--- /dev/null
+/*
+ * arch/arm/kernel/kprobes-test.c
+ *
+ * Copyright (C) 2011 Jon Medhurst <tixy@yxit.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This file contains test code for ARM kprobes.
+ *
+ * The top level function run_all_tests() executes tests for all of the
+ * supported instruction sets: ARM, 16-bit Thumb, and 32-bit Thumb. These tests
+ * fall into two categories; run_api_tests() checks basic functionality of the
+ * kprobes API, and run_test_cases() is a comprehensive test for kprobes
+ * instruction decoding and simulation.
+ *
+ * run_test_cases() first checks the kprobes decoding table for self consistency
+ * (using table_test()) then executes a series of test cases for each of the CPU
+ * instruction forms. coverage_start() and coverage_end() are used to verify
+ * that these test cases cover all of the possible combinations of instructions
+ * described by the kprobes decoding tables.
+ *
+ * The individual test cases are in kprobes-test-arm.c and kprobes-test-thumb.c
+ * which use the macros defined in kprobes-test.h. The rest of this
+ * documentation will describe the operation of the framework used by these
+ * test cases.
+ */
+
+/*
+ * TESTING METHODOLOGY
+ * -------------------
+ *
+ * The methodology used to test an ARM instruction 'test_insn' is to use
+ * inline assembler like:
+ *
+ * test_before: nop
+ * test_case: test_insn
+ * test_after: nop
+ *
+ * When the test case is run a kprobe is placed of each nop. The
+ * post-handler of the test_before probe is used to modify the saved CPU
+ * register context to that which we require for the test case. The
+ * pre-handler of the of the test_after probe saves a copy of the CPU
+ * register context. In this way we can execute test_insn with a specific
+ * register context and see the results afterwards.
+ *
+ * To actually test the kprobes instruction emulation we perform the above
+ * step a second time but with an additional kprobe on the test_case
+ * instruction itself. If the emulation is accurate then the results seen
+ * by the test_after probe will be identical to the first run which didn't
+ * have a probe on test_case.
+ *
+ * Each test case is run several times with a variety of variations in the
+ * flags value of stored in CPSR, and for Thumb code, different ITState.
+ *
+ * For instructions which can modify PC, a second test_after probe is used
+ * like this:
+ *
+ * test_before: nop
+ * test_case: test_insn
+ * test_after: nop
+ * b test_done
+ * test_after2: nop
+ * test_done:
+ *
+ * The test case is constructed such that test_insn branches to
+ * test_after2, or, if testing a conditional instruction, it may just
+ * continue to test_after. The probes inserted at both locations let us
+ * determine which happened. A similar approach is used for testing
+ * backwards branches...
+ *
+ * b test_before
+ * b test_done @ helps to cope with off by 1 branches
+ * test_after2: nop
+ * b test_done
+ * test_before: nop
+ * test_case: test_insn
+ * test_after: nop
+ * test_done:
+ *
+ * The macros used to generate the assembler instructions describe above
+ * are TEST_INSTRUCTION, TEST_BRANCH_F (branch forwards) and TEST_BRANCH_B
+ * (branch backwards). In these, the local variables numbered 1, 50, 2 and
+ * 99 represent: test_before, test_case, test_after2 and test_done.
+ *
+ * FRAMEWORK
+ * ---------
+ *
+ * Each test case is wrapped between the pair of macros TESTCASE_START and
+ * TESTCASE_END. As well as performing the inline assembler boilerplate,
+ * these call out to the kprobes_test_case_start() and
+ * kprobes_test_case_end() functions which drive the execution of the test
+ * case. The specific arguments to use for each test case are stored as
+ * inline data constructed using the various TEST_ARG_* macros. Putting
+ * this all together, a simple test case may look like:
+ *
+ * TESTCASE_START("Testing mov r0, r7")
+ * TEST_ARG_REG(7, 0x12345678) // Set r7=0x12345678
+ * TEST_ARG_END("")
+ * TEST_INSTRUCTION("mov r0, r7")
+ * TESTCASE_END
+ *
+ * Note, in practice the single convenience macro TEST_R would be used for this
+ * instead.
+ *
+ * The above would expand to assembler looking something like:
+ *
+ * @ TESTCASE_START
+ * bl __kprobes_test_case_start
+ * .pushsection .rodata
+ * "10:
+ * .ascii "mov r0, r7" @ text title for test case
+ * .byte 0
+ * .popsection
+ * @ start of inline data...
+ * .word 10b @ pointer to title in .rodata section
+ *
+ * @ TEST_ARG_REG
+ * .byte ARG_TYPE_REG
+ * .byte 7
+ * .short 0
+ * .word 0x1234567
+ *
+ * @ TEST_ARG_END
+ * .byte ARG_TYPE_END
+ * .byte TEST_ISA @ flags, including ISA being tested
+ * .short 50f-0f @ offset of 'test_before'
+ * .short 2f-0f @ offset of 'test_after2' (if relevent)
+ * .short 99f-0f @ offset of 'test_done'
+ * @ start of test case code...
+ * 0:
+ * .code TEST_ISA @ switch to ISA being tested
+ *
+ * @ TEST_INSTRUCTION
+ * 50: nop @ location for 'test_before' probe
+ * 1: mov r0, r7 @ the test case instruction 'test_insn'
+ * nop @ location for 'test_after' probe
+ *
+ * // TESTCASE_END
+ * 2:
+ * 99: bl __kprobes_test_case_end_##TEST_ISA
+ * .code NONMAL_ISA
+ *
+ * When the above is execute the following happens...
+ *
+ * __kprobes_test_case_start() is an assembler wrapper which sets up space
+ * for a stack buffer and calls the C function kprobes_test_case_start().
+ * This C function will do some initial processing of the inline data and
+ * setup some global state. It then inserts the test_before and test_after
+ * kprobes and returns a value which causes the assembler wrapper to jump
+ * to the start of the test case code, (local label '0').
+ *
+ * When the test case code executes, the test_before probe will be hit and
+ * test_before_post_handler will call setup_test_context(). This fills the
+ * stack buffer and CPU registers with a test pattern and then processes
+ * the test case arguments. In our example there is one TEST_ARG_REG which
+ * indicates that R7 should be loaded with the value 0x12345678.
+ *
+ * When the test_before probe ends, the test case continues and executes
+ * the "mov r0, r7" instruction. It then hits the test_after probe and the
+ * pre-handler for this (test_after_pre_handler) will save a copy of the
+ * CPU register context. This should now have R0 holding the same value as
+ * R7.
+ *
+ * Finally we get to the call to __kprobes_test_case_end_{32,16}. This is
+ * an assembler wrapper which switches back to the ISA used by the test
+ * code and calls the C function kprobes_test_case_end().
+ *
+ * For each run through the test case, test_case_run_count is incremented
+ * by one. For even runs, kprobes_test_case_end() saves a copy of the
+ * register and stack buffer contents from the test case just run. It then
+ * inserts a kprobe on the test case instruction 'test_insn' and returns a
+ * value to cause the test case code to be re-run.
