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