linux/lib/test_fprobe.c
Jason A. Donenfeld a251c17aa5 treewide: use get_random_u32() when possible
The prandom_u32() function has been a deprecated inline wrapper around
get_random_u32() for several releases now, and compiles down to the
exact same code. Replace the deprecated wrapper with a direct call to
the real function. The same also applies to get_random_int(), which is
just a wrapper around get_random_u32(). This was done as a basic find
and replace.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake
Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Acked-by: Helge Deller <deller@gmx.de> # for parisc
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-11 17:42:58 -06:00

175 lines
4.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* test_fprobe.c - simple sanity test for fprobe
*/
#include <linux/kernel.h>
#include <linux/fprobe.h>
#include <linux/random.h>
#include <kunit/test.h>
#define div_factor 3
static struct kunit *current_test;
static u32 rand1, entry_val, exit_val;
/* Use indirect calls to avoid inlining the target functions */
static u32 (*target)(u32 value);
static u32 (*target2)(u32 value);
static unsigned long target_ip;
static unsigned long target2_ip;
static noinline u32 fprobe_selftest_target(u32 value)
{
return (value / div_factor);
}
static noinline u32 fprobe_selftest_target2(u32 value)
{
return (value / div_factor) + 1;
}
static notrace void fp_entry_handler(struct fprobe *fp, unsigned long ip, struct pt_regs *regs)
{
KUNIT_EXPECT_FALSE(current_test, preemptible());
/* This can be called on the fprobe_selftest_target and the fprobe_selftest_target2 */
if (ip != target_ip)
KUNIT_EXPECT_EQ(current_test, ip, target2_ip);
entry_val = (rand1 / div_factor);
}
static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip, struct pt_regs *regs)
{
unsigned long ret = regs_return_value(regs);
KUNIT_EXPECT_FALSE(current_test, preemptible());
if (ip != target_ip) {
KUNIT_EXPECT_EQ(current_test, ip, target2_ip);
KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor) + 1);
} else
KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor));
KUNIT_EXPECT_EQ(current_test, entry_val, (rand1 / div_factor));
exit_val = entry_val + div_factor;
}
/* Test entry only (no rethook) */
static void test_fprobe_entry(struct kunit *test)
{
struct fprobe fp_entry = {
.entry_handler = fp_entry_handler,
};
current_test = test;
/* Before register, unregister should be failed. */
KUNIT_EXPECT_NE(test, 0, unregister_fprobe(&fp_entry));
KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp_entry, "fprobe_selftest_target*", NULL));
entry_val = 0;
exit_val = 0;
target(rand1);
KUNIT_EXPECT_NE(test, 0, entry_val);
KUNIT_EXPECT_EQ(test, 0, exit_val);
entry_val = 0;
exit_val = 0;
target2(rand1);
KUNIT_EXPECT_NE(test, 0, entry_val);
KUNIT_EXPECT_EQ(test, 0, exit_val);
KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp_entry));
}
static void test_fprobe(struct kunit *test)
{
struct fprobe fp = {
.entry_handler = fp_entry_handler,
.exit_handler = fp_exit_handler,
};
current_test = test;
KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target*", NULL));
entry_val = 0;
exit_val = 0;
target(rand1);
KUNIT_EXPECT_NE(test, 0, entry_val);
KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
entry_val = 0;
exit_val = 0;
target2(rand1);
KUNIT_EXPECT_NE(test, 0, entry_val);
KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
}
static void test_fprobe_syms(struct kunit *test)
{
static const char *syms[] = {"fprobe_selftest_target", "fprobe_selftest_target2"};
struct fprobe fp = {
.entry_handler = fp_entry_handler,
.exit_handler = fp_exit_handler,
};
current_test = test;
KUNIT_EXPECT_EQ(test, 0, register_fprobe_syms(&fp, syms, 2));
entry_val = 0;
exit_val = 0;
target(rand1);
KUNIT_EXPECT_NE(test, 0, entry_val);
KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
entry_val = 0;
exit_val = 0;
target2(rand1);
KUNIT_EXPECT_NE(test, 0, entry_val);
KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
}
static unsigned long get_ftrace_location(void *func)
{
unsigned long size, addr = (unsigned long)func;
if (!kallsyms_lookup_size_offset(addr, &size, NULL) || !size)
return 0;
return ftrace_location_range(addr, addr + size - 1);
}
static int fprobe_test_init(struct kunit *test)
{
do {
rand1 = get_random_u32();
} while (rand1 <= div_factor);
target = fprobe_selftest_target;
target2 = fprobe_selftest_target2;
target_ip = get_ftrace_location(target);
target2_ip = get_ftrace_location(target2);
return 0;
}
static struct kunit_case fprobe_testcases[] = {
KUNIT_CASE(test_fprobe_entry),
KUNIT_CASE(test_fprobe),
KUNIT_CASE(test_fprobe_syms),
{}
};
static struct kunit_suite fprobe_test_suite = {
.name = "fprobe_test",
.init = fprobe_test_init,
.test_cases = fprobe_testcases,
};
kunit_test_suites(&fprobe_test_suite);
MODULE_LICENSE("GPL");