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selftests/bpf: Add test for sleepable bpf iterator programs 

This adds a test for bpf iterator programs to make use of sleepable
bpf helpers.

Signed-off-by: Kenny Yu <kennyyu@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124185403.468466-5-kennyyu@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Kenny Yu 2022-01-24 10:54:03 -08:00 committed by Alexei Starovoitov
parent a8b77f7463
commit 45105c2eb7
2 changed files with 74 additions and 0 deletions
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20
tools/testing/selftests/bpf/prog_tests/bpf_iter.c
View File

@ -138,6 +138,24 @@ static void test_task(void)
bpf_iter_task__destroy(skel);
}
static void test_task_sleepable(void)
{
struct bpf_iter_task *skel;
skel = bpf_iter_task__open_and_load();
if (!ASSERT_OK_PTR(skel, "bpf_iter_task__open_and_load"))
return;
do_dummy_read(skel->progs.dump_task_sleepable);
ASSERT_GT(skel->bss->num_expected_failure_copy_from_user_task, 0,
"num_expected_failure_copy_from_user_task");
ASSERT_GT(skel->bss->num_success_copy_from_user_task, 0,
"num_success_copy_from_user_task");
bpf_iter_task__destroy(skel);
}
static void test_task_stack(void)
{
struct bpf_iter_task_stack *skel;
@ -1252,6 +1270,8 @@ void test_bpf_iter(void)
test_bpf_map();
if (test__start_subtest("task"))
test_task();
if (test__start_subtest("task_sleepable"))
test_task_sleepable();
if (test__start_subtest("task_stack"))
test_task_stack();
if (test__start_subtest("task_file"))

54
tools/testing/selftests/bpf/progs/bpf_iter_task.c
View File

@ -2,6 +2,7 @@
/* Copyright (c) 2020 Facebook */
#include "bpf_iter.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
char _license[] SEC("license") = "GPL";
@ -23,3 +24,56 @@ int dump_task(struct bpf_iter__task *ctx)
BPF_SEQ_PRINTF(seq, "%8d %8d\n", task->tgid, task->pid);
return 0;
}
int num_expected_failure_copy_from_user_task = 0;
int num_success_copy_from_user_task = 0;
SEC("iter.s/task")
int dump_task_sleepable(struct bpf_iter__task *ctx)
{
struct seq_file *seq = ctx->meta->seq;
struct task_struct *task = ctx->task;
static const char info[] = " === END ===";
struct pt_regs *regs;
void *ptr;
uint32_t user_data = 0;
int ret;
if (task == (void *)0) {
BPF_SEQ_PRINTF(seq, "%s\n", info);
return 0;
}
/* Read an invalid pointer and ensure we get an error */
ptr = NULL;
ret = bpf_copy_from_user_task(&user_data, sizeof(uint32_t), ptr, task, 0);
if (ret) {
++num_expected_failure_copy_from_user_task;
} else {
BPF_SEQ_PRINTF(seq, "%s\n", info);
return 0;
}
/* Try to read the contents of the task's instruction pointer from the
* remote task's address space.
*/
regs = (struct pt_regs *)bpf_task_pt_regs(task);
if (regs == (void *)0) {
BPF_SEQ_PRINTF(seq, "%s\n", info);
return 0;
}
ptr = (void *)PT_REGS_IP(regs);
ret = bpf_copy_from_user_task(&user_data, sizeof(uint32_t), ptr, task, 0);
if (ret) {
BPF_SEQ_PRINTF(seq, "%s\n", info);
return 0;
}
++num_success_copy_from_user_task;
if (ctx->meta->seq_num == 0)
BPF_SEQ_PRINTF(seq, " tgid gid data\n");
BPF_SEQ_PRINTF(seq, "%8d %8d %8d\n", task->tgid, task->pid, user_data);
return 0;
}