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kvm: drop parameter validation

PATCH Superseded Michael S. Tsirkin 3 participants 5 messages Aug 13, 2012 – Aug 14, 2012

Subsystems (3)

v1 of 2 Superseded Latest is v2 →

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#0 lore raw

PATCH 1/1 kvm: drop parameter validation

We validate irq pin number when routing is setup, so code handling illegal irq # in pic and ioapic on each injection is never called.
Drop it.

---

Reposting, applies without changes to kvm/next.

 arch/x86/kvm/i8259.c | 16 +++++++---------
 virt/kvm/ioapic.c    | 35 +++++++++++++++++------------------
 2 files changed, 24 insertions(+), 27 deletions(-)
arch/x86/kvm/i8259.c +7 -9
index 1df8fb9..277ec0d 100644
@@ -190,17 +190,15 @@ void kvm_pic_update_irq(struct kvm_pic *s)
 
 int kvm_pic_set_irq(struct kvm_pic *s, int irq, int irq_source_id, int level)
 {
-	int ret = -1;
+	int ret, irq_level;
 
 	pic_lock(s);
-	if (irq >= 0 && irq < PIC_NUM_PINS) {
-		int irq_level = __kvm_irq_line_state(&s->irq_states[irq],
-						     irq_source_id, level);
-		ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
-		pic_update_irq(s);
-		trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
-				      s->pics[irq >> 3].imr, ret == 0);
-	}
+	irq_level = __kvm_irq_line_state(&s->irq_states[irq],
+					 irq_source_id, level);
+	ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
+	pic_update_irq(s);
+	trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
+			      s->pics[irq >> 3].imr, ret == 0);
 	pic_unlock(s);
 
 	return ret;
virt/kvm/ioapic.c +17 -18
index ef61d52..4d824c7 100644
@@ -197,28 +197,27 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
 	u32 old_irr;
 	u32 mask = 1 << irq;
 	union kvm_ioapic_redirect_entry entry;
-	int ret = 1;
+	int ret, irq_level;
 
 	spin_lock(&ioapic->lock);
 	old_irr = ioapic->irr;
-	if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
-		int irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
-						     irq_source_id, level);
-		entry = ioapic->redirtbl[irq];
-		irq_level ^= entry.fields.polarity;
-		if (!irq_level)
-			ioapic->irr &= ~mask;
-		else {
-			int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
-			ioapic->irr |= mask;
-			if ((edge && old_irr != ioapic->irr) ||
-			    (!edge && !entry.fields.remote_irr))
-				ret = ioapic_service(ioapic, irq);
-			else
-				ret = 0; /* report coalesced interrupt */
-		}
-		trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
+	irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
+					 irq_source_id, level);
+	entry = ioapic->redirtbl[irq];
+	irq_level ^= entry.fields.polarity;
+	if (!irq_level) {
+		ioapic->irr &= ~mask;
+		ret = 1;
+	} else {
+		int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
+		ioapic->irr |= mask;
+		if ((edge && old_irr != ioapic->irr) ||
+		    (!edge && !entry.fields.remote_irr))
+			ret = ioapic_service(ioapic, irq);
+		else
+			ret = 0; /* report coalesced interrupt */
 	}
+	trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
 	spin_unlock(&ioapic->lock);
 
 	return ret;
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#1 lore raw
Quoted 5 lines · Michael S. Tsirkin

We validate irq pin number when routing is setup, so code handling illegal irq # in pic and ioapic on each injection is never called.
Drop it.

I would leave BUG_ON there for a while.

Quoted 90 lines

---

Reposting, applies without changes to kvm/next.

