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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_core_read.h>
#include <bpf/bpf_tracing.h>
char _license[] SEC("license") = "GPL";
struct bpf_testmod_test_read_ctx {
/* field order is mixed up */
size_t len;
char *buf;
loff_t off;
} __attribute__((preserve_access_index));
struct {
char in[256];
char out[256];
bool skip;
uint64_t my_pid_tgid;
} data = {};
struct core_reloc_module_output {
long long len;
long long off;
int read_ctx_sz;
bool read_ctx_exists;
bool buf_exists;
bool len_exists;
bool off_exists;
/* we have test_progs[-flavor], so cut flavor part */
char comm[sizeof("test_progs")];
int comm_len;
};
SEC("raw_tp/bpf_testmod_test_read")
int BPF_PROG(test_core_module_probed,
struct task_struct *task,
struct bpf_testmod_test_read_ctx *read_ctx)
{
#if __has_builtin(__builtin_preserve_enum_value)
struct core_reloc_module_output *out = (void *)&data.out;
__u64 pid_tgid = bpf_get_current_pid_tgid();
__u32 real_tgid = (__u32)(pid_tgid >> 32);
__u32 real_pid = (__u32)pid_tgid;
if (data.my_pid_tgid != pid_tgid)
return 0;
if (BPF_CORE_READ(task, pid) != real_pid || BPF_CORE_READ(task, tgid) != real_tgid)
return 0;
out->len = BPF_CORE_READ(read_ctx, len);
out->off = BPF_CORE_READ(read_ctx, off);
out->read_ctx_sz = bpf_core_type_size(struct bpf_testmod_test_read_ctx);
out->read_ctx_exists = bpf_core_type_exists(struct bpf_testmod_test_read_ctx);
out->buf_exists = bpf_core_field_exists(read_ctx->buf);
out->off_exists = bpf_core_field_exists(read_ctx->off);
out->len_exists = bpf_core_field_exists(read_ctx->len);
out->comm_len = BPF_CORE_READ_STR_INTO(&out->comm, task, comm);
#else
data.skip = true;
#endif
return 0;
}
SEC("tp_btf/bpf_testmod_test_read")
int BPF_PROG(test_core_module_direct,
struct task_struct *task,
struct bpf_testmod_test_read_ctx *read_ctx)
{
#if __has_builtin(__builtin_preserve_enum_value)
struct core_reloc_module_output *out = (void *)&data.out;
__u64 pid_tgid = bpf_get_current_pid_tgid();
__u32 real_tgid = (__u32)(pid_tgid >> 32);
__u32 real_pid = (__u32)pid_tgid;
if (data.my_pid_tgid != pid_tgid)
return 0;
if (task->pid != real_pid || task->tgid != real_tgid)
return 0;
out->len = read_ctx->len;
out->off = read_ctx->off;
out->read_ctx_sz = bpf_core_type_size(struct bpf_testmod_test_read_ctx);
out->read_ctx_exists = bpf_core_type_exists(struct bpf_testmod_test_read_ctx);
out->buf_exists = bpf_core_field_exists(read_ctx->buf);
out->off_exists = bpf_core_field_exists(read_ctx->off);
out->len_exists = bpf_core_field_exists(read_ctx->len);
out->comm_len = BPF_CORE_READ_STR_INTO(&out->comm, task, comm);
#else
data.skip = true;
#endif
return 0;
}
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