Commit-ID: 5a2df662aafdabffb2cf3adb780a5adf66dfb3bc
Gitweb: http://git.kernel.org/tip/5a2df662aafdabffb2cf3adb780a5adf66dfb3bc
Author: Oleg Nesterov <oleg@xxxxxxxxxx>
AuthorDate: Mon, 31 Dec 2012 17:03:32 +0100
Committer: Oleg Nesterov <oleg@xxxxxxxxxx>
CommitDate: Fri, 8 Feb 2013 17:47:12 +0100
uprobes: Turn add_utask() into get_utask()
Rename add_utask() into get_utask() and change it to allocate on
demand to simplify the caller. Like get_xol_area() it will have
more users.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Anton Arapov <anton@xxxxxxxxxx>
Acked-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
---
kernel/events/uprobes.c | 27 +++++++++------------------
1 file changed, 9 insertions(+), 18 deletions(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 7e3e5c5..16e54d6 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1290,23 +1290,18 @@ void uprobe_copy_process(struct task_struct *t)
}
/*
- * Allocate a uprobe_task object for the task.
- * Called when the thread hits a breakpoint for the first time.
+ * Allocate a uprobe_task object for the task if if necessary.
+ * Called when the thread hits a breakpoint.
*
* Returns:
* - pointer to new uprobe_task on success
* - NULL otherwise
*/
-static struct uprobe_task *add_utask(void)
+static struct uprobe_task *get_utask(void)
{
- struct uprobe_task *utask;
-
- utask = kzalloc(sizeof *utask, GFP_KERNEL);
- if (unlikely(!utask))
- return NULL;
-
- current->utask = utask;
- return utask;
+ if (!current->utask)
+ current->utask = kzalloc(sizeof(struct uprobe_task), GFP_KERNEL);
+ return current->utask;
}
/* Prepare to single-step probed instruction out of line. */
@@ -1505,13 +1500,9 @@ static void handle_swbp(struct pt_regs *regs)
if (unlikely(!test_bit(UPROBE_COPY_INSN, &uprobe->flags)))
goto out;
- utask = current->utask;
- if (!utask) {
- utask = add_utask();
- /* Cannot allocate; re-execute the instruction. */
- if (!utask)
- goto out;
- }
+ utask = get_utask();
+ if (!utask)
+ goto out; /* re-execute the instruction. */
handler_chain(uprobe, regs);
if (can_skip_sstep(uprobe, regs))
--
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