Commit 1cee988c authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Peter Zijlstra
Browse files

uprobes: move the initialization of utask->xol_vaddr from pre_ssout() to xol_get_insn_slot() 



This simplifies the code and makes xol_get_insn_slot() symmetric with
xol_free_insn_slot() which clears utask->xol_vaddr.

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/20240929144248.GA9483@redhat.com
parent 6ffe8c7d

kernel/events/uprobes.c

+8 −14
Original line number Diff line number Diff line
@@ -1646,21 +1646,19 @@ static unsigned long xol_take_insn_slot(struct xol_area *area) 


/*

 * xol_get_insn_slot - allocate a slot for xol.

 * Returns the allocated slot address or 0.

 */

static unsigned long xol_get_insn_slot(struct uprobe *uprobe)

static bool xol_get_insn_slot(struct uprobe *uprobe)

{

	struct xol_area *area;

	unsigned long xol_vaddr;

	struct uprobe_task *utask = current->utask;

	struct xol_area *area = get_xol_area();



	area = get_xol_area();

	if (!area)

		return 0;

		return false;



	xol_vaddr = xol_take_insn_slot(area);

	arch_uprobe_copy_ixol(area->page, xol_vaddr,

	utask->xol_vaddr = xol_take_insn_slot(area);

	arch_uprobe_copy_ixol(area->page, utask->xol_vaddr,

			      &uprobe->arch.ixol, sizeof(uprobe->arch.ixol));

	return xol_vaddr;

	return true;

}



/*
@@ -1948,21 +1946,17 @@ static int 
pre_ssout(struct uprobe *uprobe, struct pt_regs *regs, unsigned long bp_vaddr)

{

	struct uprobe_task *utask = current->utask;

	unsigned long xol_vaddr;

	int err;



	if (!try_get_uprobe(uprobe))

		return -EINVAL;



	xol_vaddr = xol_get_insn_slot(uprobe);

	if (!xol_vaddr) {

	if (!xol_get_insn_slot(uprobe)) {

		err = -ENOMEM;

		goto err_out;

	}



	utask->xol_vaddr = xol_vaddr;

	utask->vaddr = bp_vaddr;



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

	if (unlikely(err)) {

		xol_free_insn_slot(current);