niansa-misc/linux
1
0
Fork 0
mirror of synced 2025-03-06 20:59:54 +01:00
Code Issues Projects Releases Packages Wiki Activity
linux/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
Andrii Nakryiko 46ba0e49b6 bpf: fix multi-uprobe PID filtering logic 
Current implementation of PID filtering logic for multi-uprobes in
uprobe_prog_run() is filtering down to exact *thread*, while the intent
for PID filtering it to filter by *process* instead. The check in
uprobe_prog_run() also differs from the analogous one in
uprobe_multi_link_filter() for some reason. The latter is correct,
checking task->mm, not the task itself.

Fix the check in uprobe_prog_run() to perform the same task->mm check.

While doing this, we also update get_pid_task() use to use PIDTYPE_TGID
type of lookup, given the intent is to get a representative task of an
entire process. This doesn't change behavior, but seems more logical. It
would hold task group leader task now, not any random thread task.

Last but not least, given multi-uprobe support is half-broken due to
this PID filtering logic (depending on whether PID filtering is
important or not), we need to make it easy for user space consumers
(including libbpf) to easily detect whether PID filtering logic was
already fixed.

We do it here by adding an early check on passed pid parameter. If it's
negative (and so has no chance of being a valid PID), we return -EINVAL.
Previous behavior would eventually return -ESRCH ("No process found"),
given there can't be any process with negative PID. This subtle change
won't make any practical change in behavior, but will allow applications
to detect PID filtering fixes easily. Libbpf fixes take advantage of
this in the next patch.

Cc: stable@vger.kernel.org
Acked-by: Jiri Olsa <jolsa@kernel.org>
Fixes: b733eeade4 ("bpf: Add pid filter support for uprobe_multi link")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240521163401.3005045-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-25 10:46:02 -07:00

588 lines
15 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0
#include <unistd.h>
#include <test_progs.h>
#include "uprobe_multi.skel.h"
#include "uprobe_multi_bench.skel.h"
#include "uprobe_multi_usdt.skel.h"
#include "bpf/libbpf_internal.h"
#include "testing_helpers.h"
static char test_data[] = "test_data";
noinline void uprobe_multi_func_1(void)
{
asm volatile ("");
}
noinline void uprobe_multi_func_2(void)
{
asm volatile ("");
}
noinline void uprobe_multi_func_3(void)
{
asm volatile ("");
}
struct child {
int go[2];
int pid;
};
static void release_child(struct child *child)
{
int child_status;
if (!child)
return;
close(child->go[1]);
close(child->go[0]);
if (child->pid > 0)
waitpid(child->pid, &child_status, 0);
}
static void kick_child(struct child *child)
{
char c = 1;
if (child) {
write(child->go[1], &c, 1);
release_child(child);
}
fflush(NULL);
}
static struct child *spawn_child(void)
{
static struct child child;
int err;
int c;
/* pipe to notify child to execute the trigger functions */
if (pipe(child.go))
return NULL;
child.pid = fork();
if (child.pid < 0) {
release_child(&child);
errno = EINVAL;
return NULL;
}
/* child */
if (child.pid == 0) {
close(child.go[1]);
/* wait for parent's kick */
err = read(child.go[0], &c, 1);
if (err != 1)
exit(err);
uprobe_multi_func_1();
uprobe_multi_func_2();
uprobe_multi_func_3();
exit(errno);
}
return &child;
}
static void uprobe_multi_test_run(struct uprobe_multi *skel, struct child *child)
{
skel->bss->uprobe_multi_func_1_addr = (__u64) uprobe_multi_func_1;
skel->bss->uprobe_multi_func_2_addr = (__u64) uprobe_multi_func_2;
skel->bss->uprobe_multi_func_3_addr = (__u64) uprobe_multi_func_3;
skel->bss->user_ptr = test_data;
/*
* Disable pid check in bpf program if we are pid filter test,
* because the probe should be executed only by child->pid
* passed at the probe attach.
