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// SPDX-License-Identifier: GPL-2.0
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include "../../../include/linux/filter.h"
#include "bpf_misc.h"
/* The targets are global_unwinds() and global_never_unwinds() in verifier_unwind.c */
#define unwind_exit ".8byte %[insn_unwind_exit];"
#define __imm_unwind_exit \
__imm_insn(insn_unwind_exit, \
BPF_RAW_INSN(BPF_JMP | BPF_EXIT, 0, BPF_UNWIND_EXIT, 0, 0))
extern void bpf_throw(__u64 cookie) __ksym;
int fentry_cnt;
SEC("?fentry/global_unwinds")
int BPF_PROG(fentry_unwind)
{
fentry_cnt++;
return 0;
}
SEC("?fexit/global_unwinds")
int BPF_PROG(fexit_unwind)
{
return 0;
}
SEC("?freplace/global_unwinds")
unsigned long freplace_returns(void)
{
return 9;
}
SEC("?freplace/global_unwinds")
__naked unsigned long freplace_unwinds(void)
{
asm volatile (
"r0 = 3;"
unwind_exit
:
: __imm_unwind_exit
);
}
/* Not naked: the argument has to have a name in BTF */
__noinline int throws_cb(__u64 cookie)
{
if (cookie)
asm volatile ("r0 = 3;" unwind_exit :: __imm_unwind_exit : "r0");
return 0;
}
/* It has no unwind_exit, so it can replace a subprog that cannot unwind */
SEC("?freplace/global_never_unwinds")
__attribute__((btf_decl_tag("exception_callback:throws_cb")))
unsigned long freplace_throws(void)
{
bpf_throw(1);
return 0;
}
char _license[] SEC("license") = "GPL";
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