| Message ID | 20211105155704.3293957-1-nathan@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | NFS: Avoid using error uninitialized in nfs_lookup() | expand |
On Fri, Nov 5, 2021 at 8:57 AM Nathan Chancellor <nathan@kernel.org> wrote: > > Clang warns: > > fs/nfs/dir.c:1772:6: error: variable 'error' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] > if (fhandle == NULL || fattr == NULL) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > fs/nfs/dir.c:1801:44: note: uninitialized use occurs here > trace_nfs_lookup_exit(dir, dentry, flags, error); > ^~~~~ > fs/nfs/dir.c:1772:2: note: remove the 'if' if its condition is always false > if (fhandle == NULL || fattr == NULL) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > fs/nfs/dir.c:1772:6: error: variable 'error' is used uninitialized whenever '||' condition is true [-Werror,-Wsometimes-uninitialized] > if (fhandle == NULL || fattr == NULL) > ^~~~~~~~~~~~~~~ > fs/nfs/dir.c:1801:44: note: uninitialized use occurs here > trace_nfs_lookup_exit(dir, dentry, flags, error); > ^~~~~ > fs/nfs/dir.c:1772:6: note: remove the '||' if its condition is always false > if (fhandle == NULL || fattr == NULL) > ^~~~~~~~~~~~~~~~~~ > fs/nfs/dir.c:1754:11: note: initialize the variable 'error' to silence this warning > int error; > ^ > = 0 > 2 errors generated. > > Add a label to skip the call to trace_nfs_lookup_exit() when the call to > nfs_alloc_fhandle() or nfs_alloc_fattr_with_label() fails because > trace_nfs_lookup_enter() has not been called at that point so tracing > the exit does not make sense. > > Fixes: 8d3df1d0387e ("NFS: Remove the label from the nfs4_lookup_res struct") > Link: https://github.com/ClangBuiltLinux/linux/issues/1498 > Signed-off-by: Nathan Chancellor <nathan@kernel.org> Thanks for the patch! Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > --- > fs/nfs/dir.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c > index 8de99f426183..1c978a7cf730 100644 > --- a/fs/nfs/dir.c > +++ b/fs/nfs/dir.c > @@ -1770,7 +1770,7 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in > fhandle = nfs_alloc_fhandle(); > fattr = nfs_alloc_fattr_with_label(NFS_SERVER(dir)); > if (fhandle == NULL || fattr == NULL) > - goto out; > + goto out_no_trace; > > dir_verifier = nfs_save_change_attribute(dir); > trace_nfs_lookup_enter(dir, dentry, flags); > @@ -1799,6 +1799,7 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in > nfs_set_verifier(dentry, dir_verifier); > out: > trace_nfs_lookup_exit(dir, dentry, flags, error); > +out_no_trace: > nfs_free_fattr(fattr); > nfs_free_fhandle(fhandle); > return res; > > base-commit: cb66e0e973daa668dadd43441f877377a1b7b1ff > -- > 2.34.0.rc0 > >
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 8de99f426183..1c978a7cf730 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1770,7 +1770,7 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in fhandle = nfs_alloc_fhandle(); fattr = nfs_alloc_fattr_with_label(NFS_SERVER(dir)); if (fhandle == NULL || fattr == NULL) - goto out; + goto out_no_trace; dir_verifier = nfs_save_change_attribute(dir); trace_nfs_lookup_enter(dir, dentry, flags); @@ -1799,6 +1799,7 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in nfs_set_verifier(dentry, dir_verifier); out: trace_nfs_lookup_exit(dir, dentry, flags, error); +out_no_trace: nfs_free_fattr(fattr); nfs_free_fhandle(fhandle); return res;
Clang warns: fs/nfs/dir.c:1772:6: error: variable 'error' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] if (fhandle == NULL || fattr == NULL) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/nfs/dir.c:1801:44: note: uninitialized use occurs here trace_nfs_lookup_exit(dir, dentry, flags, error); ^~~~~ fs/nfs/dir.c:1772:2: note: remove the 'if' if its condition is always false if (fhandle == NULL || fattr == NULL) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/nfs/dir.c:1772:6: error: variable 'error' is used uninitialized whenever '||' condition is true [-Werror,-Wsometimes-uninitialized] if (fhandle == NULL || fattr == NULL) ^~~~~~~~~~~~~~~ fs/nfs/dir.c:1801:44: note: uninitialized use occurs here trace_nfs_lookup_exit(dir, dentry, flags, error); ^~~~~ fs/nfs/dir.c:1772:6: note: remove the '||' if its condition is always false if (fhandle == NULL || fattr == NULL) ^~~~~~~~~~~~~~~~~~ fs/nfs/dir.c:1754:11: note: initialize the variable 'error' to silence this warning int error; ^ = 0 2 errors generated. Add a label to skip the call to trace_nfs_lookup_exit() when the call to nfs_alloc_fhandle() or nfs_alloc_fattr_with_label() fails because trace_nfs_lookup_enter() has not been called at that point so tracing the exit does not make sense. Fixes: 8d3df1d0387e ("NFS: Remove the label from the nfs4_lookup_res struct") Link: https://github.com/ClangBuiltLinux/linux/issues/1498 Signed-off-by: Nathan Chancellor <nathan@kernel.org> --- fs/nfs/dir.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) base-commit: cb66e0e973daa668dadd43441f877377a1b7b1ff