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1673 lines
41 KiB
1673 lines
41 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* arch/arm/kernel/kprobes-test.c |
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* |
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* Copyright (C) 2011 Jon Medhurst <[email protected]>. |
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*/ |
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|
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/* |
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* This file contains test code for ARM kprobes. |
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* |
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* The top level function run_all_tests() executes tests for all of the |
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* supported instruction sets: ARM, 16-bit Thumb, and 32-bit Thumb. These tests |
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* fall into two categories; run_api_tests() checks basic functionality of the |
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* kprobes API, and run_test_cases() is a comprehensive test for kprobes |
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* instruction decoding and simulation. |
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* |
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* run_test_cases() first checks the kprobes decoding table for self consistency |
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* (using table_test()) then executes a series of test cases for each of the CPU |
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* instruction forms. coverage_start() and coverage_end() are used to verify |
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* that these test cases cover all of the possible combinations of instructions |
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* described by the kprobes decoding tables. |
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* |
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* The individual test cases are in kprobes-test-arm.c and kprobes-test-thumb.c |
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* which use the macros defined in kprobes-test.h. The rest of this |
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* documentation will describe the operation of the framework used by these |
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* test cases. |
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*/ |
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|
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/* |
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* TESTING METHODOLOGY |
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* ------------------- |
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* |
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* The methodology used to test an ARM instruction 'test_insn' is to use |
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* inline assembler like: |
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* |
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* test_before: nop |
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* test_case: test_insn |
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* test_after: nop |
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* |
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* When the test case is run a kprobe is placed of each nop. The |
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* post-handler of the test_before probe is used to modify the saved CPU |
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* register context to that which we require for the test case. The |
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* pre-handler of the of the test_after probe saves a copy of the CPU |
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* register context. In this way we can execute test_insn with a specific |
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* register context and see the results afterwards. |
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* |
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* To actually test the kprobes instruction emulation we perform the above |
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* step a second time but with an additional kprobe on the test_case |
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* instruction itself. If the emulation is accurate then the results seen |
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* by the test_after probe will be identical to the first run which didn't |
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* have a probe on test_case. |
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* |
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* Each test case is run several times with a variety of variations in the |
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* flags value of stored in CPSR, and for Thumb code, different ITState. |
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* |
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* For instructions which can modify PC, a second test_after probe is used |
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* like this: |
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* |
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* test_before: nop |
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* test_case: test_insn |
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* test_after: nop |
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* b test_done |
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* test_after2: nop |
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* test_done: |
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* |
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* The test case is constructed such that test_insn branches to |
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* test_after2, or, if testing a conditional instruction, it may just |
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* continue to test_after. The probes inserted at both locations let us |
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* determine which happened. A similar approach is used for testing |
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* backwards branches... |
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* |
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* b test_before |
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* b test_done @ helps to cope with off by 1 branches |
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* test_after2: nop |
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* b test_done |
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* test_before: nop |
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* test_case: test_insn |
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* test_after: nop |
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* test_done: |
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* |
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* The macros used to generate the assembler instructions describe above |
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* are TEST_INSTRUCTION, TEST_BRANCH_F (branch forwards) and TEST_BRANCH_B |
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* (branch backwards). In these, the local variables numbered 1, 50, 2 and |
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* 99 represent: test_before, test_case, test_after2 and test_done. |
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* |
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* FRAMEWORK |
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* --------- |
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* |
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* Each test case is wrapped between the pair of macros TESTCASE_START and |
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* TESTCASE_END. As well as performing the inline assembler boilerplate, |
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* these call out to the kprobes_test_case_start() and |
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* kprobes_test_case_end() functions which drive the execution of the test |