+ *
+ * For odd numbered runs, kprobes_test_case_end() compares the register and
+ * stack buffer contents to those that were saved on the previous even
+ * numbered run (the one without the kprobe on test_insn). These should be
+ * the same if the kprobe instruction simulation routine is correct.
+ *
+ * The pair of test case runs is repeated with different combinations of
+ * flag values in CPSR and, for Thumb, different ITState. This is
+ * controlled by test_context_cpsr().
+ *
+ * BUILDING TEST CASES
+ * -------------------
+ *
+ *
+ * As an aid to building test cases, the stack buffer is initialised with
+ * some special values:
+ *
+ * [SP+13*4] Contains SP+120. This can be used to test instructions
+ * which load a value into SP.
+ *
+ * [SP+15*4] When testing branching instructions using TEST_BRANCH_{F,B},
+ * this holds the target address of the branch, 'test_after2'.
+ * This can be used to test instructions which load a PC value
+ * from memory.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/kprobes.h>
+#include <linux/errno.h>
+#include <linux/stddef.h>
+#include <linux/bug.h>
+#include <asm/opcodes.h>
+
+#include "core.h"
+#include "test-core.h"
+#include "../decode-arm.h"
+#include "../decode-thumb.h"
+
+
+#define BENCHMARKING 1
+
+
+/*
+ * Test basic API
+ */
+
+static bool test_regs_ok;
+static int test_func_instance;
+static int pre_handler_called;
+static int post_handler_called;
+static int jprobe_func_called;
+static int kretprobe_handler_called;
+static int tests_failed;
+
+#define FUNC_ARG1 0x12345678
+#define FUNC_ARG2 0xabcdef
+
+
+#ifndef CONFIG_THUMB2_KERNEL
+
+#define RET(reg) "mov pc, "#reg
+
+long arm_func(long r0, long r1);
+
+static void __used __naked __arm_kprobes_test_func(void)
+{
+ __asm__ __volatile__ (
+ ".arm \n\t"
+ ".type arm_func, %%function \n\t"
+ "arm_func: \n\t"
+ "adds r0, r0, r1 \n\t"
+ "mov pc, lr \n\t"
+ ".code "NORMAL_ISA /* Back to Thumb if necessary */
+ : : : "r0", "r1", "cc"
+ );
+}
+
+#else /* CONFIG_THUMB2_KERNEL */
+
+#define RET(reg) "bx "#reg
+
+long thumb16_func(long r0, long r1);
+long thumb32even_func(long r0, long r1);
+long thumb32odd_func(long r0, long r1);
+
+static void __used __naked __thumb_kprobes_test_funcs(void)
+{
+ __asm__ __volatile__ (
+ ".type thumb16_func, %%function \n\t"
+ "thumb16_func: \n\t"
+ "adds.n r0, r0, r1 \n\t"
+ "bx lr \n\t"
+
+ ".align \n\t"
+ ".type thumb32even_func, %%function \n\t"
+ "thumb32even_func: \n\t"
+ "adds.w r0, r0, r1 \n\t"
+ "bx lr \n\t"
+
+ ".align \n\t"
+ "nop.n \n\t"
+ ".type thumb32odd_func, %%function \n\t"
+ "thumb32odd_func: \n\t"
+ "adds.w r0, r0, r1 \n\t"
+ "bx lr \n\t"
+
+ : : : "r0", "r1", "cc"
+ );
+}
+
+#endif /* CONFIG_THUMB2_KERNEL */
+
+
+static int call_test_func(long (*func)(long, long), bool check_test_regs)
+{
+ long ret;
+
+ ++test_func_instance;
+ test_regs_ok = false;
+
+ ret = (*func)(FUNC_ARG1, FUNC_ARG2);
+ if (ret != FUNC_ARG1 + FUNC_ARG2) {
+ pr_err("FAIL: call_test_func: func returned %lx\n", ret);
+ return false;
+ }
+
+ if (check_test_regs && !test_regs_ok) {
+ pr_err("FAIL: test regs not OK\n");
+ return false;
+ }
+
+ return true;
+}
+
+static int __kprobes pre_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ pre_handler_called = test_func_instance;
+ if (regs->ARM_r0 == FUNC_ARG1 && regs->ARM_r1 == FUNC_ARG2)
+ test_regs_ok = true;
+ return 0;
+}
+
+static void __kprobes post_handler(struct kprobe *p, struct pt_regs *regs,
+ unsigned long flags)
+{
+ post_handler_called = test_func_instance;
+ if (regs->ARM_r0 != FUNC_ARG1 + FUNC_ARG2 || regs->ARM_r1 != FUNC_ARG2)
+ test_regs_ok = false;
+}
+
+static struct kprobe the_kprobe = {
+ .addr = 0,
+ .pre_handler = pre_handler,
+ .post_handler = post_handler
+};
+
+static int test_kprobe(long (*func)(long, long))
+{
+ int ret;
+
+ the_kprobe.addr = (kprobe_opcode_t *)func;
+ ret = register_kprobe(&the_kprobe);
+ if (ret < 0) {
+ pr_err("FAIL: register_kprobe failed with %d\n", ret);
+ return ret;
+ }
+
+ ret = call_test_func(func, true);
+
+ unregister_kprobe(&the_kprobe);
+ the_kprobe.flags = 0; /* Clear disable flag to allow reuse */
+
+ if (!ret)
+ return -EINVAL;
+ if (pre_handler_called != test_func_instance) {
+ pr_err("FAIL: kprobe pre_handler not called\n");
+ return -EINVAL;
+ }
+ if (post_handler_called != test_func_instance) {
+ pr_err("FAIL: kprobe post_handler not called\n");
+ return -EINVAL;
+ }
+ if (!call_test_func(func, false))
+ return -EINVAL;
+ if (pre_handler_called == test_func_instance ||
+ post_handler_called == test_func_instance) {
+ pr_err("FAIL: probe called after unregistering\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void __kprobes jprobe_func(long r0, long r1)
+{
+ jprobe_func_called = test_func_instance;
