5.4-stable review patch. If anyone has any objections, please let me know.
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From: Ido Schimmel idosch@nvidia.com
[ Upstream commit b4a3a89fffcdf09702b1f161b914e52abca1894d ]
The library supports aggregation of objects into other objects only if the parent object does not have a parent itself. That is, nesting is not supported.
Aggregation happens in two cases: Without and with hints, where hints are a pre-computed recommendation on how to aggregate the provided objects.
Nesting is not possible in the first case due to a check that prevents it, but in the second case there is no check because the assumption is that nesting cannot happen when creating objects based on hints. The violation of this assumption leads to various warnings and eventually to a general protection fault [1].
Before fixing the root cause, error out when nesting happens and warn.
[1] general protection fault, probably for non-canonical address 0xdead000000000d90: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 1083 Comm: kworker/1:9 Tainted: G W 6.9.0-rc6-custom-gd9b4f1cca7fb #7 Hardware name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019 Workqueue: mlxsw_core mlxsw_sp_acl_tcam_vregion_rehash_work RIP: 0010:mlxsw_sp_acl_erp_bf_insert+0x25/0x80 [...] Call Trace: <TASK> mlxsw_sp_acl_atcam_entry_add+0x256/0x3c0 mlxsw_sp_acl_tcam_entry_create+0x5e/0xa0 mlxsw_sp_acl_tcam_vchunk_migrate_one+0x16b/0x270 mlxsw_sp_acl_tcam_vregion_rehash_work+0xbe/0x510 process_one_work+0x151/0x370 worker_thread+0x2cb/0x3e0 kthread+0xd0/0x100 ret_from_fork+0x34/0x50 ret_from_fork_asm+0x1a/0x30 </TASK>
Fixes: 9069a3817d82 ("lib: objagg: implement optimization hints assembly and use hints for object creation") Reported-by: Alexander Zubkov green@qrator.net Signed-off-by: Ido Schimmel idosch@nvidia.com Reviewed-by: Amit Cohen amcohen@nvidia.com Tested-by: Alexander Zubkov green@qrator.net Signed-off-by: Petr Machata petrm@nvidia.com Reviewed-by: Simon Horman horms@kernel.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- lib/objagg.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/lib/objagg.c b/lib/objagg.c index 55621fb82e0a3..e380e95de7702 100644 --- a/lib/objagg.c +++ b/lib/objagg.c @@ -167,6 +167,9 @@ static int objagg_obj_parent_assign(struct objagg *objagg, { void *delta_priv;
+ if (WARN_ON(!objagg_obj_is_root(parent))) + return -EINVAL; + delta_priv = objagg->ops->delta_create(objagg->priv, parent->obj, objagg_obj->obj); if (IS_ERR(delta_priv))