bpf_timed_may_goto.S

 1// SPDX-License-Identifier: GPL-2.0
 2/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */
 3
 4#include <linux/export.h>
 5#include <linux/linkage.h>
 6#include <asm/nospec-branch.h>
 7
 8	.code64
 9	.section .text, "ax"
10
11SYM_FUNC_START(arch_bpf_timed_may_goto)
12	ANNOTATE_NOENDBR
13
14	/*
15	 * r10 passes us stack depth, load the pointer to count and timestamp
16	 * into r10 by adding it to BPF frame pointer.
17	 */
18	leaq (%rbp, %r10, 1), %r10
19
20	/* Setup frame. */
21	pushq %rbp
22	movq %rsp, %rbp
23
24	/* Save r0-r5. */
25	pushq %rax
26	pushq %rdi
27	pushq %rsi
28	pushq %rdx
29	pushq %rcx
30	pushq %r8
31
32	/*
33	 * r10 has the pointer to count and timestamp, pass it as first
34	 * argument.
35	 */
36	movq %r10, %rdi
37
38	/* Emit call depth accounting for call below. */
39	CALL_DEPTH_ACCOUNT
40	call bpf_check_timed_may_goto
41
42	/* BPF_REG_AX=r10 will be stored into count, so move return value to it. */
43	movq %rax, %r10
44
45	/* Restore r5-r0. */
46	popq %r8
47	popq %rcx
48	popq %rdx
49	popq %rsi
50	popq %rdi
51	popq %rax
52
53	leave
54	RET
55SYM_FUNC_END(arch_bpf_timed_may_goto)