Following multiple build warnings / errors noticed while building
Linux next-20230323 with clang-16 for x86_64.
Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
Build warnings / errors:
---------
mm/mmap.c:939:11: error: variable 'next' is used uninitialized
whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
else if (!curr)
^~~~~
mm/mmap.c:952:15: note: uninitialized use occurs here
merge_next = next && mpol_equal(policy, vma_policy(next)) &&
^~~~
mm/mmap.c:939:7: note: remove the 'if' if its condition is always true
else if (!curr)
^~~~~~~~~~
mm/mmap.c:912:36: note: initialize the variable 'next' to silence this warning
struct vm_area_struct *curr, *next, *res;
^
= NULL
1 error generated.
make[3]: *** [scripts/Makefile.build:252: mm/mmap.o] Error 1
mm/vmalloc.c:3543:6: error: variable 'remains' is used uninitialized
whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
if (bitmap_empty(vb->used_map, VMAP_BBMAP_BITS)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/vmalloc.c:3587:17: note: uninitialized use occurs here
return count - remains + zero_iter(iter, remains);
^~~~~~~
mm/vmalloc.c:3543:2: note: remove the 'if' if its condition is always false
if (bitmap_empty(vb->used_map, VMAP_BBMAP_BITS)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/vmalloc.c:3539:6: error: variable 'remains' is used uninitialized
whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
if (!vb)
^~~
mm/vmalloc.c:3587:17: note: uninitialized use occurs here
return count - remains + zero_iter(iter, remains);
^~~~~~~
mm/vmalloc.c:3539:2: note: remove the 'if' if its condition is always false
if (!vb)
^~~~~~~~
mm/vmalloc.c:3524:16: note: initialize the variable 'remains' to
silence this warning
size_t remains, n;
^
= 0
2 errors generated.
make[3]: *** [scripts/Makefile.build:252: mm/vmalloc.o] Error 1
make[3]: Target 'mm/' not remade because of errors.
steps to reproduce:
----------
tuxmake \
--runtime podman \
--target-arch x86_64 \
--toolchain clang-16 LLVM=1 LLVM_IAS=1 \
--kconfig https://storage.tuxsuite.com/public/linaro/lkft/builds/2NOjxURhByyb4dR3Ld788iuYvAR/config
Related discussion on mailing list,
- https://lore.kernel.org/llvm/202303231055.DeninwHS-lkp@xxxxxxxxx/
- https://lore.kernel.org/llvm/14c60785-2427-45db-9613-683410ff6802@lucifer.local/T/#t
--
Linaro LKFT
https://lkft.linaro.org
