From: Alex Williamson Date: Wed, 12 Feb 2025 18:53:32 +0000 (-0700) Subject: PCI: Fix BUILD_BUG_ON usage for old gcc X-Git-Tag: v6.14-rc3~20^2~1 X-Git-Url: https://repo.jachan.dev/linux.git/commitdiff_plain/472ff48e2c09e49f2f90eeb6922f747306559506 PCI: Fix BUILD_BUG_ON usage for old gcc As reported in the below link, it seems older versions of gcc cannot determine that the howmany variable is known for all callers. Include a test so that newer compilers can enforce this sanity check and older compilers can still work. Add __always_inline attribute to give the compiler an even better chance to know the inputs. Link: https://lore.kernel.org/r/20250212185337.293023-1-alex.williamson@redhat.com Fixes: 4453f360862e ("PCI: Batch BAR sizing operations") Reported-by: Oleg Nesterov Link: https://lore.kernel.org/all/20250209154512.GA18688@redhat.com Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas Tested-by: Oleg Nesterov Tested-by: Mitchell Augustin --- diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index b6536ed599c3..246744d8d268 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -339,13 +339,14 @@ out: return (res->flags & IORESOURCE_MEM_64) ? 1 : 0; } -static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) +static __always_inline void pci_read_bases(struct pci_dev *dev, + unsigned int howmany, int rom) { u32 rombar, stdbars[PCI_STD_NUM_BARS]; unsigned int pos, reg; u16 orig_cmd; - BUILD_BUG_ON(howmany > PCI_STD_NUM_BARS); + BUILD_BUG_ON(statically_true(howmany > PCI_STD_NUM_BARS)); if (dev->non_compliant_bars) return;