*/
skel->bss->pid = child ? 0 : getpid();
if (child)
kick_child(child);
/* trigger all probes */
uprobe_multi_func_1();
uprobe_multi_func_2();
uprobe_multi_func_3();
/*
* There are 2 entry and 2 exit probe called for each uprobe_multi_func_[123]
* function and each slepable probe (6) increments uprobe_multi_sleep_result.
*/
ASSERT_EQ(skel->bss->uprobe_multi_func_1_result, 2, "uprobe_multi_func_1_result");
ASSERT_EQ(skel->bss->uprobe_multi_func_2_result, 2, "uprobe_multi_func_2_result");
ASSERT_EQ(skel->bss->uprobe_multi_func_3_result, 2, "uprobe_multi_func_3_result");
ASSERT_EQ(skel->bss->uretprobe_multi_func_1_result, 2, "uretprobe_multi_func_1_result");
ASSERT_EQ(skel->bss->uretprobe_multi_func_2_result, 2, "uretprobe_multi_func_2_result");
ASSERT_EQ(skel->bss->uretprobe_multi_func_3_result, 2, "uretprobe_multi_func_3_result");
ASSERT_EQ(skel->bss->uprobe_multi_sleep_result, 6, "uprobe_multi_sleep_result");
if (child)
ASSERT_EQ(skel->bss->child_pid, child->pid, "uprobe_multi_child_pid");
}
static void test_skel_api(void)
{
struct uprobe_multi *skel = NULL;
int err;
skel = uprobe_multi__open_and_load();
if (!ASSERT_OK_PTR(skel, "uprobe_multi__open_and_load"))
goto cleanup;
err = uprobe_multi__attach(skel);
if (!ASSERT_OK(err, "uprobe_multi__attach"))
goto cleanup;
uprobe_multi_test_run(skel, NULL);
cleanup:
uprobe_multi__destroy(skel);
}
static void
__test_attach_api(const char *binary, const char *pattern, struct bpf_uprobe_multi_opts *opts,
struct child *child)
{
pid_t pid = child ? child->pid : -1;
struct uprobe_multi *skel = NULL;
skel = uprobe_multi__open_and_load();
if (!ASSERT_OK_PTR(skel, "uprobe_multi__open_and_load"))
goto cleanup;
opts->retprobe = false;
skel->links.uprobe = bpf_program__attach_uprobe_multi(skel->progs.uprobe, pid,
binary, pattern, opts);
if (!ASSERT_OK_PTR(skel->links.uprobe, "bpf_program__attach_uprobe_multi"))
goto cleanup;
opts->retprobe = true;
skel->links.uretprobe = bpf_program__attach_uprobe_multi(skel->progs.uretprobe, pid,
binary, pattern, opts);
if (!ASSERT_OK_PTR(skel->links.uretprobe, "bpf_program__attach_uprobe_multi"))
goto cleanup;
opts->retprobe = false;
skel->links.uprobe_sleep = bpf_program__attach_uprobe_multi(skel->progs.uprobe_sleep, pid,
binary, pattern, opts);
if (!ASSERT_OK_PTR(skel->links.uprobe_sleep, "bpf_program__attach_uprobe_multi"))
goto cleanup;
opts->retprobe = true;
skel->links.uretprobe_sleep = bpf_program__attach_uprobe_multi(skel->progs.uretprobe_sleep,
pid, binary, pattern, opts);
if (!ASSERT_OK_PTR(skel->links.uretprobe_sleep, "bpf_program__attach_uprobe_multi"))
goto cleanup;
opts->retprobe = false;
skel->links.uprobe_extra = bpf_program__attach_uprobe_multi(skel->progs.uprobe_extra, -1,
binary, pattern, opts);
if (!ASSERT_OK_PTR(skel->links.uprobe_extra, "bpf_program__attach_uprobe_multi"))
goto cleanup;
uprobe_multi_test_run(skel, child);
cleanup:
uprobe_multi__destroy(skel);
}
static void
test_attach_api(const char *binary, const char *pattern, struct bpf_uprobe_multi_opts *opts)
{
struct child *child;
/* no pid filter */
__test_attach_api(binary, pattern, opts, NULL);
/* pid filter */
child = spawn_child();
if (!ASSERT_OK_PTR(child, "spawn_child"))
