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[Qemu-trivial] [PATCH v2 5/5] ppc: Remove a potential overflow in muldiv
From: |
Laurent Vivier |
Subject: |
[Qemu-trivial] [PATCH v2 5/5] ppc: Remove a potential overflow in muldiv64() |
Date: |
Mon, 9 May 2016 15:24:59 +0200 |
The coccinelle script:
scripts/coccinelle/overflow_muldiv64.cocci
gives us a list of potential overflows in muldiv64()
(the two first parameters are 64bit values).
This patch fixes one, as the fix seems obvious:
replace muldiv64(a, b, c) by muldiv64(b, a, c)
as "a" and "b" are 64bit values but a <= NANOSECONDS_PER_SECOND.
(10^9 -> 30bit value).
Signed-off-by: Laurent Vivier <address@hidden>
---
hw/ppc/ppc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c
index 38ff2e1..07ea47c 100644
--- a/hw/ppc/ppc.c
+++ b/hw/ppc/ppc.c
@@ -880,7 +880,7 @@ static int timebase_post_load(void *opaque, int version_id)
host_ns = qemu_clock_get_ns(QEMU_CLOCK_HOST);
ns_diff = MAX(0, host_ns - tb_remote->time_of_the_day_ns);
migration_duration_ns = MIN(NANOSECONDS_PER_SECOND, ns_diff);
- migration_duration_tb = muldiv64(migration_duration_ns, freq,
+ migration_duration_tb = muldiv64(freq, migration_duration_ns,
NANOSECONDS_PER_SECOND);
guest_tb = tb_remote->guest_timebase + MIN(0, migration_duration_tb);
--
2.5.5
- [Qemu-trivial] [PATCH v2 0/5] muldiv64() trivial fixes, Laurent Vivier, 2016/05/09
- [Qemu-trivial] [PATCH v2 1/5] scripts: add muldiv64() checking coccinelle scripts, Laurent Vivier, 2016/05/09
- [Qemu-trivial] [PATCH v2 2/5] The only 64bit parameter of muldiv64() is the first one., Laurent Vivier, 2016/05/09
- [Qemu-trivial] [PATCH v2 3/5] remove useless muldiv64(), Laurent Vivier, 2016/05/09
- [Qemu-trivial] [PATCH v2 4/5] replace muldiv64(a, b, c) by (uint64_t)a * b / c, Laurent Vivier, 2016/05/09
- [Qemu-trivial] [PATCH v2 5/5] ppc: Remove a potential overflow in muldiv64(),
Laurent Vivier <=
- Re: [Qemu-trivial] [PATCH v2 0/5] muldiv64() trivial fixes, Michael Tokarev, 2016/05/29