+ if (r0 == FUNC_ARG1 && r1 == FUNC_ARG2)
+ test_regs_ok = true;
+ jprobe_return();
+}
+
+static struct jprobe the_jprobe = {
+ .entry = jprobe_func,
+};
+
+static int test_jprobe(long (*func)(long, long))
+{
+ int ret;
+
+ the_jprobe.kp.addr = (kprobe_opcode_t *)func;
+ ret = register_jprobe(&the_jprobe);
+ if (ret < 0) {
+ pr_err("FAIL: register_jprobe failed with %d\n", ret);
+ return ret;
+ }
+
+ ret = call_test_func(func, true);
+
+ unregister_jprobe(&the_jprobe);
+ the_jprobe.kp.flags = 0; /* Clear disable flag to allow reuse */
+
+ if (!ret)
+ return -EINVAL;
+ if (jprobe_func_called != test_func_instance) {
+ pr_err("FAIL: jprobe handler function not called\n");
+ return -EINVAL;
+ }
+ if (!call_test_func(func, false))
+ return -EINVAL;
+ if (jprobe_func_called == test_func_instance) {
+ pr_err("FAIL: probe called after unregistering\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int __kprobes
+kretprobe_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+ kretprobe_handler_called = test_func_instance;
+ if (regs_return_value(regs) == FUNC_ARG1 + FUNC_ARG2)
+ test_regs_ok = true;
+ return 0;
+}
+
+static struct kretprobe the_kretprobe = {
+ .handler = kretprobe_handler,
+};
+
+static int test_kretprobe(long (*func)(long, long))
+{
+ int ret;
+
+ the_kretprobe.kp.addr = (kprobe_opcode_t *)func;
+ ret = register_kretprobe(&the_kretprobe);
+ if (ret < 0) {
+ pr_err("FAIL: register_kretprobe failed with %d\n", ret);
+ return ret;
+ }
+
+ ret = call_test_func(func, true);
+
+ unregister_kretprobe(&the_kretprobe);
+ the_kretprobe.kp.flags = 0; /* Clear disable flag to allow reuse */
+
+ if (!ret)
+ return -EINVAL;
+ if (kretprobe_handler_called != test_func_instance) {
+ pr_err("FAIL: kretprobe handler not called\n");
+ return -EINVAL;
+ }
+ if (!call_test_func(func, false))
+ return -EINVAL;
+ if (jprobe_func_called == test_func_instance) {
+ pr_err("FAIL: kretprobe called after unregistering\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int run_api_tests(long (*func)(long, long))
+{
+ int ret;
+
+ pr_info(" kprobe\n");
+ ret = test_kprobe(func);
+ if (ret < 0)
+ return ret;
+
+ pr_info(" jprobe\n");
+ ret = test_jprobe(func);
+#if defined(CONFIG_THUMB2_KERNEL) && !defined(MODULE)
+ if (ret == -EINVAL) {
+ pr_err("FAIL: Known longtime bug with jprobe on Thumb kernels\n");
+ tests_failed = ret;
+ ret = 0;
+ }
+#endif
+ if (ret < 0)
+ return ret;
+
+ pr_info(" kretprobe\n");
+ ret = test_kretprobe(func);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+
+/*
+ * Benchmarking
+ */
+
+#if BENCHMARKING
+
+static void __naked benchmark_nop(void)
+{
+ __asm__ __volatile__ (
+ "nop \n\t"
+ RET(lr)" \n\t"
+ );
+}
+
+#ifdef CONFIG_THUMB2_KERNEL
+#define wide ".w"
+#else
+#define wide
+#endif
+
+static void __naked benchmark_pushpop1(void)
+{
+ __asm__ __volatile__ (
+ "stmdb"wide" sp!, {r3-r11,lr} \n\t"
+ "ldmia"wide" sp!, {r3-r11,pc}"
+ );
+}
+
+static void __naked benchmark_pushpop2(void)
+{
+ __asm__ __volatile__ (
+ "stmdb"wide" sp!, {r0-r8,lr} \n\t"
+ "ldmia"wide" sp!, {r0-r8,pc}"
+ );
+}
+
+static void __naked benchmark_pushpop3(void)
+{
+ __asm__ __volatile__ (
+ "stmdb"wide" sp!, {r4,lr} \n\t"
+ "ldmia"wide" sp!, {r4,pc}"
+ );
+}
+
+static void __naked benchmark_pushpop4(void)
+{
+ __asm__ __volatile__ (
+ "stmdb"wide" sp!, {r0,lr} \n\t"
+ "ldmia"wide" sp!, {r0,pc}"
+ );
+}
+
+
+#ifdef CONFIG_THUMB2_KERNEL
+
+static void __naked benchmark_pushpop_thumb(void)
+{
+ __asm__ __volatile__ (
+ "push.n {r0-r7,lr} \n\t"
+ "pop.n {r0-r7,pc}"
+ );
+}
+
+#endif
+
+static int __kprobes
+benchmark_pre_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ return 0;
+}
+
+static int benchmark(void(*fn)(void))
+{
+ unsigned n, i, t, t0;
+
+ for (n = 1000; ; n *= 2) {
+ t0 = sched_clock();
+ for (i = n; i > 0; --i)
+ fn();
+ t = sched_clock() - t0;
+ if (t >= 250000000)
+ break; /* Stop once we took more than 0.25 seconds */
+ }
+ return t / n; /* Time for one iteration in nanoseconds */
+};
+
+static int kprobe_benchmark(void(*fn)(void), unsigned offset)
+{
+ struct kprobe k = {
+ .addr = (kprobe_opcode_t *)((uintptr_t)fn + offset),
+ .pre_handler = benchmark_pre_handler,
+ };
+
+ int ret = register_kprobe(&k);
+ if (ret < 0) {
+ pr_err("FAIL: register_kprobe failed with %d\n", ret);
+ return ret;
+ }
+
+ ret = benchmark(fn);
+
+ unregister_kprobe(&k);
+ return ret;
+};
+
+struct benchmarks {
+ void (*fn)(void);
+ unsigned offset;
+ const char *title;
+};
+
+static int run_benchmarks(void)
+{
+ int ret;
+ struct benchmarks list[] = {
+ {&benchmark_nop, 0, "nop"},
+ /*
+ * benchmark_pushpop{1,3} will have the optimised
+ * instruction emulation, whilst benchmark_pushpop{2,4} will
+ * be the equivalent unoptimised instructions.
