[PATCH 1/7] uprobes: don't abuse get_utask() in pre_ssout() and prepare_uretprobe()
From: Oleg Nesterov <oleg@redhat.com>
Date: 2024-09-29 14:42:51
Also in:
lkml
Subsystem:
performance events subsystem, the rest, uprobes · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds, Masami Hiramatsu, Oleg Nesterov
handle_swbp() calls get_utask() before prepare_uretprobe() or pre_ssout() can be called, they can simply use current->utask which can't be NULL. Signed-off-by: Oleg Nesterov <oleg@redhat.com> --- kernel/events/uprobes.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 4b52cb2ae6d6..2a9cdd5c82d7 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c@@ -1908,18 +1908,14 @@ static void cleanup_return_instances(struct uprobe_task *utask, bool chained, static void prepare_uretprobe(struct uprobe *uprobe, struct pt_regs *regs) { - struct return_instance *ri; - struct uprobe_task *utask; + struct uprobe_task *utask = current->utask; unsigned long orig_ret_vaddr, trampoline_vaddr; + struct return_instance *ri; bool chained; if (!get_xol_area()) return; - utask = get_utask(); - if (!utask) - return; - if (utask->depth >= MAX_URETPROBE_DEPTH) { printk_ratelimited(KERN_INFO "uprobe: omit uretprobe due to" " nestedness limit pid/tgid=%d/%d\n",
@@ -1980,14 +1976,10 @@ static void prepare_uretprobe(struct uprobe *uprobe, struct pt_regs *regs) static int pre_ssout(struct uprobe *uprobe, struct pt_regs *regs, unsigned long bp_vaddr) { - struct uprobe_task *utask; + struct uprobe_task *utask = current->utask; unsigned long xol_vaddr; int err; - utask = get_utask(); - if (!utask) - return -ENOMEM; - if (!try_get_uprobe(uprobe)) return -EINVAL;
--
2.25.1.362.g51ebf55