[U-Boot] [PATCH v5 3/9] lib: lmb: reserving overlapping regions should fail

[Simon Goldschmidt]

lmb_add_region handles overlapping regions wrong: instead of merging
or rejecting to add a new reserved region that overlaps an existing
one, it just adds the new region.

Since internally the same function is used for lmb_alloc, change
lmb_add_region to reject overlapping regions.

Add test to assert this.

Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>
---

Changes in v5:
- added a test for this bug

Changes in v4: None
Changes in v2: None

 lib/lmb.c      |  3 +++
 test/lib/lmb.c | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/lib/lmb.c b/lib/lmb.c
index 6d3dcf4e09..62a306c5b9 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -131,6 +131,9 @@ static long lmb_add_region(struct lmb_region *rgn, phys_addr_t base, phys_size_t
 			rgn->region[i].size += size;
 			coalesced++;
 			break;
+		} else if (lmb_addrs_overlap(base, size, rgnbase, rgnsize)) {
+			/* regions overlap */
+			return -1;
 		}
 	}
 
diff --git a/test/lib/lmb.c b/test/lib/lmb.c
index fb7ca45ef1..c6823b3f3d 100644
--- a/test/lib/lmb.c
+++ b/test/lib/lmb.c
@@ -318,3 +318,42 @@ static int lib_test_lmb_at_0(struct unit_test_state *uts)
 }
 
 DM_TEST(lib_test_lmb_at_0, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+
+/* Check that calling lmb_reserve with overlapping regions fails. */
+static int lib_test_lmb_overlapping_reserve(struct unit_test_state *uts)
+{
+	const phys_addr_t ram = 0x40000000;
+	const phys_size_t ram_size = 0x20000000;
+	struct lmb lmb;
+	long ret;
+
+	lmb_init(&lmb);
+
+	ret = lmb_add(&lmb, ram, ram_size);
+	ut_asserteq(ret, 0);
+
+	ret = lmb_reserve(&lmb, 0x40010000, 0x10000);
+	ut_asserteq(ret, 0);
+	ASSERT_LMB(&lmb, ram, ram_size, 1, 0x40010000, 0x10000,
+		   0, 0, 0, 0);
+	/* allocate overlapping region should fail */
+	ret = lmb_reserve(&lmb, 0x40011000, 0x10000);
+	ut_asserteq(ret, -1);
+	ASSERT_LMB(&lmb, ram, ram_size, 1, 0x40010000, 0x10000,
+		   0, 0, 0, 0);
+	/* allocate 3nd region */
+	ret = lmb_reserve(&lmb, 0x40030000, 0x10000);
+	ut_asserteq(ret, 0);
+	ASSERT_LMB(&lmb, ram, ram_size, 2, 0x40010000, 0x10000,
+		   0x40030000, 0x10000, 0, 0);
+	/* allocate 2nd region */
+	ret = lmb_reserve(&lmb, 0x40020000, 0x10000);
+	ut_assert(ret >= 0);
+	ASSERT_LMB(&lmb, ram, ram_size, 1, 0x40010000, 0x30000,
+		   0, 0, 0, 0);
+
+	return 0;
+}
+
+DM_TEST(lib_test_lmb_overlapping_reserve,
+	DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
-- 
2.17.1