return;
__test_attach_api(binary, pattern, opts, child);
}
static void test_attach_api_pattern(void)
{
LIBBPF_OPTS(bpf_uprobe_multi_opts, opts);
test_attach_api("/proc/self/exe", "uprobe_multi_func_*", &opts);
test_attach_api("/proc/self/exe", "uprobe_multi_func_?", &opts);
}
static void test_attach_api_syms(void)
{
LIBBPF_OPTS(bpf_uprobe_multi_opts, opts);
const char *syms[3] = {
"uprobe_multi_func_1",
"uprobe_multi_func_2",
"uprobe_multi_func_3",
};
opts.syms = syms;
opts.cnt = ARRAY_SIZE(syms);
test_attach_api("/proc/self/exe", NULL, &opts);
}
static void test_attach_api_fails(void)
{
LIBBPF_OPTS(bpf_link_create_opts, opts);
const char *path = "/proc/self/exe";
struct uprobe_multi *skel = NULL;
int prog_fd, link_fd = -1;
unsigned long offset = 0;
skel = uprobe_multi__open_and_load();
if (!ASSERT_OK_PTR(skel, "uprobe_multi__open_and_load"))
goto cleanup;
prog_fd = bpf_program__fd(skel->progs.uprobe_extra);
/* abnormal cnt */
opts.uprobe_multi.path = path;
opts.uprobe_multi.offsets = &offset;
opts.uprobe_multi.cnt = INT_MAX;
link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_ERR(link_fd, "link_fd"))
goto cleanup;
if (!ASSERT_EQ(link_fd, -E2BIG, "big cnt"))
goto cleanup;
/* cnt is 0 */
LIBBPF_OPTS_RESET(opts,
.uprobe_multi.path = path,
.uprobe_multi.offsets = (unsigned long *) &offset,
);
link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_ERR(link_fd, "link_fd"))
goto cleanup;
if (!ASSERT_EQ(link_fd, -EINVAL, "cnt_is_zero"))
goto cleanup;
/* negative offset */
offset = -1;
opts.uprobe_multi.path = path;
opts.uprobe_multi.offsets = (unsigned long *) &offset;
opts.uprobe_multi.cnt = 1;
link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_ERR(link_fd, "link_fd"))
goto cleanup;
if (!ASSERT_EQ(link_fd, -EINVAL, "offset_is_negative"))
goto cleanup;
/* offsets is NULL */
LIBBPF_OPTS_RESET(opts,
.uprobe_multi.path = path,
.uprobe_multi.cnt = 1,
);
link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_ERR(link_fd, "link_fd"))
goto cleanup;
if (!ASSERT_EQ(link_fd, -EINVAL, "offsets_is_null"))
goto cleanup;
/* wrong offsets pointer */
LIBBPF_OPTS_RESET(opts,
.uprobe_multi.path = path,
.uprobe_multi.offsets = (unsigned long *) 1,
.uprobe_multi.cnt = 1,
);
link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_ERR(link_fd, "link_fd"))
goto cleanup;
if (!ASSERT_EQ(link_fd, -EFAULT, "offsets_is_wrong"))
goto cleanup;
/* path is NULL */
offset = 1;
LIBBPF_OPTS_RESET(opts,
.uprobe_multi.offsets = (unsigned long *) &offset,
.uprobe_multi.cnt = 1,
);
link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_ERR(link_fd, "link_fd"))
goto cleanup;
if (!ASSERT_EQ(link_fd, -EINVAL, "path_is_null"))
goto cleanup;
/* wrong path pointer */
LIBBPF_OPTS_RESET(opts,
.uprobe_multi.path = (const char *) 1,
.uprobe_multi.offsets = (unsigned long *) &offset,
.uprobe_multi.cnt = 1,
);
link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_ERR(link_fd, "link_fd"))
goto cleanup;
if (!ASSERT_EQ(link_fd, -EFAULT, "path_is_wrong"))
goto cleanup;
/* wrong path type */
LIBBPF_OPTS_RESET(opts,
.uprobe_multi.path = "/",
.uprobe_multi.offsets = (unsigned long *) &offset,
.uprobe_multi.cnt = 1,
);
