Subject: [PATCH 2/3] powerpc/64: Convert patch_instruction() to patch_u32()

From: Benjamin Gray <[email-masked]>
Date: Tue, 7 Feb 2023 12:56:42 +1100

This use of patch_instruction() is working on 32 bit data, and can fail
if the data looks like a prefixed instruction and the extra write
crosses a page boundary. Use patch_u32() to fix the write size.

Signed-off-by: Benjamin Gray <[email-masked]>

---

patch_u64() should be more efficient, but judging from the bug report[1]
it doesn't seem like the data is doubleword aligned.

[1]: https://lore.kernel.org/all/20230203004649.1f59dbd4@yea/
---
 arch/powerpc/kernel/module_64.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 2ac78d207f77..a1693d38eb27 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -458,12 +458,11 @@ static inline int create_stub(const Elf64_Shdr *sechdrs,
 	// func_desc_t is 8 bytes if ABIv2, else 16 bytes
 	desc = func_desc(addr);
 	for (i = 0; i < sizeof(func_desc_t) / sizeof(u32); i++) {
-		if (patch_instruction(((u32 *)&entry->funcdata) + i,
-				      ppc_inst(((u32 *)(&desc))[i])))
+		if (patch_u32(((u32 *)&entry->funcdata) + i, ((u32 *)&desc)[i]))
 			return 0;
 	}
 
-	if (patch_instruction(&entry->magic, ppc_inst(STUB_MAGIC)))
+	if (patch_u32(&entry->magic, STUB_MAGIC))
 		return 0;
 
 	return 1;
-- 
2.39.1