lib: lmb: reserving overlapping regions should fail

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.

Also, to keep reserved memory correct after 'free', reserved entries
created by allocating memory must not set their size to a multiple
of alignment but to the original size. This ensures the reserved
region is completely removed when the caller calls 'lmb_free', as
this one takes the same size as passed to 'lmb_alloc' etc.

Add test to assert this.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>

1 files changed, 4 insertions, 7 deletions

diff --git a/lib/lmb.c b/lib/lmb.c
index 6d3dcf4e09..cd297f8202 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;
 		}
 	}
 
@@ -269,11 +272,6 @@ static phys_addr_t lmb_align_down(phys_addr_t addr, phys_size_t size)
 	return addr & ~(size - 1);
 }
 
-static phys_addr_t lmb_align_up(phys_addr_t addr, ulong size)
-{
-	return (addr + (size - 1)) & ~(size - 1);
-}
-
 phys_addr_t __lmb_alloc_base(struct lmb *lmb, phys_size_t size, ulong align, phys_addr_t max_addr)
 {
 	long i, j;
@@ -302,8 +300,7 @@ phys_addr_t __lmb_alloc_base(struct lmb *lmb, phys_size_t size, ulong align, phy
 			if (j < 0) {
 				/* This area isn't reserved, take it */
 				if (lmb_add_region(&lmb->reserved, base,
-							lmb_align_up(size,
-								align)) < 0)
+						   size) < 0)
 					return 0;
 				return base;
 			}