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* case. The specific arguments to use for each test case are stored as |
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* inline data constructed using the various TEST_ARG_* macros. Putting |
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* this all together, a simple test case may look like: |
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* |
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* TESTCASE_START("Testing mov r0, r7") |
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* TEST_ARG_REG(7, 0x12345678) // Set r7=0x12345678 |
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* TEST_ARG_END("") |
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* TEST_INSTRUCTION("mov r0, r7") |
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* TESTCASE_END |
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* |
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* Note, in practice the single convenience macro TEST_R would be used for this |
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* instead. |
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* |
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* The above would expand to assembler looking something like: |
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* |
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* @ TESTCASE_START |
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* bl __kprobes_test_case_start |
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* .pushsection .rodata |
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* "10: |
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* .ascii "mov r0, r7" @ text title for test case |
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* .byte 0 |
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* .popsection |
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* @ start of inline data... |
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* .word 10b @ pointer to title in .rodata section |
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* |
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* @ TEST_ARG_REG |
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* .byte ARG_TYPE_REG |
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* .byte 7 |
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* .short 0 |
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* .word 0x1234567 |
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* |
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* @ TEST_ARG_END |
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* .byte ARG_TYPE_END |
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* .byte TEST_ISA @ flags, including ISA being tested |
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* .short 50f-0f @ offset of 'test_before' |
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* .short 2f-0f @ offset of 'test_after2' (if relevent) |
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* .short 99f-0f @ offset of 'test_done' |
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* @ start of test case code... |
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* 0: |
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* .code TEST_ISA @ switch to ISA being tested |
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* |
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* @ TEST_INSTRUCTION |
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* 50: nop @ location for 'test_before' probe |
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* 1: mov r0, r7 @ the test case instruction 'test_insn' |
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* nop @ location for 'test_after' probe |
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* |
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* // TESTCASE_END |
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* 2: |
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* 99: bl __kprobes_test_case_end_##TEST_ISA |
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* .code NONMAL_ISA |
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* |
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* When the above is execute the following happens... |
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* |
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* __kprobes_test_case_start() is an assembler wrapper which sets up space |
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* for a stack buffer and calls the C function kprobes_test_case_start(). |
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* This C function will do some initial processing of the inline data and |
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* setup some global state. It then inserts the test_before and test_after |
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* kprobes and returns a value which causes the assembler wrapper to jump |
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* to the start of the test case code, (local label '0'). |
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* |
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* When the test case code executes, the test_before probe will be hit and |
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* test_before_post_handler will call setup_test_context(). This fills the |
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* stack buffer and CPU registers with a test pattern and then processes |
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* the test case arguments. In our example there is one TEST_ARG_REG which |
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* indicates that R7 should be loaded with the value 0x12345678. |
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* |
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* When the test_before probe ends, the test case continues and executes |
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* the "mov r0, r7" instruction. It then hits the test_after probe and the |
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* pre-handler for this (test_after_pre_handler) will save a copy of the |
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* CPU register context. This should now have R0 holding the same value as |
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* R7. |
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* |
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* Finally we get to the call to __kprobes_test_case_end_{32,16}. This is |
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* an assembler wrapper which switches back to the ISA used by the test |
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* code and calls the C function kprobes_test_case_end(). |
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* |
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* For each run through the test case, test_case_run_count is incremented |
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* by one. For even runs, kprobes_test_case_end() saves a copy of the |
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* register and stack buffer contents from the test case just run. It then |
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* inserts a kprobe on the test case instruction 'test_insn' and returns a |
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* value to cause the test case code to be re-run. |
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* |
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* For odd numbered runs, kprobes_test_case_end() compares the register and |
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* stack buffer contents to those that were saved on the previous even |
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* numbered run (the one without the kprobe on test_insn). These should be |
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* the same if the kprobe instruction simulation routine is correct. |
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* |
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* The pair of test case runs is repeated with different combinations of |
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* flag values in CPSR and, for Thumb, different ITState. This is |
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* controlled by test_context_cpsr(). |
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* |
