Re: [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 <bg...@linux.ibm.com>

Reviewed-by: Hari Bathini <hbath...@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;

  }