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authorGravatar Ilie Halip <ilie.halip@gmail.com> 2021-11-17 19:48:21 +0200
committerGravatar Heiko Carstens <hca@linux.ibm.com> 2021-11-25 13:38:31 +0100
commit53ae7230918154d1f4281d7aa3aae9650436eadf (patch)
tree88e0db85941c0c2ac500cc05c08f1181cd0c8667 /arch/s390
parentLinux 5.16-rc2 (diff)
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s390/test_unwind: use raw opcode instead of invalid instruction
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>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/lib/test_unwind.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/s390/lib/test_unwind.c b/arch/s390/lib/test_unwind.c
index cfc5f5557c06..bc7973359ae2 100644
--- a/arch/s390/lib/test_unwind.c
+++ b/arch/s390/lib/test_unwind.c
@@ -173,10 +173,11 @@ 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)
:);