 arch/x86/kvm/i8259.c | 16 +++++++---------
 virt/kvm/ioapic.c    | 35 +++++++++++++++++------------------
 2 files changed, 24 insertions(+), 27 deletions(-)
arch/x86/kvm/i8259.c +7 -9
index 1df8fb9..277ec0d 100644
@@ -190,17 +190,15 @@ void kvm_pic_update_irq(struct kvm_pic *s)
 
 int kvm_pic_set_irq(struct kvm_pic *s, int irq, int irq_source_id, int level)
 {
-	int ret = -1;
+	int ret, irq_level;
 
 	pic_lock(s);
-	if (irq >= 0 && irq < PIC_NUM_PINS) {
-		int irq_level = __kvm_irq_line_state(&s->irq_states[irq],
-						     irq_source_id, level);
-		ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
-		pic_update_irq(s);
-		trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
-				      s->pics[irq >> 3].imr, ret == 0);
-	}
+	irq_level = __kvm_irq_line_state(&s->irq_states[irq],
+					 irq_source_id, level);
+	ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
+	pic_update_irq(s);
+	trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
+			      s->pics[irq >> 3].imr, ret == 0);
 	pic_unlock(s);
 
 	return ret;
virt/kvm/ioapic.c +17 -18
index ef61d52..4d824c7 100644
@@ -197,28 +197,27 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
 	u32 old_irr;
 	u32 mask = 1 << irq;
 	union kvm_ioapic_redirect_entry entry;
-	int ret = 1;
+	int ret, irq_level;
 
 	spin_lock(&ioapic->lock);
 	old_irr = ioapic->irr;
-	if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
-		int irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
-						     irq_source_id, level);
-		entry = ioapic->redirtbl[irq];
-		irq_level ^= entry.fields.polarity;
-		if (!irq_level)
-			ioapic->irr &= ~mask;
-		else {
-			int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
-			ioapic->irr |= mask;
-			if ((edge && old_irr != ioapic->irr) ||
-			    (!edge && !entry.fields.remote_irr))
-				ret = ioapic_service(ioapic, irq);
-			else
-				ret = 0; /* report coalesced interrupt */
-		}
-		trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
+	irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
+					 irq_source_id, level);
+	entry = ioapic->redirtbl[irq];
+	irq_level ^= entry.fields.polarity;
+	if (!irq_level) {
+		ioapic->irr &= ~mask;
+		ret = 1;
+	} else {
+		int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
+		ioapic->irr |= mask;
+		if ((edge && old_irr != ioapic->irr) ||
+		    (!edge && !entry.fields.remote_irr))
+			ret = ioapic_service(ioapic, irq);
+		else
+			ret = 0; /* report coalesced interrupt */
 	}
+	trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
 	spin_unlock(&ioapic->lock);
 
 	return ret;
Signature · 1 line
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#2 lore raw
Quoted 7 lines · Gleb Natapov
Quoted 5 lines · Michael S. Tsirkin

We validate irq pin number when routing is setup, so code handling illegal irq # in pic and ioapic on each injection is never called.
Drop it.

I would leave BUG_ON there for a while.

Which BUG_ON?

Quoted 98 lines
Quoted 91 lines

---

Reposting, applies without changes to kvm/next.

 arch/x86/kvm/i8259.c | 16 +++++++---------
 virt/kvm/ioapic.c    | 35 +++++++++++++++++------------------
 2 files changed, 24 insertions(+), 27 deletions(-)
arch/x86/kvm/i8259.c +7 -9
index 1df8fb9..277ec0d 100644
@@ -190,17 +190,15 @@ void kvm_pic_update_irq(struct kvm_pic *s)
 
 int kvm_pic_set_irq(struct kvm_pic *s, int irq, int irq_source_id, int level)
 {
-	int ret = -1;
+	int ret, irq_level;
 
 	pic_lock(s);
-	if (irq >= 0 && irq < PIC_NUM_PINS) {
-		int irq_level = __kvm_irq_line_state(&s->irq_states[irq],
-						     irq_source_id, level);
-		ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
-		pic_update_irq(s);
-		trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
-				      s->pics[irq >> 3].imr, ret == 0);
-	}
+	irq_level = __kvm_irq_line_state(&s->irq_states[irq],
+					 irq_source_id, level);
+	ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
+	pic_update_irq(s);
+	trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
+			      s->pics[irq >> 3].imr, ret == 0);
 	pic_unlock(s);
 
 	return ret;
virt/kvm/ioapic.c +17 -18
index ef61d52..4d824c7 100644
@@ -197,28 +197,27 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
 	u32 old_irr;
 	u32 mask = 1 << irq;
 	union kvm_ioapic_redirect_entry entry;
-	int ret = 1;
+	int ret, irq_level;
 
