* [kvm:queue 27/38] arch/x86/kvm/hyperv.c:186:41: sparse: incorrect type in argument 2 (different modifiers)
@ 2015-09-18 13:39 kbuild test robot
2015-09-18 13:51 ` Denis V. Lunev
0 siblings, 1 reply; 8+ messages in thread
From: kbuild test robot @ 2015-09-18 13:39 UTC (permalink / raw)
To: Andrey Smetanin
Cc: kbuild-all, Paolo Bonzini, Roman Kagan, Denis V. Lunev, kvm
tree: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue
head: ed393e4134de0dd02d8ba98ca8ce3ae65d1eb567
commit: 46f4c309534b10ca1026273abe38955d3cff4023 [27/38] kvm/x86: Hyper-V HV_X64_MSR_VP_RUNTIME support
reproduce:
# apt-get install sparse
git checkout 46f4c309534b10ca1026273abe38955d3cff4023
make ARCH=x86_64 allmodconfig
make C=1 CF=-D__CHECK_ENDIAN__
sparse warnings: (new ones prefixed by >>)
>> arch/x86/kvm/hyperv.c:186:41: sparse: incorrect type in argument 2 (different modifiers)
arch/x86/kvm/hyperv.c:186:41: expected unsigned long [nocast] [usertype] *ut
arch/x86/kvm/hyperv.c:186:41: got unsigned long *<noident>
>> arch/x86/kvm/hyperv.c:186:41: sparse: implicit cast to nocast type
>> arch/x86/kvm/hyperv.c:186:49: sparse: incorrect type in argument 3 (different modifiers)
arch/x86/kvm/hyperv.c:186:49: expected unsigned long [nocast] [usertype] *st
arch/x86/kvm/hyperv.c:186:49: got unsigned long *<noident>
arch/x86/kvm/hyperv.c:186:49: sparse: implicit cast to nocast type
vim +186 arch/x86/kvm/hyperv.c
170 kvm_make_request(KVM_REQ_HV_RESET, vcpu);
171 }
172 break;
173 default:
174 vcpu_unimpl(vcpu, "Hyper-V uhandled wrmsr: 0x%x data 0x%llx\n",
175 msr, data);
176 return 1;
177 }
178 return 0;
179 }
180
181 /* Calculate cpu time spent by current task in 100ns units */
182 static u64 current_task_runtime_100ns(void)
183 {
184 cputime_t utime, stime;
185
> 186 task_cputime_adjusted(current, &utime, &stime);
187 return div_u64(cputime_to_nsecs(utime + stime), 100);
188 }
189
190 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
191 {
192 struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
193
194 switch (msr) {
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [kvm:queue 27/38] arch/x86/kvm/hyperv.c:186:41: sparse: incorrect type in argument 2 (different modifiers)
2015-09-18 13:39 [kvm:queue 27/38] arch/x86/kvm/hyperv.c:186:41: sparse: incorrect type in argument 2 (different modifiers) kbuild test robot
@ 2015-09-18 13:51 ` Denis V. Lunev
2015-09-18 13:55 ` Paolo Bonzini
0 siblings, 1 reply; 8+ messages in thread
From: Denis V. Lunev @ 2015-09-18 13:51 UTC (permalink / raw)
To: kbuild test robot, Andrey Smetanin
Cc: kbuild-all, Paolo Bonzini, Roman Kagan, kvm
On 09/18/2015 04:39 PM, kbuild test robot wrote:
> tree: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue
> head: ed393e4134de0dd02d8ba98ca8ce3ae65d1eb567
> commit: 46f4c309534b10ca1026273abe38955d3cff4023 [27/38] kvm/x86: Hyper-V HV_X64_MSR_VP_RUNTIME support
> reproduce:
> # apt-get install sparse
> git checkout 46f4c309534b10ca1026273abe38955d3cff4023
> make ARCH=x86_64 allmodconfig
> make C=1 CF=-D__CHECK_ENDIAN__
>
>
> sparse warnings: (new ones prefixed by >>)
>
>>> arch/x86/kvm/hyperv.c:186:41: sparse: incorrect type in argument 2 (different modifiers)
> arch/x86/kvm/hyperv.c:186:41: expected unsigned long [nocast] [usertype] *ut
> arch/x86/kvm/hyperv.c:186:41: got unsigned long *<noident>
>>> arch/x86/kvm/hyperv.c:186:41: sparse: implicit cast to nocast type
>>> arch/x86/kvm/hyperv.c:186:49: sparse: incorrect type in argument 3 (different modifiers)
