kprobes: add testcases for s390

Add a few testcases to make sure that it's not possible to place
a kprobe in the mid of an instruction on s390.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Sven Schnelle 2021-09-09 20:59:17 +02:00 committed by Vasily Gorbik
parent f768a20c0a
commit d340d28a96
6 changed files with 145 additions and 0 deletions

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@ -946,4 +946,16 @@ config S390_UNWIND_SELFTEST
Say N if you are unsure.
config S390_KPROBES_SANITY_TEST
def_tristate n
prompt "Enable s390 specific kprobes tests"
depends on KPROBES
depends on KUNIT
help
This option enables an s390 specific kprobes test module. This option
is not useful for distributions or general kernels, but only for kernel
developers working on architecture code.
Say N if you are unsure.
endmenu

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@ -62,6 +62,7 @@ CONFIG_CMM=m
CONFIG_APPLDATA_BASE=y
CONFIG_KVM=m
CONFIG_S390_UNWIND_SELFTEST=y
CONFIG_S390_KPROBES_SANITY_TEST=y
CONFIG_KPROBES=y
CONFIG_JUMP_LABEL=y
CONFIG_STATIC_KEYS_SELFTEST=y

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@ -7,6 +7,8 @@ lib-y += delay.o string.o uaccess.o find.o spinlock.o
obj-y += mem.o xor.o
lib-$(CONFIG_KPROBES) += probes.o
lib-$(CONFIG_UPROBES) += probes.o
obj-$(CONFIG_S390_KPROBES_SANITY_TEST) += test_kprobes_s390.o
test_kprobes_s390-objs += test_kprobes_asm.o test_kprobes.o
# Instrumenting memory accesses to __user data (in different address space)
# produce false positives

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@ -0,0 +1,75 @@
// SPDX-License-Identifier: GPL-2.0+
#include <linux/kernel.h>
#include <linux/kprobes.h>
#include <linux/random.h>
#include <kunit/test.h>
#include "test_kprobes.h"
static struct kprobe kp;
static void setup_kprobe(struct kunit *test, struct kprobe *kp,
const char *symbol, int offset)
{
kp->offset = offset;
kp->addr = NULL;
kp->symbol_name = symbol;
}
static void test_kprobe_offset(struct kunit *test, struct kprobe *kp,
const char *target, int offset)
{
int ret;
setup_kprobe(test, kp, target, 0);
ret = register_kprobe(kp);
if (!ret)
unregister_kprobe(kp);
KUNIT_EXPECT_EQ(test, 0, ret);
setup_kprobe(test, kp, target, offset);
ret = register_kprobe(kp);
KUNIT_EXPECT_EQ(test, -EINVAL, ret);
if (!ret)
unregister_kprobe(kp);
}
static void test_kprobe_odd(struct kunit *test)
{
test_kprobe_offset(test, &kp, "kprobes_target_odd",
kprobes_target_odd_offs);
}
static void test_kprobe_in_insn4(struct kunit *test)
{
test_kprobe_offset(test, &kp, "kprobes_target_in_insn4",
kprobes_target_in_insn4_offs);
}
static void test_kprobe_in_insn6_lo(struct kunit *test)
{
test_kprobe_offset(test, &kp, "kprobes_target_in_insn6_lo",
kprobes_target_in_insn6_lo_offs);
}
static void test_kprobe_in_insn6_hi(struct kunit *test)
{
test_kprobe_offset(test, &kp, "kprobes_target_in_insn6_hi",
kprobes_target_in_insn6_hi_offs);
}
static struct kunit_case kprobes_testcases[] = {
KUNIT_CASE(test_kprobe_odd),
KUNIT_CASE(test_kprobe_in_insn4),
KUNIT_CASE(test_kprobe_in_insn6_lo),
KUNIT_CASE(test_kprobe_in_insn6_hi),
{}
};
static struct kunit_suite kprobes_test_suite = {
.name = "kprobes_test_s390",
.test_cases = kprobes_testcases,
};
kunit_test_suites(&kprobes_test_suite);
MODULE_LICENSE("GPL");

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@ -0,0 +1,10 @@
/* SPDX-License-Identifier: GPL-2.0+ */
#ifndef TEST_KPROBES_H
#define TEST_KPROBES_H
extern unsigned long kprobes_target_odd_offs;
extern unsigned long kprobes_target_in_insn4_offs;
extern unsigned long kprobes_target_in_insn6_lo_offs;
extern unsigned long kprobes_target_in_insn6_hi_offs;
#endif

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@ -0,0 +1,45 @@
/* SPDX-License-Identifier: GPL-2.0+ */
#include <linux/linkage.h>
#include <asm/ftrace.h>
#define KPROBES_TARGET_START(name) \
SYM_FUNC_START(name); \
FTRACE_GEN_NOP_ASM(name)
#define KPROBES_TARGET_END(name) \
SYM_FUNC_END(name); \
SYM_DATA(name##_offs, .quad 1b - name)
KPROBES_TARGET_START(kprobes_target_in_insn4)
.word 0x4700 // bc 0,0
1: .word 0x0000
br %r14
KPROBES_TARGET_END(kprobes_target_in_insn4)
KPROBES_TARGET_START(kprobes_target_in_insn6_lo)
.word 0xe310 // ly 1,0
1: .word 0x0000
.word 0x0058
br %r14
KPROBES_TARGET_END(kprobes_target_in_insn6_lo)
KPROBES_TARGET_START(kprobes_target_in_insn6_hi)
.word 0xe310 // ly 1,0
.word 0x0000
1: .word 0x0058
br %r14
KPROBES_TARGET_END(kprobes_target_in_insn6_hi)
KPROBES_TARGET_START(kprobes_target_bp)
nop
.word 0x0000
nop
1: br %r14
KPROBES_TARGET_END(kprobes_target_bp)
KPROBES_TARGET_START(kprobes_target_odd)
.byte 0x07
1: .byte 0x07
br %r14
KPROBES_TARGET_END(kprobes_target_odd)