From: Ilie Halip ilie.halip@gmail.com
[ Upstream commit 53ae7230918154d1f4281d7aa3aae9650436eadf ]
Building with clang & LLVM_IAS=1 leads to an error: arch/s390/lib/test_unwind.c:179:4: error: invalid register pair " mvcl %%r1,%%r1\n" ^
The test creates an invalid instruction that would trap at runtime, but the LLVM inline assembler tries to validate it at compile time too.
Use the raw instruction opcode instead.
Reported-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Ilie Halip ilie.halip@gmail.com Reviewed-by: Nick Desaulniers ndesaulniers@google.com Suggested-by: Ulrich Weigand Ulrich.Weigand@de.ibm.com Link: https://github.com/ClangBuiltLinux/linux/issues/1421 Link: https://lore.kernel.org/r/20211117174822.3632412-1-ilie.halip@gmail.com Reviewed-by: Christian Borntraeger borntraeger@de.ibm.com Signed-off-by: Christian Borntraeger borntraeger@de.ibm.com [hca@linux.ibm.com: use illegal opcode, and update comment] Signed-off-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/lib/test_unwind.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/s390/lib/test_unwind.c b/arch/s390/lib/test_unwind.c index 6bad84c372dcb..b0b67e6d1f6e2 100644 --- a/arch/s390/lib/test_unwind.c +++ b/arch/s390/lib/test_unwind.c @@ -171,10 +171,11 @@ static noinline int unwindme_func4(struct unwindme *u) }
/* - * trigger specification exception + * Trigger operation exception; use insn notation to bypass + * llvm's integrated assembler sanity checks. */ asm volatile( - " mvcl %%r1,%%r1\n" + " .insn e,0x0000\n" /* illegal opcode */ "0: nopr %%r7\n" EX_TABLE(0b, 0b) :);