On Sun, Jun 23, 2019 at 10:12:59PM +0700, Phong Tran wrote: > fix "Shifting signed 32-bit value by 31 bits is undefined behaviour > errors" > > [arch/arm/kernel/perf_event_v7.c:1080]: (error) Shifting signed 32-bit > value by 31 bits is undefined behaviour > [arch/arm/kernel/perf_event_v7.c:1436]: (error) Shifting signed 32-bit > value by 31 bits is undefined behaviour > [arch/arm/kernel/perf_event_v7.c:1783]: (error) Shifting signed 32-bit > value by 31 bits is undefined behaviour I don't think that is true; the kernel uses -fno-strict-overflow (which implies -fwrapv) and that takes away all the signed UB.
