On Fri, Nov 5, 2021 at 1:45 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote: > > On Fri, Nov 5, 2021 at 9:35 PM Nick Desaulniers <ndesaulniers@xxxxxxxxxx> wrote: > > > > On Fri, Nov 5, 2021 at 9:31 AM Anders Roxell <anders.roxell@xxxxxxxxxx> wrote: > > > > > > When building selftests/timens with clang, the compiler warn about the > > > function abs() see below: > > > > > > exec.c:33:8: error: absolute value function 'abs' given an argument of type 'long' but has parameter of type 'int' which may cause truncation of value [-Werror,-Wabsolute-value] > > > if (abs(tst.tv_sec - now.tv_sec) > 5) > > > ^ > > > exec.c:33:8: note: use function 'labs' instead > > > if (abs(tst.tv_sec - now.tv_sec) > 5) > > > ^~~ > > > labs > > > > Careful. > > > > Isn't the tv_sec member of `struct timespec` a `time_t` which is 32b > > on 32b hosts and 64b on 64b hosts? If I'm recalling that correctly, > > then this patch results in a harmless (though unnecessary) sign > > extension for 32b targets. That should be fine, but someone like Arnd > > should triple check if my concern is valid or not. > > It could actually be 'int', 'long' or 'long long' depending on the architecture > and C library. Maybe we need a temporary variable of type 'long long' > to hold the difference, and pass that to llabs()? Yeah, that SGTM. Thanks for the review! -- Thanks, ~Nick Desaulniers
