diff options
| author | Suzuki K Poulose <suzuki.poulose@arm.com> | 2016-09-09 14:07:11 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2016-09-09 15:03:28 +0100 |
| commit | baa763b565386b1383b87b6fb76e72db84a0ff16 (patch) | |
| tree | 9c046ca20a4e8b7cbae0424a3ddf15cc8a5fac2a /arch/arm64 | |
| parent | c47a1900ad710fd2c97127e2ba19da1df79cf733 (diff) | |
arm64: alternative: Disallow patching instructions using literals
The alternative code patching doesn't check if the replaced instruction
uses a pc relative literal. This could cause silent corruption in the
instruction stream as the instruction will be executed from a different
address than what it was compiled for. Catch all such cases.
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Suggested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kernel/alternative.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c index 4434dabde898..992918dfbe2d 100644 --- a/arch/arm64/kernel/alternative.c +++ b/arch/arm64/kernel/alternative.c @@ -79,6 +79,12 @@ 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_uses_literal(insn)) { + /* + * Disallow patching unhandled instructions using PC relative + * literal addresses + */ + BUG(); } return insn; |