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* BUILDING TEST CASES |
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* ------------------- |
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* |
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* |
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* As an aid to building test cases, the stack buffer is initialised with |
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* some special values: |
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* |
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* [SP+13*4] Contains SP+120. This can be used to test instructions |
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* which load a value into SP. |
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* |
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* [SP+15*4] When testing branching instructions using TEST_BRANCH_{F,B}, |
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* this holds the target address of the branch, 'test_after2'. |
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* This can be used to test instructions which load a PC value |
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* from memory. |
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*/ |
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|
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/sched/clock.h> |
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#include <linux/kprobes.h> |
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#include <linux/errno.h> |
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#include <linux/stddef.h> |
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#include <linux/bug.h> |
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#include <asm/opcodes.h> |
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#include "core.h" |
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#include "test-core.h" |
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#include "../decode-arm.h" |
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#include "../decode-thumb.h" |
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#define BENCHMARKING 1 |
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/* |
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* Test basic API |
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*/ |
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static bool test_regs_ok; |
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static int test_func_instance; |
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static int pre_handler_called; |
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static int post_handler_called; |
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static int kretprobe_handler_called; |
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static int tests_failed; |
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|
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#define FUNC_ARG1 0x12345678 |
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#define FUNC_ARG2 0xabcdef |
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#ifndef CONFIG_THUMB2_KERNEL |
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#define RET(reg) "mov pc, "#reg |
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long arm_func(long r0, long r1); |
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static void __used __naked __arm_kprobes_test_func(void) |
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{ |
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__asm__ __volatile__ ( |
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".arm \n\t" |
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".type arm_func, %%function \n\t" |
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"arm_func: \n\t" |
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"adds r0, r0, r1 \n\t" |
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"mov pc, lr \n\t" |
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".code "NORMAL_ISA /* Back to Thumb if necessary */ |
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: : : "r0", "r1", "cc" |
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); |
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} |
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#else /* CONFIG_THUMB2_KERNEL */ |
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|
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#define RET(reg) "bx "#reg |
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|
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long thumb16_func(long r0, long r1); |
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long thumb32even_func(long r0, long r1); |
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long thumb32odd_func(long r0, long r1); |
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|
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static void __used __naked __thumb_kprobes_test_funcs(void) |
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{ |
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__asm__ __volatile__ ( |
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".type thumb16_func, %%function \n\t" |
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"thumb16_func: \n\t" |
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"adds.n r0, r0, r1 \n\t" |
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"bx lr \n\t" |
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|
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".align \n\t" |
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".type thumb32even_func, %%function \n\t" |
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"thumb32even_func: \n\t" |
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"adds.w r0, r0, r1 \n\t" |
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"bx lr \n\t" |
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|
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".align \n\t" |
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"nop.n \n\t" |
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".type thumb32odd_func, %%function \n\t" |
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"thumb32odd_func: \n\t" |
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"adds.w r0, r0, r1 \n\t" |
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"bx lr \n\t" |
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: : : "r0", "r1", "cc" |
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); |
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} |
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#endif /* CONFIG_THUMB2_KERNEL */ |
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static int call_test_func(long (*func)(long, long), bool check_test_regs) |
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{ |
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long ret; |
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++test_func_instance; |
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test_regs_ok = false; |
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ret = (*func)(FUNC_ARG1, FUNC_ARG2); |
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if (ret != FUNC_ARG1 + FUNC_ARG2) { |
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pr_err("FAIL: call_test_func: func returned %lx\n", ret); |
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return false; |
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} |
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|
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if (check_test_regs && !test_regs_ok) { |
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pr_err("FAIL: test regs not OK\n"); |
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return false; |
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} |
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return true; |
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} |
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static int __kprobes pre_handler(struct kprobe *p, struct pt_regs *regs) |
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{ |
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pre_handler_called = test_func_instance; |
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if (regs->ARM_r0 == FUNC_ARG1 && regs->ARM_r1 == FUNC_ARG2) |
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test_regs_ok = true; |