 	spin_lock(&ioapic->lock);
 	old_irr = ioapic->irr;
-	if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
-		int irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
-						     irq_source_id, level);
-		entry = ioapic->redirtbl[irq];
-		irq_level ^= entry.fields.polarity;
-		if (!irq_level)
-			ioapic->irr &= ~mask;
-		else {
-			int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
-			ioapic->irr |= mask;
-			if ((edge && old_irr != ioapic->irr) ||
-			    (!edge && !entry.fields.remote_irr))
-				ret = ioapic_service(ioapic, irq);
-			else
-				ret = 0; /* report coalesced interrupt */
-		}
-		trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
+	irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
+					 irq_source_id, level);
+	entry = ioapic->redirtbl[irq];
+	irq_level ^= entry.fields.polarity;
+	if (!irq_level) {
+		ioapic->irr &= ~mask;
+		ret = 1;
+	} else {
+		int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
+		ioapic->irr |= mask;
+		if ((edge && old_irr != ioapic->irr) ||
+		    (!edge && !entry.fields.remote_irr))
+			ret = ioapic_service(ioapic, irq);
+		else
+			ret = 0; /* report coalesced interrupt */
 	}
+	trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
 	spin_unlock(&ioapic->lock);
 
 	return ret;
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#3 lore raw
Quoted 11 lines · Marcelo Tosatti
Quoted 7 lines · Gleb Natapov
Quoted 5 lines · Michael S. Tsirkin

We validate irq pin number when routing is setup, so code handling illegal irq # in pic and ioapic on each injection is never called.
Drop it.

I would leave BUG_ON there for a while.

Which BUG_ON?

I mean changing if() to BUG_ON().

BUG_ON (!(irq >= 0 && irq < PIC_NUM_PINS))

Quoted 88 lines
Quoted 88 lines
Quoted 88 lines

---

Reposting, applies without changes to kvm/next.

 arch/x86/kvm/i8259.c | 16 +++++++---------
 virt/kvm/ioapic.c    | 35 +++++++++++++++++------------------
 2 files changed, 24 insertions(+), 27 deletions(-)
arch/x86/kvm/i8259.c +7 -9
index 1df8fb9..277ec0d 100644
@@ -190,17 +190,15 @@ void kvm_pic_update_irq(struct kvm_pic *s)
 
 int kvm_pic_set_irq(struct kvm_pic *s, int irq, int irq_source_id, int level)
 {
-	int ret = -1;
+	int ret, irq_level;
 
 	pic_lock(s);
-	if (irq >= 0 && irq < PIC_NUM_PINS) {
-		int irq_level = __kvm_irq_line_state(&s->irq_states[irq],
-						     irq_source_id, level);
-		ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
-		pic_update_irq(s);
-		trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
-				      s->pics[irq >> 3].imr, ret == 0);
-	}
+	irq_level = __kvm_irq_line_state(&s->irq_states[irq],
+					 irq_source_id, level);
+	ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
+	pic_update_irq(s);
+	trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
+			      s->pics[irq >> 3].imr, ret == 0);
 	pic_unlock(s);
 
 	return ret;
virt/kvm/ioapic.c +17 -18
index ef61d52..4d824c7 100644
@@ -197,28 +197,27 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
 	u32 old_irr;
 	u32 mask = 1 << irq;
 	union kvm_ioapic_redirect_entry entry;
-	int ret = 1;
+	int ret, irq_level;
 
 	spin_lock(&ioapic->lock);
 	old_irr = ioapic->irr;
-	if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
-		int irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
-						     irq_source_id, level);
-		entry = ioapic->redirtbl[irq];
-		irq_level ^= entry.fields.polarity;
-		if (!irq_level)
-			ioapic->irr &= ~mask;
-		else {
-			int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
-			ioapic->irr |= mask;
-			if ((edge && old_irr != ioapic->irr) ||
-			    (!edge && !entry.fields.remote_irr))
-				ret = ioapic_service(ioapic, irq);
-			else
-				ret = 0; /* report coalesced interrupt */
-		}
-		trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
+	irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
+					 irq_source_id, level);
+	entry = ioapic->redirtbl[irq];
+	irq_level ^= entry.fields.polarity;
+	if (!irq_level) {
+		ioapic->irr &= ~mask;
+		ret = 1;
+	} else {
+		int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
+		ioapic->irr |= mask;
+		if ((edge && old_irr != ioapic->irr) ||
+		    (!edge && !entry.fields.remote_irr))
+			ret = ioapic_service(ioapic, irq);
+		else
+			ret = 0; /* report coalesced interrupt */
 	}
+	trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
 	spin_unlock(&ioapic->lock);
 
