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.
>
> 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
