| Message ID | 50C18168.305@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Dec 07, 2012 at 01:40:56PM +0800, Zhang Yanfei wrote: > This removes the sparse warning: > arch/x86/kernel/crash.c:49:32: sparse: incompatible types in comparison expression (different address spaces) > > Reported-by: kbuild test robot <fengguang.wu@intel.com> > Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> > --- > arch/x86/include/asm/kexec.h | 4 +++- > arch/x86/kernel/crash.c | 4 ++-- > 2 files changed, 5 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h > index 28feeba..16882cd 100644 > --- a/arch/x86/include/asm/kexec.h > +++ b/arch/x86/include/asm/kexec.h > @@ -163,7 +163,9 @@ struct kimage_arch { > }; > #endif > > -extern void (*crash_vmclear_loaded_vmcss)(void); > +extern void __rcu (*crash_vmclear_loaded_vmcss)(void); > +#define vmclear_func_rcu(vmclear_func) \ > + ((void (*)(void)) rcu_dereference(vmclear_func)) > > #endif /* __ASSEMBLY__ */ > > diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c > index 2f6b8e8..50ce1d6 100644 > --- a/arch/x86/kernel/crash.c > +++ b/arch/x86/kernel/crash.c > @@ -38,7 +38,7 @@ int in_crash_kexec; > * > * protected by rcu. > */ > -void (*crash_vmclear_loaded_vmcss)(void) = NULL; > +void __rcu (*crash_vmclear_loaded_vmcss)(void) = NULL; Isnt this (__rcu AS tag) sufficient? After all, sparse is complaining about namespaces. Creating a #define to cast seems excessive. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
? 2012?12?11? 04:30, Marcelo Tosatti ??: > On Fri, Dec 07, 2012 at 01:40:56PM +0800, Zhang Yanfei wrote: >> This removes the sparse warning: >> arch/x86/kernel/crash.c:49:32: sparse: incompatible types in comparison expression (different address spaces) >> >> Reported-by: kbuild test robot <fengguang.wu@intel.com> >> Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> >> --- >> arch/x86/include/asm/kexec.h | 4 +++- >> arch/x86/kernel/crash.c | 4 ++-- >> 2 files changed, 5 insertions(+), 3 deletions(-) >> >> diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h >> index 28feeba..16882cd 100644 >> --- a/arch/x86/include/asm/kexec.h >> +++ b/arch/x86/include/asm/kexec.h >> @@ -163,7 +163,9 @@ struct kimage_arch { >> }; >> #endif >> >> -extern void (*crash_vmclear_loaded_vmcss)(void); >> +extern void __rcu (*crash_vmclear_loaded_vmcss)(void); >> +#define vmclear_func_rcu(vmclear_func) \ >> + ((void (*)(void)) rcu_dereference(vmclear_func)) >> >> #endif /* __ASSEMBLY__ */ >> >> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c >> index 2f6b8e8..50ce1d6 100644 >> --- a/arch/x86/kernel/crash.c >> +++ b/arch/x86/kernel/crash.c >> @@ -38,7 +38,7 @@ int in_crash_kexec; >> * >> * protected by rcu. >> */ >> -void (*crash_vmclear_loaded_vmcss)(void) = NULL; >> +void __rcu (*crash_vmclear_loaded_vmcss)(void) = NULL; > > Isnt this (__rcu AS tag) sufficient? After all, sparse is complaining > about namespaces. > > Creating a #define to cast seems excessive. > > I am not very familiar with the rcu. Adding __rcu tag could solve the problem. But it imported another warning when I try to assign rcu_dereference(crash_vmclear_loaded_vmcss) to do_vmclear_operation: arch/x86/kernel/crash.c:49:30: warning: incorrect type in assignment (different modifiers) arch/x86/kernel/crash.c:49:30: expected void ( *do_vmclear_operation )( ... ) arch/x86/kernel/crash.c:49:30: got void ( [noderef] *<noident> )( ... ) arch/x86/kernel/crash.c:49:30: warning: incorrect type in assignment (different modifiers) arch/x86/kernel/crash.c:49:30: expected void ( *do_vmclear_operation )( ... ) arch/x86/kernel/crash.c:49:30: got void ( [noderef] *<noident> )( ... ) So I made the #define to cast its type. If you have any suggestion, that'll be helpful. Thanks Zhang Yanfei -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Dec 11, 2012 at 04:04:55PM +0800, Zhang Yanfei wrote: > ? 