link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_ERR(link_fd, "link_fd"))
goto cleanup;
if (!ASSERT_EQ(link_fd, -EBADF, "path_is_wrong_type"))
goto cleanup;
/* wrong cookies pointer */
LIBBPF_OPTS_RESET(opts,
.uprobe_multi.path = path,
.uprobe_multi.offsets = (unsigned long *) &offset,
.uprobe_multi.cookies = (__u64 *) 1ULL,
.uprobe_multi.cnt = 1,
);
link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_ERR(link_fd, "link_fd"))
goto cleanup;
if (!ASSERT_EQ(link_fd, -EFAULT, "cookies_is_wrong"))
goto cleanup;
/* wrong ref_ctr_offsets pointer */
LIBBPF_OPTS_RESET(opts,
.uprobe_multi.path = path,
.uprobe_multi.offsets = (unsigned long *) &offset,
.uprobe_multi.cookies = (__u64 *) &offset,
.uprobe_multi.ref_ctr_offsets = (unsigned long *) 1,
.uprobe_multi.cnt = 1,
);
link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_ERR(link_fd, "link_fd"))
goto cleanup;
if (!ASSERT_EQ(link_fd, -EFAULT, "ref_ctr_offsets_is_wrong"))
goto cleanup;
/* wrong flags */
LIBBPF_OPTS_RESET(opts,
.uprobe_multi.flags = 1 << 31,
);
link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_ERR(link_fd, "link_fd"))
goto cleanup;
if (!ASSERT_EQ(link_fd, -EINVAL, "wrong_flags"))
goto cleanup;
/* wrong pid */
LIBBPF_OPTS_RESET(opts,
.uprobe_multi.path = path,
.uprobe_multi.offsets = (unsigned long *) &offset,
.uprobe_multi.cnt = 1,
.uprobe_multi.pid = -2,
);
link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_ERR(link_fd, "link_fd"))
goto cleanup;
ASSERT_EQ(link_fd, -EINVAL, "pid_is_wrong");
cleanup:
if (link_fd >= 0)
close(link_fd);
uprobe_multi__destroy(skel);
}
static void __test_link_api(struct child *child)
{
int prog_fd, link1_fd = -1, link2_fd = -1, link3_fd = -1, link4_fd = -1;
LIBBPF_OPTS(bpf_link_create_opts, opts);
const char *path = "/proc/self/exe";
struct uprobe_multi *skel = NULL;
unsigned long *offsets = NULL;
const char *syms[3] = {
"uprobe_multi_func_1",
"uprobe_multi_func_2",
"uprobe_multi_func_3",
};
int link_extra_fd = -1;
int err;
err = elf_resolve_syms_offsets(path, 3, syms, (unsigned long **) &offsets, STT_FUNC);
if (!ASSERT_OK(err, "elf_resolve_syms_offsets"))
return;
opts.uprobe_multi.path = path;
opts.uprobe_multi.offsets = offsets;
opts.uprobe_multi.cnt = ARRAY_SIZE(syms);
opts.uprobe_multi.pid = child ? child->pid : 0;
skel = uprobe_multi__open_and_load();
if (!ASSERT_OK_PTR(skel, "uprobe_multi__open_and_load"))
goto cleanup;
opts.kprobe_multi.flags = 0;
prog_fd = bpf_program__fd(skel->progs.uprobe);
link1_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_GE(link1_fd, 0, "link1_fd"))
goto cleanup;
opts.kprobe_multi.flags = BPF_F_UPROBE_MULTI_RETURN;
prog_fd = bpf_program__fd(skel->progs.uretprobe);
link2_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_GE(link2_fd, 0, "link2_fd"))
goto cleanup;
opts.kprobe_multi.flags = 0;
prog_fd = bpf_program__fd(skel->progs.uprobe_sleep);
link3_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_GE(link3_fd, 0, "link3_fd"))
goto cleanup;
opts.kprobe_multi.flags = BPF_F_UPROBE_MULTI_RETURN;
prog_fd = bpf_program__fd(skel->progs.uretprobe_sleep);
link4_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_GE(link4_fd, 0, "link4_fd"))
goto cleanup;
opts.kprobe_multi.flags = 0;
opts.uprobe_multi.pid = 0;
