Commit b302d5a6 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Peter Zijlstra
Browse files

uprobes: don't abuse get_utask() in pre_ssout() and prepare_uretprobe() 



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: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144230.GA9468@redhat.com
parent d3fe6f0a

kernel/events/uprobes.c

+3 −11
Original line number Diff line number Diff line
@@ -1905,18 +1905,14 @@ 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",
@@ -1977,14 +1973,10 @@ 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;