+ */
+ {&benchmark_pushpop1, 0, "stmdb sp!, {r3-r11,lr}"},
+ {&benchmark_pushpop1, 4, "ldmia sp!, {r3-r11,pc}"},
+ {&benchmark_pushpop2, 0, "stmdb sp!, {r0-r8,lr}"},
+ {&benchmark_pushpop2, 4, "ldmia sp!, {r0-r8,pc}"},
+ {&benchmark_pushpop3, 0, "stmdb sp!, {r4,lr}"},
+ {&benchmark_pushpop3, 4, "ldmia sp!, {r4,pc}"},
+ {&benchmark_pushpop4, 0, "stmdb sp!, {r0,lr}"},
+ {&benchmark_pushpop4, 4, "ldmia sp!, {r0,pc}"},
+#ifdef CONFIG_THUMB2_KERNEL
+ {&benchmark_pushpop_thumb, 0, "push.n {r0-r7,lr}"},
+ {&benchmark_pushpop_thumb, 2, "pop.n {r0-r7,pc}"},
+#endif
+ {0}
+ };
+
+ struct benchmarks *b;
+ for (b = list; b->fn; ++b) {
+ ret = kprobe_benchmark(b->fn, b->offset);
+ if (ret < 0)
+ return ret;
+ pr_info(" %dns for kprobe %s\n", ret, b->title);
+ }
+
+ pr_info("\n");
+ return 0;
+}
+
+#endif /* BENCHMARKING */
+
+
+/*
+ * Decoding table self-consistency tests
+ */
+
+static const int decode_struct_sizes[NUM_DECODE_TYPES] = {
+ [DECODE_TYPE_TABLE] = sizeof(struct decode_table),
+ [DECODE_TYPE_CUSTOM] = sizeof(struct decode_custom),
+ [DECODE_TYPE_SIMULATE] = sizeof(struct decode_simulate),
+ [DECODE_TYPE_EMULATE] = sizeof(struct decode_emulate),
+ [DECODE_TYPE_OR] = sizeof(struct decode_or),
+ [DECODE_TYPE_REJECT] = sizeof(struct decode_reject)
+};
+
+static int table_iter(const union decode_item *table,
+ int (*fn)(const struct decode_header *, void *),
+ void *args)
+{
+ const struct decode_header *h = (struct decode_header *)table;
+ int result;
+
+ for (;;) {
+ enum decode_type type = h->type_regs.bits & DECODE_TYPE_MASK;
+
+ if (type == DECODE_TYPE_END)
+ return 0;
+
+ result = fn(h, args);
+ if (result)
+ return result;
+
+ h = (struct decode_header *)
+ ((uintptr_t)h + decode_struct_sizes[type]);
+
+ }
+}
+
+static int table_test_fail(const struct decode_header *h, const char* message)
+{
+
+ pr_err("FAIL: kprobes test failure \"%s\" (mask %08x, value %08x)\n",
+ message, h->mask.bits, h->value.bits);
+ return -EINVAL;
+}
+
+struct table_test_args {
+ const union decode_item *root_table;
+ u32 parent_mask;
+ u32 parent_value;
+};
+
+static int table_test_fn(const struct decode_header *h, void *args)
+{
+ struct table_test_args *a = (struct table_test_args *)args;
+ enum decode_type type = h->type_regs.bits & DECODE_TYPE_MASK;
+
+ if (h->value.bits & ~h->mask.bits)
+ return table_test_fail(h, "Match value has bits not in mask");
+
+ if ((h->mask.bits & a->parent_mask) != a->parent_mask)
+ return table_test_fail(h, "Mask has bits not in parent mask");
+
+ if ((h->value.bits ^ a->parent_value) & a->parent_mask)
+ return table_test_fail(h, "Value is inconsistent with parent");
+
+ if (type == DECODE_TYPE_TABLE) {
+ struct decode_table *d = (struct decode_table *)h;
+ struct table_test_args args2 = *a;
+ args2.parent_mask = h->mask.bits;
+ args2.parent_value = h->value.bits;
+ return table_iter(d->table.table, table_test_fn, &args2);
+ }
+
+ return 0;
+}
+
+static int table_test(const union decode_item *table)
+{
+ struct table_test_args args = {
+ .root_table = table,
+ .parent_mask = 0,
+ .parent_value = 0
+ };
+ return table_iter(args.root_table, table_test_fn, &args);
+}
+
+
+/*
+ * Decoding table test coverage analysis
+ *
+ * coverage_start() builds a coverage_table which contains a list of
+ * coverage_entry's to match each entry in the specified kprobes instruction
+ * decoding table.
+ *
+ * When test cases are run, coverage_add() is called to process each case.
+ * This looks up the corresponding entry in the coverage_table and sets it as
+ * being matched, as well as clearing the regs flag appropriate for the test.
+ *
+ * After all test cases have been run, coverage_end() is called to check that
+ * all entries in coverage_table have been matched and that all regs flags are
+ * cleared. I.e. that all possible combinations of instructions described by
+ * the kprobes decoding tables have had a test case executed for them.
+ */
+
+bool coverage_fail;
+
+#define MAX_COVERAGE_ENTRIES 256
+
+struct coverage_entry {
+ const struct decode_header *header;
+ unsigned regs;
+ unsigned nesting;
+ char matched;
+};
+
+struct coverage_table {
+ struct coverage_entry *base;
+ unsigned num_entries;
+ unsigned nesting;
+};
+
+struct coverage_table coverage;
+
+#define COVERAGE_ANY_REG (1<<0)
+#define COVERAGE_SP (1<<1)
+#define COVERAGE_PC (1<<2)
+#define COVERAGE_PCWB (1<<3)
+
+static const char coverage_register_lookup[16] = {
+ [REG_TYPE_ANY] = COVERAGE_ANY_REG | COVERAGE_SP | COVERAGE_PC,
+ [REG_TYPE_SAMEAS16] = COVERAGE_ANY_REG,
+ [REG_TYPE_SP] = COVERAGE_SP,
+ [REG_TYPE_PC] = COVERAGE_PC,
+ [REG_TYPE_NOSP] = COVERAGE_ANY_REG | COVERAGE_SP,
+ [REG_TYPE_NOSPPC] = COVERAGE_ANY_REG | COVERAGE_SP | COVERAGE_PC,
+ [REG_TYPE_NOPC] = COVERAGE_ANY_REG | COVERAGE_PC,
+ [REG_TYPE_NOPCWB] = COVERAGE_ANY_REG | COVERAGE_PC | COVERAGE_PCWB,
+ [REG_TYPE_NOPCX] = COVERAGE_ANY_REG,
+ [REG_TYPE_NOSPPCX] = COVERAGE_ANY_REG | COVERAGE_SP,
+};
+
+unsigned coverage_start_registers(const struct decode_header *h)
+{
+ unsigned regs = 0;
+ int i;
+ for (i = 0; i < 20; i += 4) {
+ int r = (h->type_regs.bits >> (DECODE_TYPE_BITS + i)) & 0xf;
+ regs |= coverage_register_lookup[r] << i;
+ }
+ return regs;