2012?12?11? 04:30, Marcelo Tosatti ??: > > On Fri, Dec 07, 2012 at 01:40:56PM +0800, Zhang Yanfei wrote: > >> This removes the sparse warning: > >> arch/x86/kernel/crash.c:49:32: sparse: incompatible types in comparison expression (different address spaces) > >> > >> Reported-by: kbuild test robot <fengguang.wu@intel.com> > >> Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> > >> --- > >> arch/x86/include/asm/kexec.h | 4 +++- > >> arch/x86/kernel/crash.c | 4 ++-- > >> 2 files changed, 5 insertions(+), 3 deletions(-) > >> > >> diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h > >> index 28feeba..16882cd 100644 > >> --- a/arch/x86/include/asm/kexec.h > >> +++ b/arch/x86/include/asm/kexec.h > >> @@ -163,7 +163,9 @@ struct kimage_arch { > >> }; > >> #endif > >> > >> -extern void (*crash_vmclear_loaded_vmcss)(void); > >> +extern void __rcu (*crash_vmclear_loaded_vmcss)(void); > >> +#define vmclear_func_rcu(vmclear_func) \ > >> + ((void (*)(void)) rcu_dereference(vmclear_func)) > >> > >> #endif /* __ASSEMBLY__ */ > >> > >> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c > >> index 2f6b8e8..50ce1d6 100644 > >> --- a/arch/x86/kernel/crash.c > >> +++ b/arch/x86/kernel/crash.c > >> @@ -38,7 +38,7 @@ int in_crash_kexec; > >> * > >> * protected by rcu. > >> */ > >> -void (*crash_vmclear_loaded_vmcss)(void) = NULL; > >> +void __rcu (*crash_vmclear_loaded_vmcss)(void) = NULL; > > > > Isnt this (__rcu AS tag) sufficient? After all, sparse is complaining > > about namespaces. > > > > Creating a #define to cast seems excessive. > > > > > > I am not very familiar with the rcu. > Adding __rcu tag could solve the problem. But it imported another warning > when I try to assign rcu_dereference(crash_vmclear_loaded_vmcss) to > do_vmclear_operation: > > arch/x86/kernel/crash.c:49:30: warning: incorrect type in assignment (different modifiers) > arch/x86/kernel/crash.c:49:30: expected void ( *do_vmclear_operation )( ... ) > arch/x86/kernel/crash.c:49:30: got void ( [noderef] *<noident> )( ... ) > arch/x86/kernel/crash.c:49:30: warning: incorrect type in assignment (different modifiers) > arch/x86/kernel/crash.c:49:30: expected void ( *do_vmclear_operation )( ... ) > arch/x86/kernel/crash.c:49:30: got void ( [noderef] *<noident> )( ... ) > > So I made the #define to cast its type. > > If you have any suggestion, that'll be helpful. > Try to use typedef. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
? 2012?12?11? 16:10, Gleb Natapov ??: > On Tue, Dec 11, 2012 at 04:04:55PM +0800, Zhang Yanfei wrote: >> ? 2012?12?11? 