Messages in this thread | | | Subject | Re: [PATCH] lib/vsprintf: add %pT format specifier | From | Tetsuo Handa <> | Date | Sat, 11 Jan 2014 10:48:19 +0900 |
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Joe Perches wrote: > On Sat, 2014-01-11 at 10:28 +0900, Tetsuo Handa wrote: > > Step 1: (targeted to 3.14-rc1) > > Add "%pT" format specifier and commcpy() wrapper function. > > > > Step 2: (started after step 1 is reflected to other git trees) > > Replace printk("%s", p->comm) with printk("%pT", p). > > Replace printk("%s", current->comm) with printk("%pT", NULL); > > ?
Right. I forgot to add it.
> > > Replace strcpy(buf, p->comm) with commcpy(buf, p). > > > Step 3: (started after step 2 is reflected to other git trees) > > Add rcu_read_lock()/rcu_read_unlock() into commcpy(). > > Modify set_task_comm() etc. to replace ->comm using RCU. > > Aren't steps 2 and 3 independent? >
If step 3 is merged before step 2 complete, those who are not using "%pT" or commcpy() might crash due to reading RCU protected ->comm without rcu_read_lock()/rcu_read_unlock().
Step 2 depends on step 1 for avoiding compile time errors. Step 3 depends on step 2 for avoiding run time errors.
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