From fa93384f40deeb294fd29f2fdcadbd0ebc2dedf1 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 23 May 2014 13:20:42 +0300 Subject: [PATCH] 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 Reviewed-by: Raghavendra Signed-off-by: Peter Zijlstra Cc: Gleb Natapov Cc: Linus Torvalds Cc: Paolo Bonzini Cc: kvm@vger.kernel.org Link: http://lkml.kernel.org/r/20140523102042.GA7267@mwanda Signed-off-by: Ingo Molnar --- include/linux/kvm_host.h | 2 +- include/linux/sched.h | 2 +- kernel/sched/core.c | 2 +- virt/kvm/kvm_main.c | 4 ++-- 4 files changed, 5 insertions(+), 5 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 7d21cf9..3c4bcf1 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -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); diff --git a/include/linux/sched.h b/include/linux/sched.h index 0f91d00..6790c3b 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -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); /** diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 321d800..afcc842 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -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; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 56baae8..86d1c45 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -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); -- 2.7.4