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return 0; |
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} |
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|
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static void __kprobes post_handler(struct kprobe *p, struct pt_regs *regs, |
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unsigned long flags) |
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{ |
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post_handler_called = test_func_instance; |
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if (regs->ARM_r0 != FUNC_ARG1 + FUNC_ARG2 || regs->ARM_r1 != FUNC_ARG2) |
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test_regs_ok = false; |
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} |
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static struct kprobe the_kprobe = { |
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.addr = 0, |
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.pre_handler = pre_handler, |
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.post_handler = post_handler |
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}; |
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static int test_kprobe(long (*func)(long, long)) |
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{ |
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int ret; |
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|
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the_kprobe.addr = (kprobe_opcode_t *)func; |
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ret = register_kprobe(&the_kprobe); |
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if (ret < 0) { |
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pr_err("FAIL: register_kprobe failed with %d\n", ret); |
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return ret; |
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} |
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|
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ret = call_test_func(func, true); |
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unregister_kprobe(&the_kprobe); |
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the_kprobe.flags = 0; /* Clear disable flag to allow reuse */ |
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if (!ret) |
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return -EINVAL; |
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if (pre_handler_called != test_func_instance) { |
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pr_err("FAIL: kprobe pre_handler not called\n"); |
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return -EINVAL; |
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} |
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if (post_handler_called != test_func_instance) { |
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pr_err("FAIL: kprobe post_handler not called\n"); |
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return -EINVAL; |
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} |
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if (!call_test_func(func, false)) |
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return -EINVAL; |
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if (pre_handler_called == test_func_instance || |
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post_handler_called == test_func_instance) { |
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pr_err("FAIL: probe called after unregistering\n"); |
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return -EINVAL; |
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} |
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return 0; |
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} |
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|
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static int __kprobes |
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kretprobe_handler(struct kretprobe_instance *ri, struct pt_regs *regs) |
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{ |
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kretprobe_handler_called = test_func_instance; |
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if (regs_return_value(regs) == FUNC_ARG1 + FUNC_ARG2) |
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test_regs_ok = true; |
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return 0; |
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} |
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|
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static struct kretprobe the_kretprobe = { |
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.handler = kretprobe_handler, |
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}; |
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|
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static int test_kretprobe(long (*func)(long, long)) |
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{ |
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int ret; |
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|
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the_kretprobe.kp.addr = (kprobe_opcode_t *)func; |
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ret = register_kretprobe(&the_kretprobe); |
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if (ret < 0) { |
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pr_err("FAIL: register_kretprobe failed with %d\n", ret); |
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return ret; |
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} |
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|
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ret = call_test_func(func, true); |
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|
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unregister_kretprobe(&the_kretprobe); |
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the_kretprobe.kp.flags = 0; /* Clear disable flag to allow reuse */ |
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|
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if (!ret) |
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return -EINVAL; |
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if (kretprobe_handler_called != test_func_instance) { |
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pr_err("FAIL: kretprobe handler not called\n"); |
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return -EINVAL; |
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} |
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if (!call_test_func(func, false)) |
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return -EINVAL; |
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if (kretprobe_handler_called == test_func_instance) { |
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pr_err("FAIL: kretprobe called after unregistering\n"); |
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return -EINVAL; |
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} |
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return 0; |
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} |
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|
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static int run_api_tests(long (*func)(long, long)) |
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{ |
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int ret; |
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pr_info(" kprobe\n"); |
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ret = test_kprobe(func); |
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if (ret < 0) |
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return ret; |
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|
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pr_info(" kretprobe\n"); |
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ret = test_kretprobe(func); |
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if (ret < 0) |
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return ret; |
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|
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return 0; |
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} |
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|
|
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/* |
