Commit c5356ab1 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Peter Zijlstra
Browse files

uprobes: pass utask to xol_get_insn_slot() and xol_free_insn_slot() 



Add the "struct uprobe_task *utask" argument to xol_get_insn_slot() and
xol_free_insn_slot(), their callers already have it so we can avoid the
unnecessary dereference and simplify the code.

Kill the "tsk" argument of xol_free_insn_slot(), it is always current.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144253.GA9487@redhat.com
parent 1cee988c

kernel/events/uprobes.c

+8 −9
Original line number Diff line number Diff line
@@ -1647,9 +1647,8 @@ static unsigned long xol_take_insn_slot(struct xol_area *area) 
/*

 * xol_get_insn_slot - allocate a slot for xol.

 */

static bool xol_get_insn_slot(struct uprobe *uprobe)

static bool xol_get_insn_slot(struct uprobe *uprobe, struct uprobe_task *utask)

{

	struct uprobe_task *utask = current->utask;

	struct xol_area *area = get_xol_area();



	if (!area)
@@ -1664,12 +1663,12 @@ static bool xol_get_insn_slot(struct uprobe *uprobe) 
/*

 * xol_free_insn_slot - free the slot allocated by xol_get_insn_slot()

 */

static void xol_free_insn_slot(struct task_struct *tsk)

static void xol_free_insn_slot(struct uprobe_task *utask)

{

	struct xol_area *area = tsk->mm->uprobes_state.xol_area;

	unsigned long offset = tsk->utask->xol_vaddr - area->vaddr;

	struct xol_area *area = current->mm->uprobes_state.xol_area;

	unsigned long offset = utask->xol_vaddr - area->vaddr;



	tsk->utask->xol_vaddr = 0;

	utask->xol_vaddr = 0;

	/*

	 * xol_vaddr must fit into [area->vaddr, area->vaddr + PAGE_SIZE).

	 * This check can only fail if the "[uprobes]" vma was mremap'ed.
@@ -1951,7 +1950,7 @@ pre_ssout(struct uprobe *uprobe, struct pt_regs *regs, unsigned long bp_vaddr) 
	if (!try_get_uprobe(uprobe))

		return -EINVAL;



	if (!xol_get_insn_slot(uprobe)) {

	if (!xol_get_insn_slot(uprobe, utask)) {

		err = -ENOMEM;

		goto err_out;

	}
@@ -1959,7 +1958,7 @@ pre_ssout(struct uprobe *uprobe, struct pt_regs *regs, unsigned long bp_vaddr) 
	utask->vaddr = bp_vaddr;

	err = arch_uprobe_pre_xol(&uprobe->arch, regs);

	if (unlikely(err)) {

		xol_free_insn_slot(current);

		xol_free_insn_slot(utask);

		goto err_out;

	}
@@ -2307,7 +2306,7 @@ static void handle_singlestep(struct uprobe_task *utask, struct pt_regs *regs) 
	put_uprobe(uprobe);

	utask->active_uprobe = NULL;

	utask->state = UTASK_RUNNING;

	xol_free_insn_slot(current);

	xol_free_insn_slot(utask);



	spin_lock_irq(&current->sighand->siglock);

	recalc_sigpending(); /* see uprobe_deny_signal() */