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![Masami Hiramatsu (Google)](/assets/img/avatar_default.png)
Pass return address as 'ret_ip' to the fprobe entry and return handlers so that the fprobe user handler can get the reutrn address without analyzing arch-dependent pt_regs. Link: https://lore.kernel.org/all/168507467664.913472.11642316698862778600.stgit@mhiramat.roam.corp.google.com/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
275 lines
6.9 KiB
C
275 lines
6.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* test_fprobe.c - simple sanity test for fprobe
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*/
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#include <linux/kernel.h>
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#include <linux/fprobe.h>
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#include <linux/random.h>
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#include <kunit/test.h>
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#define div_factor 3
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static struct kunit *current_test;
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static u32 rand1, entry_val, exit_val;
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/* Use indirect calls to avoid inlining the target functions */
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static u32 (*target)(u32 value);
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static u32 (*target2)(u32 value);
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static u32 (*target_nest)(u32 value, u32 (*nest)(u32));
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static unsigned long target_ip;
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static unsigned long target2_ip;
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static unsigned long target_nest_ip;
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static int entry_return_value;
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static noinline u32 fprobe_selftest_target(u32 value)
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{
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return (value / div_factor);
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}
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static noinline u32 fprobe_selftest_target2(u32 value)
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{
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return (value / div_factor) + 1;
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}
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static noinline u32 fprobe_selftest_nest_target(u32 value, u32 (*nest)(u32))
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{
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return nest(value + 2);
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}
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static notrace int fp_entry_handler(struct fprobe *fp, unsigned long ip,
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unsigned long ret_ip,
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struct pt_regs *regs, void *data)
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{
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KUNIT_EXPECT_FALSE(current_test, preemptible());
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/* This can be called on the fprobe_selftest_target and the fprobe_selftest_target2 */
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if (ip != target_ip)
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KUNIT_EXPECT_EQ(current_test, ip, target2_ip);
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entry_val = (rand1 / div_factor);
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if (fp->entry_data_size) {
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KUNIT_EXPECT_NOT_NULL(current_test, data);
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if (data)
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*(u32 *)data = entry_val;
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} else
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KUNIT_EXPECT_NULL(current_test, data);
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return entry_return_value;
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}
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static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip,
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unsigned long ret_ip,
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struct pt_regs *regs, void *data)
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{
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unsigned long ret = regs_return_value(regs);
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KUNIT_EXPECT_FALSE(current_test, preemptible());
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if (ip != target_ip) {
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KUNIT_EXPECT_EQ(current_test, ip, target2_ip);
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KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor) + 1);
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} else
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KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor));
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KUNIT_EXPECT_EQ(current_test, entry_val, (rand1 / div_factor));
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exit_val = entry_val + div_factor;
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if (fp->entry_data_size) {
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KUNIT_EXPECT_NOT_NULL(current_test, data);
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if (data)
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KUNIT_EXPECT_EQ(current_test, *(u32 *)data, entry_val);
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} else
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KUNIT_EXPECT_NULL(current_test, data);
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}
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static notrace int nest_entry_handler(struct fprobe *fp, unsigned long ip,
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unsigned long ret_ip,
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struct pt_regs *regs, void *data)
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{
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KUNIT_EXPECT_FALSE(current_test, preemptible());
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return 0;
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}
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static notrace void nest_exit_handler(struct fprobe *fp, unsigned long ip,
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unsigned long ret_ip,
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struct pt_regs *regs, void *data)
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{
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KUNIT_EXPECT_FALSE(current_test, preemptible());
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KUNIT_EXPECT_EQ(current_test, ip, target_nest_ip);
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}
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/* Test entry only (no rethook) */
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static void test_fprobe_entry(struct kunit *test)
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{
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struct fprobe fp_entry = {
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.entry_handler = fp_entry_handler,
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};
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current_test = test;
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/* Before register, unregister should be failed. */
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KUNIT_EXPECT_NE(test, 0, unregister_fprobe(&fp_entry));
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KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp_entry, "fprobe_selftest_target*", NULL));
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entry_val = 0;
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exit_val = 0;
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target(rand1);
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KUNIT_EXPECT_NE(test, 0, entry_val);
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KUNIT_EXPECT_EQ(test, 0, exit_val);
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entry_val = 0;
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exit_val = 0;
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target2(rand1);
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KUNIT_EXPECT_NE(test, 0, entry_val);
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KUNIT_EXPECT_EQ(test, 0, exit_val);
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KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp_entry));
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}
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static void test_fprobe(struct kunit *test)
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{
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struct fprobe fp = {
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.entry_handler = fp_entry_handler,
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.exit_handler = fp_exit_handler,