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* Benchmarking |
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*/ |
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|
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#if BENCHMARKING |
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|
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static void __naked benchmark_nop(void) |
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{ |
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__asm__ __volatile__ ( |
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"nop \n\t" |
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RET(lr)" \n\t" |
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); |
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} |
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|
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#ifdef CONFIG_THUMB2_KERNEL |
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#define wide ".w" |
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#else |
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#define wide |
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#endif |
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|
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static void __naked benchmark_pushpop1(void) |
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{ |
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__asm__ __volatile__ ( |
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"stmdb"wide" sp!, {r3-r11,lr} \n\t" |
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"ldmia"wide" sp!, {r3-r11,pc}" |
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); |
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} |
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|
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static void __naked benchmark_pushpop2(void) |
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{ |
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__asm__ __volatile__ ( |
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"stmdb"wide" sp!, {r0-r8,lr} \n\t" |
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"ldmia"wide" sp!, {r0-r8,pc}" |
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); |
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} |
|
|
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static void __naked benchmark_pushpop3(void) |
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{ |
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__asm__ __volatile__ ( |
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"stmdb"wide" sp!, {r4,lr} \n\t" |
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"ldmia"wide" sp!, {r4,pc}" |
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); |
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} |
|
|
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static void __naked benchmark_pushpop4(void) |
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{ |
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__asm__ __volatile__ ( |
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"stmdb"wide" sp!, {r0,lr} \n\t" |
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"ldmia"wide" sp!, {r0,pc}" |
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); |
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} |
|
|
|
|
|
#ifdef CONFIG_THUMB2_KERNEL |
|
|
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static void __naked benchmark_pushpop_thumb(void) |
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{ |
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__asm__ __volatile__ ( |
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"push.n {r0-r7,lr} \n\t" |
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"pop.n {r0-r7,pc}" |
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); |
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} |
|
|
|
#endif |
|
|
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static int __kprobes |
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benchmark_pre_handler(struct kprobe *p, struct pt_regs *regs) |
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{ |
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return 0; |
|
} |
|
|
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static int benchmark(void(*fn)(void)) |
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{ |
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unsigned n, i, t, t0; |
|
|
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for (n = 1000; ; n *= 2) { |
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t0 = sched_clock(); |
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for (i = n; i > 0; --i) |
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fn(); |
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t = sched_clock() - t0; |
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if (t >= 250000000) |
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break; /* Stop once we took more than 0.25 seconds */ |
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} |
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return t / n; /* Time for one iteration in nanoseconds */ |
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}; |
|
|
|
static int kprobe_benchmark(void(*fn)(void), unsigned offset) |
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{ |
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struct kprobe k = { |
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.addr = (kprobe_opcode_t *)((uintptr_t)fn + offset), |
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.pre_handler = benchmark_pre_handler, |
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}; |
|
|
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int ret = register_kprobe(&k); |
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if (ret < 0) { |
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pr_err("FAIL: register_kprobe failed with %d\n", ret); |
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return ret; |
|
} |
|
|
|
ret = benchmark(fn); |
|
|
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unregister_kprobe(&k); |
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return ret; |
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}; |
|
|
|
struct benchmarks { |
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void (*fn)(void); |
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unsigned offset; |
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const char *title; |
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}; |
|
|
|
static int run_benchmarks(void) |
|
{ |
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int ret; |
|
struct benchmarks list[] = { |
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{&benchmark_nop, 0, "nop"}, |
|
/* |
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* 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}"}, |
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{&benchmark_pushpop1, 4, "ldmia sp!, {r3-r11,pc}"}, |
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{&benchmark_pushpop2, 0, "stmdb sp!, {r0-r8,lr}"}, |
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{&benchmark_pushpop2, 4, "ldmia sp!, {r0-r8,pc}"}, |
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{&benchmark_pushpop3, 0, "stmdb sp!, {r4,lr}"}, |
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{&benchmark_pushpop3, 4, "ldmia sp!, {r4,pc}"}, |
|
{&benchmark_pushpop4, 0, "stmdb sp!, {r0,lr}"}, |
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{&benchmark_pushpop4, 4, "ldmia sp!, {r0,pc}"}, |
|
#ifdef CONFIG_THUMB2_KERNEL |
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{&benchmark_pushpop_thumb, 0, "push.n {r0-r7,lr}"}, |
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{&benchmark_pushpop_thumb, 2, "pop.n {r0-r7,pc}"}, |
|
#endif |
|
{0} |
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}; |
|
|
|
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_array(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__ ( |
|
"mov r2, sp \n\t" |
|
"bic r3, r2, #7 \n\t" |
|
"mov sp, r3 \n\t" |
|
"stmdb sp!, {r2-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!, {r2-r11} \n\t" |
|
"mov sp, r2 \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!, {r2-r11} \n\t" |
|
"mov sp, r2 \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("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
|
|
|