> arch/x86/kvm/hyperv.c:186:49: expected unsigned long [nocast] [usertype] *st
> arch/x86/kvm/hyperv.c:186:49: got unsigned long *<noident>
> arch/x86/kvm/hyperv.c:186:49: sparse: implicit cast to nocast type
>
> vim +186 arch/x86/kvm/hyperv.c
>
> 170 kvm_make_request(KVM_REQ_HV_RESET, vcpu);
> 171 }
> 172 break;
> 173 default:
> 174 vcpu_unimpl(vcpu, "Hyper-V uhandled wrmsr: 0x%x data 0x%llx\n",
> 175 msr, data);
> 176 return 1;
> 177 }
> 178 return 0;
> 179 }
> 180
> 181 /* Calculate cpu time spent by current task in 100ns units */
> 182 static u64 current_task_runtime_100ns(void)
> 183 {
> 184 cputime_t utime, stime;
> 185
> > 186 task_cputime_adjusted(current, &utime, &stime);
> 187 return div_u64(cputime_to_nsecs(utime + stime), 100);
> 188 }
> 189
> 190 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
> 191 {
> 192 struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
> 193
> 194 switch (msr) {
>
> ---
> 0-DAY kernel test infrastructure Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all Intel Corporation
can not get an idea what is this warning about...
For me it looks pretty lame.
Den
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [kvm:queue 27/38] arch/x86/kvm/hyperv.c:186:41: sparse: incorrect type in argument 2 (different modifiers)
2015-09-18 13:51 ` Denis V. Lunev
@ 2015-09-18 13:55 ` Paolo Bonzini
2015-09-18 13:57 ` Denis V. Lunev
2015-09-18 14:40 ` Roman Kagan
0 siblings, 2 replies; 8+ messages in thread
From: Paolo Bonzini @ 2015-09-18 13:55 UTC (permalink / raw)
To: Denis V. Lunev, kbuild test robot, Andrey Smetanin
Cc: kbuild-all, Roman Kagan, kvm
On 18/09/2015 15:51, Denis V. Lunev wrote:
>> 185
>> > 186 task_cputime_adjusted(current, &utime, &stime);
>> 187 return div_u64(cputime_to_nsecs(utime + stime), 100);
>> 188 }
>> 189
>> 190 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr,
>> u64 data, bool host)
>> 191 {
>> 192 struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
>> 193
>> 194 switch (msr) {
>>
>> ---
>> 0-DAY kernel test infrastructure Open Source Technology
>> Center
>> https://lists.01.org/pipermail/kbuild-all Intel
>> Corporation
> can not get an idea what is this warning about...
> For me it looks pretty lame.
I think it wants you to do
- return div_u64(cputime_to_nsecs(utime + stime), 100);
+ return div_u64(cputime_to_nsecs(utime) +
+ cputime_to_nsecs(stime), 100);
Paolo
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [kvm:queue 27/38] arch/x86/kvm/hyperv.c:186:41: sparse: incorrect type in argument 2 (different modifiers)
2015-09-18 13:55 ` Paolo Bonzini
@ 2015-09-18 13:57 ` Denis V. Lunev
2015-09-18 14:40 ` Roman Kagan
1 sibling, 0 replies; 8+ messages in thread
From: Denis V. Lunev @ 2015-09-18 13:57 UTC (permalink / raw)
To: Paolo Bonzini, kbuild test robot, Andrey Smetanin
Cc: kbuild-all, Roman Kagan, kvm
On 09/18/2015 04:55 PM, Paolo Bonzini wrote:
>
> On 18/09/2015 15:51, Denis V. Lunev wrote:
>>> 185
>>> > 186 task_cputime_adjusted(current, &utime, &stime);
>>> 187 return div_u64(cputime_to_nsecs(utime + stime), 100);
>>> 188 }
>>> 189
>>> 190 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr,
>>> u64 data, bool host)
>>> 191 {
>>> 192 struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
>>> 193
>>> 194 switch (msr) {
>>>
>>> ---
>>> 0-DAY kernel test infrastructure Open Source Technology
>>> Center
>>> https://lists.01.org/pipermail/kbuild-all Intel
>>> Corporation
>> can not get an idea what is this warning about...
>> For me it looks pretty lame.
