On Thu, Sep 05, 2024 at 08:03:56PM +0300, Andy Shevchenko wrote: > When percpu_add_op() is used with unsigned argument, it prevents kernel builds > with clang, `make W=1` and CONFIG_WERROR=y: > > net/ipv4/tcp_output.c:187:3: error: result of comparison of constant -1 with expression of type 'u8' (aka 'unsigned char') is always false [-Werror,-Wtautological-constant-out-of-range-compare] > 187 | NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPACKCOMPRESSED, > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 188 | tp->compressed_ack); > | ~~~~~~~~~~~~~~~~~~~ > ... > arch/x86/include/asm/percpu.h:238:31: note: expanded from macro 'percpu_add_op' > 238 | ((val) == 1 || (val) == -1)) ? \ > | ~~~~~ ^ ~~ > > Fix this by casting -1 to the type of the parameter and then compare. Any comments? Or can it be taken in? -- With Best Regards, Andy Shevchenko
