Messages in this thread | | | From | Nick Desaulniers <> | Date | Wed, 10 Apr 2019 15:52:25 -0700 | Subject | Re: [PATCH v2] afs: use correct format characters |
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On Wed, Apr 10, 2019 at 3:41 PM Louis Taylor <louis@kragniz.eu> wrote: > > When compiling with -Wformat, clang warns: > > fs/afs/flock.c:632:29: warning: format specifies type 'short' but the argument has type > 'unsigned char' [-Wformat] > _leave(" = %d [%hd]", ret, fl->fl_type); > ~~~ ^~~~~~~~~~~ > > fs/afs/dir.c:138:11: warning: format specifies type 'unsigned short' but > the argument has type 'int' [-Wformat] > ntohs(dbuf->blocks[tmp].hdr.magic)); > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > fl_type is declared as an unsigned char unconditionally in > include/linux/fs.h, so use the correct format characters.
Thanks for the v2, probably should include a note about ntohs. That case in particular looks more complicated, due to the definition of ntohs (which uses __swab16).
If you keep the previous flag of %04hx, but add an explicit cast to u16, does the warning go away? If so, that might be a better fix.
- ntohs(dbuf->blocks[tmp].hdr.magic)); + (u16)ntohs(dbuf->blocks[tmp].hdr.magic));
?
Particularly, I'm curious about the return type of GNU C statement expressions, in the definition of __swab16 if __HAVE_BUILTIN_BSWAP16__ is not defined.
> > Link: https://github.com/ClangBuiltLinux/linux/issues/378 > Signed-off-by: Louis Taylor <louis@kragniz.eu> > --- > fs/afs/dir.c | 2 +- > fs/afs/flock.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/afs/dir.c b/fs/afs/dir.c > index 8a2562e3a316..4ceaec94e9c5 100644 > --- a/fs/afs/dir.c > +++ b/fs/afs/dir.c > @@ -133,7 +133,7 @@ static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page, > dbuf = kmap(page); > for (tmp = 0; tmp < qty; tmp++) { > if (dbuf->blocks[tmp].hdr.magic != AFS_DIR_MAGIC) { > - printk("kAFS: %s(%lx): bad magic %d/%d is %04hx\n", > + printk("kAFS: %s(%lx): bad magic %d/%d is %04x\n", > __func__, dvnode->vfs_inode.i_ino, tmp, qty, > ntohs(dbuf->blocks[tmp].hdr.magic)); > trace_afs_dir_check_failed(dvnode, off, i_size); > diff --git a/fs/afs/flock.c b/fs/afs/flock.c > index 6a0174258382..be4c3f6a3178 100644 > --- a/fs/afs/flock.c > +++ b/fs/afs/flock.c > @@ -629,7 +629,7 @@ static int afs_do_getlk(struct file *file, struct file_lock *fl) > > ret = 0; > error: > - _leave(" = %d [%hd]", ret, fl->fl_type); > + _leave(" = %d [%hhu]", ret, fl->fl_type); > return ret; > }
- Thanks, ~Nick Desaulniers
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