> I think it wants you to do
>
> - return div_u64(cputime_to_nsecs(utime + stime), 100);
> + return div_u64(cputime_to_nsecs(utime) +
> + cputime_to_nsecs(stime), 100);
>
> Paolo
ok, I'll check but warning points here
> 186 task_cputime_adjusted(current, &utime, &stime);
and says about parameters 2 and 3. There is no parameter 3
in div_u64 call :)
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [kvm:queue 27/38] arch/x86/kvm/hyperv.c:186:41: sparse: incorrect type in argument 2 (different modifiers)
2015-09-18 13:55 ` Paolo Bonzini
2015-09-18 13:57 ` Denis V. Lunev
@ 2015-09-18 14:40 ` Roman Kagan
2015-09-18 14:41 ` Paolo Bonzini
1 sibling, 1 reply; 8+ messages in thread
From: Roman Kagan @ 2015-09-18 14:40 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Denis V. Lunev, kbuild test robot, Andrey Smetanin, kbuild-all,
kvm
On Fri, Sep 18, 2015 at 03:55:00PM +0200, Paolo Bonzini wrote:
>
>
> On 18/09/2015 15:51, Denis V. Lunev wrote:
> >> 185
> >> > 186 task_cputime_adjusted(current, &utime, &stime);
> >> 187 return div_u64(cputime_to_nsecs(utime + stime), 100);
> >> 188 }
> >> 189
> >> 190 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr,
> >> u64 data, bool host)
> >> 191 {
> >> 192 struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
> >> 193
> >> 194 switch (msr) {
> >>
> >> ---
> >> 0-DAY kernel test infrastructure Open Source Technology
> >> Center
> >> https://lists.01.org/pipermail/kbuild-all Intel
> >> Corporation
> > can not get an idea what is this warning about...
> > For me it looks pretty lame.
>
> I think it wants you to do
>
> - return div_u64(cputime_to_nsecs(utime + stime), 100);
> + return div_u64(cputime_to_nsecs(utime) +
> + cputime_to_nsecs(stime), 100);
The warning is pretty specific about the point where it triggered.
I have reduced it to the following standalone reproducer:
%%% cat x.c
#ifdef __CHECKER__
# define __nocast __attribute__((nocast))
#else
# define __nocast
#endif
typedef unsigned long __nocast cputime_t;
extern void task_cputime_adjusted(cputime_t *);
extern void current_task_runtime_100ns(void);
void current_task_runtime_100ns(void)
{
cputime_t utime;
task_cputime_adjusted(&utime);
}
%%% gcc -c x.c -Wall -Werror -O2; echo $?
0
%%% sparse x.c
x.c:16:32: warning: incorrect type in argument 1 (different modifiers)
x.c:16:32: expected unsigned long [nocast] [usertype] *<noident>
x.c:16:32: got unsigned long *<noident>
x.c:16:32: warning: implicit cast to nocast type
Looks like a sparse bug to me.
Roman.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [kvm:queue 27/38] arch/x86/kvm/hyperv.c:186:41: sparse: incorrect type in argument 2 (different modifiers)
2015-09-18 14:40 ` Roman Kagan
@ 2015-09-18 14:41 ` Paolo Bonzini
2015-09-18 15:06 ` [kbuild-all] " Fengguang Wu
0 siblings, 1 reply; 8+ messages in thread
From: Paolo Bonzini @ 2015-09-18 14:41 UTC (permalink / raw)
To: Roman Kagan, Denis V. Lunev, kbuild test robot, Andrey Smetanin,
kbuild-all, kvm
On 18/09/2015 16:40, Roman Kagan wrote:
> typedef unsigned long __nocast cputime_t;
>
> extern void task_cputime_adjusted(cputime_t *);
> extern void current_task_runtime_100ns(void);
>
> void current_task_runtime_100ns(void)
> {
> cputime_t utime;
>
> task_cputime_adjusted(&utime);
> }
> %%% gcc -c x.c -Wall -Werror -O2; echo $?
> 0
> %%% sparse x.c
> x.c:16:32: warning: incorrect type in argument 1 (different modifiers)
> x.c:16:32: expected unsigned long [nocast] [usertype] *<noident>
> x.c:16:32: got unsigned long *<noident>
> x.c:16:32: warning: implicit cast to nocast type
>
> Looks like a sparse bug to me.
Indeed...
