On Tue, Oct 04, 2022 at 03:56:45PM -0700, Nick Desaulniers wrote:
> On Tue, Oct 4, 2022 at 7:42 AM Nathan Chancellor <nathan@xxxxxxxxxx> wrote:
> >
> > Clang warns:
> >
> > 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:2789:65: 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:2789:65: 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.
> >
> > There is no point in calling __putname() in these particular error
> > paths, as there has been no corresponding __getname() call yet. Just
> > return directly in these blocks to clear up the warning.
> >
> > Fixes: a3a956c78efa ("fs/ntfs3: Add option "nocase"")
> > Link: https://github.com/ClangBuiltLinux/linux/issues/1729
> > Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> > ---
> > fs/ntfs3/namei.c | 12 ++++--------
> > 1 file changed, 4 insertions(+), 8 deletions(-)
> >
> > diff --git a/fs/ntfs3/namei.c b/fs/ntfs3/namei.c
> > index 315763eb05ff..5d3a6ce3f05f 100644
> > --- a/fs/ntfs3/namei.c
> > +++ b/fs/ntfs3/namei.c
> > @@ -431,10 +431,8 @@ static int ntfs_d_compare(const struct dentry *dentry, unsigned int len1,
> >
> > /* First try fast implementation. */
> > for (;;) {
> > - if (!lm--) {
> > - ret = len1 == len2 ? 0 : 1;
> > - goto out;
> > - }
> > + if (!lm--)
> > + return len1 == len2 ? 0 : 1;
>
> I know the code originally used this, but I can't help but look at
> this and think that it should be:
>
> return len1 != len2;
>
> Do you mind cleaning it up while you're here?
>
> Otherwise LGTM;
>
> Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
>
> You may retain my RB tag whether you send that suggestion in a v2 or not.
I sent a v2 but I kept the changes separate:
https://lore.kernel.org/20221004232359.285685-1-nathan@xxxxxxxxxx/
https://lore.kernel.org/20221004232359.285685-2-nathan@xxxxxxxxxx/
Thanks for taking a look!
> >
> > if ((c1 = *n1++) == (c2 = *n2++))
> > continue;
> > @@ -442,10 +440,8 @@ static int ntfs_d_compare(const struct dentry *dentry, unsigned int len1,
> > if (c1 >= 0x80 || c2 >= 0x80)
> > break;
> >
> > - if (toupper(c1) != toupper(c2)) {
> > - ret = 1;
> > - goto out;
> > - }
> > + if (toupper(c1) != toupper(c2))
> > + return 1;
> > }
> >
> > /*
> >
> > base-commit: d45da67caedacd500879de5e649360cc70777af7
> > --
> > 2.37.3
> >
>
>
> --
> Thanks,
> ~Nick Desaulniers
