[PATCH v4 5/5] powerpc/code-patching: Add boot selftest for data patching

[Hari Bathini]

On 15/05/24 8:14 am, Benjamin Gray wrote:
> Extend the code patching selftests with some basic coverage of the new
> data patching variants too.
> 
> Signed-off-by: Benjamin Gray <bgray at linux.ibm.com>

Reviewed-by: Hari Bathini <hbathini at linux.ibm.com>

> 
> ---
> 
> v4: * Change store to a check
>      * Account for doubleword alignment
> v3: * New in v3
> ---
>   arch/powerpc/lib/test-code-patching.c | 41 +++++++++++++++++++++++++++
>   1 file changed, 41 insertions(+)
> 
> diff --git a/arch/powerpc/lib/test-code-patching.c b/arch/powerpc/lib/test-code-patching.c
> index f76030087f98..8cd3b32f805b 100644
> --- a/arch/powerpc/lib/test-code-patching.c
> +++ b/arch/powerpc/lib/test-code-patching.c
> @@ -438,6 +438,46 @@ static void __init test_multi_instruction_patching(void)
>   	vfree(buf);
>   }
>   
> +static void __init test_data_patching(void)
> +{
> +	void *buf;
> +	u32 *addr32;
> +
> +	buf = vzalloc(PAGE_SIZE);
> +	check(buf);
> +	if (!buf)
> +		return;
> +
> +	addr32 = buf + 128;
> +
> +	addr32[1] = 0xA0A1A2A3;
> +	addr32[2] = 0xB0B1B2B3;
> +
> +	check(!patch_uint(&addr32[1], 0xC0C1C2C3));
> +
> +	check(addr32[0] == 0);
> +	check(addr32[1] == 0xC0C1C2C3);
> +	check(addr32[2] == 0xB0B1B2B3);
> +	check(addr32[3] == 0);
> +
> +	/* Unaligned patch_ulong() should fail */
> +	if (IS_ENABLED(CONFIG_PPC64))
> +		check(patch_ulong(&addr32[1], 0xD0D1D2D3) == -EINVAL);
> +
> +	check(!patch_ulong(&addr32[2], 0xD0D1D2D3));
> +
> +	check(addr32[0] == 0);
> +	check(addr32[1] == 0xC0C1C2C3);
> +	check(*(unsigned long *)(&addr32[2]) == 0xD0D1D2D3);
> +
> +	if (!IS_ENABLED(CONFIG_PPC64))
> +		check(addr32[3] == 0);
> +
> +	check(addr32[4] == 0);
> +
> +	vfree(buf);
> +}
> +
>   static int __init test_code_patching(void)
>   {
>   	pr_info("Running code patching self-tests ...\n");
> @@ -448,6 +488,7 @@ static int __init test_code_patching(void)
>   	test_translate_branch();
>   	test_prefixed_patching();
>   	test_multi_instruction_patching();
> +	test_data_patching();
>   
>   	return 0;
>   }