[PATCH] x86_64: serialize assign_irq_vector() use of static variables

Since assign_irq_vector() can be called at runtime, its access of static
variables should be protected by a lock.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index a62df3e764c51c4b24e60287fb9b3de8634faa20..43ffdd012d269c98a47cada3ba9596303856e83b 100644 (file)
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -50,6 +50,7 @@ atomic_t irq_mis_count;
 static struct { int pin, apic; } ioapic_i8259 = { -1, -1 };
 
 static DEFINE_SPINLOCK(ioapic_lock);
+static DEFINE_SPINLOCK(vector_lock);
 
 int timer_over_8254 __initdata = 1;
 
@@ -1161,10 +1162,16 @@ u8 irq_vector[NR_IRQ_VECTORS] __read_mostly = { FIRST_DEVICE_VECTOR , 0 };
 int assign_irq_vector(int irq)
 {
        static int current_vector = FIRST_DEVICE_VECTOR, offset = 0;
+       int vector;
+
+       BUG_ON(irq != AUTO_ASSIGN && (unsigned)irq >= NR_IRQ_VECTORS);
+
+       spin_lock(&vector_lock);
 
-       BUG_ON(irq >= NR_IRQ_VECTORS);
-       if (irq != AUTO_ASSIGN && IO_APIC_VECTOR(irq) > 0)
+       if (irq != AUTO_ASSIGN && IO_APIC_VECTOR(irq) > 0) {
+               spin_unlock(&vector_lock);
                return IO_APIC_VECTOR(irq);
+       }
 next:
        current_vector += 8;
        if (current_vector == SYSCALL_VECTOR)
@@ -1172,16 +1179,21 @@ next:
 
        if (current_vector >= FIRST_SYSTEM_VECTOR) {
                offset++;
-               if (!(offset%8))
+               if (!(offset%8)) {
+                       spin_unlock(&vector_lock);
                        return -ENOSPC;
+               }
                current_vector = FIRST_DEVICE_VECTOR + offset;
        }
 
-       vector_irq[current_vector] = irq;
+       vector = current_vector;
+       vector_irq[vector] = irq;
        if (irq != AUTO_ASSIGN)
-               IO_APIC_VECTOR(irq) = current_vector;
+               IO_APIC_VECTOR(irq) = vector;
+
+       spin_unlock(&vector_lock);
 
-       return current_vector;
+       return vector;
 }
 
 static struct hw_interrupt_type ioapic_level_type;

diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index 9cc7031b715178cb069243fffb1bdbbe49483e1e..062b10daebac3dafb77702bff9ba7d3f9e3aafa0 100644 (file)
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -56,6 +56,7 @@ int timer_over_8254 __initdata = 0;
 static struct { int pin, apic; } ioapic_i8259 = { -1, -1 };
 
 static DEFINE_SPINLOCK(ioapic_lock);
+static DEFINE_SPINLOCK(vector_lock);
 
 /*
  * # of IRQ routing registers
@@ -834,10 +835,16 @@ u8 irq_vector[NR_IRQ_VECTORS] __read_mostly = { FIRST_DEVICE_VECTOR , 0 };
 int assign_irq_vector(int irq)
 {
        static int current_vector = FIRST_DEVICE_VECTOR, offset = 0;
+       int vector;
 
        BUG_ON(irq != AUTO_ASSIGN && (unsigned)irq >= NR_IRQ_VECTORS);
-       if (irq != AUTO_ASSIGN && IO_APIC_VECTOR(irq) > 0)
+
+       spin_lock(&vector_lock);
+
+       if (irq != AUTO_ASSIGN && IO_APIC_VECTOR(irq) > 0) {
+               spin_unlock(&vector_lock);
                return IO_APIC_VECTOR(irq);
+       }
 next:
        current_vector += 8;
        if (current_vector == IA32_SYSCALL_VECTOR)
@@ -849,11 +856,14 @@ next:
                current_vector = FIRST_DEVICE_VECTOR + offset;
        }
 
-       vector_irq[current_vector] = irq;
+       vector = current_vector;
+       vector_irq[vector] = irq;
        if (irq != AUTO_ASSIGN)
-               IO_APIC_VECTOR(irq) = current_vector;
+               IO_APIC_VECTOR(irq) = vector;
+
+       spin_unlock(&vector_lock);
 
-       return current_vector;
+       return vector;
 }
 
 extern void (*interrupt[NR_IRQS])(void);