fix 32-bit compile warning from printk()

My patch "Fix kvm's use of __pa() on percpu areas" introduced a compile warning:

arch/x86/kernel/kvm.c: In function 'kvm_register_steal_time':
arch/x86/kernel/kvm.c:302:3: warning: format '%lx' expects argument of type 'long unsigned int', but argument 3 has type 'phys_addr_t' [-Wformat]

According to: Documentation/printk-formats.txt

If <type> is dependent on a config option for its size (e.g., phys_addr_t) ... use a format specifier of its largest possible type and explicitly cast to it.

So, we'll do just that. We will consider it an unsigned long long, and cast to it explicitly.

Quoted 12 lines · On Mon, 28 Jan 2013 11:19:39 -0800 Dave Hansen <[email protected]> wrote:

My patch "Fix kvm's use of __pa() on percpu areas" introduced a compile warning:

arch/x86/kernel/kvm.c: In function 'kvm_register_steal_time':
arch/x86/kernel/kvm.c:302:3: warning: format '%lx' expects argument of type 'long unsigned int', but argument 3 has type 'phys_addr_t' [-Wformat]

According to: Documentation/printk-formats.txt

If <type> is dependent on a config option for its size (e.g., phys_addr_t) ... use a format specifier of its largest possible type and explicitly cast to it.

Quoted 2 lines

So, we'll do just that. We will consider it an unsigned long long, and cast to it explicitly.

Please note that I have
http://ozlabs.org/~akpm/mmots/broken-out/lib-vsprintf-add-%25pa-format-specifier-for-phys_addr_t-types.patch
queued for 3.8.

My patch "Fix kvm's use of __pa() on percpu areas" introduced a compile warning:

arch/x86/kernel/kvm.c: In function 'kvm_register_steal_time':
arch/x86/kernel/kvm.c:302:3: warning: format '%lx' expects argument of type 'long unsigned int', but argument 3 has type 'phys_addr_t' [-Wformat]

According to: Documentation/printk-formats.txt

If <type> is dependent on a config option for its size (e.g., phys_addr_t) ... use a format specifier of its largest possible type and explicitly cast to it.

So, we'll do just that. We will consider it an unsigned long long, and cast to it explicitly.

Signed-off-by Dave Hansen <[email protected]>

---

 linux-2.6.git-dave/arch/x86/kernel/kvm.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff -puN arch/x86/kernel/kvm.c~fix-32-bit-compile-warning arch/x86/kernel/kvm.c

arch/x86/kernel/kvm.c renamed from arch/x86/kernel/kvm.c~fix-32-bit-compile-warning +2 -2

@@ -298,8 +298,8 @@ static void kvm_register_steal_time(void
 	memset(st, 0, sizeof(*st));
 
 	wrmsrl(MSR_KVM_STEAL_TIME, (slow_virt_to_phys(st) | KVM_MSR_ENABLED));
-	printk(KERN_INFO "kvm-stealtime: cpu %d, msr %lx\n",
-		cpu, slow_virt_to_phys(st));
+	printk(KERN_INFO "kvm-stealtime: cpu %d, msr %llx\n",
+		cpu, (unsigned long long)slow_virt_to_phys(st));
 }
 
 static DEFINE_PER_CPU(unsigned long, kvm_apic_eoi) = KVM_PV_EOI_DISABLED;

_

This warning is still present in linux-next (20130213).

Acked-by Randy Dunlap <[email protected]>

Thanks.

Someone please merge... (kvm@ cc added)