Changeset 25ebfbd in mainline

Timestamp:

2012-05-06T19:34:33Z (12 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

c8d0f9e5

Parents:

1295a1da

Message:

Make slab_mag_cache_t's spinlock IRQ safe.

• slab_cache_destroy() was taking this lock while interrupts were not disabled.
• Some TLB shootdown sequences could allocate memory, which may involve taking the lock.
• The above could lead to a deadlock if one CPU took the lock and another one started the TLB shootdown sequence which also takes this lock.

Location:

kernel/generic

Files:

• include/mm/slab.h (modified) (1 diff)
• src/mm/slab.c (modified) (9 diffs)

kernel/generic/include/mm/slab.h

@@ -81 +81 @@
         slab_magazine_t *current;
         slab_magazine_t *last;
-        SPINLOCK_DECLARE(lock);
+        IRQ_SPINLOCK_DECLARE(lock);
 } slab_mag_cache_t;
 

kernel/generic/src/mm/slab.c

@@ -366 +366 @@
                 atomic_dec(&cache->magazine_counter);
         }
-        
         spinlock_unlock(&cache->maglock);
+
         return mag;
 }
@@ -414 +414 @@
         slab_magazine_t *lastmag = cache->mag_cache[CPU->id].last;
         
-        ASSERT(spinlock_locked(&cache->mag_cache[CPU->id].lock));
+        ASSERT(irq_spinlock_locked(&cache->mag_cache[CPU->id].lock));
         
         if (cmag) { /* First try local CPU magazines */
@@ -451 +451 @@
                 return NULL;
         
-        spinlock_lock(&cache->mag_cache[CPU->id].lock);
+        irq_spinlock_lock(&cache->mag_cache[CPU->id].lock, true);
         
         slab_magazine_t *mag = get_full_current_mag(cache);
         if (!mag) {
-                spinlock_unlock(&cache->mag_cache[CPU->id].lock);
+                irq_spinlock_unlock(&cache->mag_cache[CPU->id].lock, true);
                 return NULL;
         }
         
         void *obj = mag->objs[--mag->busy];
-        spinlock_unlock(&cache->mag_cache[CPU->id].lock);
+        irq_spinlock_unlock(&cache->mag_cache[CPU->id].lock, true);
         
         atomic_dec(&cache->cached_objs);
@@ -481 +481 @@
         slab_magazine_t *lastmag = cache->mag_cache[CPU->id].last;
         
-        ASSERT(spinlock_locked(&cache->mag_cache[CPU->id].lock));
+        ASSERT(irq_spinlock_locked(&cache->mag_cache[CPU->id].lock));
         
         if (cmag) {
@@ -531 +531 @@
                 return -1;
         
-        spinlock_lock(&cache->mag_cache[CPU->id].lock);
+        irq_spinlock_lock(&cache->mag_cache[CPU->id].lock, true);
         
         slab_magazine_t *mag = make_empty_current_mag(cache);
         if (!mag) {
-                spinlock_unlock(&cache->mag_cache[CPU->id].lock);
+                irq_spinlock_unlock(&cache->mag_cache[CPU->id].lock, true);
                 return -1;
         }
@@ -541 +541 @@
         mag->objs[mag->busy++] = obj;
         
-        spinlock_unlock(&cache->mag_cache[CPU->id].lock);
+        irq_spinlock_unlock(&cache->mag_cache[CPU->id].lock, true);
         
         atomic_inc(&cache->cached_objs);
@@ -593 +593 @@
         for (i = 0; i < config.cpu_count; i++) {
                 memsetb(&cache->mag_cache[i], sizeof(cache->mag_cache[i]), 0);
-                spinlock_initialize(&cache->mag_cache[i].lock,
+                irq_spinlock_initialize(&cache->mag_cache[i].lock,
                     "slab.cache.mag_cache[].lock");
         }
@@ -704 +704 @@
                 size_t i;
                 for (i = 0; i < config.cpu_count; i++) {
-                        spinlock_lock(&cache->mag_cache[i].lock);
+                        irq_spinlock_lock(&cache->mag_cache[i].lock, true);
                         
                         mag = cache->mag_cache[i].current;
@@ -716 +716 @@
                         cache->mag_cache[i].last = NULL;
                         
-                        spinlock_unlock(&cache->mag_cache[i].lock);
+                        irq_spinlock_unlock(&cache->mag_cache[i].lock, true);
                 }
         }