[PATCH 2.6.27-rc6] pci: fix resource_size_t type errors

[PATCH 2.6.27-rc6] pci: fix resource_size_t type errors

[Mikael Pettersson]

Fix type errors introduced by commits 9bf8a1a79d549a0cf3b26c88d1ac8cdf07deafee
and 76fbc263ff7e42ce8b21b8aee176e3c74b45f81a, "pci: debug extra pci resources range"
and "pci: debug extra pci bus resources".

These commits added printks of resource_size_t values using "%llx" formats.
This is wrong for two reasons:
- resource_size_t may be u32 or u64, depending on arch and config options,
  but "%llx" only works with 64-bit integers; if there is a size mismatch,
  printk's argument pointer will move past the corresponding parameters on
  the stack (undefined behaviour)
- even if resource_size_t is u64, that type may be unsigned long or
  unsigned long long, depending on arch; if resource_size_t isn't unsigned
  long long, the compiler will generate type mismatch warnings

On my 32-bit x86 laptop, the first problem is visible in obviously bogus
kernel messages:

PCI: bridge 0000:00:01.0 io port: [2fff00002000, f787964000000300]
PCI: bridge 0000:00:01.0 32bit mmio: [d01fffffd0100000, f787964000000300]
PCI: bridge 0000:00:01.0 32bit mmio pref: [dfffffffd8000000, cf7879640]
...
bus: 00 index 0 io port: [ffff00000000, f7887c00]
bus: 00 index 1 mmio: [ffffffff00000000, f7887c00]
bus: 01 index 0 io port: [2fff00002000, f7887c14f7879400]
bus: 01 index 1 mmio: [d01fffffd0100000, f7887c14f7879400]
bus: 01 index 2 mmio: [dfffffffd8000000, f7887c14f7879400]
bus: 01 index 3 mmio: [0, f7887c14f7879400]
bus: 02 index 0 io port: [30ff00003000, f7887c14f7879000]
bus: 02 index 1 io port: [34ff00003400, f7887c14f7879000]
bus: 02 index 2 mmio: [73ffffff70000000, f7887c14f7879000]
bus: 02 index 3 mmio: [77ffffff74000000, f7887c14f7879000]

These aren't just cosmetic, that's printk running off the stack and
printing return addresses, kernel pointers, and similar nonsense.

The second problem is obvious from the warnings gcc-4.3.2 throws:

drivers/pci/probe.c:386: warning: format '%llx' expects type 'long long unsigned int', but argument 3 has type 'resource_size_t'
drivers/pci/probe.c:386: warning: format '%llx' expects type 'long long unsigned int', but argument 4 has type 'resource_size_t'
drivers/pci/probe.c:398: warning: format '%llx' expects type 'long long unsigned int', but argument 3 has type 'resource_size_t'
drivers/pci/probe.c:398: warning: format '%llx' expects type 'long long unsigned int', but argument 4 has type 'resource_size_t'
drivers/pci/probe.c:434: warning: format '%llx' expects type 'long long unsigned int', but argument 4 has type 'resource_size_t'
drivers/pci/probe.c:434: warning: format '%llx' expects type 'long long unsigned int', but argument 5 has type 'resource_size_t'
drivers/pci/setup-bus.c:543: warning: format '%llx' expects type 'long long unsigned int', but argument 5 has type 'resource_size_t'
drivers/pci/setup-bus.c:543: warning: format '%llx' expects type 'long long unsigned int', but argument 6 has type 'resource_size_t'

The only correct type to pass to a "%llx" format is unsigned long long,
so this patch fixes the errors by adding (unsigned long long) casts to
the offending printk parameters.

Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
---
 drivers/pci/probe.c     |   16 +++++++++++++---
 drivers/pci/setup-bus.c |    6 +++++-
 2 files changed, 18 insertions(+), 4 deletions(-)

diff -rupN linux-2.6.27-rc6/drivers/pci/probe.c linux-2.6.27-rc6.resource_size_t-printks/drivers/pci/probe.c
--- linux-2.6.27-rc6/drivers/pci/probe.c	2008-09-10 19:19:26.000000000 +0200
+++ linux-2.6.27-rc6.resource_size_t-printks/drivers/pci/probe.c	2008-09-10 20:22:28.000000000 +0200
@@ -383,7 +383,10 @@ void __devinit pci_read_bridge_bases(str
 			res->start = base;
 		if (!res->end)
 			res->end = limit + 0xfff;
-		printk(KERN_INFO "PCI: bridge %s io port: [%llx, %llx]\n", pci_name(dev), res->start, res->end);
+		printk(KERN_INFO "PCI: bridge %s io port: [%llx, %llx]\n",
+		       pci_name(dev),
+		       (unsigned long long)res->start,
+		       (unsigned long long)res->end);
 	}
 
