linux-zen-desktop/tools/testing/selftests/bpf/progs/jit_probe_mem.c

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2023-08-30 17:31:07 +02:00
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
#include <vmlinux.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_helpers.h>
static struct prog_test_ref_kfunc __kptr_ref *v;
long total_sum = -1;
extern struct prog_test_ref_kfunc *bpf_kfunc_call_test_acquire(unsigned long *sp) __ksym;
extern void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p) __ksym;
SEC("tc")
int test_jit_probe_mem(struct __sk_buff *ctx)
{
struct prog_test_ref_kfunc *p;
unsigned long zero = 0, sum;
p = bpf_kfunc_call_test_acquire(&zero);
if (!p)
return 1;
p = bpf_kptr_xchg(&v, p);
if (p)
goto release_out;
/* Direct map value access of kptr, should be PTR_UNTRUSTED */
p = v;
if (!p)
return 1;
asm volatile (
"r9 = %[p];"
"%[sum] = 0;"
/* r8 = p->a */
"r8 = *(u32 *)(r9 + 0);"
"%[sum] += r8;"
/* r8 = p->b */
"r8 = *(u32 *)(r9 + 4);"
"%[sum] += r8;"
"r9 += 8;"
/* r9 = p->a */
"r9 = *(u32 *)(r9 - 8);"
"%[sum] += r9;"
: [sum] "=r"(sum)
: [p] "r"(p)
: "r8", "r9"
);
total_sum = sum;
return 0;
release_out:
bpf_kfunc_call_test_release(p);
return 1;
}
char _license[] SEC("license") = "GPL";