diff options
Diffstat (limited to 'arch/x86/net/bpf_timed_may_goto.S')
| -rw-r--r-- | arch/x86/net/bpf_timed_may_goto.S | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/arch/x86/net/bpf_timed_may_goto.S b/arch/x86/net/bpf_timed_may_goto.S new file mode 100644 index 000000000000..54c690cae190 --- /dev/null +++ b/arch/x86/net/bpf_timed_may_goto.S @@ -0,0 +1,55 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */ + +#include <linux/export.h> +#include <linux/linkage.h> +#include <asm/nospec-branch.h> + + .code64 + .section .text, "ax" + +SYM_FUNC_START(arch_bpf_timed_may_goto) + ANNOTATE_NOENDBR + + /* + * r10 passes us stack depth, load the pointer to count and timestamp + * into r10 by adding it to BPF frame pointer. + */ + leaq (%rbp, %r10, 1), %r10 + + /* Setup frame. */ + pushq %rbp + movq %rsp, %rbp + + /* Save r0-r5. */ + pushq %rax + pushq %rdi + pushq %rsi + pushq %rdx + pushq %rcx + pushq %r8 + + /* + * r10 has the pointer to count and timestamp, pass it as first + * argument. + */ + movq %r10, %rdi + + /* Emit call depth accounting for call below. */ + CALL_DEPTH_ACCOUNT + call bpf_check_timed_may_goto + + /* BPF_REG_AX=r10 will be stored into count, so move return value to it. */ + movq %rax, %r10 + + /* Restore r5-r0. */ + popq %r8 + popq %rcx + popq %rdx + popq %rsi + popq %rdi + popq %rax + + leave + RET +SYM_FUNC_END(arch_bpf_timed_may_goto) |