From a5436ae2516edc955f26c6aa4103f5946ee8653c Mon Sep 17 00:00:00 2001 From: Steven Luong Date: Fri, 8 May 2020 04:50:05 -0700 Subject: vppinfra: set explicit found in search_free_list loop While https://gerrit.fd.io/r/c/vpp/+/26948 fixed avoid using -1 to index into h->free_lists[b][l] by changing the loop counter, the check for the value of the loop counter (l < 0) cannot be trusted to decide whether we've found a large enough object within the bin or not. When the loop is terminated, the value of the variable l could be ambiguous if it equals to 0 and it is never less than 0, ie, when we bail out of the loop, we don't know if it was due to the breaking out of the condition in if ((s = f_size - size) >= 0) break; or while (l > 0); The fix is to explicitly set a variable when we have found a large enough object inside the loop to be used to test whether the loop was prematurely terminated (found == 1) or the loop just ran exhausted (found == 0) Type: fix Signed-off-by: Steven Luong Change-Id: I0161813fbd44dcba8982a767eac2e0930e9d77e3 --- src/vppinfra/heap.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/vppinfra/heap.c b/src/vppinfra/heap.c index d48136c4c94..e91dc64f568 100644 --- a/src/vppinfra/heap.c +++ b/src/vppinfra/heap.c @@ -297,6 +297,7 @@ search_free_list (void *v, uword size) /* Find an object that is large enough. Search list in reverse so that more recently freed objects will be allocated again sooner. */ + u8 found = 0; do { l--; @@ -304,12 +305,15 @@ search_free_list (void *v, uword size) f = elt_at (h, f_index); f_size = heap_elt_size (v, f); if ((s = f_size - size) >= 0) - break; + { + found = 1; + break; + } } while (l > 0); /* If we fail to find a large enough object, try the next larger size. */ - if (l < 0) + if (found == 0) continue; ASSERT (heap_is_free (f)); -- cgit 1.2.3-korg