On Mon, 10 Feb 2025 13:48:48 -0700 Alex Williamson <alex.williamson@xxxxxxxxxx> wrote: > On Mon, 10 Feb 2025 21:08:19 +0100 > Oleg Nesterov <oleg@xxxxxxxxxx> wrote: > > > On 02/10, Oleg Nesterov wrote: > > > > > > On 02/10, Alex Williamson wrote: > > > > > > > > --- a/drivers/pci/probe.c > > > > +++ b/drivers/pci/probe.c > > > > @@ -345,7 +345,8 @@ static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) You probably need __always_inline to have any chance of a compile-time test of howmany. > > > > unsigned int pos, reg; > > > > u16 orig_cmd; > > > > > > > > - BUILD_BUG_ON(howmany > PCI_STD_NUM_BARS); > > > > + if (__builtin_constant_p(howmany)) > > > > + BUILD_BUG_ON(howmany > PCI_STD_NUM_BARS); > > > > > > Or just > > > > > > BUILD_BUG_ON(__builtin_constant_p(howmany) && howmany > PCI_STD_NUM_BARS); statically_true(howmany > PCI_STD_NUM_BARS) > > > > > > I dunno... Works for me in any case. > > > > > > I don't know if this is "right" solution though, > > > > I mean, atm I simply don't know if with the newer compiler > > __builtin_constant_p(howmany) will be true in this case. > > That I can confirm. With gcc 14.2.1, if I change the call in > pci_setup_device() to use 7 rather than 6 for howmany, the build fails. > If you confirm this resolves the build on older gcc, it seems like a > valid fix. I installed a VM with Fedora 23, which uses gcc 3.5.1, but > I haven't yet been able to successfully build any kernel with it. I'll > post a patch if you want to provide a Tested-by. Thanks, Far too old a version to be supported. David > > Alex > >
