Re: drivers/pci/probe.c compile warnings on -tip

From: Steven Noonan
Date: Sat Oct 04 2008 - 23:55:32 EST


On Wed, Oct 1, 2008 at 8:51 AM, Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> wrote:
> On Wednesday, October 1, 2008 3:47 am Mikael Pettersson wrote:
>> 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.
>
> AFAICT, these are fixed in Linus' tree, maybe the x86 tree needs an update?
>

Hey Ingo, these warnings are still showing up on the latest -tip. Any idea why?

- Steven
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