+}
+
+static int coverage_start_fn(const struct decode_header *h, void *args)
+{
+ struct coverage_table *coverage = (struct coverage_table *)args;
+ enum decode_type type = h->type_regs.bits & DECODE_TYPE_MASK;
+ struct coverage_entry *entry = coverage->base + coverage->num_entries;
+
+ if (coverage->num_entries == MAX_COVERAGE_ENTRIES - 1) {
+ pr_err("FAIL: Out of space for test coverage data");
+ return -ENOMEM;
+ }
+
+ ++coverage->num_entries;
+
+ entry->header = h;
+ entry->regs = coverage_start_registers(h);
+ entry->nesting = coverage->nesting;
+ entry->matched = false;
+
+ if (type == DECODE_TYPE_TABLE) {
+ struct decode_table *d = (struct decode_table *)h;
+ int ret;
+ ++coverage->nesting;
+ ret = table_iter(d->table.table, coverage_start_fn, coverage);
+ --coverage->nesting;
+ return ret;
+ }
+
+ return 0;
+}
+
+static int coverage_start(const union decode_item *table)
+{
+ coverage.base = kmalloc(MAX_COVERAGE_ENTRIES *
+ sizeof(struct coverage_entry), GFP_KERNEL);
+ coverage.num_entries = 0;
+ coverage.nesting = 0;
+ return table_iter(table, coverage_start_fn, &coverage);
+}
+
+static void
+coverage_add_registers(struct coverage_entry *entry, kprobe_opcode_t insn)
+{
+ int regs = entry->header->type_regs.bits >> DECODE_TYPE_BITS;
+ int i;
+ for (i = 0; i < 20; i += 4) {
+ enum decode_reg_type reg_type = (regs >> i) & 0xf;
+ int reg = (insn >> i) & 0xf;
+ int flag;
+
+ if (!reg_type)
+ continue;
+
+ if (reg == 13)
+ flag = COVERAGE_SP;
+ else if (reg == 15)
+ flag = COVERAGE_PC;
+ else
+ flag = COVERAGE_ANY_REG;
+ entry->regs &= ~(flag << i);
+
+ switch (reg_type) {
+
+ case REG_TYPE_NONE:
+ case REG_TYPE_ANY:
+ case REG_TYPE_SAMEAS16:
+ break;
+
+ case REG_TYPE_SP:
+ if (reg != 13)
+ return;
+ break;
+
+ case REG_TYPE_PC:
+ if (reg != 15)
+ return;
+ break;
+
+ case REG_TYPE_NOSP:
+ if (reg == 13)
+ return;
+ break;
+
+ case REG_TYPE_NOSPPC:
+ case REG_TYPE_NOSPPCX:
+ if (reg == 13 || reg == 15)
+ return;
+ break;
+
+ case REG_TYPE_NOPCWB:
+ if (!is_writeback(insn))
+ break;
+ if (reg == 15) {
+ entry->regs &= ~(COVERAGE_PCWB << i);
+ return;
+ }
+ break;
+
+ case REG_TYPE_NOPC:
+ case REG_TYPE_NOPCX:
+ if (reg == 15)
+ return;
+ break;
+ }
+
+ }
+}
+
+static void coverage_add(kprobe_opcode_t insn)
+{
+ struct coverage_entry *entry = coverage.base;
+ struct coverage_entry *end = coverage.base + coverage.num_entries;
+ bool matched = false;
+ unsigned nesting = 0;
+
+ for (; entry < end; ++entry) {
+ const struct decode_header *h = entry->header;
+ enum decode_type type = h->type_regs.bits & DECODE_TYPE_MASK;
+
+ if (entry->nesting > nesting)
+ continue; /* Skip sub-table we didn't match */
+
+ if (entry->nesting < nesting)
+ break; /* End of sub-table we were scanning */
+
+ if (!matched) {
+ if ((insn & h->mask.bits) != h->value.bits)
+ continue;
+ entry->matched = true;
+ }
+
+ switch (type) {
+
+ case DECODE_TYPE_TABLE:
+ ++nesting;
+ break;
+
+ case DECODE_TYPE_CUSTOM:
+ case DECODE_TYPE_SIMULATE:
+ case DECODE_TYPE_EMULATE:
+ coverage_add_registers(entry, insn);
+ return;
+
+ case DECODE_TYPE_OR:
+ matched = true;
+ break;
+
+ case DECODE_TYPE_REJECT:
+ default:
+ return;
+ }
+
+ }
+}
+
+static void coverage_end(void)
+{
+ struct coverage_entry *entry = coverage.base;
+ struct coverage_entry *end = coverage.base + coverage.num_entries;
+
+ for (; entry < end; ++entry) {
+ u32 mask = entry->header->mask.bits;
+ u32 value = entry->header->value.bits;
+
+ if (entry->regs) {
+ pr_err("FAIL: Register test coverage missing for %08x %08x (%05x)\n",
+ mask, value, entry->regs);
+ coverage_fail = true;
+ }
+ if (!entry->matched) {
+ pr_err("FAIL: Test coverage entry missing for %08x %08x\n",
+ mask, value);
+ coverage_fail = true;
+ }
+ }
+
+ kfree(coverage.base);
+}
+
+
+/*
+ * Framework for instruction set test cases
+ */
+
+void __naked __kprobes_test_case_start(void)
+{
+ __asm__ __volatile__ (
+ "stmdb sp!, {r4-r11} \n\t"
+ "sub sp, sp, #"__stringify(TEST_MEMORY_SIZE)"\n\t"
+ "bic r0, lr, #1 @ r0 = inline data \n\t"
+ "mov r1, sp \n\t"
+ "bl kprobes_test_case_start \n\t"
+ RET(r0)" \n\t"
+ );
+}
+
+#ifndef CONFIG_THUMB2_KERNEL
+
+void __naked __kprobes_test_case_end_32(void)
+{
+ __asm__ __volatile__ (
+ "mov r4, lr \n\t"
+ "bl kprobes_test_case_end \n\t"
+ "cmp r0, #0 \n\t"
+ "movne pc, r0 \n\t"
+ "mov r0, r4 \n\t"
+ "add sp, sp, #"__stringify(TEST_MEMORY_SIZE)"\n\t"
+ "ldmia sp!, {r4-r11} \n\t"
+ "mov pc, r0 \n\t"
+ );
+}
+
+#else /* CONFIG_THUMB2_KERNEL */
+
+void __naked __kprobes_test_case_end_16(void)
+{
+ __asm__ __volatile__ (
+ "mov r4, lr \n\t"
+ "bl kprobes_test_case_end \n\t"
+ "cmp r0, #0 \n\t"
+ "bxne r0 \n\t"
+ "mov r0, r4 \n\t"
+ "add sp, sp, #"__stringify(TEST_MEMORY_SIZE)"\n\t"
+ "ldmia sp!, {r4-r11} \n\t"
+ "bx r0 \n\t"
+ );
+}
+
+void __naked __kprobes_test_case_end_32(void)
+{
+ __asm__ __volatile__ (
+ ".arm \n\t"
+ "orr lr, lr, #1 @ will return to Thumb code \n\t"
+ "ldr pc, 1f \n\t"
+ "1: \n\t"
+ ".word __kprobes_test_case_end_16 \n\t"
+ );
+}
+
+#endif
+
+
+int kprobe_test_flags;
+int kprobe_test_cc_position;
+
+static int test_try_count;
+static int test_pass_count;
+static int test_fail_count;
+
+static struct pt_regs initial_regs;
