On Fri, 20 Apr 2018 09:56:25 -0700 Song Liu <songliubrav...@fb.com> wrote:
> Caller of uprobe_register is required to keep the inode and containing > mount point referenced. I would add a little more background to why this is the case. Also a possible link to the conversation? Link: http://lkml.kernel.org/r/CAELBmZB2XX=qeoladvgg4cpx4gentcsnwqqujluk1ongrj3...@mail.gmail.com ? -- Steve > > Cc: Steven Rostedt <rost...@goodmis.org> > Cc: Ingo Molnar <mi...@redhat.com> > Cc: Howard McLauchlan <hmclauch...@fb.com> > Cc: Josef Bacik <jba...@fb.com> > Cc: Srikar Dronamraju <sri...@linux.vnet.ibm.com> > Cc: Miklos Szeredi <mik...@szeredi.hu> > Signed-off-by: Song Liu <songliubrav...@fb.com> > --- > kernel/events/uprobes.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c > index ce6848e..20486bb 100644 > --- a/kernel/events/uprobes.c > +++ b/kernel/events/uprobes.c > @@ -491,7 +491,6 @@ static struct uprobe *alloc_uprobe(struct inode *inode, > loff_t offset) > if (!uprobe) > return NULL; > > - uprobe->inode = igrab(inode); > uprobe->offset = offset; > init_rwsem(&uprobe->register_rwsem); > init_rwsem(&uprobe->consumer_rwsem); > @@ -502,7 +501,6 @@ static struct uprobe *alloc_uprobe(struct inode *inode, > loff_t offset) > if (cur_uprobe) { > kfree(uprobe); > uprobe = cur_uprobe; > - iput(inode); > } > > return uprobe; > @@ -701,7 +699,6 @@ static void delete_uprobe(struct uprobe *uprobe) > rb_erase(&uprobe->rb_node, &uprobes_tree); > spin_unlock(&uprobes_treelock); > RB_CLEAR_NODE(&uprobe->rb_node); /* for uprobe_is_active() */ > - iput(uprobe->inode); > put_uprobe(uprobe); > } > > @@ -873,7 +870,8 @@ static void __uprobe_unregister(struct uprobe *uprobe, > struct uprobe_consumer *u > * tuple). Creation refcount stops uprobe_unregister from freeing the > * @uprobe even before the register operation is complete. Creation > * refcount is released when the last @uc for the @uprobe > - * unregisters. > + * unregisters. Caller of uprobe_register() is required to keep @inode > + * (and the containing mount) referenced. > * > * Return errno if it cannot successully install probes > * else return 0 (success)
