Re: [Qemu-devel] [PATCH v2 11/28] s390x/tcg: MVCS/MVCP: Properly wrap the length

2019-09-11 Thread David Hildenbrand 
On 11.09.19 17:11, Richard Henderson wrote:
> On 9/6/19 3:57 AM, David Hildenbrand wrote:
>> +l = wrap_length(env, l);
>>  if (l > 256) {
>>  /* max 256 */
>>  l = 256;
>>  cc = 3;
>> +} else if (!l) {
>> +return cc;
>>  }
> 
> Um, wrap_length only takes 31 bits.
> These insns take 32 bits in 24/31-bit modes.

Nice observation! Thanks!

-- 

Thanks,

David / dhildenb

Re: [Qemu-devel] [PATCH v2 11/28] s390x/tcg: MVCS/MVCP: Properly wrap the length

2019-09-11 Thread Richard Henderson 
On 9/6/19 3:57 AM, David Hildenbrand wrote:
> +l = wrap_length(env, l);
>  if (l > 256) {
>  /* max 256 */
>  l = 256;
>  cc = 3;
> +} else if (!l) {
> +return cc;
>  }

Um, wrap_length only takes 31 bits.
These insns take 32 bits in 24/31-bit modes.


r~

[Qemu-devel] [PATCH v2 11/28] s390x/tcg: MVCS/MVCP: Properly wrap the length

2019-09-06 Thread David Hildenbrand 
... and don't perform any move in case the length is zero.

Signed-off-by: David Hildenbrand 
---
 target/s390x/mem_helper.c | 6 ++
 1 file changed, 6 insertions(+)

diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c
index 041d01d63d..de5e69b500 100644
--- a/target/s390x/mem_helper.c
+++ b/target/s390x/mem_helper.c
@@ -1973,10 +1973,13 @@ uint32_t HELPER(mvcs)(CPUS390XState *env, uint64_t l, 
uint64_t a1, uint64_t a2)
 s390_program_interrupt(env, PGM_SPECIAL_OP, ILEN_AUTO, ra);
 }
 
+l = wrap_length(env, l);
 if (l > 256) {
 /* max 256 */
 l = 256;
 cc = 3;
+} else if (!l) {
+return cc;
 }
 
 /* XXX replace w/ memcpy */
@@ -2002,10 +2005,13 @@ uint32_t HELPER(mvcp)(CPUS390XState *env, uint64_t l, 
uint64_t a1, uint64_t a2)
 s390_program_interrupt(env, PGM_SPECIAL_OP, ILEN_AUTO, ra);
 }
 
+l = wrap_length(env, l);
 if (l > 256) {
 /* max 256 */
 l = 256;
 cc = 3;
+} else if (!l) {
+return cc;
 }
 
 /* XXX replace w/ memcpy */
-- 
2.21.0