- a/arch/powerpc/lib/code-patching.c
> +++ b/arch/powerpc/lib/code-patching.c
> @@ -699,6 +699,24 @@ static void __init test_translate_branch(void)
>  	vfree(buf);
>  }
> 
> +#ifdef __powerpc64__
> +static void __init test_prefixed_patching(void)
> +{
> +	extern unsigned int code_patching_test1[];
> +	extern unsigned int code_patching_test1_expected[];
> +	extern unsigned int end_code_patching_test1[];
> +
> +	__patch_instruction((struct ppc_inst *)code_patching_test1,
> +			    ppc_inst_prefix(1 << 26, 0x00000000),
> +			    (struct ppc_inst *)code_patching_test1);
> +
> +	check(!memcmp(code_patching_test1,
> +		      code_patching_test1_expected,
> +		      sizeof(unsigned int) *
> +		      (end_code_patching_test1 - code_patching_test1)));
> +}
> +#endif
> +
>  static int __init test_code_patching(void)
>  {
>  	printk(KERN_DEBUG "Running code patching self-tests ...\n");
> @@ -707,6 +725,9 @@ static int __init test_code_patching(void)
>  	test_branch_bform();
>  	test_create_function_call();
>  	test_translate_branch();
> +#ifdef __powerpc64__
> +	test_prefixed_patching();
> +#endif
> 
>  	return 0;
>  }
> diff --git a/arch/powerpc/lib/test_code-patching.S
> b/arch/powerpc/lib/test_code-patching.S new file mode 100644
> index 000000000000..91aab208a804
> --- /dev/null
> +++ b/arch/powerpc/lib/test_code-patching.S
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020 IBM Corporation
> + */
> +
> +	.text
> +
> +#define globl(x)		\
> +	.globl x;	\
> +x:
> +
> +globl(code_patching_test1)
> +	nop
> +	nop
> +globl(end_code_patching_test1)
> +
> +globl(code_patching_test1_expected)
> +	.long 1 << 26
> +	.long 0x0000000