From: Shaokun Zhang <[email protected]> Date: Sat, 16 May 2020 11:46:49 +0800
> From: Yuqi Jin <[email protected]> > > Commit adb03115f459 ("net: get rid of an signed integer overflow in > ip_idents_reserve()") > used atomic_cmpxchg to replace "atomic_add_return" inside the function > "ip_idents_reserve". The reason was to avoid UBSAN warning. > However, this change has caused performance degrade and in GCC-8, > fno-strict-overflow is now mapped to -fwrapv -fwrapv-pointer > and signed integer overflow is now undefined by default at all > optimization levels[1]. Moreover, it was a bug in UBSAN vs -fwrapv > /-fno-strict-overflow, so Let's revert it safely. > > [1] https://gcc.gnu.org/gcc-8/changes.html > > Suggested-by: Peter Zijlstra <[email protected]> > Suggested-by: Eric Dumazet <[email protected]> ... > Signed-off-by: Yuqi Jin <[email protected]> > Signed-off-by: Shaokun Zhang <[email protected]> Applied, thanks.
