Re: [PATCH -next] iwlwifi: pcie: Use bitwise instead of arithmetic operator for flags

[Samuel Zou]

Both of you are right.
I neglected, and this patch is wrong.

Thanks.

On 2020/5/6 23:15, Joe Perches wrote:
> On Wed, 2020-05-06 at 16:51 +0300, Luciano Coelho wrote:
> > On Tue, 2020-05-05 at 20:19 -0700, Joe Perches wrote:
> > > On Wed, 2020-05-06 at 11:07 +0800, Samuel Zou wrote:
> > > > This silences the following coccinelle warning:
> > > >
> > > > "WARNING: sum of probable bitmasks, consider |"
> > >
> > > I suggest instead ignoring bad and irrelevant warnings.
> > >
> > > PREFIX_LEN is 32 not 0x20 or BIT(5)
> > > PCI_DUMP_SIZE is 352
> > >
> > > > diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
> > > []
> > > > @@ -109,9 +109,9 @@ void iwl_trans_pcie_dump_regs(struct iwl_trans *trans)
> > > >   
> > > >   	/* Alloc a max size buffer */
> > > >   	alloc_size = PCI_ERR_ROOT_ERR_SRC +  4 + PREFIX_LEN;
> > > > -	alloc_size = max_t(u32, alloc_size, PCI_DUMP_SIZE + PREFIX_LEN);
> > > > -	alloc_size = max_t(u32, alloc_size, PCI_MEM_DUMP_SIZE + PREFIX_LEN);
> > > > -	alloc_size = max_t(u32, alloc_size, PCI_PARENT_DUMP_SIZE + PREFIX_LEN);
> > > > +	alloc_size = max_t(u32, alloc_size, PCI_DUMP_SIZE | PREFIX_LEN);
> > > > +	alloc_size = max_t(u32, alloc_size, PCI_MEM_DUMP_SIZE | PREFIX_LEN);
> > > > +	alloc_size = max_t(u32, alloc_size, PCI_PARENT_DUMP_SIZE | PREFIX_LEN);
> > > >   
> > > >   	buf = kmalloc(alloc_size, GFP_ATOMIC);
> > > >   	if (!buf)
> >
> > Yeah, those macros are clearly not bitmasks.  I'm dropping this patch.
>
> Can the cocci script that generated this warning
>
> scripts/coccinelle/misc/orplus.cocci
>
> be dropped or improved to validate the likelihood that
> the defines or constants used are more likely than
> not are bit values?
>
> Maybe these should be defined as hex or BIT or BIT_ULL
> or GENMASK or the like?
>
>
> Right now it seems it just tests for two constants.
>
>
>
> .