Paolo
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [kbuild-all] [kvm:queue 27/38] arch/x86/kvm/hyperv.c:186:41: sparse: incorrect type in argument 2 (different modifiers)
2015-09-18 14:41 ` Paolo Bonzini
@ 2015-09-18 15:06 ` Fengguang Wu
2016-01-05 13:51 ` Luc Van Oostenryck
0 siblings, 1 reply; 8+ messages in thread
From: Fengguang Wu @ 2015-09-18 15:06 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Roman Kagan, Denis V. Lunev, Andrey Smetanin, kbuild-all, kvm,
Christopher Li, Linux-Sparse
[CC sparse people]
On Fri, Sep 18, 2015 at 04:41:56PM +0200, Paolo Bonzini wrote:
>
>
> On 18/09/2015 16:40, Roman Kagan wrote:
> > typedef unsigned long __nocast cputime_t;
> >
> > extern void task_cputime_adjusted(cputime_t *);
> > extern void current_task_runtime_100ns(void);
> >
> > void current_task_runtime_100ns(void)
> > {
> > cputime_t utime;
> >
> > task_cputime_adjusted(&utime);
> > }
> > %%% gcc -c x.c -Wall -Werror -O2; echo $?
> > 0
> > %%% sparse x.c
> > x.c:16:32: warning: incorrect type in argument 1 (different modifiers)
> > x.c:16:32: expected unsigned long [nocast] [usertype] *<noident>
> > x.c:16:32: got unsigned long *<noident>
> > x.c:16:32: warning: implicit cast to nocast type
> >
> > Looks like a sparse bug to me.
>
> Indeed...
>
> Paolo
> _______________________________________________
> kbuild-all mailing list
> kbuild-all@lists.01.org
> https://lists.01.org/mailman/listinfo/kbuild-all
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [kbuild-all] [kvm:queue 27/38] arch/x86/kvm/hyperv.c:186:41: sparse: incorrect type in argument 2 (different modifiers)
2015-09-18 15:06 ` [kbuild-all] " Fengguang Wu
@ 2016-01-05 13:51 ` Luc Van Oostenryck
0 siblings, 0 replies; 8+ messages in thread
From: Luc Van Oostenryck @ 2016-01-05 13:51 UTC (permalink / raw)
To: Fengguang Wu
Cc: Paolo Bonzini, Roman Kagan, Denis V. Lunev, Andrey Smetanin,
kbuild-all, kvm, Christopher Li, Linux-Sparse
On Fri, Sep 18, 2015 at 11:06:44PM +0800, Fengguang Wu wrote:
> [CC sparse people]
>
> On Fri, Sep 18, 2015 at 04:41:56PM +0200, Paolo Bonzini wrote:
> >
> >
> > On 18/09/2015 16:40, Roman Kagan wrote:
> > > typedef unsigned long __nocast cputime_t;
> > >
> > > extern void task_cputime_adjusted(cputime_t *);
> > > extern void current_task_runtime_100ns(void);
> > >
> > > void current_task_runtime_100ns(void)
> > > {
> > > cputime_t utime;
> > >
> > > task_cputime_adjusted(&utime);
> > > }
> > > %%% gcc -c x.c -Wall -Werror -O2; echo $?
> > > 0
> > > %%% sparse x.c
> > > x.c:16:32: warning: incorrect type in argument 1 (different modifiers)
> > > x.c:16:32: expected unsigned long [nocast] [usertype] *<noident>
> > > x.c:16:32: got unsigned long *<noident>
> > > x.c:16:32: warning: implicit cast to nocast type
> > >
> > > Looks like a sparse bug to me.
> >
> > Indeed...
> >
> > Paolo
The problem is that the intent and semantic of 'nocast' is not clear at all.
There is an explanation about 'nocast' vs. 'bitwise' here:
https://git.kernel.org/cgit/devel/sparse/sparse.git/tree/Documentation/sparse.txt
but it doesn't give much info about the exact wanted behaviour.
Since for the kernel 'nocast' is only used for cputime_t & cputime64_t,
I think it should be clarified and fixed if needed.
A patch proposal is following.
Regards,
Luc
^ permalink raw reply [flat|nested] 8+ messages in thread
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2015-09-18 13:39 [kvm:queue 27/38] arch/x86/kvm/hyperv.c:186:41: sparse: incorrect type in argument 2 (different modifiers) kbuild test robot
2015-09-18 13:51 ` Denis V. Lunev
2015-09-18 13:55 ` Paolo Bonzini
2015-09-18 13:57 ` Denis V. Lunev
2015-09-18 14:40 ` Roman Kagan
2015-09-18 14:41 ` Paolo Bonzini
2015-09-18 15:06 ` [kbuild-all] " Fengguang Wu
2016-01-05 13:51 ` Luc Van Oostenryck
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