From c3dfbfb39a71061c08d9f4cb874fd5b8a92e8fc5 Mon Sep 17 00:00:00 2001
From: Stefan Lankes <slankes@eonerc.rwth-aachen.de>
Date: Sat, 23 Sep 2017 23:27:12 +0200
Subject: [PATCH] use one lock for the memory management to avoid deadlocks

---
 mm/malloc.c | 12 ++++++------
 mm/vma.c    | 12 ++++++------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/mm/malloc.c b/mm/malloc.c
index dac637062..0718eb62a 100644
--- a/mm/malloc.c
+++ b/mm/malloc.c
@@ -38,8 +38,8 @@
 
 /// A linked list for each binary size exponent
 static buddy_t* buddy_lists[BUDDY_LISTS] = { [0 ... BUDDY_LISTS-1] = NULL };
-/// Lock for the buddy lists
-static spinlock_irqsave_t buddy_lock = SPINLOCK_IRQSAVE_INIT;
+
+extern spinlock_irqsave_t hermit_mm_lock;
 
 /** @brief Check if larger free buddies are available */
 static inline int buddy_large_avail(uint8_t exp)
@@ -67,7 +67,7 @@ static inline int buddy_exp(size_t sz)
 /** @brief Get a free buddy by potentially splitting a larger one */
 static buddy_t* buddy_get(int exp)
 {
-	spinlock_irqsave_lock(&buddy_lock);
+	spinlock_irqsave_lock(&hermit_mm_lock);
 	buddy_t** list = &buddy_lists[exp-BUDDY_MIN];
 	buddy_t* buddy = *list;
 	buddy_t* split;
@@ -93,7 +93,7 @@ static buddy_t* buddy_get(int exp)
 	}
 
 out:
-	spinlock_irqsave_unlock(&buddy_lock);
+	spinlock_irqsave_unlock(&hermit_mm_lock);
 
 	return buddy;
 }
@@ -104,11 +104,11 @@ out:
  */
 static void buddy_put(buddy_t* buddy)
 {
-	spinlock_irqsave_lock(&buddy_lock);
+	spinlock_irqsave_lock(&hermit_mm_lock);
 	buddy_t** list = &buddy_lists[buddy->prefix.exponent-BUDDY_MIN];
 	buddy->next = *list;
 	*list = buddy;
-	spinlock_irqsave_unlock(&buddy_lock);
+	spinlock_irqsave_unlock(&hermit_mm_lock);
 }
 
 void buddy_dump(void)
diff --git a/mm/vma.c b/mm/vma.c
index c89b5a3c4..4c99cec1d 100644
--- a/mm/vma.c
+++ b/mm/vma.c
@@ -47,7 +47,7 @@ extern const void kernel_start;
  */
 static vma_t vma_boot = { VMA_MIN, VMA_MIN, VMA_HEAP };
 static vma_t* vma_list = &vma_boot;
-static spinlock_irqsave_t vma_lock = SPINLOCK_IRQSAVE_INIT;
+spinlock_irqsave_t hermit_mm_lock = SPINLOCK_IRQSAVE_INIT;
 
 int vma_init(void)
 {
@@ -79,7 +79,7 @@ out:
 
 size_t vma_alloc(size_t size, uint32_t flags)
 {
-	spinlock_irqsave_t* lock = &vma_lock;
+	spinlock_irqsave_t* lock = &hermit_mm_lock;
 	vma_t** list = &vma_list;
 
 	LOG_DEBUG("vma_alloc: size = %#lx, flags = %#x\n", size, flags);
@@ -144,7 +144,7 @@ found:
 
 int vma_free(size_t start, size_t end)
 {
-	spinlock_irqsave_t* lock = &vma_lock;
+	spinlock_irqsave_t* lock = &hermit_mm_lock;
 	vma_t* vma;
 	vma_t** list = &vma_list;
 
@@ -206,7 +206,7 @@ int vma_free(size_t start, size_t end)
 
 int vma_add(size_t start, size_t end, uint32_t flags)
 {
-	spinlock_irqsave_t* lock = &vma_lock;
+	spinlock_irqsave_t* lock = &hermit_mm_lock;
 	vma_t** list = &vma_list;
 	int ret = 0;
 
@@ -280,7 +280,7 @@ void vma_dump(void)
 	}
 
 	LOG_INFO("VMAs:\n");
-	spinlock_irqsave_lock(&vma_lock);
+	spinlock_irqsave_lock(&hermit_mm_lock);
 	print_vma(&vma_boot);
-	spinlock_irqsave_unlock(&vma_lock);
+	spinlock_irqsave_unlock(&hermit_mm_lock);
 }