From: Oleg Nesterov Date: Wed, 21 Nov 2012 17:01:43 +0000 (+0100) Subject: uprobes: Kill the pointless inode/uc checks in register/unregister X-Git-Tag: v3.9-rc1~173^2~2^2~36 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=f0744af7d0fde190674064c54e2ff60b34ac71fe;p=linux.git uprobes: Kill the pointless inode/uc checks in register/unregister register/unregister verifies that inode/uc != NULL. For what? This really looks like "hide the potential problem", the caller should pass the valid data. register() also checks uc->next == NULL, probably to prevent the double-register but the caller can do other stupid/wrong things. If we do this check, then we should document that uc->next should be cleared before register() and add BUG_ON(). Also add the small comment about the i_size_read() check. Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju --- diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index afbab2cb2742..a39d8163b713 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -844,9 +844,7 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer * struct uprobe *uprobe; int ret; - if (!inode || !uc || uc->next) - return -EINVAL; - + /* Racy, just to catch the obvious mistakes */ if (offset > i_size_read(inode)) return -EINVAL; @@ -883,9 +881,6 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume { struct uprobe *uprobe; - if (!inode || !uc) - return; - uprobe = find_uprobe(inode, offset); if (!uprobe) return;