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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2024 Google */
#include <test_progs.h>
#include <bpf/libbpf.h>
#include <bpf/btf.h>
#include "kmem_cache_iter.skel.h"
#define SLAB_NAME_MAX 32
struct kmem_cache_result {
char name[SLAB_NAME_MAX];
long obj_size;
};
static void subtest_kmem_cache_iter_check_task_struct(struct kmem_cache_iter *skel)
{
LIBBPF_OPTS(bpf_test_run_opts, opts,
.flags = 0, /* Run it with the current task */
);
int prog_fd = bpf_program__fd(skel->progs.check_task_struct);
/* Get task_struct and check it if's from a slab cache */
ASSERT_OK(bpf_prog_test_run_opts(prog_fd, &opts), "prog_test_run");
/* The BPF program should set 'found' variable */
ASSERT_EQ(skel->bss->task_struct_found, 1, "task_struct_found");
}
static void subtest_kmem_cache_iter_check_slabinfo(struct kmem_cache_iter *skel)
{
FILE *fp;
int map_fd;
char name[SLAB_NAME_MAX];
unsigned long objsize;
char rest_of_line[1000];
struct kmem_cache_result r;
int seen = 0;
fp = fopen("/proc/slabinfo", "r");
if (fp == NULL) {
/* CONFIG_SLUB_DEBUG is not enabled */
return;
}
map_fd = bpf_map__fd(skel->maps.slab_result);
/* Ignore first two lines for header */
fscanf(fp, "slabinfo - version: %*d.%*d\n");
fscanf(fp, "# %*s %*s %*s %*s %*s %*s : %[^\n]\n", rest_of_line);
/* Compare name and objsize only - others can be changes frequently */
while (fscanf(fp, "%s %*u %*u %lu %*u %*u : %[^\n]\n",
name, &objsize, rest_of_line) == 3) {
int ret = bpf_map_lookup_elem(map_fd, &seen, &r);
if (!ASSERT_OK(ret, "kmem_cache_lookup"))
break;
ASSERT_STREQ(r.name, name, "kmem_cache_name");
ASSERT_EQ(r.obj_size, objsize, "kmem_cache_objsize");
seen++;
}
ASSERT_EQ(skel->bss->kmem_cache_seen, seen, "kmem_cache_seen_eq");
fclose(fp);
}
static void subtest_kmem_cache_iter_open_coded(struct kmem_cache_iter *skel)
{
LIBBPF_OPTS(bpf_test_run_opts, topts);
int err, fd;
/* No need to attach it, just run it directly */
fd = bpf_program__fd(skel->progs.open_coded_iter);
err = bpf_prog_test_run_opts(fd, &topts);
if (!ASSERT_OK(err, "test_run_opts err"))
return;
if (!ASSERT_OK(topts.retval, "test_run_opts retval"))
return;
/* It should be same as we've seen from the explicit iterator */
ASSERT_EQ(skel->bss->open_coded_seen, skel->bss->kmem_cache_seen, "open_code_seen_eq");
}
void test_kmem_cache_iter(void)
{
struct kmem_cache_iter *skel = NULL;
char buf[256];
int iter_fd;
skel = kmem_cache_iter__open_and_load();
if (!ASSERT_OK_PTR(skel, "kmem_cache_iter__open_and_load"))
return;
if (!ASSERT_OK(kmem_cache_iter__attach(skel), "skel_attach"))
goto destroy;
iter_fd = bpf_iter_create(bpf_link__fd(skel->links.slab_info_collector));
if (!ASSERT_GE(iter_fd, 0, "iter_create"))
goto destroy;
memset(buf, 0, sizeof(buf));
while (read(iter_fd, buf, sizeof(buf) > 0)) {
/* Read out all contents */
printf("%s", buf);
}
/* Next reads should return 0 */
ASSERT_EQ(read(iter_fd, buf, sizeof(buf)), 0, "read");
if (test__start_subtest("check_task_struct"))
subtest_kmem_cache_iter_check_task_struct(skel);
if (test__start_subtest("check_slabinfo"))
subtest_kmem_cache_iter_check_slabinfo(skel);
if (test__start_subtest("open_coded_iter"))
subtest_kmem_cache_iter_open_coded(skel);
close(iter_fd);
destroy:
kmem_cache_iter__destroy(skel);
}
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