Extend the kprobes KUnit test with a function containing an LR/SC sequence and assert that register_kprobe() accepts a probe placed right before or right after the sequence, and rejects a probe placed on the LR, on an instruction inside the sequence, or on the SC.
Signed-off-by: Xiaofeng Yuan <[email protected]> --- .../kernel/tests/kprobes/test-kprobes-asm.S | 30 ++++++++++++++++++ .../riscv/kernel/tests/kprobes/test-kprobes.c | 31 +++++++++++++++++++ .../riscv/kernel/tests/kprobes/test-kprobes.h | 3 ++ 3 files changed, 64 insertions(+) diff --git a/arch/riscv/kernel/tests/kprobes/test-kprobes-asm.S b/arch/riscv/kernel/tests/kprobes/test-kprobes-asm.S index 15e50934b..76826bf7e 100644 --- a/arch/riscv/kernel/tests/kprobes/test-kprobes-asm.S +++ b/arch/riscv/kernel/tests/kprobes/test-kprobes-asm.S @@ -100,6 +100,27 @@ test_kprobes_branch_addr8: .option pop SYM_FUNC_END(test_kprobes_branch) +/* + * This function is never executed; it only provides the probe addresses + * in test_kprobes_lrsc_offsets[] for test_kprobe_lrsc(). The lr.w/sc.w + * use the invalid address 0(x0) and would fault if executed, so do not + * add this function to test_kprobes_functions[]. + */ +SYM_FUNC_START(test_kprobes_lrsc) +.Llrsc_before: + nop +1: +.Llrsc_lr: + lr.w t0, 0(x0) +.Llrsc_inside: + addi t0, t0, 1 +.Llrsc_sc: + sc.w t0, t0, 0(x0) + bnez t0, 1b +.Llrsc_after: + ret +SYM_FUNC_END(test_kprobes_lrsc) + #ifdef CONFIG_RISCV_ISA_C SYM_FUNC_START(test_kprobes_c_j) @@ -253,3 +274,12 @@ SYM_DATA_START(test_kprobes_functions) #endif /* CONFIG_RISCV_ISA_C */ RISCV_PTR 0 SYM_DATA_END(test_kprobes_functions) + +.section .rodata +SYM_DATA_START(test_kprobes_lrsc_offsets) + RISCV_PTR .Llrsc_before + RISCV_PTR .Llrsc_lr + RISCV_PTR .Llrsc_inside + RISCV_PTR .Llrsc_sc + RISCV_PTR .Llrsc_after +SYM_DATA_END(test_kprobes_lrsc_offsets) diff --git a/arch/riscv/kernel/tests/kprobes/test-kprobes.c b/arch/riscv/kernel/tests/kprobes/test-kprobes.c index 027424a3f..c2d9c87f2 100644 --- a/arch/riscv/kernel/tests/kprobes/test-kprobes.c +++ b/arch/riscv/kernel/tests/kprobes/test-kprobes.c @@ -43,8 +43,39 @@ static void test_kprobe_riscv(struct kunit *test) kfree(kp); } +static void test_kprobe_lrsc(struct kunit *test) +{ + /* + * test_kprobes_lrsc_offsets[] points, in order, at an instruction + * right before an LR/SC sequence, the LR itself, an instruction + * inside the sequence, the SC, and an instruction right after it. + * reject[] must have the same number of entries. + */ + bool reject[] = { false, true, true, true, false }; + int i; + + for (i = 0; i < ARRAY_SIZE(reject); i++) { + struct kprobe kp = {}; + int ret; + + kp.pre_handler = kprobe_dummy_handler; + kp.addr = (kprobe_opcode_t *)test_kprobes_lrsc_offsets[i]; + + ret = register_kprobe(&kp); + + if (reject[i]) + KUNIT_EXPECT_LT(test, ret, 0); + else + KUNIT_EXPECT_EQ(test, ret, 0); + + if (!ret) + unregister_kprobe(&kp); + } +} + static struct kunit_case kprobes_testcases[] = { KUNIT_CASE(test_kprobe_riscv), + KUNIT_CASE(test_kprobe_lrsc), {} }; diff --git a/arch/riscv/kernel/tests/kprobes/test-kprobes.h b/arch/riscv/kernel/tests/kprobes/test-kprobes.h index 537f44aa9..65a8e7217 100644 --- a/arch/riscv/kernel/tests/kprobes/test-kprobes.h +++ b/arch/riscv/kernel/tests/kprobes/test-kprobes.h @@ -19,6 +19,9 @@ extern void *test_kprobes_addresses[]; /* array of functions that return KPROBE_TEST_MAGIC */ extern long (*test_kprobes_functions[])(void); +/* offsets of the probe points inside test_kprobes_lrsc() */ +extern void *test_kprobes_lrsc_offsets[]; + #endif /* __ASSEMBLER__ */ #endif /* TEST_KPROBES_H */ -- 2.34.1
