Re: [PATCH v3 1/2] selftests: kselftest.h: mark functions with 'noreturn'

From: Shuah Khan
Date: Fri Nov 19 2021 - 18:35:35 EST


On 11/18/21 2:58 AM, Anders Roxell wrote:
When building kselftests/capabilities the following warning shows up:

clang -O2 -g -std=gnu99 -Wall test_execve.c -lcap-ng -lrt -ldl -o test_execve
test_execve.c:121:13: warning: variable 'have_outer_privilege' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
} else if (unshare(CLONE_NEWUSER | CLONE_NEWNS) == 0) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test_execve.c:136:9: note: uninitialized use occurs here
return have_outer_privilege;
^~~~~~~~~~~~~~~~~~~~
test_execve.c:121:9: note: remove the 'if' if its condition is always true
} else if (unshare(CLONE_NEWUSER | CLONE_NEWNS) == 0) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test_execve.c:94:27: note: initialize the variable 'have_outer_privilege' to silence this warning
bool have_outer_privilege;
^
= false

Rework so all the ksft_exit_*() functions have attribue
'__attribute__((noreturn))' so the compiler knows that there wont be

won't be

any return from the function. That said, without
'__attribute__((noreturn))' the compiler warns about the above issue
since it thinks that it will get back from the ksft_exit_skip()
function, which it wont.
Cleaning up the callers that rely on ksft_exit_*() return code, since
the functions ksft_exit_*() have never returned anything.

Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
---

My commit script failed due to checkpatch warns. Run checkpatchp.l --strict
to find the problems and send me v4

thanks,
-- Shuah