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};
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current_test = test;
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KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target*", NULL));
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entry_val = 0;
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exit_val = 0;
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target(rand1);
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KUNIT_EXPECT_NE(test, 0, entry_val);
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KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
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entry_val = 0;
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exit_val = 0;
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target2(rand1);
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KUNIT_EXPECT_NE(test, 0, entry_val);
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KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
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KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
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}
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static void test_fprobe_syms(struct kunit *test)
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{
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static const char *syms[] = {"fprobe_selftest_target", "fprobe_selftest_target2"};
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struct fprobe fp = {
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.entry_handler = fp_entry_handler,
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.exit_handler = fp_exit_handler,
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};
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current_test = test;
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KUNIT_EXPECT_EQ(test, 0, register_fprobe_syms(&fp, syms, 2));
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entry_val = 0;
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exit_val = 0;
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target(rand1);
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KUNIT_EXPECT_NE(test, 0, entry_val);
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KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
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entry_val = 0;
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exit_val = 0;
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target2(rand1);
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KUNIT_EXPECT_NE(test, 0, entry_val);
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KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
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KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
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}
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/* Test private entry_data */
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static void test_fprobe_data(struct kunit *test)
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{
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struct fprobe fp = {
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.entry_handler = fp_entry_handler,
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.exit_handler = fp_exit_handler,
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.entry_data_size = sizeof(u32),
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};
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current_test = test;
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KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target", NULL));
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target(rand1);
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KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
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}
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/* Test nr_maxactive */
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static void test_fprobe_nest(struct kunit *test)
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{
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static const char *syms[] = {"fprobe_selftest_target", "fprobe_selftest_nest_target"};
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struct fprobe fp = {
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.entry_handler = nest_entry_handler,
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.exit_handler = nest_exit_handler,
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.nr_maxactive = 1,
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};
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current_test = test;
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KUNIT_EXPECT_EQ(test, 0, register_fprobe_syms(&fp, syms, 2));
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target_nest(rand1, target);
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KUNIT_EXPECT_EQ(test, 1, fp.nmissed);
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KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
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}
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static void test_fprobe_skip(struct kunit *test)
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{
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struct fprobe fp = {
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.entry_handler = fp_entry_handler,
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.exit_handler = fp_exit_handler,
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};
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current_test = test;
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KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target", NULL));
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entry_return_value = 1;
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entry_val = 0;
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exit_val = 0;
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target(rand1);
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KUNIT_EXPECT_NE(test, 0, entry_val);
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KUNIT_EXPECT_EQ(test, 0, exit_val);
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KUNIT_EXPECT_EQ(test, 0, fp.nmissed);
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entry_return_value = 0;
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KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
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}
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static unsigned long get_ftrace_location(void *func)
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{
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unsigned long size, addr = (unsigned long)func;
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if (!kallsyms_lookup_size_offset(addr, &size, NULL) || !size)
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return 0;
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return ftrace_location_range(addr, addr + size - 1);
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}
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static int fprobe_test_init(struct kunit *test)
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{
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rand1 = get_random_u32_above(div_factor);
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target = fprobe_selftest_target;
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target2 = fprobe_selftest_target2;
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target_nest = fprobe_selftest_nest_target;
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target_ip = get_ftrace_location(target);
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target2_ip = get_ftrace_location(target2);
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target_nest_ip = get_ftrace_location(target_nest);
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return 0;
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}
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static struct kunit_case fprobe_testcases[] = {
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KUNIT_CASE(test_fprobe_entry),
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KUNIT_CASE(test_fprobe),
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KUNIT_CASE(test_fprobe_syms),
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KUNIT_CASE(test_fprobe_data),
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KUNIT_CASE(test_fprobe_nest),
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KUNIT_CASE(test_fprobe_skip),
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{}
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};
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static struct kunit_suite fprobe_test_suite = {
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.name = "fprobe_test",
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.init = fprobe_test_init,
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.test_cases = fprobe_testcases,
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};
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kunit_test_suites(&fprobe_test_suite);
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