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// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2023. Huawei Technologies Co., Ltd */
#include <linux/types.h>
#include <bpf/bpf_helpers.h>
#include "bpf_experimental.h"
#include "bpf_misc.h"
char _license[] SEC("license") = "GPL";
struct bin_data {
char blob[32];
};
#define private(name) SEC(".bss." #name) __hidden __attribute__((aligned(8)))
private(kptr) struct bin_data __kptr * ptr;
SEC("tc")
__naked int kptr_xchg_inline(void)
{
asm volatile (
"r1 = %[ptr] ll;"
"r2 = 0;"
"call %[bpf_kptr_xchg];"
"if r0 == 0 goto 1f;"
"r1 = r0;"
"r2 = 0;"
"call %[bpf_obj_drop_impl];"
"1:"
"r0 = 0;"
"exit;"
:
: __imm_addr(ptr),
__imm(bpf_kptr_xchg),
__imm(bpf_obj_drop_impl)
: __clobber_all
);
}
/* BTF FUNC records are not generated for kfuncs referenced
* from inline assembly. These records are necessary for
* libbpf to link the program. The function below is a hack
* to ensure that BTF FUNC records are generated.
*/
void __btf_root(void)
{
bpf_obj_drop(NULL);
}
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