sched: Fix signedness bug in yield_to()

yield_to() is supposed to return -ESRCH if there is no task to
yield to, but because the type is bool that is the same as returning
true.

The only place I see which cares is kvm_vcpu_on_spin().

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Raghavendra <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Link: http://lkml.kernel.org/r/20140523102042.GA7267@mwanda
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Dan Carpenter 2014-05-23 13:20:42 +03:00 committed by Ingo Molnar
parent 2538d960d0
commit fa93384f40
4 changed files with 5 additions and 5 deletions

View file

@ -584,7 +584,7 @@ void mark_page_dirty(struct kvm *kvm, gfn_t gfn);
void kvm_vcpu_block(struct kvm_vcpu *vcpu);
void kvm_vcpu_kick(struct kvm_vcpu *vcpu);
bool kvm_vcpu_yield_to(struct kvm_vcpu *target);
int kvm_vcpu_yield_to(struct kvm_vcpu *target);
void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu);
void kvm_load_guest_fpu(struct kvm_vcpu *vcpu);
void kvm_put_guest_fpu(struct kvm_vcpu *vcpu);

View file

@ -2180,7 +2180,7 @@ static inline void sched_autogroup_fork(struct signal_struct *sig) { }
static inline void sched_autogroup_exit(struct signal_struct *sig) { }
#endif
extern bool yield_to(struct task_struct *p, bool preempt);
extern int yield_to(struct task_struct *p, bool preempt);
extern void set_user_nice(struct task_struct *p, long nice);
extern int task_prio(const struct task_struct *p);
/**

View file

@ -4195,7 +4195,7 @@ EXPORT_SYMBOL(yield);
* false (0) if we failed to boost the target.
* -ESRCH if there's no task to yield to.
*/
bool __sched yield_to(struct task_struct *p, bool preempt)
int __sched yield_to(struct task_struct *p, bool preempt)
{
struct task_struct *curr = current;
struct rq *rq, *p_rq;

View file

@ -1708,11 +1708,11 @@ void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
EXPORT_SYMBOL_GPL(kvm_vcpu_kick);
#endif /* !CONFIG_S390 */
bool kvm_vcpu_yield_to(struct kvm_vcpu *target)
int kvm_vcpu_yield_to(struct kvm_vcpu *target)
{
struct pid *pid;
struct task_struct *task = NULL;
bool ret = false;
int ret = 0;
rcu_read_lock();
pid = rcu_dereference(target->pid);