[v3] s390x/tcg: mem_helper: Fault-safe handling

[Qemu-devel] [PATCH v3 12/29] s390x/tcg: MVCS/MVCP: Properly wrap the length

Posted by David Hildenbrand 6 years, 4 months ago

... and don't perform any move in case the length is zero.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 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 320e9ee65c..41d7336a1a 100644
--- a/target/s390x/mem_helper.c
+++ b/target/s390x/mem_helper.c
@@ -1980,10 +1980,13 @@ 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_length32(env, l);
     if (l > 256) {
         /* max 256 */
         l = 256;
         cc = 3;
+    } else if (!l) {
+        return cc;
     }
 
     /* XXX replace w/ memcpy */
@@ -2009,10 +2012,13 @@ 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_length32(env, l);
     if (l > 256) {
         /* max 256 */
         l = 256;
         cc = 3;
+    } else if (!l) {
+        return cc;
     }
 
     /* XXX replace w/ memcpy */
-- 
2.21.0

Re: [Qemu-devel] [PATCH v3 12/29] s390x/tcg: MVCS/MVCP: Properly wrap the length

Posted by Richard Henderson 6 years, 4 months ago

On 9/16/19 9:57 AM, David Hildenbrand wrote:
> ... and don't perform any move in case the length is zero.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  target/s390x/mem_helper.c | 6 ++++++
>  1 file changed, 6 insertions(+)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~