 	res = child->resource[1];
@@ -395,7 +398,10 @@ void __devinit pci_read_bridge_bases(str
 		res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM;
 		res->start = base;
 		res->end = limit + 0xfffff;
-		printk(KERN_INFO "PCI: bridge %s 32bit mmio: [%llx, %llx]\n", pci_name(dev), res->start, res->end);
+		printk(KERN_INFO "PCI: bridge %s 32bit mmio: [%llx, %llx]\n",
+		       pci_name(dev),
+		       (unsigned long long)res->start,
+		       (unsigned long long)res->end);
 	}
 
 	res = child->resource[2];
@@ -431,7 +437,11 @@ void __devinit pci_read_bridge_bases(str
 		res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM | IORESOURCE_PREFETCH;
 		res->start = base;
 		res->end = limit + 0xfffff;
-		printk(KERN_INFO "PCI: bridge %s %sbit mmio pref: [%llx, %llx]\n", pci_name(dev), (res->flags & PCI_PREF_RANGE_TYPE_64)?"64":"32",res->start, res->end);
+		printk(KERN_INFO "PCI: bridge %s %sbit mmio pref: [%llx, %llx]\n",
+		       pci_name(dev),
+		       (res->flags & PCI_PREF_RANGE_TYPE_64) ? "64" : "32",
+		       (unsigned long long)res->start,
+		       (unsigned long long)res->end);
 	}
 }
 
diff -rupN linux-2.6.27-rc6/drivers/pci/setup-bus.c linux-2.6.27-rc6.resource_size_t-printks/drivers/pci/setup-bus.c
--- linux-2.6.27-rc6/drivers/pci/setup-bus.c	2008-09-10 19:19:26.000000000 +0200
+++ linux-2.6.27-rc6.resource_size_t-printks/drivers/pci/setup-bus.c	2008-09-10 20:23:30.000000000 +0200
@@ -540,7 +540,11 @@ static void pci_bus_dump_res(struct pci_
                 if (!res)
                         continue;
 
-		printk(KERN_INFO "bus: %02x index %x %s: [%llx, %llx]\n", bus->number, i, (res->flags & IORESOURCE_IO)? "io port":"mmio", res->start, res->end);
+		printk(KERN_INFO "bus: %02x index %x %s: [%llx, %llx]\n",
+		       bus->number, i,
+		       (res->flags & IORESOURCE_IO) ? "io port" : "mmio",
+		       (unsigned long long)res->start,
+		       (unsigned long long)res->end);
         }
 }
 

Re: [PATCH 2.6.27-rc6] pci: fix resource_size_t type errors

[Jesse Barnes]

On Wednesday, September 10, 2008 12:42 pm Mikael Pettersson wrote:
> Fix type errors introduced by commits
> 9bf8a1a79d549a0cf3b26c88d1ac8cdf07deafee and
> 76fbc263ff7e42ce8b21b8aee176e3c74b45f81a, "pci: debug extra pci resources
> range" and "pci: debug extra pci bus resources".
>
> These commits added printks of resource_size_t values using "%llx" formats.
> This is wrong for two reasons:
> - resource_size_t may be u32 or u64, depending on arch and config options,
>   but "%llx" only works with 64-bit integers; if there is a size mismatch,
>   printk's argument pointer will move past the corresponding parameters on
>   the stack (undefined behaviour)
> - even if resource_size_t is u64, that type may be unsigned long or
>   unsigned long long, depending on arch; if resource_size_t isn't unsigned
>   long long, the compiler will generate type mismatch warnings
>
> On my 32-bit x86 laptop, the first problem is visible in obviously bogus
> kernel messages:

Thanks Mikael, but I already integrated patches from Johann to fix this issue 
(53bc88701be91e7f631ad31418b32392aa952e9b and 
4ca8a7726fb0e8094fdb56f2ae2d69fcf9254eae in my for-linus tree).  I've queued 
it up for 2.6.27.

Thanks,
Jesse