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// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019 Facebook
#include <linux/bpf.h>
#include <stdint.h>
#include <stdbool.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_core_read.h>
char _license[] SEC("license") = "GPL";
struct {
char in[256];
char out[256];
bool skip;
uint64_t my_pid_tgid;
} data = {};
struct core_reloc_kernel_output {
int valid[10];
/* we have test_progs[-flavor], so cut flavor part */
char comm[sizeof("test_progs")];
int comm_len;
bool local_task_struct_matches;
};
struct task_struct {
int pid;
int tgid;
char comm[16];
struct task_struct *group_leader;
};
struct mm_struct___wrong {
int abc_whatever_should_not_exist;
};
struct task_struct___local {
int pid;
struct mm_struct___wrong *mm;
};
#define CORE_READ(dst, src) bpf_core_read(dst, sizeof(*(dst)), src)
SEC("raw_tracepoint/sys_enter")
int test_core_kernel(void *ctx)
{
/* Support for the BPF_TYPE_MATCHES argument to the
* __builtin_preserve_type_info builtin was added at some point during
* development of clang 15 and it's what we require for this test.
*/
#if __has_builtin(__builtin_preserve_type_info) && __clang_major__ >= 15
struct task_struct *task = (void *)bpf_get_current_task();
struct core_reloc_kernel_output *out = (void *)&data.out;
uint64_t pid_tgid = bpf_get_current_pid_tgid();
uint32_t real_tgid = (uint32_t)pid_tgid;
int pid, tgid;
if (data.my_pid_tgid != pid_tgid)
return 0;
if (CORE_READ(&pid, &task->pid) ||
CORE_READ(&tgid, &task->tgid))
return 1;
/* validate pid + tgid matches */
out->valid[0] = (((uint64_t)pid << 32) | tgid) == pid_tgid;
/* test variadic BPF_CORE_READ macros */
out->valid[1] = BPF_CORE_READ(task,
tgid) == real_tgid;
out->valid[2] = BPF_CORE_READ(task,
group_leader,
tgid) == real_tgid;
out->valid[3] = BPF_CORE_READ(task,
group_leader, group_leader,
tgid) == real_tgid;
out->valid[4] = BPF_CORE_READ(task,
group_leader, group_leader, group_leader,
tgid) == real_tgid;
out->valid[5] = BPF_CORE_READ(task,
group_leader, group_leader, group_leader,
group_leader,
tgid) == real_tgid;
out->valid[6] = BPF_CORE_READ(task,
group_leader, group_leader, group_leader,
group_leader, group_leader,
tgid) == real_tgid;
out->valid[7] = BPF_CORE_READ(task,
group_leader, group_leader, group_leader,
group_leader, group_leader, group_leader,
tgid) == real_tgid;
out->valid[8] = BPF_CORE_READ(task,
group_leader, group_leader, group_leader,
group_leader, group_leader, group_leader,
group_leader,
tgid) == real_tgid;
out->valid[9] = BPF_CORE_READ(task,
group_leader, group_leader, group_leader,
group_leader, group_leader, group_leader,
group_leader, group_leader,
tgid) == real_tgid;
/* test BPF_CORE_READ_STR_INTO() returns correct code and contents */
out->comm_len = BPF_CORE_READ_STR_INTO(
&out->comm, task,
group_leader, group_leader, group_leader, group_leader,
group_leader, group_leader, group_leader, group_leader,
comm);
out->local_task_struct_matches = bpf_core_type_matches(struct task_struct___local);
#else
data.skip = true;
#endif
return 0;
}
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