* Oleg Nesterov <[email protected]> [2012-11-23 21:28:17]: > To support the filtering uprobe_register() should do > register_for_each_vma(true) every time the new consumer comes, > we need to install the previously nacked breakpoints. > > Note: > - uprobes_mutex[] should die, what is actually protects is > alloc_uprobe(). > > - UPROBE_RUN_HANDLER should die too, obviously it can't work > unless uprobe has a single consumer. The consumer should > serialize with _register/_unregister itself. Or this flag > should live in uprobe_consumer->state. > > - Perhaps we can do some optimizations later. For example, if > filter_chain() never returns false uprobe can record this > fact and avoid the unnecessary register_for_each_vma(). > > Signed-off-by: Oleg Nesterov <[email protected]>
Acked-by: Srikar Dronamraju <[email protected]> > --- > kernel/events/uprobes.c | 31 +++++++++++++------------------ > 1 files changed, 13 insertions(+), 18 deletions(-) > > diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c > index 7c98671..c80507d 100644 > --- a/kernel/events/uprobes.c > +++ b/kernel/events/uprobes.c > @@ -482,16 +482,12 @@ static void handler_chain(struct uprobe *uprobe, struct > pt_regs *regs) > up_read(&uprobe->consumer_rwsem); > } > > -/* Returns the previous consumer */ > -static struct uprobe_consumer * > -consumer_add(struct uprobe *uprobe, struct uprobe_consumer *uc) > +static void consumer_add(struct uprobe *uprobe, struct uprobe_consumer *uc) > { > down_write(&uprobe->consumer_rwsem); > uc->next = uprobe->consumers; > uprobe->consumers = uc; > up_write(&uprobe->consumer_rwsem); > - > - return uc->next; > } > > /* > @@ -820,9 +816,15 @@ static int register_for_each_vma(struct uprobe *uprobe, > bool is_register) > return err; > } > > -static int __uprobe_register(struct uprobe *uprobe) > +static int __uprobe_register(struct uprobe *uprobe, struct uprobe_consumer > *uc) > { > - return register_for_each_vma(uprobe, true); > + int err; > + > + consumer_add(uprobe, uc); > + err = register_for_each_vma(uprobe, true); > + if (!err) /* TODO: pointless unless the first consumer */ > + set_bit(UPROBE_RUN_HANDLER, &uprobe->flags); > + return err; > } > > static void __uprobe_unregister(struct uprobe *uprobe, struct > uprobe_consumer *uc) > @@ -867,21 +869,14 @@ int uprobe_register(struct inode *inode, loff_t offset, > struct uprobe_consumer * > if (offset > i_size_read(inode)) > return -EINVAL; > > - ret = 0; > + ret = -ENOMEM; > mutex_lock(uprobes_hash(inode)); > uprobe = alloc_uprobe(inode, offset); > - > - if (!uprobe) { > - ret = -ENOMEM; > - } else if (!consumer_add(uprobe, uc)) { > - ret = __uprobe_register(uprobe); > - if (ret) { > + if (uprobe) { > + ret = __uprobe_register(uprobe, uc); > + if (ret) > __uprobe_unregister(uprobe, uc); > - } else { > - set_bit(UPROBE_RUN_HANDLER, &uprobe->flags); > - } > } > - > mutex_unlock(uprobes_hash(inode)); > if (uprobe) > put_uprobe(uprobe); > -- > 1.5.5.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
