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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2023 Hengqi Chen */
#include <test_progs.h>
#include <asm/ptrace.h>
#include "test_uprobe.skel.h"
static FILE *urand_spawn(int *pid)
{
FILE *f;
/* urandom_read's stdout is wired into f */
f = popen("./urandom_read 1 report-pid", "r");
if (!f)
return NULL;
if (fscanf(f, "%d", pid) != 1) {
pclose(f);
errno = EINVAL;
return NULL;
}
return f;
}
static int urand_trigger(FILE **urand_pipe)
{
int exit_code;
/* pclose() waits for child process to exit and returns their exit code */
exit_code = pclose(*urand_pipe);
*urand_pipe = NULL;
return exit_code;
}
static void test_uprobe_attach(void)
{
LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
struct test_uprobe *skel;
FILE *urand_pipe = NULL;
int urand_pid = 0, err;
skel = test_uprobe__open_and_load();
if (!ASSERT_OK_PTR(skel, "skel_open"))
return;
urand_pipe = urand_spawn(&urand_pid);
if (!ASSERT_OK_PTR(urand_pipe, "urand_spawn"))
goto cleanup;
skel->bss->my_pid = urand_pid;
/* Manual attach uprobe to urandlib_api
* There are two `urandlib_api` symbols in .dynsym section:
* - urandlib_api@LIBURANDOM_READ_1.0.0
* - urandlib_api@@LIBURANDOM_READ_2.0.0
* Both are global bind and would cause a conflict if user
* specify the symbol name without a version suffix
*/
uprobe_opts.func_name = "urandlib_api";
skel->links.test4 = bpf_program__attach_uprobe_opts(skel->progs.test4,
urand_pid,
"./liburandom_read.so",
0 /* offset */,
&uprobe_opts);
if (!ASSERT_ERR_PTR(skel->links.test4, "urandlib_api_attach_conflict"))
goto cleanup;
uprobe_opts.func_name = "urandlib_api@LIBURANDOM_READ_1.0.0";
skel->links.test4 = bpf_program__attach_uprobe_opts(skel->progs.test4,
urand_pid,
"./liburandom_read.so",
0 /* offset */,
&uprobe_opts);
if (!ASSERT_OK_PTR(skel->links.test4, "urandlib_api_attach_ok"))
goto cleanup;
/* Auto attach 3 u[ret]probes to urandlib_api_sameoffset */
err = test_uprobe__attach(skel);
if (!ASSERT_OK(err, "skel_attach"))
goto cleanup;
/* trigger urandom_read */
ASSERT_OK(urand_trigger(&urand_pipe), "urand_exit_code");
ASSERT_EQ(skel->bss->test1_result, 1, "urandlib_api_sameoffset");
ASSERT_EQ(skel->bss->test2_result, 1, "urandlib_api_sameoffset@v1");
ASSERT_EQ(skel->bss->test3_result, 3, "urandlib_api_sameoffset@@v2");
ASSERT_EQ(skel->bss->test4_result, 1, "urandlib_api");
cleanup:
if (urand_pipe)
pclose(urand_pipe);
test_uprobe__destroy(skel);
}
#ifdef __x86_64__
__naked __maybe_unused unsigned long uprobe_regs_change_trigger(void)
{
asm volatile (
"ret\n"
);
}
static __naked void uprobe_regs_change(struct pt_regs *before, struct pt_regs *after)
{
asm volatile (
"movq %r11, 48(%rdi)\n"
"movq %r10, 56(%rdi)\n"
"movq %r9, 64(%rdi)\n"
"movq %r8, 72(%rdi)\n"
"movq %rax, 80(%rdi)\n"
"movq %rcx, 88(%rdi)\n"
"movq %rdx, 96(%rdi)\n"
"movq %rsi, 104(%rdi)\n"
"movq %rdi, 112(%rdi)\n"
/* save 2nd argument */