+static struct pt_regs expected_regs;
+static struct pt_regs result_regs;
+
+static u32 expected_memory[TEST_MEMORY_SIZE/sizeof(u32)];
+
+static const char *current_title;
+static struct test_arg *current_args;
+static u32 *current_stack;
+static uintptr_t current_branch_target;
+
+static uintptr_t current_code_start;
+static kprobe_opcode_t current_instruction;
+
+
+#define TEST_CASE_PASSED -1
+#define TEST_CASE_FAILED -2
+
+static int test_case_run_count;
+static bool test_case_is_thumb;
+static int test_instance;
+
+static unsigned long test_check_cc(int cc, unsigned long cpsr)
+{
+ int ret = arm_check_condition(cc << 28, cpsr);
+
+ return (ret != ARM_OPCODE_CONDTEST_FAIL);
+}
+
+static int is_last_scenario;
+static int probe_should_run; /* 0 = no, 1 = yes, -1 = unknown */
+static int memory_needs_checking;
+
+static unsigned long test_context_cpsr(int scenario)
+{
+ unsigned long cpsr;
+
+ probe_should_run = 1;
+
+ /* Default case is that we cycle through 16 combinations of flags */
+ cpsr = (scenario & 0xf) << 28; /* N,Z,C,V flags */
+ cpsr |= (scenario & 0xf) << 16; /* GE flags */
+ cpsr |= (scenario & 0x1) << 27; /* Toggle Q flag */
+
+ if (!test_case_is_thumb) {
+ /* Testing ARM code */
+ int cc = current_instruction >> 28;
+
+ probe_should_run = test_check_cc(cc, cpsr) != 0;
+ if (scenario == 15)
+ is_last_scenario = true;
+
+ } else if (kprobe_test_flags & TEST_FLAG_NO_ITBLOCK) {
+ /* Testing Thumb code without setting ITSTATE */
+ if (kprobe_test_cc_position) {
+ int cc = (current_instruction >> kprobe_test_cc_position) & 0xf;
+ probe_should_run = test_check_cc(cc, cpsr) != 0;
+ }
+
+ if (scenario == 15)
+ is_last_scenario = true;
+
+ } else if (kprobe_test_flags & TEST_FLAG_FULL_ITBLOCK) {
+ /* Testing Thumb code with all combinations of ITSTATE */
+ unsigned x = (scenario >> 4);
+ unsigned cond_base = x % 7; /* ITSTATE<7:5> */
+ unsigned mask = x / 7 + 2; /* ITSTATE<4:0>, bits reversed */
+
+ if (mask > 0x1f) {
+ /* Finish by testing state from instruction 'itt al' */
+ cond_base = 7;
+ mask = 0x4;
+ if ((scenario & 0xf) == 0xf)
+ is_last_scenario = true;
+ }
+
+ cpsr |= cond_base << 13; /* ITSTATE<7:5> */
+ cpsr |= (mask & 0x1) << 12; /* ITSTATE<4> */
+ cpsr |= (mask & 0x2) << 10; /* ITSTATE<3> */
+ cpsr |= (mask & 0x4) << 8; /* ITSTATE<2> */
+ cpsr |= (mask & 0x8) << 23; /* ITSTATE<1> */
+ cpsr |= (mask & 0x10) << 21; /* ITSTATE<0> */
+
+ probe_should_run = test_check_cc((cpsr >> 12) & 0xf, cpsr) != 0;
+
+ } else {
+ /* Testing Thumb code with several combinations of ITSTATE */
+ switch (scenario) {
+ case 16: /* Clear NZCV flags and 'it eq' state (false as Z=0) */
+ cpsr = 0x00000800;
+ probe_should_run = 0;
+ break;
+ case 17: /* Set NZCV flags and 'it vc' state (false as V=1) */
+ cpsr = 0xf0007800;
+ probe_should_run = 0;
+ break;
+ case 18: /* Clear NZCV flags and 'it ls' state (true as C=0) */
+ cpsr = 0x00009800;
+ break;
+ case 19: /* Set NZCV flags and 'it cs' state (true as C=1) */
+ cpsr = 0xf0002800;
+ is_last_scenario = true;
+ break;
+ }
+ }
+
+ return cpsr;
+}
+
+static void setup_test_context(struct pt_regs *regs)
+{
+ int scenario = test_case_run_count>>1;
+ unsigned long val;
+ struct test_arg *args;
+ int i;
+
+ is_last_scenario = false;
+ memory_needs_checking = false;
+
+ /* Initialise test memory on stack */
+ val = (scenario & 1) ? VALM : ~VALM;
+ for (i = 0; i < TEST_MEMORY_SIZE / sizeof(current_stack[0]); ++i)
+ current_stack[i] = val + (i << 8);
+ /* Put target of branch on stack for tests which load PC from memory */
+ if (current_branch_target)
+ current_stack[15] = current_branch_target;
+ /* Put a value for SP on stack for tests which load SP from memory */
+ current_stack[13] = (u32)current_stack + 120;
+
+ /* Initialise register values to their default state */
+ val = (scenario & 2) ? VALR : ~VALR;
+ for (i = 0; i < 13; ++i)
+ regs->uregs[i] = val ^ (i << 8);
+ regs->ARM_lr = val ^ (14 << 8);
+ regs->ARM_cpsr &= ~(APSR_MASK | PSR_IT_MASK);
+ regs->ARM_cpsr |= test_context_cpsr(scenario);
+
+ /* Perform testcase specific register setup */
+ args = current_args;
+ for (; args[0].type != ARG_TYPE_END; ++args)
+ switch (args[0].type) {
+ case ARG_TYPE_REG: {
+ struct test_arg_regptr *arg =
+ (struct test_arg_regptr *)args;
+ regs->uregs[arg->reg] = arg->val;
+ break;
+ }
+ case ARG_TYPE_PTR: {
+ struct test_arg_regptr *arg =
+ (struct test_arg_regptr *)args;
+ regs->uregs[arg->reg] =
+ (unsigned long)current_stack + arg->val;
+ memory_needs_checking = true;
+ /*
+ * Test memory at an address below SP is in danger of
+ * being altered by an interrupt occurring and pushing
+ * data onto the stack. Disable interrupts to stop this.
+ */
+ if (arg->reg == 13)
+ regs->ARM_cpsr |= PSR_I_BIT;
+ break;
+ }
+ case ARG_TYPE_MEM: {
+ struct test_arg_mem *arg = (struct test_arg_mem *)args;
+ current_stack[arg->index] = arg->val;
+ break;
+ }
+ default:
+ break;
+ }
+}
+
+struct test_probe {
+ struct kprobe kprobe;
+ bool registered;
+ int hit;
+};
+
+static void unregister_test_probe(struct test_probe *probe)
+{
+ if (probe->registered) {
+ unregister_kprobe(&probe->kprobe);
+ probe->kprobe.flags = 0; /* Clear disable flag to allow reuse */
