arm64: module: ensure instruction is little-endian before manipulation

Relocations that require an instruction immediate to be re-encoded must
ensure that the instruction pattern is represented in a little-endian
format for the manipulation code to work correctly.

This patch converts the loaded instruction into native-endianess prior
to encoding and then converts back to little-endian byteorder before
updating memory.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Tested-by: Matthew Leach <matthew.leach@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index ca0e3d55da99..2c28a6cf93e6 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -111,6 +111,9 @@ static u32 encode_insn_immediate(enum aarch64_imm_type type, u32 insn, u64 imm)
 	u32 immlo, immhi, lomask, himask, mask;
 	int shift;
 
+	/* The instruction stream is always little endian. */
+	insn = le32_to_cpu(insn);
+
 	switch (type) {
 	case INSN_IMM_MOVNZ:
 		/*
@@ -179,7 +182,7 @@ static u32 encode_insn_immediate(enum aarch64_imm_type type, u32 insn, u64 imm)
 	insn &= ~(mask << shift);
 	insn |= (imm & mask) << shift;
 
-	return insn;
+	return cpu_to_le32(insn);
 }
 
 static int reloc_insn_movw(enum aarch64_reloc_op op, void *place, u64 val,