build failure of next-20221005 due to a3a956c78efa ("fs/ntfs3: Add option "nocase"")

From: "Sudip Mukherjee (Codethink)" <sudipm.mukherjee@gmail.com>
To: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Tom Rix <trix@redhat.com>,
	ntfs3@lists.linux.dev, linux-kernel@vger.kernel.org,
	llvm@lists.linux.dev, linux-next@vger.kernel.org
Subject: build failure of next-20221005 due to a3a956c78efa ("fs/ntfs3: Add option "nocase"")
Date: Wed, 5 Oct 2022 12:19:42 +0100	[thread overview]
Message-ID: <Yz1oTvzDpCkOE+fr@debian> (raw)

Hi All,

The builds of x86_84 allmodconfig with clang have failed to build
next-20221005 with the error:

fs/ntfs3/namei.c:445:7: error: variable 'uni1' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
                if (toupper(c1) != toupper(c2)) {
                    ^~~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/ctype.h:64:20: note: expanded from macro 'toupper'
#define toupper(c) __toupper(c)
                   ^
fs/ntfs3/namei.c:487:12: note: uninitialized use occurs here
        __putname(uni1);
                  ^~~~
./include/linux/fs.h:2803:65: note: expanded from macro '__putname'
#define __putname(name)         kmem_cache_free(names_cachep, (void *)(name))
                                                                       ^~~~
fs/ntfs3/namei.c:445:3: note: remove the 'if' if its condition is always false
                if (toupper(c1) != toupper(c2)) {
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/ntfs3/namei.c:434:7: error: variable 'uni1' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
                if (!lm--) {
                    ^~~~~
fs/ntfs3/namei.c:487:12: note: uninitialized use occurs here
        __putname(uni1);
                  ^~~~
./include/linux/fs.h:2803:65: note: expanded from macro '__putname'
#define __putname(name)         kmem_cache_free(names_cachep, (void *)(name))
                                                                       ^~~~
fs/ntfs3/namei.c:434:3: note: remove the 'if' if its condition is always false
                if (!lm--) {
                ^~~~~~~~~~~~
fs/ntfs3/namei.c:430:22: note: initialize the variable 'uni1' to silence this warning
        struct cpu_str *uni1, *uni2;
                            ^
                             = NULL
2 errors generated.

git bisect pointed to a3a956c78efa ("fs/ntfs3: Add option "nocase"").

I will be happy to test any patch or provide any extra log if needed.

-- 
Regards
Sudip