uprobes: Simplify the usage of uprobe->pending_list

uprobe->pending_list is only used to create the temporary list,
it has no meaning after we drop uprobes_mmap_hash(inode).

No need to initialize this node or remove it from tmp_list, and
we can use list_for_each_entry().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20120615154353.GA9614@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index b9c61bda9029d15db22d242d1b21d875945102b2..7d5c78f063aed5c40fcfe88d2606c7a2d9ff204b 100644 (file)
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -513,7 +513,6 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset)
        uprobe->inode = igrab(inode);
        uprobe->offset = offset;
        init_rwsem(&uprobe->consumer_rwsem);
-       INIT_LIST_HEAD(&uprobe->pending_list);
 
        /* add to uprobes_tree, sorted on inode:offset */
        cur_uprobe = insert_uprobe(uprobe);
@@ -1037,7 +1036,7 @@ static void build_probe_list(struct inode *inode, struct list_head *head)
 int uprobe_mmap(struct vm_area_struct *vma)
 {
        struct list_head tmp_list;
-       struct uprobe *uprobe, *u;
+       struct uprobe *uprobe;
        struct inode *inode;
        int ret, count;
 
@@ -1055,10 +1054,9 @@ int uprobe_mmap(struct vm_area_struct *vma)
        ret = 0;
        count = 0;
 
-       list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
+       list_for_each_entry(uprobe, &tmp_list, pending_list) {
                loff_t vaddr;
 
-               list_del(&uprobe->pending_list);
                if (!ret) {
                        vaddr = vma_address(vma, uprobe->offset);
 
@@ -1106,7 +1104,7 @@ int uprobe_mmap(struct vm_area_struct *vma)
 void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end)
 {
        struct list_head tmp_list;
-       struct uprobe *uprobe, *u;
+       struct uprobe *uprobe;
        struct inode *inode;
 
        if (!atomic_read(&uprobe_events) || !valid_vma(vma, false))
@@ -1123,12 +1121,10 @@ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned lon
        mutex_lock(uprobes_mmap_hash(inode));
        build_probe_list(inode, &tmp_list);
 
-       list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
+       list_for_each_entry(uprobe, &tmp_list, pending_list) {
                loff_t vaddr;
 
-               list_del(&uprobe->pending_list);
                vaddr = vma_address(vma, uprobe->offset);
-
                if (vaddr >= start && vaddr < end) {
                        /*
                         * An unregister could have removed the probe before