Hi Oleg, On 04/09/2018 06:59 PM, Oleg Nesterov wrote: > On 04/04, Ravi Bangoria wrote: >> +static void sdt_add_mm_list(struct trace_uprobe *tu, struct mm_struct *mm) >> +{ >> + struct mmu_notifier *mn; >> + struct sdt_mm_list *sml = kzalloc(sizeof(*sml), GFP_KERNEL); >> + >> + if (!sml) >> + return; >> + sml->mm = mm; >> + list_add(&(sml->list), &(tu->sml.list)); >> + >> + /* Register mmu_notifier for this mm. */ >> + mn = kzalloc(sizeof(*mn), GFP_KERNEL); >> + if (!mn) >> + return; >> + >> + mn->ops = &sdt_mmu_notifier_ops; >> + __mmu_notifier_register(mn, mm); >> +} > and what if __mmu_notifier_register() fails simply because signal_pending() == T? > see mm_take_all_locks(). > > at first glance this all look suspicious and sub-optimal, Yes. I should have added checks for failure cases. Will fix them in v3. Thanks for the review, Ravi > but let me repeat that > I didn't read this version yet. > > Oleg. >