[Qemu-devel] [PATCH] tcg-s390: Fix movi

[Qemu-devel] [PATCH] tcg-s390: Fix movi

[Richard Henderson]

The code to load the high 64 bits assumed that the insn used to
load the low 64 bits zero-extended.  Enforce that.

Cc: Alexander Graf <agraf@suse.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 tcg/s390/tcg-target.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tcg/s390/tcg-target.c b/tcg/s390/tcg-target.c
index e12a152..0132010 100644
--- a/tcg/s390/tcg-target.c
+++ b/tcg/s390/tcg-target.c
@@ -770,7 +770,7 @@ static void tcg_out_movi(TCGContext *s, TCGType type,
     /* If we get here, both the high and low parts have non-zero bits.  */
 
     /* Recurse to load the lower 32-bits.  */
-    tcg_out_movi(s, TCG_TYPE_I32, ret, sval);
+    tcg_out_movi(s, TCG_TYPE_I64, ret, uval & 0xffffffff);
 
     /* Insert data into the high 32-bits.  */
     uval = uval >> 31 >> 1;
-- 
1.8.1.4

Re: [Qemu-devel] [PATCH] tcg-s390: Fix movi

[Alexander Graf]

On 26.03.2013, at 01:11, Richard Henderson wrote:

> The code to load the high 64 bits assumed that the insn used to
> load the low 64 bits zero-extended.  Enforce that.
> 
> Cc: Alexander Graf <agraf@suse.de>
> Signed-off-by: Richard Henderson <rth@twiddle.net>

Tested-by: Alexander Graf <agraf@suse.de>

Though running an s390x guest on an s390x host gives me this happy error when it wants to enter user space:

  Inconsistency detected by ld.so: rtld.c: 1091: dl_main: Assertion `main_map != ((void *)0)' failed!

The very same s390x guest kernel+initrd run fine on an x86_64 host.


Alex

> ---
> tcg/s390/tcg-target.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tcg/s390/tcg-target.c b/tcg/s390/tcg-target.c
> index e12a152..0132010 100644
> --- a/tcg/s390/tcg-target.c
> +++ b/tcg/s390/tcg-target.c
> @@ -770,7 +770,7 @@ static void tcg_out_movi(TCGContext *s, TCGType type,
>     /* If we get here, both the high and low parts have non-zero bits.  */
> 
>     /* Recurse to load the lower 32-bits.  */
> -    tcg_out_movi(s, TCG_TYPE_I32, ret, sval);
> +    tcg_out_movi(s, TCG_TYPE_I64, ret, uval & 0xffffffff);
> 
>     /* Insert data into the high 32-bits.  */
>     uval = uval >> 31 >> 1;
> -- 
> 1.8.1.4
>