[PATCH next] KVM: Fix debugfs_simple_attr.cocci warnings

From: Chen Wandun
Date: Mon Dec 23 2019 - 20:34:21 EST


Use DEFINE_DEBUGFS_ATTRIBUTE rather than DEFINE_SIMPLE_ATTRIBUTE
for debugfs files.

Semantic patch information:
Rationale: DEFINE_SIMPLE_ATTRIBUTE + debugfs_create_file()
imposes some significant overhead as compared to
DEFINE_DEBUGFS_ATTRIBUTE + debugfs_create_file_unsafe().

Signed-off-by: Chen Wandun <chenwandun@xxxxxxxxxx>
---
arch/x86/kvm/debugfs.c | 34 +++++++++++++++++++---------------
1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kvm/debugfs.c b/arch/x86/kvm/debugfs.c
index 018aebc..0867d7d 100644
--- a/arch/x86/kvm/debugfs.c
+++ b/arch/x86/kvm/debugfs.c
@@ -15,7 +15,8 @@ static int vcpu_get_timer_advance_ns(void *data, u64 *val)
return 0;
}

-DEFINE_SIMPLE_ATTRIBUTE(vcpu_timer_advance_ns_fops, vcpu_get_timer_advance_ns, NULL, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(vcpu_timer_advance_ns_fops,
+ vcpu_get_timer_advance_ns, NULL, "%llu\n");

static int vcpu_get_tsc_offset(void *data, u64 *val)
{
@@ -24,7 +25,8 @@ static int vcpu_get_tsc_offset(void *data, u64 *val)
return 0;
}

-DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_offset_fops, vcpu_get_tsc_offset, NULL, "%lld\n");
+DEFINE_DEBUGFS_ATTRIBUTE(vcpu_tsc_offset_fops, vcpu_get_tsc_offset, NULL,
+ "%lld\n");

static int vcpu_get_tsc_scaling_ratio(void *data, u64 *val)
{
@@ -33,7 +35,8 @@ static int vcpu_get_tsc_scaling_ratio(void *data, u64 *val)
return 0;
}

-DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_scaling_fops, vcpu_get_tsc_scaling_ratio, NULL, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(vcpu_tsc_scaling_fops, vcpu_get_tsc_scaling_ratio,
+ NULL, "%llu\n");

static int vcpu_get_tsc_scaling_frac_bits(void *data, u64 *val)
{
@@ -41,24 +44,25 @@ static int vcpu_get_tsc_scaling_frac_bits(void *data, u64 *val)
return 0;
}

-DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_scaling_frac_fops, vcpu_get_tsc_scaling_frac_bits, NULL, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(vcpu_tsc_scaling_frac_fops,
+ vcpu_get_tsc_scaling_frac_bits, NULL, "%llu\n");

void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
{
- debugfs_create_file("tsc-offset", 0444, vcpu->debugfs_dentry, vcpu,
- &vcpu_tsc_offset_fops);
+ debugfs_create_file_unsafe("tsc-offset", 0444, vcpu->debugfs_dentry,
+ vcpu, &vcpu_tsc_offset_fops);

if (lapic_in_kernel(vcpu))
- debugfs_create_file("lapic_timer_advance_ns", 0444,
- vcpu->debugfs_dentry, vcpu,
- &vcpu_timer_advance_ns_fops);
+ debugfs_create_file_unsafe("lapic_timer_advance_ns", 0444,
+ vcpu->debugfs_dentry, vcpu,
+ &vcpu_timer_advance_ns_fops);

if (kvm_has_tsc_control) {
- debugfs_create_file("tsc-scaling-ratio", 0444,
- vcpu->debugfs_dentry, vcpu,
- &vcpu_tsc_scaling_fops);
- debugfs_create_file("tsc-scaling-ratio-frac-bits", 0444,
- vcpu->debugfs_dentry, vcpu,
- &vcpu_tsc_scaling_frac_fops);
+ debugfs_create_file_unsafe("tsc-scaling-ratio", 0444,
+ vcpu->debugfs_dentry, vcpu,
+ &vcpu_tsc_scaling_fops);
+ debugfs_create_file_unsafe("tsc-scaling-ratio-frac-bits", 0444,
+ vcpu->debugfs_dentry, vcpu,
+ &vcpu_tsc_scaling_frac_fops);
}
}
--
2.7.4