+ }
+ probe->registered = false;
+}
+
+static int register_test_probe(struct test_probe *probe)
+{
+ int ret;
+
+ if (probe->registered)
+ BUG();
+
+ ret = register_kprobe(&probe->kprobe);
+ if (ret >= 0) {
+ probe->registered = true;
+ probe->hit = -1;
+ }
+ return ret;
+}
+
+static int __kprobes
+test_before_pre_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ container_of(p, struct test_probe, kprobe)->hit = test_instance;
+ return 0;
+}
+
+static void __kprobes
+test_before_post_handler(struct kprobe *p, struct pt_regs *regs,
+ unsigned long flags)
+{
+ setup_test_context(regs);
+ initial_regs = *regs;
+ initial_regs.ARM_cpsr &= ~PSR_IGNORE_BITS;
+}
+
+static int __kprobes
+test_case_pre_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ container_of(p, struct test_probe, kprobe)->hit = test_instance;
+ return 0;
+}
+
+static int __kprobes
+test_after_pre_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ struct test_arg *args;
+
+ if (container_of(p, struct test_probe, kprobe)->hit == test_instance)
+ return 0; /* Already run for this test instance */
+
+ result_regs = *regs;
+
+ /* Mask out results which are indeterminate */
+ result_regs.ARM_cpsr &= ~PSR_IGNORE_BITS;
+ for (args = current_args; args[0].type != ARG_TYPE_END; ++args)
+ if (args[0].type == ARG_TYPE_REG_MASKED) {
+ struct test_arg_regptr *arg =
+ (struct test_arg_regptr *)args;
+ result_regs.uregs[arg->reg] &= arg->val;
+ }
+
+ /* Undo any changes done to SP by the test case */
+ regs->ARM_sp = (unsigned long)current_stack;
+ /* Enable interrupts in case setup_test_context disabled them */
+ regs->ARM_cpsr &= ~PSR_I_BIT;
+
+ container_of(p, struct test_probe, kprobe)->hit = test_instance;
+ return 0;
+}
+
+static struct test_probe test_before_probe = {
+ .kprobe.pre_handler = test_before_pre_handler,
+ .kprobe.post_handler = test_before_post_handler,
+};
+
+static struct test_probe test_case_probe = {
+ .kprobe.pre_handler = test_case_pre_handler,
+};
+
+static struct test_probe test_after_probe = {
+ .kprobe.pre_handler = test_after_pre_handler,
+};
+
+static struct test_probe test_after2_probe = {
+ .kprobe.pre_handler = test_after_pre_handler,
+};
+
+static void test_case_cleanup(void)
+{
+ unregister_test_probe(&test_before_probe);
+ unregister_test_probe(&test_case_probe);
+ unregister_test_probe(&test_after_probe);
+ unregister_test_probe(&test_after2_probe);
+}
+
+static void print_registers(struct pt_regs *regs)
+{
+ pr_err("r0 %08lx | r1 %08lx | r2 %08lx | r3 %08lx\n",
+ regs->ARM_r0, regs->ARM_r1, regs->ARM_r2, regs->ARM_r3);
+ pr_err("r4 %08lx | r5 %08lx | r6 %08lx | r7 %08lx\n",
+ regs->ARM_r4, regs->ARM_r5, regs->ARM_r6, regs->ARM_r7);
+ pr_err("r8 %08lx | r9 %08lx | r10 %08lx | r11 %08lx\n",
+ regs->ARM_r8, regs->ARM_r9, regs->ARM_r10, regs->ARM_fp);
+ pr_err("r12 %08lx | sp %08lx | lr %08lx | pc %08lx\n",
+ regs->ARM_ip, regs->ARM_sp, regs->ARM_lr, regs->ARM_pc);
+ pr_err("cpsr %08lx\n", regs->ARM_cpsr);
+}
+
+static void print_memory(u32 *mem, size_t size)
+{
+ int i;
+ for (i = 0; i < size / sizeof(u32); i += 4)
+ pr_err("%08x %08x %08x %08x\n", mem[i], mem[i+1],
+ mem[i+2], mem[i+3]);
+}
+
+static size_t expected_memory_size(u32 *sp)
+{
+ size_t size = sizeof(expected_memory);
+ int offset = (uintptr_t)sp - (uintptr_t)current_stack;
+ if (offset > 0)
+ size -= offset;
+ return size;
+}
+
+static void test_case_failed(const char *message)
+{
+ test_case_cleanup();
+
+ pr_err("FAIL: %s\n", message);
+ pr_err("FAIL: Test %s\n", current_title);
+ pr_err("FAIL: Scenario %d\n", test_case_run_count >> 1);
+}
+
+static unsigned long next_instruction(unsigned long pc)
+{
+#ifdef CONFIG_THUMB2_KERNEL
+ if ((pc & 1) &&
+ !is_wide_instruction(__mem_to_opcode_thumb16(*(u16 *)(pc - 1))))
+ return pc + 2;
+ else
+#endif
+ return pc + 4;
+}
+
+static uintptr_t __used kprobes_test_case_start(const char **title, void *stack)
+{
+ struct test_arg *args;
+ struct test_arg_end *end_arg;
+ unsigned long test_code;
+
+ current_title = *title++;
+ args = (struct test_arg *)title;
+ current_args = args;
+ current_stack = stack;
+
+ ++test_try_count;
+
+ while (args->type != ARG_TYPE_END)
+ ++args;
+ end_arg = (struct test_arg_end *)args;
+
+ test_code = (unsigned long)(args + 1); /* Code starts after args */
+
+ test_case_is_thumb = end_arg->flags & ARG_FLAG_THUMB;
+ if (test_case_is_thumb)
+ test_code |= 1;
+
+ current_code_start = test_code;
+
+ current_branch_target = 0;
+ if (end_arg->branch_offset != end_arg->end_offset)
+ current_branch_target = test_code + end_arg->branch_offset;
+
+ test_code += end_arg->code_offset;
+ test_before_probe.kprobe.addr = (kprobe_opcode_t *)test_code;
+
+ test_code = next_instruction(test_code);
+ test_case_probe.kprobe.addr = (kprobe_opcode_t *)test_code;
+
+ if (test_case_is_thumb) {
+ u16 *p = (u16 *)(test_code & ~1);
+ current_instruction = __mem_to_opcode_thumb16(p[0]);
+ if (is_wide_instruction(current_instruction)) {
+ u16 instr2 = __mem_to_opcode_thumb16(p[1]);
+ current_instruction = __opcode_thumb32_compose(current_instruction, instr2);
+ }
+ } else {
+ current_instruction = __mem_to_opcode_arm(*(u32 *)test_code);
+ }
+
+ if (current_title[0] == '.')
