diff options
| -rw-r--r-- | arch/arm64/kernel/alternative.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c index 992918dfbe2d..06d650f61da7 100644 --- a/arch/arm64/kernel/alternative.c +++ b/arch/arm64/kernel/alternative.c @@ -58,6 +58,8 @@ static bool branch_insn_requires_update(struct alt_instr *alt, unsigned long pc) BUG(); } +#define align_down(x, a) ((unsigned long)(x) & ~(((unsigned long)(a)) - 1)) + static u32 get_alt_insn(struct alt_instr *alt, u32 *insnptr, u32 *altinsnptr) { u32 insn; @@ -79,6 +81,19 @@ static u32 get_alt_insn(struct alt_instr *alt, u32 *insnptr, u32 *altinsnptr) offset = target - (unsigned long)insnptr; insn = aarch64_set_branch_offset(insn, offset); } + } else if (aarch64_insn_is_adrp(insn)) { + s32 orig_offset, new_offset; + unsigned long target; + + /* + * If we're replacing an adrp instruction, which uses PC-relative + * immediate addressing, adjust the offset to reflect the new + * PC. adrp operates on 4K aligned addresses. + */ + orig_offset = aarch64_insn_adrp_get_offset(insn); + target = align_down(altinsnptr, SZ_4K) + orig_offset; + new_offset = target - align_down(insnptr, SZ_4K); + insn = aarch64_insn_adrp_set_offset(insn, new_offset); } else if (aarch64_insn_uses_literal(insn)) { /* * Disallow patching unhandled instructions using PC relative |
