lmb: Return -EFAULT when requested region is not part of memory map

lmb_alloc_addr() is documented to return -EINVAL when the requested
memory region is not part of the LMB memory map. However, -EINVAL is
also used to e.g. indicate that a NULL pointer is passed as the addr
parameter or when the requested memory region partially overlaps an
existing region.

Change lmb_alloc_addr() to return -EFAULT when the requested memory
region is not part of the LMB memory map to make the type of error known
to callers. Also extend unit tests to validate that the return code has
stay the same when the requested memory region partially overlaps.

No caller of lmb_alloc_addr() is checking what type of error code is
returned, so this change has no intended behavior change.

Signed-off-by: Jonas Karlman <[email protected]>
Reviewed-by: Randolph Sapp <[email protected]>

3 files changed, 13 insertions, 3 deletions

diff --git a/include/lmb.h b/include/lmb.h
index ed472e9ef2e..028dabb19e8 100644
--- a/include/lmb.h
+++ b/include/lmb.h
@@ -124,7 +124,7 @@ struct lmb {
  * Return: 0 on success, -ve value on failure
  *
  * When the allocation is of type @LMB_MEM_ALLOC_ADDR, the return value can
- * be -EINVAL if the requested memory region is not part of the LMB memory
+ * be -EFAULT if the requested memory region is not part of the LMB memory
  * map, and -EEXIST if the requested region is already allocated.
  */
 int lmb_alloc_mem(enum lmb_mem_type type, u64 align, phys_addr_t *addr,
diff --git a/lib/lmb.c b/lib/lmb.c
index 77440a48486..f7c2e826d06 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -752,9 +752,11 @@ static int _lmb_alloc_addr(phys_addr_t base, phys_size_t size, u32 flags)
 				      base + size - 1, 1))
 			/* ok, reserve the memory */
 			return lmb_reserve(base, size, flags);
+
+		return -EINVAL;
 	}
 
-	return -EINVAL;
+	return -EFAULT;
 }
 
 int lmb_alloc_mem(enum lmb_mem_type type, u64 align, phys_addr_t *addr,
diff --git a/test/lib/lmb.c b/test/lib/lmb.c
index b6259bef442..b93b903f99f 100644
--- a/test/lib/lmb.c
+++ b/test/lib/lmb.c
@@ -779,11 +779,19 @@ static int test_alloc_addr(struct unit_test_state *uts, const phys_addr_t ram)
 	/* check that allocating outside memory fails */
 	if (ram_end != 0) {
 		ret = lmb_alloc_addr(ram_end, 1, LMB_NONE);
+		ut_asserteq(ret, -EFAULT);
+		ret = lmb_alloc_addr(ram_end - 1, 2, LMB_NOMAP);
+		ut_asserteq(ret, -EINVAL);
+		ret = lmb_alloc_addr(ram_end - 1, 2, LMB_NOOVERWRITE);
 		ut_asserteq(ret, -EINVAL);
 	}
 	if (ram != 0) {
 		ret = lmb_alloc_addr(ram - 1, 1, LMB_NONE);
-		ut_asserteq(ret, -EINVAL);
+		ut_asserteq(ret, -EFAULT);
+		ret = lmb_alloc_addr(ram - 1, 2, LMB_NOMAP);
+		ut_asserteq(ret, -EEXIST);
+		ret = lmb_alloc_addr(ram - 1, 2, LMB_NOOVERWRITE);
+		ut_asserteq(ret, -EEXIST);
 	}
 
 	lmb_pop(&store);