Messages in this thread | | | Date | Wed, 1 Oct 2008 12:47:57 +0200 | From | Mikael Pettersson <> | Subject | Re: drivers/pci/probe.c compile warnings on -tip |
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Steven Noonan writes: > I was hunting down some warnings I got when compiling -tip, and with > one of them, I'm not sure what would be a proper way to handle it. > > If CONFIG_PHYS_ADDR_T_64BIT is not enabled, these warnings show up: > > drivers/pci/probe.c: In function '__pci_read_base': > drivers/pci/probe.c:308: warning: format '%llx' expects type 'long > long unsigned int', but argument 4 has type 'resource_size_t' > drivers/pci/probe.c:308: warning: format '%llx' expects type 'long > long unsigned int', but argument 5 has type 'resource_size_t' > drivers/pci/probe.c:320: warning: format '%llx' expects type 'long > long unsigned int', but argument 5 has type 'resource_size_t' > drivers/pci/probe.c:320: warning: format '%llx' expects type 'long > long unsigned int', but argument 6 has type 'resource_size_t' > drivers/pci/probe.c: In function 'pci_read_bridge_bases': > drivers/pci/probe.c:392: warning: format '%llx' expects type 'long > long unsigned int', but argument 3 has type 'resource_size_t' > drivers/pci/probe.c:392: warning: format '%llx' expects type 'long > long unsigned int', but argument 4 has type 'resource_size_t' > drivers/pci/probe.c:405: warning: format '%llx' expects type 'long > long unsigned int', but argument 3 has type 'resource_size_t' > drivers/pci/probe.c:405: warning: format '%llx' expects type 'long > long unsigned int', but argument 4 has type 'resource_size_t' > drivers/pci/probe.c:443: warning: format '%llx' expects type 'long > long unsigned int', but argument 4 has type 'resource_size_t' > drivers/pci/probe.c:443: warning: format '%llx' expects type 'long > long unsigned int', but argument 5 has type 'resource_size_t' > > > Each of the lines is something like this: > > printk(KERN_DEBUG "PCI: %s reg %x 64bit mmio: [%llx, %llx]\n", > pci_name(dev), pos, res->start, res->end); > > res->start and res->end are resource_size_t (which is phys_addr_t), > and are sized either 32-bit or 64-bit, based on whether > CONFIG_PHYS_ADDR_T_64BIT is set.
Oh not those again. Similar warnings in 27-rc's drivers/pci were fixed recently, but apparently someone out there likes to create new ones.
The fix is to cast the resource_size_t arguments to unsigned long long. With "%llx" that's the /only/ valid argument type.
Also note that these warnings aren't harmless. On 32-bit machines with parameters passed on the stack the mismatch in size between 32-bit resource_size_t and the 64-bit %llx causes undefined behaviour as printk mis-enumerates its parameters.
/Mikael
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