ppc-for-6.2 queue 20210930

[PULL 01/44] host-utils: Fix overflow detection in divu128()

David Gibson posted 44 patches 4 years, 4 months ago

Download mbox

Maintainers: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, "Michael S. Tsirkin" <mst@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Markus Armbruster <armbru@redhat.com>, David Gibson <david@gibson.dropbear.id.au>, Eric Blake <eblake@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Paolo Bonzini <pbonzini@redhat.com>, Greg Kurz <groug@kaod.org>, Igor Mammedov <imammedo@redhat.com>, Eduardo Habkost <ehabkost@redhat.com>, Ani Sinha <ani@anisinha.ca>

Expand all Fold all

[PULL 01/44] host-utils: Fix overflow detection in divu128()

Posted by David Gibson 4 years, 4 months ago

From: Luis Pires <luis.pires@eldorado.org.br>

The previous code didn't detect overflows if the high 64-bit
of the dividend were equal to the 64-bit divisor. In that case,
64 bits wouldn't be enough to hold the quotient.

Signed-off-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210910112624.72748-2-luis.pires@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 util/host-utils.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/util/host-utils.c b/util/host-utils.c
index 7b9322071d..a789a11b46 100644
--- a/util/host-utils.c
+++ b/util/host-utils.c
@@ -102,7 +102,7 @@ int divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor)
         *plow  = dlo / divisor;
         *phigh = dlo % divisor;
         return 0;
-    } else if (dhi > divisor) {
+    } else if (dhi >= divisor) {
         return 1;
     } else {
 
-- 
2.31.1