Quoted 10 lines
Quoted 10 lines
Quoted 3 lines
virt/kvm/ioapic.c +0 -0
 	return ret;
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#4 lore raw
Quoted 8 lines · Gleb Natapov
Quoted 7 lines · Marcelo Tosatti
Quoted 6 lines · Gleb Natapov
Quoted 5 lines · Michael S. Tsirkin

We validate irq pin number when routing is setup, so code handling illegal irq # in pic and ioapic on each injection is never called.
Drop it.

Quoted 7 lines
Quoted 4 lines
Quoted 1 line

I would leave BUG_ON there for a while.

Which BUG_ON?

I mean changing if() to BUG_ON().

BUG_ON (!(irq >= 0 && irq < PIC_NUM_PINS))

Yes posting v2 that does this soon.

Quoted 101 lines
Quoted 88 lines
Quoted 88 lines
Quoted 88 lines

---

Reposting, applies without changes to kvm/next.

 arch/x86/kvm/i8259.c | 16 +++++++---------
 virt/kvm/ioapic.c    | 35 +++++++++++++++++------------------
 2 files changed, 24 insertions(+), 27 deletions(-)
arch/x86/kvm/i8259.c +7 -9
index 1df8fb9..277ec0d 100644
@@ -190,17 +190,15 @@ void kvm_pic_update_irq(struct kvm_pic *s)
 
 int kvm_pic_set_irq(struct kvm_pic *s, int irq, int irq_source_id, int level)
 {
-	int ret = -1;
+	int ret, irq_level;
 
 	pic_lock(s);
-	if (irq >= 0 && irq < PIC_NUM_PINS) {
-		int irq_level = __kvm_irq_line_state(&s->irq_states[irq],
-						     irq_source_id, level);
-		ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
-		pic_update_irq(s);
-		trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
-				      s->pics[irq >> 3].imr, ret == 0);
-	}
+	irq_level = __kvm_irq_line_state(&s->irq_states[irq],
+					 irq_source_id, level);
+	ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
+	pic_update_irq(s);
+	trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
+			      s->pics[irq >> 3].imr, ret == 0);
 	pic_unlock(s);
 
 	return ret;
virt/kvm/ioapic.c +17 -18
index ef61d52..4d824c7 100644
@@ -197,28 +197,27 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
 	u32 old_irr;
 	u32 mask = 1 << irq;
 	union kvm_ioapic_redirect_entry entry;
-	int ret = 1;
+	int ret, irq_level;
 
 	spin_lock(&ioapic->lock);
 	old_irr = ioapic->irr;
-	if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
-		int irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
-						     irq_source_id, level);
-		entry = ioapic->redirtbl[irq];
-		irq_level ^= entry.fields.polarity;
-		if (!irq_level)
-			ioapic->irr &= ~mask;
-		else {
-			int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
-			ioapic->irr |= mask;
-			if ((edge && old_irr != ioapic->irr) ||
-			    (!edge && !entry.fields.remote_irr))
-				ret = ioapic_service(ioapic, irq);
-			else
-				ret = 0; /* report coalesced interrupt */
-		}
-		trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
+	irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
+					 irq_source_id, level);
+	entry = ioapic->redirtbl[irq];
+	irq_level ^= entry.fields.polarity;
+	if (!irq_level) {
+		ioapic->irr &= ~mask;
+		ret = 1;
+	} else {
+		int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
+		ioapic->irr |= mask;
+		if ((edge && old_irr != ioapic->irr) ||
+		    (!edge && !entry.fields.remote_irr))
+			ret = ioapic_service(ioapic, irq);
+		else
+			ret = 0; /* report coalesced interrupt */
 	}
+	trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
 	spin_unlock(&ioapic->lock);
 
Quoted 10 lines
Quoted 10 lines
Quoted 3 lines
virt/kvm/ioapic.c +0 -0
 	return ret;
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