prog_fd = bpf_program__fd(skel->progs.uprobe_extra);
link_extra_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
if (!ASSERT_GE(link_extra_fd, 0, "link_extra_fd"))
goto cleanup;
uprobe_multi_test_run(skel, child);
cleanup:
if (link1_fd >= 0)
close(link1_fd);
if (link2_fd >= 0)
close(link2_fd);
if (link3_fd >= 0)
close(link3_fd);
if (link4_fd >= 0)
close(link4_fd);
if (link_extra_fd >= 0)
close(link_extra_fd);
uprobe_multi__destroy(skel);
free(offsets);
}
static void test_link_api(void)
{
struct child *child;
/* no pid filter */
__test_link_api(NULL);
/* pid filter */
child = spawn_child();
if (!ASSERT_OK_PTR(child, "spawn_child"))
return;
__test_link_api(child);
}
static void test_bench_attach_uprobe(void)
{
long attach_start_ns = 0, attach_end_ns = 0;
struct uprobe_multi_bench *skel = NULL;
long detach_start_ns, detach_end_ns;
double attach_delta, detach_delta;
int err;
skel = uprobe_multi_bench__open_and_load();
if (!ASSERT_OK_PTR(skel, "uprobe_multi_bench__open_and_load"))
goto cleanup;
attach_start_ns = get_time_ns();
err = uprobe_multi_bench__attach(skel);
if (!ASSERT_OK(err, "uprobe_multi_bench__attach"))
goto cleanup;
attach_end_ns = get_time_ns();
system("./uprobe_multi bench");
ASSERT_EQ(skel->bss->count, 50000, "uprobes_count");
cleanup:
detach_start_ns = get_time_ns();
uprobe_multi_bench__destroy(skel);
detach_end_ns = get_time_ns();
attach_delta = (attach_end_ns - attach_start_ns) / 1000000000.0;
detach_delta = (detach_end_ns - detach_start_ns) / 1000000000.0;
printf("%s: attached in %7.3lfs\n", __func__, attach_delta);
printf("%s: detached in %7.3lfs\n", __func__, detach_delta);
}
static void test_bench_attach_usdt(void)
{
long attach_start_ns = 0, attach_end_ns = 0;
struct uprobe_multi_usdt *skel = NULL;
long detach_start_ns, detach_end_ns;
double attach_delta, detach_delta;
skel = uprobe_multi_usdt__open_and_load();
if (!ASSERT_OK_PTR(skel, "uprobe_multi__open"))
goto cleanup;
attach_start_ns = get_time_ns();
skel->links.usdt0 = bpf_program__attach_usdt(skel->progs.usdt0, -1, "./uprobe_multi",
"test", "usdt", NULL);
if (!ASSERT_OK_PTR(skel->links.usdt0, "bpf_program__attach_usdt"))
goto cleanup;
attach_end_ns = get_time_ns();
system("./uprobe_multi usdt");
ASSERT_EQ(skel->bss->count, 50000, "usdt_count");
cleanup:
detach_start_ns = get_time_ns();
uprobe_multi_usdt__destroy(skel);
detach_end_ns = get_time_ns();
attach_delta = (attach_end_ns - attach_start_ns) / 1000000000.0;
detach_delta = (detach_end_ns - detach_start_ns) / 1000000000.0;
printf("%s: attached in %7.3lfs\n", __func__, attach_delta);
printf("%s: detached in %7.3lfs\n", __func__, detach_delta);
}
void test_uprobe_multi_test(void)
{
if (test__start_subtest("skel_api"))
test_skel_api();
if (test__start_subtest("attach_api_pattern"))
test_attach_api_pattern();
if (test__start_subtest("attach_api_syms"))
test_attach_api_syms();
if (test__start_subtest("link_api"))
test_link_api();
if (test__start_subtest("bench_uprobe"))
test_bench_attach_uprobe();
if (test__start_subtest("bench_usdt"))
test_bench_attach_usdt();
if (test__start_subtest("attach_api_fails"))
test_attach_api_fails();
}
Reference in a new issue View git blame Copy permalink