uprobes: fold xol_take_insn_slot() into xol_get_insn_slot()

After the previous change xol_take_insn_slot() becomes trivial, kill it.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241001142503.GA13633@redhat.com

Author: oleg-nesterov

kernel/events/uprobes.c

@@ -1640,29 +1640,20 @@ static unsigned long xol_get_slot_nr(struct xol_area *area)
 	return UINSNS_PER_PAGE;
 }
 
-/*
- *  - search for a free slot.
- */
-static unsigned long xol_take_insn_slot(struct xol_area *area)
-{
-	unsigned long slot_nr;
-
-	wait_event(area->wq, (slot_nr = xol_get_slot_nr(area)) < UINSNS_PER_PAGE);
-
-	return area->vaddr + slot_nr * UPROBE_XOL_SLOT_BYTES;
-}
-
 /*
  * xol_get_insn_slot - allocate a slot for xol.
  */
 static bool xol_get_insn_slot(struct uprobe *uprobe, struct uprobe_task *utask)
 {
 	struct xol_area *area = get_xol_area();
+	unsigned long slot_nr;
 
 	if (!area)
 		return false;
 
-	utask->xol_vaddr = xol_take_insn_slot(area);
+	wait_event(area->wq, (slot_nr = xol_get_slot_nr(area)) < UINSNS_PER_PAGE);
+
+	utask->xol_vaddr = area->vaddr + slot_nr * UPROBE_XOL_SLOT_BYTES;
 	arch_uprobe_copy_ixol(area->page, utask->xol_vaddr,
 			      &uprobe->arch.ixol, sizeof(uprobe->arch.ixol));
 	return true;