[PATCH] fix 32-bit compile warning from printk()

[PATCH] fix 32-bit compile warning from printk()

[Dave Hansen]

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 <dave@linux.vnet.ibm.com>
---

 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
--- linux-2.6.git/arch/x86/kernel/kvm.c~fix-32-bit-compile-warning	2013-01-28 11:16:39.786938232 -0800
+++ linux-2.6.git-dave/arch/x86/kernel/kvm.c	2013-01-28 11:16:39.790938273 -0800
@@ -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;
_

Re: [PATCH] fix 32-bit compile warning from printk()

[Andrew Morton]

On Mon, 28 Jan 2013 11:19:39 -0800 Dave Hansen <dave@linux.vnet.ibm.com> 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.
> 
> 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.

Re: [PATCH] fix 32-bit compile warning from printk()

[Andrew Morton]

On Tue, 29 Jan 2013 02:54:28 -0800 Andrew Morton <akpm@linux-foundation.org> wrote:

> On Mon, 28 Jan 2013 11:19:39 -0800 Dave Hansen <dave@linux.vnet.ibm.com> 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.
> > 
> > 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.
> 

err, I meant 3.9.  

Re: [PATCH] fix 32-bit compile warning from printk()

[Randy Dunlap]

On 01/28/13 11:19, Dave Hansen 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.
> 
> So, we'll do just that.  We will consider it an unsigned long
> long, and cast to it explicitly.
> 
> Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>

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

Acked-by: Randy Dunlap <rdunlap@infradead.org>

Thanks.

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

> ---
> 
>  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
> --- linux-2.6.git/arch/x86/kernel/kvm.c~fix-32-bit-compile-warning	2013-01-28 11:16:39.786938232 -0800
> +++ linux-2.6.git-dave/arch/x86/kernel/kvm.c	2013-01-28 11:16:39.790938273 -0800
> @@ -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;
> _



-- 
~Randy

Re: [PATCH] fix 32-bit compile warning from printk()

[Borislav Petkov]

On Wed, Feb 13, 2013 at 08:31:00AM -0800, Randy Dunlap wrote:
> This warning is still present in linux-next (20130213).
> 
> Acked-by: Randy Dunlap <rdunlap@infradead.org>
> 
> Thanks.
> 
> Someone please merge...  (kvm@ cc added)

There's a fix already in tip for this:

http://git.kernel.org/tip/136867f517cbc3f8a91f035677911a6b503c3323

which needs to change again once the %pa printk stuff get merged.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--