Are clang unsigned comparison warnings in kern/kern_* ok?

I've got following warnings [no errors had been generated while
-Werror is in command line] and want to know if they are ok. There are
much more same warnings in modules, but I worry about kernel :
Kernel config: http://eroese.org/_/_/pub/bsd/240070/GENERIC_PF.amd64
src.conf: http://eroese.org/_/_/pub/bsd/240070/src.conf
make.conf: /dev/null
kernel build logs: http://eroese.org/_/_/pub/bsd/240070/kernel.amd64.GENERIC_PF

cc -c -O2 -pipe -fno-strict-aliasing  -std=c99  -Wall
-Wredundant-decls -Wnested-externs -Wstrict-prototypes
-Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual  -Wundef
-Wno-pointer-sign -fformat-extensions  -Wmissing-include-dirs
-fdiagnostics-show-option  -Wno-error-tautological-compare
-Wno-error-empty-body  -Wno-error-parentheses-equality -nostdinc  -I.
-I/usr/head/src/sys -I/usr/head/src/sys/contrib/altq -D_KERNEL
-DHAVE_KERNEL_OPTION_HEADERS -include opt_global.h
-fno-omit-frame-pointer -mno-aes -mno-avx -mcmodel=kernel
-mno-red-zone -mno-mmx -mno-sse -msoft-float
-fno-asynchronous-unwind-tables -ffreestanding -fstack-protector
-Werror  /usr/head/src/sys/kern/kern_cpuset.c
/usr/head/src/sys/kern/kern_cpuset.c:654:16: warning: comparison of
unsigned expression < 0 is always false [-Wtautological-compare]
        for (i = 0; i < (_NCPUWORDS - 1); i++) {
                    ~ ^ ~~~~~~~~~~~~~~~~
1 warning generated.

/usr/head/src/sys/kern/kern_poll.c:173:10: warning: comparison of
unsigned expression < 0 is always false [-Wtautological-compare]
        if (val < 0 || val > 99)
            ~~~ ^ ~
1 warning generated.

cc -c -O2 -pipe -fno-strict-aliasing  -std=c99  -Wall
-Wredundant-decls -Wnested-externs -Wstrict-prototypes
-Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual  -Wundef
-Wno-pointer-sign -fformat-extensions  -Wmissing-include-dirs
-fdiagnostics-show-option  -Wno-error-tautological-compare
-Wno-error-empty-body  -Wno-error-parentheses-equality -nostdinc  -I.
-I/usr/head/src/sys -I/usr/head/src/sys/contrib/altq -D_KERNEL
-DHAVE_KERNEL_OPTION_HEADERS -include opt_global.h
-fno-omit-frame-pointer -mno-aes -mno-avx -mcmodel=kernel
-mno-red-zone -mno-mmx -mno-sse -msoft-float
-fno-asynchronous-unwind-tables -ffreestanding -fstack-protector
-Werror  /usr/head/src/sys/kern/kern_umtx.c
/usr/head/src/sys/kern/kern_umtx.c:3312:19: warning: comparison of
unsigned expression < 0 is always false [-Wtautological-compare]
                if (ts32.tv_sec < 0 ||
                    ~~~~~~~~~~~ ^ ~
/usr/head/src/sys/kern/kern_umtx.c:3314:20: warning: comparison of
unsigned expression < 0 is always false [-Wtautological-compare]
                    ts32.tv_nsec < 0)
                    ~~~~~~~~~~~~ ^ ~
/usr/head/src/sys/kern/kern_umtx.c:3338:25: warning: comparison of
unsigned expression < 0 is always false [-Wtautological-compare]
        if (t32.timeout.tv_sec < 0 ||
            ~~~~~~~~~~~~~~~~~~ ^ ~
/usr/head/src/sys/kern/kern_umtx.c:3339:63: warning: comparison of
unsigned expression < 0 is always false [-Wtautological-compare]
            t32.timeout.tv_nsec >= 1000000000 || t32.timeout.tv_nsec < 0)
                                                 ~~~~~~~~~~~~~~~~~~~ ^ ~
4 warnings generated.


cc -c -O2 -pipe -fno-strict-aliasing  -std=c99  -Wall
-Wredundant-decls -Wnested-externs -Wstrict-prototypes
-Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual  -Wundef
-Wno-pointer-sign -fformat-extensions  -Wmissing-include-dirs
-fdiagnostics-show-option  -Wno-error-tautological-compare
-Wno-error-empty-body  -Wno-error-parentheses-equality -nostdinc  -I.
-I/usr/head/src/sys -I/usr/head/src/sys/contrib/altq -D_KERNEL
-DHAVE_KERNEL_OPTION_HEADERS -include opt_global.h
-fno-omit-frame-pointer -mno-aes -mno-avx -mcmodel=kernel
-mno-red-zone -mno-mmx -mno-sse -msoft-float
-fno-asynchronous-unwind-tables -ffreestanding -fstack-protector
-Werror  /usr/head/src/sys/kern/uipc_syscalls.c
/usr/head/src/sys/kern/uipc_syscalls.c:356:16: warning: comparison of
unsigned expression < 0 is always false [-Wtautological-compare]
                if (*namelen < 0)
                    ~~~~~~~~ ^ ~
/usr/head/src/sys/kern/uipc_syscalls.c:1487:12: warning: comparison of
unsigned expression < 0 is always false [-Wtautological-compare]
        if (*alen < 0)
            ~~~~~ ^ ~
/usr/head/src/sys/kern/uipc_syscalls.c:1587:12: warning: comparison of
unsigned expression < 0 is always false [-Wtautological-compare]
        if (*alen < 0)
            ~~~~~ ^ ~
3 warnings generated.

-- Eir Nym