fix(mpu): dealloate vMPU entry if mpu fails to insert region

Added a function that deallocates a vMPU entry whenever the mpu fails
to insert a region.

Signed-off-by: Miguel Silva <[email protected]>

Author: miguelafsilva5

src/core/mpu/mem.c

@@ -107,6 +107,18 @@ static mpid_t mem_vmpu_allocate_entry(struct addr_space* as)
     return mpid;
 }
 
+static void mem_vmpu_deallocate_entry(struct addr_space* as, mpid_t mpid)
+{
+    struct mpe* mpe = mem_vmpu_get_entry(as, mpid);
+
+    mpe->region.base = 0;
+    mpe->region.size = 0;
+    mpe->region.mem_flags = PTE_INVALID;
+    mpe->region.as_sec = SEC_UNKNOWN;
+    mpe->state = MPE_S_FREE;
+    mpe->lock = false;
+}
+
 static mpid_t mem_vmpu_get_entry_by_addr(struct addr_space* as, vaddr_t addr)
 {
     mpid_t mpid = INVALID_MPID;
@@ -496,6 +508,7 @@ static void mem_vmpu_coalesce_contiguous(struct addr_space* as, bool broadcast)
 bool mem_map(struct addr_space* as, struct mp_region* mpr, bool broadcast, bool locked)
 {
     bool mapped = false;
+    mpid_t mpid = INVALID_MPID;
 
     if (mpr->size == 0) {
         return true;
@@ -509,9 +522,11 @@ bool mem_map(struct addr_space* as, struct mp_region* mpr, bool broadcast, bool
     spin_lock(&as->lock);
 
     if (mem_vmpu_find_overlapping_region(as, mpr) == INVALID_MPID) {
-        mpid_t mpid = mem_vmpu_allocate_entry(as);
+        mpid = mem_vmpu_allocate_entry(as);
         if (mpid != INVALID_MPID) {
             mapped = mem_vmpu_insert_region(as, mpid, mpr, broadcast, locked);
+        } else {
+            mem_vmpu_deallocate_entry(as, mpid);
         }
     }