From 5a2df662aafdabffb2cf3adb780a5adf66dfb3bc Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 31 Dec 2012 17:03:32 +0100 Subject: [PATCH] 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 Acked-by: Anton Arapov Acked-by: Srikar Dronamraju --- 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 7e3e5c5b0d88..16e54d63a9fd 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))