From 1cee988c1d21eabc936d1401811012522083e36f Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Sun, 29 Sep 2024 16:42:48 +0200 Subject: [PATCH] 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: Oleg Nesterov Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20240929144248.GA9483@redhat.com --- kernel/events/uprobes.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 616b5ff3fd85..dfaca306443d 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -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);