"pushq %rsi\n"
"call uprobe_regs_change_trigger\n"
/* save return value and load 2nd argument pointer to rax */
"pushq %rax\n"
"movq 8(%rsp), %rax\n"
"movq %r11, 48(%rax)\n"
"movq %r10, 56(%rax)\n"
"movq %r9, 64(%rax)\n"
"movq %r8, 72(%rax)\n"
"movq %rcx, 88(%rax)\n"
"movq %rdx, 96(%rax)\n"
"movq %rsi, 104(%rax)\n"
"movq %rdi, 112(%rax)\n"
/* restore return value and 2nd argument */
"pop %rax\n"
"pop %rsi\n"
"movq %rax, 80(%rsi)\n"
"ret\n"
);
}
static void regs_common(void)
{
struct pt_regs before = {}, after = {}, expected = {
.rax = 0xc0ffe,
.rcx = 0xbad,
.rdx = 0xdead,
.r8 = 0x8,
.r9 = 0x9,
.r10 = 0x10,
.r11 = 0x11,
.rdi = 0x12,
.rsi = 0x13,
};
LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
struct test_uprobe *skel;
skel = test_uprobe__open_and_load();
if (!ASSERT_OK_PTR(skel, "skel_open"))
return;
skel->bss->my_pid = getpid();
skel->bss->regs = expected;
uprobe_opts.func_name = "uprobe_regs_change_trigger";
skel->links.test_regs_change = bpf_program__attach_uprobe_opts(skel->progs.test_regs_change,
-1,
"/proc/self/exe",
0 /* offset */,
&uprobe_opts);
if (!ASSERT_OK_PTR(skel->links.test_regs_change, "bpf_program__attach_uprobe_opts"))
goto cleanup;
uprobe_regs_change(&before, &after);
ASSERT_EQ(after.rax, expected.rax, "ax");
ASSERT_EQ(after.rcx, expected.rcx, "cx");
ASSERT_EQ(after.rdx, expected.rdx, "dx");
ASSERT_EQ(after.r8, expected.r8, "r8");
ASSERT_EQ(after.r9, expected.r9, "r9");
ASSERT_EQ(after.r10, expected.r10, "r10");
ASSERT_EQ(after.r11, expected.r11, "r11");
ASSERT_EQ(after.rdi, expected.rdi, "rdi");
ASSERT_EQ(after.rsi, expected.rsi, "rsi");
cleanup:
test_uprobe__destroy(skel);
}
static noinline unsigned long uprobe_regs_change_ip_1(void)
{
return 0xc0ffee;
}
static noinline unsigned long uprobe_regs_change_ip_2(void)
{
return 0xdeadbeef;
}
static void regs_ip(void)
{
LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
struct test_uprobe *skel;
unsigned long ret;
skel = test_uprobe__open_and_load();
if (!ASSERT_OK_PTR(skel, "skel_open"))
return;
skel->bss->my_pid = getpid();
skel->bss->ip = (unsigned long) uprobe_regs_change_ip_2;
uprobe_opts.func_name = "uprobe_regs_change_ip_1";
skel->links.test_regs_change_ip = bpf_program__attach_uprobe_opts(
skel->progs.test_regs_change_ip,
-1,
"/proc/self/exe",
0 /* offset */,
&uprobe_opts);
if (!ASSERT_OK_PTR(skel->links.test_regs_change_ip, "bpf_program__attach_uprobe_opts"))
goto cleanup;
ret = uprobe_regs_change_ip_1();
ASSERT_EQ(ret, 0xdeadbeef, "ret");
cleanup:
test_uprobe__destroy(skel);
}
static void test_uprobe_regs_change(void)
{
if (test__start_subtest("regs_change_common"))
regs_common();
if (test__start_subtest("regs_change_ip"))
regs_ip();
}
#else
static void test_uprobe_regs_change(void) { }
#endif
void test_uprobe(void)
{
if (test__start_subtest("attach"))
test_uprobe_attach();
test_uprobe_regs_change();
}
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