[dpdk-dev] [PATCH] ivshmem: avoid infinite loop when concatenating adjacent segments
David Verbeiren
david.verbeiren at intel.com
Sat Dec 19 23:39:32 CET 2015
This patch aligns the logic used to check for the presence of
adjacent segments in has_adjacent_segments() with the logic used
in cleanup_segments() when actually deciding to concatenate or
not a pair of segments.
This fixes an infinite loop that happened when segments where
adjacent in their physical or virtual addresses but not in their
ioremap addresses: has_adjacent_segments() reported the presence
of adjacent segments while cleanup_segments() was not considering
them for concatenation, resulting in an infinite loop since the
result of has_adjacent_segments() is used in the decision to
continue looping in cleanup_segments().
Signed-off-by: David Verbeiren <david.verbeiren at intel.com>
---
lib/librte_eal/linuxapp/eal/eal_ivshmem.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/lib/librte_eal/linuxapp/eal/eal_ivshmem.c b/lib/librte_eal/linuxapp/eal/eal_ivshmem.c
index 589019b..086cafb 100644
--- a/lib/librte_eal/linuxapp/eal/eal_ivshmem.c
+++ b/lib/librte_eal/linuxapp/eal/eal_ivshmem.c
@@ -254,17 +254,18 @@ adjacent(const struct rte_memzone * mz1, const struct rte_memzone * mz2)
static int
has_adjacent_segments(struct ivshmem_segment * ms, int len)
{
- int i, j, a;
+ int i, j;
for (i = 0; i < len; i++)
for (j = i + 1; j < len; j++) {
- a = adjacent(&ms[i].entry.mz, &ms[j].entry.mz);
-
- /* check if segments are adjacent virtually and/or physically but
- * not ioremap (since that would indicate that they are from
- * different PCI devices and thus don't need to be concatenated.
+
+ /* check if segments are adjacent virtually and physically.
+ * They must also be adjacent in ioremap since disjoint
+ * ioremap segments would be from different PCI devices and
+ * thus don't need to be concatenated. This is the logic
+ * used in cleanup_segments() and must be in sync.
*/
- if ((a & (VIRT|PHYS)) > 0 && (a & IOREMAP) == 0)
+ if (adjacent(&ms[i].entry.mz, &ms[j].entry.mz) == FULL)
return 1;
}
return 0;
--
1.9.1
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