+ verbose("%s\n", current_title);
+ else
+ verbose("%s\t@ %0*x\n", current_title,
+ test_case_is_thumb ? 4 : 8,
+ current_instruction);
+
+ test_code = next_instruction(test_code);
+ test_after_probe.kprobe.addr = (kprobe_opcode_t *)test_code;
+
+ if (kprobe_test_flags & TEST_FLAG_NARROW_INSTR) {
+ if (!test_case_is_thumb ||
+ is_wide_instruction(current_instruction)) {
+ test_case_failed("expected 16-bit instruction");
+ goto fail;
+ }
+ } else {
+ if (test_case_is_thumb &&
+ !is_wide_instruction(current_instruction)) {
+ test_case_failed("expected 32-bit instruction");
+ goto fail;
+ }
+ }
+
+ coverage_add(current_instruction);
+
+ if (end_arg->flags & ARG_FLAG_UNSUPPORTED) {
+ if (register_test_probe(&test_case_probe) < 0)
+ goto pass;
+ test_case_failed("registered probe for unsupported instruction");
+ goto fail;
+ }
+
+ if (end_arg->flags & ARG_FLAG_SUPPORTED) {
+ if (register_test_probe(&test_case_probe) >= 0)
+ goto pass;
+ test_case_failed("couldn't register probe for supported instruction");
+ goto fail;
+ }
+
+ if (register_test_probe(&test_before_probe) < 0) {
+ test_case_failed("register test_before_probe failed");
+ goto fail;
+ }
+ if (register_test_probe(&test_after_probe) < 0) {
+ test_case_failed("register test_after_probe failed");
+ goto fail;
+ }
+ if (current_branch_target) {
+ test_after2_probe.kprobe.addr =
+ (kprobe_opcode_t *)current_branch_target;
+ if (register_test_probe(&test_after2_probe) < 0) {
+ test_case_failed("register test_after2_probe failed");
+ goto fail;
+ }
+ }
+
+ /* Start first run of test case */
+ test_case_run_count = 0;
+ ++test_instance;
+ return current_code_start;
+pass:
+ test_case_run_count = TEST_CASE_PASSED;
+ return (uintptr_t)test_after_probe.kprobe.addr;
+fail:
+ test_case_run_count = TEST_CASE_FAILED;
+ return (uintptr_t)test_after_probe.kprobe.addr;
+}
+
+static bool check_test_results(void)
+{
+ size_t mem_size = 0;
+ u32 *mem = 0;
+
+ if (memcmp(&expected_regs, &result_regs, sizeof(expected_regs))) {
+ test_case_failed("registers differ");
+ goto fail;
+ }
+
+ if (memory_needs_checking) {
+ mem = (u32 *)result_regs.ARM_sp;
+ mem_size = expected_memory_size(mem);
+ if (memcmp(expected_memory, mem, mem_size)) {
+ test_case_failed("test memory differs");
+ goto fail;
+ }
+ }
+
+ return true;
+
+fail:
+ pr_err("initial_regs:\n");
+ print_registers(&initial_regs);
+ pr_err("expected_regs:\n");
+ print_registers(&expected_regs);
+ pr_err("result_regs:\n");
+ print_registers(&result_regs);
+
+ if (mem) {
+ pr_err("current_stack=%p\n", current_stack);
+ pr_err("expected_memory:\n");
+ print_memory(expected_memory, mem_size);
+ pr_err("result_memory:\n");
+ print_memory(mem, mem_size);
+ }
+
+ return false;
+}
+
+static uintptr_t __used kprobes_test_case_end(void)
+{
+ if (test_case_run_count < 0) {
+ if (test_case_run_count == TEST_CASE_PASSED)
+ /* kprobes_test_case_start did all the needed testing */
+ goto pass;
+ else
+ /* kprobes_test_case_start failed */
+ goto fail;
+ }
+
+ if (test_before_probe.hit != test_instance) {
+ test_case_failed("test_before_handler not run");
+ goto fail;
+ }
+
+ if (test_after_probe.hit != test_instance &&
+ test_after2_probe.hit != test_instance) {
+ test_case_failed("test_after_handler not run");
+ goto fail;
+ }
+
+ /*
+ * Even numbered test runs ran without a probe on the test case so
+ * we can gather reference results. The subsequent odd numbered run
+ * will have the probe inserted.
+ */
+ if ((test_case_run_count & 1) == 0) {
+ /* Save results from run without probe */
+ u32 *mem = (u32 *)result_regs.ARM_sp;
+ expected_regs = result_regs;
+ memcpy(expected_memory, mem, expected_memory_size(mem));
+
+ /* Insert probe onto test case instruction */
+ if (register_test_probe(&test_case_probe) < 0) {
+ test_case_failed("register test_case_probe failed");
+ goto fail;
+ }
+ } else {
+ /* Check probe ran as expected */
+ if (probe_should_run == 1) {
+ if (test_case_probe.hit != test_instance) {
+ test_case_failed("test_case_handler not run");
+ goto fail;
+ }
+ } else if (probe_should_run == 0) {
+ if (test_case_probe.hit == test_instance) {
+ test_case_failed("test_case_handler ran");
+ goto fail;
+ }
+ }
+
+ /* Remove probe for any subsequent reference run */
+ unregister_test_probe(&test_case_probe);
+
+ if (!check_test_results())
+ goto fail;
+
+ if (is_last_scenario)
+ goto pass;
+ }
+
+ /* Do next test run */
+ ++test_case_run_count;
+ ++test_instance;
+ return current_code_start;
+fail:
+ ++test_fail_count;
+ goto end;
+pass:
+ ++test_pass_count;
+end:
+ test_case_cleanup();
+ return 0;
+}
+
+
+/*
+ * Top level test functions
+ */
+
+static int run_test_cases(void (*tests)(void), const union decode_item *table)
+{
+ int ret;
+
+ pr_info(" Check decoding tables\n");
+ ret = table_test(table);
+ if (ret)
+ return ret;
+
+ pr_info(" Run test cases\n");
+ ret = coverage_start(table);
+ if (ret)
+ return ret;
+
+ tests();
+
+ coverage_end();
+ return 0;
+}
+
+
+static int __init run_all_tests(void)
+{
+ int ret = 0;
+
+ pr_info("Beginning kprobe tests...\n");
+
+#ifndef CONFIG_THUMB2_KERNEL
+
+ pr_info("Probe ARM code\n");
+ ret = run_api_tests(arm_func);
+ if (ret)
+ goto out;
+
+ pr_info("ARM instruction simulation\n");
+ ret = run_test_cases(kprobe_arm_test_cases, probes_decode_arm_table);
+ if (ret)
+ goto out;
+
+#else /* CONFIG_THUMB2_KERNEL */
+
+ pr_info("Probe 16-bit Thumb code\n");
+ ret = run_api_tests(thumb16_func);
+ if (ret)
+ goto out;
+
+ pr_info("Probe 32-bit Thumb code, even halfword\n");
+ ret = run_api_tests(thumb32even_func);
+ if (ret)
+ goto out;
+
+ pr_info("Probe 32-bit Thumb code, odd halfword\n");
+ ret = run_api_tests(thumb32odd_func);
+ if (ret)
+ goto out;
+
+ pr_info("16-bit Thumb instruction simulation\n");
+ ret = run_test_cases(kprobe_thumb16_test_cases,
+ probes_decode_thumb16_table);
+ if (ret)
+ goto out;
+
+ pr_info("32-bit Thumb instruction simulation\n");
+ ret = run_test_cases(kprobe_thumb32_test_cases,
+ probes_decode_thumb32_table);
+ if (ret)
+ goto out;
+#endif
+
+ pr_info("Total instruction simulation tests=%d, pass=%d fail=%d\n",
+ test_try_count, test_pass_count, test_fail_count);
+ if (test_fail_count) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+#if BENCHMARKING
+ pr_info("Benchmarks\n");
+ ret = run_benchmarks();
+ if (ret)
+ goto out;
+#endif
+
+#if __LINUX_ARM_ARCH__ >= 7
+ /* We are able to run all test cases so coverage should be complete */
+ if (coverage_fail) {
+ pr_err("FAIL: Test coverage checks failed\n");
+ ret = -EINVAL;
+ goto out;
+ }
+#endif
+
+out:
+ if (ret == 0)
+ ret = tests_failed;
+ if (ret == 0)
+ pr_info("Finished kprobe tests OK\n");
+ else
+ pr_err("kprobe tests failed\n");
+
+ return ret;
+}
+
+
+/*
+ * Module setup
+ */
+
+#ifdef MODULE
+
+static void __exit kprobe_test_exit(void)
+{
+}
+
+module_init(run_all_tests)
+module_exit(kprobe_test_exit)
+MODULE_LICENSE("GPL");
+
+#else /* !MODULE */
+
+late_initcall(run_all_tests);
+
+#endif
Code Review / kvmfornfv.git / blobdiff