> -----Original Message----- > From: linux-rdma-owner@xxxxxxxxxxxxxxx [mailto:linux-rdma- > owner@xxxxxxxxxxxxxxx] On Behalf Of Doug Ledford > Sent: Tuesday, June 07, 2016 2:54 AM > To: Leon Romanovsky <leon@xxxxxxxxxx> > Cc: linux-rdma@xxxxxxxxxxxxxxx; Mark Bloch <markb@xxxxxxxxxxxx> > Subject: Re: [PATCH rdma-rc 6/7] IB/core: Fix incorrect array allocation > > This patch is both right and wrong. You're right with the intent (that > there should be a total of 2 extra entries in the array size, one for > the NULL termination and one for the lifespan entry), but wrong with the > mechanics (unless I've missed something). We already have two extra > entries because sizeof(*hsag) includes our first counter, so just > num_counters is actually enough to NULL terminate the list, and + 1 > gives us lifespan plus a NULL terminate spot. The comment could be > cleaned up to make this more clear though, so I'll do that. Hi doug, I might be missing something, but: hsag = kzalloc(sizeof(*hsag) + sizeof(void *) * (stats->num_counters + 1) GFP_KERNEL); So now we have hsag and after it num_counters + 1 slots. Now we need attrs to point to a memory location, so we do: hsag->attrs = (void *)hsag + sizeof(*hsag); which means hsag->attrs is now pointing to a memory location right after hsag (remember we have num_counters + 1) slots there. for (i = 0; i < stats->num_counters; i++) { hsag->attrs[i] = alloc_hsa(i, port_num, stats->names[i]); if (!hsag->attrs[i]) goto err; sysfs_attr_init(hsag->attrs[i]); } /* treat an error here as non-fatal */ hsag->attrs[i] = alloc_hsa_lifespan("lifespan", port_num); The for loop fills num_counters slots, and after that alloc_hsa_lifespan uses another one. Which means we used all our slots and we are missing one as the NULL slot. Of course I might be wrong/missing something, it wouldn't be the first time :) Mark -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