04:30, Marcelo Tosatti ??: >>> On Fri, Dec 07, 2012 at 01:40:56PM +0800, Zhang Yanfei wrote: >>>> This removes the sparse warning: >>>> arch/x86/kernel/crash.c:49:32: sparse: incompatible types in comparison expression (different address spaces) >>>> >>>> Reported-by: kbuild test robot <fengguang.wu@intel.com> >>>> Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> >>>> --- >>>> arch/x86/include/asm/kexec.h | 4 +++- >>>> arch/x86/kernel/crash.c | 4 ++-- >>>> 2 files changed, 5 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h >>>> index 28feeba..16882cd 100644 >>>> --- a/arch/x86/include/asm/kexec.h >>>> +++ b/arch/x86/include/asm/kexec.h >>>> @@ -163,7 +163,9 @@ struct kimage_arch { >>>> }; >>>> #endif >>>> >>>> -extern void (*crash_vmclear_loaded_vmcss)(void); >>>> +extern void __rcu (*crash_vmclear_loaded_vmcss)(void); >>>> +#define vmclear_func_rcu(vmclear_func) \ >>>> + ((void (*)(void)) rcu_dereference(vmclear_func)) >>>> >>>> #endif /* __ASSEMBLY__ */ >>>> >>>> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c >>>> index 2f6b8e8..50ce1d6 100644 >>>> --- a/arch/x86/kernel/crash.c >>>> +++ b/arch/x86/kernel/crash.c >>>> @@ -38,7 +38,7 @@ int in_crash_kexec; >>>> * >>>> * protected by rcu. >>>> */ >>>> -void (*crash_vmclear_loaded_vmcss)(void) = NULL; >>>> +void __rcu (*crash_vmclear_loaded_vmcss)(void) = NULL; >>> >>> Isnt this (__rcu AS tag) sufficient? After all, sparse is complaining >>> about namespaces. >>> >>> Creating a #define to cast seems excessive. >>> >>> >> >> I am not very familiar with the rcu. >> Adding __rcu tag could solve the problem. But it imported another warning >> when I try to assign rcu_dereference(crash_vmclear_loaded_vmcss) to >> do_vmclear_operation: >> >> arch/x86/kernel/crash.c:49:30: warning: incorrect type in assignment (different modifiers) >> arch/x86/kernel/crash.c:49:30: expected void ( *do_vmclear_operation )( ... ) >> arch/x86/kernel/crash.c:49:30: got void ( [noderef] *<noident> )( ... ) >> arch/x86/kernel/crash.c:49:30: warning: incorrect type in assignment (different modifiers) >> arch/x86/kernel/crash.c:49:30: expected void ( *do_vmclear_operation )( ... ) >> arch/x86/kernel/crash.c:49:30: got void ( [noderef] *<noident> )( ... ) >> >> So I made the #define to cast its type. >> >> If you have any suggestion, that'll be helpful. >> > Try to use typedef. > Thanks. typedef works. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h index 28feeba..16882cd 100644 --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -163,7 +163,9 @@ struct kimage_arch { }; #endif -extern void (*crash_vmclear_loaded_vmcss)(void); +extern void __rcu (*crash_vmclear_loaded_vmcss)(void); +#define vmclear_func_rcu(vmclear_func) \ + ((void (*)(void)) rcu_dereference(vmclear_func)) #endif /* __ASSEMBLY__ */ diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index 2f6b8e8..50ce1d6 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -38,7 +38,7 @@ int in_crash_kexec; * * protected by rcu. */ -void (*crash_vmclear_loaded_vmcss)(void) = NULL; +void __rcu (*crash_vmclear_loaded_vmcss)(void) = NULL; EXPORT_SYMBOL_GPL(crash_vmclear_loaded_vmcss); static inline void cpu_crash_vmclear_loaded_vmcss(void) @@ -46,7 +46,7 @@ static inline void cpu_crash_vmclear_loaded_vmcss(void) void (*do_vmclear_operation)(void) = NULL; rcu_read_lock(); - do_vmclear_operation = rcu_dereference(crash_vmclear_loaded_vmcss); + do_vmclear_operation = vmclear_func_rcu(crash_vmclear_loaded_vmcss); if (do_vmclear_operation) do_vmclear_operation(); rcu_read_unlock();
This removes the sparse warning: arch/x86/kernel/crash.c:49:32: sparse: incompatible types in comparison expression (different address spaces) Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> --- arch/x86/include/asm/kexec.h | 4 +++- arch/x86/kernel/crash.c | 4 ++-- 2 files changed, 5 insertions(+), 3 deletions(-)