Multiply in 64 bits to avoid overflow

Multiply in 64 bits to avoid overflow

A fuzzer run caused the operands of this multiplication to be 512 and
5000000, resulting in a product about 20% too large for int32_t. So
change this from a 16x32->32 to a 16x32->64 multiplication. Since we
right shift by 2 at the end, the end result will still fit in int32_t.

I also had to fix a few follow-on add/sub overflows found by the same
fuzzer input once the multiplication was fixed. I chose to saturate
these, since it wasn't just an intermediate value that overflowed.

BUG=chromium:693868
Review-Url: https://codereview.webrtc.org/2729573002
Cr-Commit-Position: refs/heads/master@{#17003}
Committed: https://chromium.googlesource.com/external/webrtc/+/3a2c803dc341a2bc266effb07df9863c14a7aeaa

[kwiberg-webrtc, 2017-03-01 14:22:01]

The CQ bit was checked by kwiberg@webrtc.org to run a CQ dry run

[commit-bot: I haz the power, 2017-03-01 14:22:06]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[kwiberg-webrtc, 2017-03-01 14:23:45]

kwiberg@webrtc.org changed reviewers:
+ henrik.lundin@webrtc.org

[commit-bot: I haz the power, 2017-03-01 15:10:04]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-03-01 15:10:05]

Dry run: This issue passed the CQ dry run.

[hlundin-webrtc, 2017-03-03 13:22:59]

lgtm

[kwiberg-webrtc, 2017-03-03 13:24:32]

The CQ bit was checked by kwiberg@webrtc.org

[commit-bot: I haz the power, 2017-03-03 13:24:36]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[commit-bot: I haz the power, 2017-03-03 13:44:50]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1488547472388760, "parent_rev":
"d0472af435cdc1f2c8d09855273ab770adc08fbc", "commit_rev":
"3a2c803dc341a2bc266effb07df9863c14a7aeaa"}

[commit-bot: I haz the power, 2017-03-03 13:44:52]

Description was changed from

==========
Multiply in 64 bits to avoid overflow

A fuzzer run caused the operands of this multiplication to be 512 and
5000000, resulting in a product about 20% too large for int32_t. So
change this from a 16x32->32 to a 16x32->64 multiplication. Since we
right shift by 2 at the end, the end result will still fit in int32_t.

I also had to fix a few follow-on add/sub overflows found by the same
fuzzer input once the multiplication was fixed. I chose to saturate
these, since it wasn't just an intermediate value that overflowed.

BUG=chromium:693868
==========

to

==========
Multiply in 64 bits to avoid overflow

A fuzzer run caused the operands of this multiplication to be 512 and
5000000, resulting in a product about 20% too large for int32_t. So
change this from a 16x32->32 to a 16x32->64 multiplication. Since we
right shift by 2 at the end, the end result will still fit in int32_t.

I also had to fix a few follow-on add/sub overflows found by the same
fuzzer input once the multiplication was fixed. I chose to saturate
these, since it wasn't just an intermediate value that overflowed.

BUG=chromium:693868

Review-Url: https://codereview.webrtc.org/2729573002
Cr-Commit-Position: refs/heads/master@{#17003}
Committed:
https://chromium.googlesource.com/external/webrtc/+/3a2c803dc341a2bc266effb07...
==========

[commit-bot: I haz the power, 2017-03-03 13:44:53]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/external/webrtc/+/3a2c803dc341a2bc266effb07...

[tommi, 2017-03-11 16:00:50]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.webrtc.org/2740423003/ by tommi@webrtc.org.

The reason for reverting is: Looks like this caused isac_fix_test to start
failing:
https://build.chromium.org/p/client.webrtc.perf/builders/Linux%20Trusty?numbu...
https://build.chromium.org/p/client.webrtc.perf/builders/Linux%20Trusty/build....

[tommi, 2017-03-11 16:02:58]

On 2017/03/11 16:00:50, tommi (webrtc) wrote:
> A revert of this CL (patchset #1 id:1) has been created in
> https://codereview.webrtc.org/2740423003/ by mailto:tommi@webrtc.org.
> 
> The reason for reverting is: Looks like this caused isac_fix_test to start
> failing:
>
https://build.chromium.org/p/client.webrtc.perf/builders/Linux%20Trusty?numbu...
>
https://build.chromium.org/p/client.webrtc.perf/builders/Linux%20Trusty/build....

I decided not to revert, since the Chromium issue that this cl fixed, has been
verified.
Can you take a look at the failing test?

[hlundin-webrtc, 2017-03-14 08:49:06]

On 2017/03/11 16:02:58, tommi (webrtc) wrote:
> On 2017/03/11 16:00:50, tommi (webrtc) wrote:
> > A revert of this CL (patchset #1 id:1) has been created in
> > https://codereview.webrtc.org/2740423003/ by mailto:tommi@webrtc.org.
> > 
> > The reason for reverting is: Looks like this caused isac_fix_test to start
> > failing:
> >
>
https://build.chromium.org/p/client.webrtc.perf/builders/Linux%20Trusty?numbu...
> >
>
https://build.chromium.org/p/client.webrtc.perf/builders/Linux%20Trusty/build....
> 
> I decided not to revert, since the Chromium issue that this cl fixed, has been
> verified.
> Can you take a look at the failing test?

The test should be good again with https://codereview.webrtc.org/2746903002.