From 04aab9b2006bbdeff78dc162f206fdfebeca97d9 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 23 Nov 2012 19:43:50 +0100 Subject: [PATCH] uprobes: _unregister() should always do register_for_each_vma(false) uprobe_unregister() removes the breakpoints only if the last consumer goes away. To support the filtering it should do this every time, we want to remove the breakpoints which nobody else want to keep. Note: given that filter_chain() is not actually implemented, this patch itself doesn't change the behaviour yet, register_for_each_vma(false) is a heavy "nop" unless there are no more consumers. Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju --- kernel/events/uprobes.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index c38bf37d0aca..940199084639 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -825,12 +825,20 @@ static int __uprobe_register(struct uprobe *uprobe) return register_for_each_vma(uprobe, true); } -static void __uprobe_unregister(struct uprobe *uprobe) +static void __uprobe_unregister(struct uprobe *uprobe, struct uprobe_consumer *uc) { - if (!register_for_each_vma(uprobe, false)) - delete_uprobe(uprobe); + int err; + + if (!consumer_del(uprobe, uc)) /* WARN? */ + return; - /* TODO : cant unregister? schedule a worker thread */ + err = register_for_each_vma(uprobe, false); + if (!uprobe->consumers) { + clear_bit(UPROBE_RUN_HANDLER, &uprobe->flags); + /* TODO : cant unregister? schedule a worker thread */ + if (!err) + delete_uprobe(uprobe); + } } /* @@ -868,8 +876,7 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer * } else if (!consumer_add(uprobe, uc)) { ret = __uprobe_register(uprobe); if (ret) { - uprobe->consumers = NULL; - __uprobe_unregister(uprobe); + __uprobe_unregister(uprobe, uc); } else { set_bit(UPROBE_RUN_HANDLER, &uprobe->flags); } @@ -897,14 +904,7 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume return; mutex_lock(uprobes_hash(inode)); - - if (consumer_del(uprobe, uc)) { - if (!uprobe->consumers) { - __uprobe_unregister(uprobe); - clear_bit(UPROBE_RUN_HANDLER, &uprobe->flags); - } - } - + __uprobe_unregister(uprobe, uc); mutex_unlock(uprobes_hash(inode)); put_uprobe(uprobe); } -- 2.30.2