Re: assert !temp_readonly(ts) in tcg_reg_alloc_op

["Nicholas Piggin" <npiggin@gmail.com>]

On Fri Apr 7, 2023 at 7:02 PM AEST, Nicholas Piggin wrote:
> I get a crash running a powerpc64 TCG machine on x86.
>
> It can be triggered by booting a custom vmlinux patched to use powerpc
> prefix instructions and pcrel addressing, I don't know if that's related
> or coincidence. I can give Linux patches or a vmlinux file to reproduce
> if needed, or I can test patches quickly.
>
> The first bad commit is 7058ff5231a0 ("target/ppc: Avoid tcg_const_* in
> translate.c")

This seems to do the trick:

diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index 9d05357d03..23869fe6cb 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -1807,8 +1807,8 @@ static inline void gen_op_arith_modw(DisasContext *ctx, TCGv ret, TCGv arg1,
         TCGv_i32 t2 = tcg_constant_i32(1);
         TCGv_i32 t3 = tcg_constant_i32(0);
         tcg_gen_movcond_i32(TCG_COND_EQ, t1, t1, t3, t2, t1);
-        tcg_gen_remu_i32(t3, t0, t1);
-        tcg_gen_extu_i32_tl(ret, t3);
+        tcg_gen_remu_i32(t1, t0, t1);
+        tcg_gen_extu_i32_tl(ret, t1);
     }
 }