[PATCH v8 3/6] powerpc/code-patching: Verify instruction patch succeeded

[Benjamin Gray]

Verifies that if the instruction patching did not return an error then
the value stored at the given address to patch is now equal to the
instruction we patched it to.

Signed-off-by: Benjamin Gray <bgray at linux.ibm.com>
---
 arch/powerpc/lib/code-patching.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 34fc7ac34d91..9b9eba574d7e 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -186,6 +186,8 @@ static int do_patch_instruction(u32 *addr, ppc_inst_t instr)
 	err = __do_patch_instruction(addr, instr);
 	local_irq_restore(flags);
 
+	WARN_ON(!err && !ppc_inst_equal(instr, ppc_inst_read(addr)));
+
 	return err;
 }
 #else /* !CONFIG_STRICT_KERNEL_RWX */
-- 
2.37.3