Hi Liqiong, On 8/25/21 1:45 PM, liqiong wrote: > Hi Mimi, > > This copy may be better. > > > subject: ima: fix deadlock when iterating over the init "ima_rules" list. > > As Mimi said, consider adding an introducing paragraph, like: 'The current IMA ruleset is identified by the variable "ima_rules", and the pointer starts pointing at the list "ima_default_rules". When loading a custom policy for the first time, the variable is updated to point to the list "ima_policy_rules" instead. That update isn't RCU-safe, and deadlocks are possible.' > > When traversing back to head, the init "ima_rules" list can't exit > iterating if "ima_rules" has been updated to "ima_policy_rules". > It causes soft lockup and RCU stalls. So we can introduce a duplicate > of "ima_rules" for each "ima_rules" list loop. Per the process (see 'Documentation/process/submitting-patches.rst'), please prefer an imperative style (written in another paragraph): 'Introduce a temporary value for "ima_rules" when iterating over the ruleset.' Thanks, Simon
