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linux-next/arch/arm/kernel/kprobes-test.h
Taras Kondratiuk 41b5368f31 ARM: kprobes-test: Workaround GAS .align bug
By default if no fill symbol is given to .align directive in a code
section it fills gap with NOPs. If previous fragment is not
instruction-aligned, additional pre-alignment is done by zero bytes
before NOPs. These zero bytes are marked as data by special symbol $d in
symbol table. Unfortunately GAS assumes that there is only code in the
code section so it "puts back" code symbol $a at the end of this
pre-alignment. So if there is some data after alignment it will be
interpreted as code and will be swapped back to LE for BE8 system during
a final linking.

If explicit fill value is given to .align, the NOP-padding code is
skipped and symbol table does not get messed-up.

So the workaround for this issue:
Use explicit fill value if data should be aligned in the code section.

Acked-by: Ben Dooks <ben.dooks@codethink.co.uk>
Acked-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Taras Kondratiuk <taras.kondratiuk@linaro.org>
2014-04-01 16:48:27 +03:00

433 lines
12 KiB
C

/*
* arch/arm/kernel/kprobes-test.h
*
* 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.
*/
#define VERBOSE 0 /* Set to '1' for more logging of test cases */
#ifdef CONFIG_THUMB2_KERNEL
#define NORMAL_ISA "16"
#else
#define NORMAL_ISA "32"
#endif
/* Flags used in kprobe_test_flags */
#define TEST_FLAG_NO_ITBLOCK (1<<0)
#define TEST_FLAG_FULL_ITBLOCK (1<<1)
#define TEST_FLAG_NARROW_INSTR (1<<2)
extern int kprobe_test_flags;
extern int kprobe_test_cc_position;
#define TEST_MEMORY_SIZE 256
/*
* Test case structures.
*
* The arguments given to test cases can be one of three types.
*
* ARG_TYPE_REG
* Load a register with the given value.
*
* ARG_TYPE_PTR
* Load a register with a pointer into the stack buffer (SP + given value).
*
* ARG_TYPE_MEM
* Store the given value into the stack buffer at [SP+index].
*
*/
#define ARG_TYPE_END 0
#define ARG_TYPE_REG 1
#define ARG_TYPE_PTR 2
#define ARG_TYPE_MEM 3
#define ARG_FLAG_UNSUPPORTED 0x01
#define ARG_FLAG_SUPPORTED 0x02
#define ARG_FLAG_THUMB 0x10 /* Must be 16 so TEST_ISA can be used */
#define ARG_FLAG_ARM 0x20 /* Must be 32 so TEST_ISA can be used */
struct test_arg {
u8 type; /* ARG_TYPE_x */
u8 _padding[7];
};
struct test_arg_regptr {
u8 type; /* ARG_TYPE_REG or ARG_TYPE_PTR */
u8 reg;
u8 _padding[2];
u32 val;
};
struct test_arg_mem {
u8 type; /* ARG_TYPE_MEM */
u8 index;
u8 _padding[2];
u32 val;
};
struct test_arg_end {
u8 type; /* ARG_TYPE_END */
u8 flags; /* ARG_FLAG_x */
u16 code_offset;
u16 branch_offset;
u16 end_offset;
};
/*
* Building blocks for test cases.
*
* Each test case is wrapped between TESTCASE_START and TESTCASE_END.
*
* To specify arguments for a test case the TEST_ARG_{REG,PTR,MEM} macros are
* used followed by a terminating TEST_ARG_END.
*
* After this, the instruction to be tested is defined with TEST_INSTRUCTION.
* Or for branches, TEST_BRANCH_B and TEST_BRANCH_F (branch forwards/backwards).
*
* Some specific test cases may make use of other custom constructs.
*/
#if VERBOSE
#define verbose(fmt, ...) pr_info(fmt, ##__VA_ARGS__)
#else
#define verbose(fmt, ...)
#endif
#define TEST_GROUP(title) \
verbose("\n"); \
verbose(title"\n"); \
verbose("---------------------------------------------------------\n");
#define TESTCASE_START(title) \
__asm__ __volatile__ ( \
"bl __kprobes_test_case_start \n\t" \
/* don't use .asciz here as 'title' may be */ \
/* multiple strings to be concatenated. */ \
".ascii "#title" \n\t" \
".byte 0 \n\t" \
".align 2, 0 \n\t"
#define TEST_ARG_REG(reg, val) \
".byte "__stringify(ARG_TYPE_REG)" \n\t" \
".byte "#reg" \n\t" \
".short 0 \n\t" \
".word "#val" \n\t"
#define TEST_ARG_PTR(reg, val) \
".byte "__stringify(ARG_TYPE_PTR)" \n\t" \
".byte "#reg" \n\t" \
".short 0 \n\t" \
".word "#val" \n\t"
#define TEST_ARG_MEM(index, val) \
".byte "__stringify(ARG_TYPE_MEM)" \n\t" \
".byte "#index" \n\t" \
".short 0 \n\t" \
".word "#val" \n\t"
#define TEST_ARG_END(flags) \
".byte "__stringify(ARG_TYPE_END)" \n\t" \
".byte "TEST_ISA flags" \n\t" \
".short 50f-0f \n\t" \
".short 2f-0f \n\t" \
".short 99f-0f \n\t" \
".code "TEST_ISA" \n\t" \
"0: \n\t"
#define TEST_INSTRUCTION(instruction) \
"50: nop \n\t" \
"1: "instruction" \n\t" \
" nop \n\t"
#define TEST_BRANCH_F(instruction) \
TEST_INSTRUCTION(instruction) \
" b 99f \n\t" \
"2: nop \n\t"
#define TEST_BRANCH_B(instruction) \
" b 50f \n\t" \
" b 99f \n\t" \
"2: nop \n\t" \
" b 99f \n\t" \
TEST_INSTRUCTION(instruction)
#define TEST_BRANCH_FX(instruction, codex) \
TEST_INSTRUCTION(instruction) \
" b 99f \n\t" \
codex" \n\t" \
" b 99f \n\t" \
"2: nop \n\t"
#define TEST_BRANCH_BX(instruction, codex) \
" b 50f \n\t" \
" b 99f \n\t" \
"2: nop \n\t" \
" b 99f \n\t" \
codex" \n\t" \
TEST_INSTRUCTION(instruction)
#define TESTCASE_END \
"2: \n\t" \
"99: \n\t" \
" bl __kprobes_test_case_end_"TEST_ISA" \n\t" \
".code "NORMAL_ISA" \n\t" \
: : \
: "r0", "r1", "r2", "r3", "ip", "lr", "memory", "cc" \
);
/*
* Macros to define test cases.
*
* Those of the form TEST_{R,P,M}* can be used to define test cases
* which take combinations of the three basic types of arguments. E.g.
*
* TEST_R One register argument
* TEST_RR Two register arguments
* TEST_RPR A register, a pointer, then a register argument
*
* For testing instructions which may branch, there are macros TEST_BF_*
* and TEST_BB_* for branching forwards and backwards.
*
* TEST_SUPPORTED and TEST_UNSUPPORTED don't cause the code to be executed,
* the just verify that a kprobe is or is not allowed on the given instruction.
*/
#define TEST(code) \
TESTCASE_START(code) \
TEST_ARG_END("") \
TEST_INSTRUCTION(code) \
TESTCASE_END
#define TEST_UNSUPPORTED(code) \
TESTCASE_START(code) \
TEST_ARG_END("|"__stringify(ARG_FLAG_UNSUPPORTED)) \
TEST_INSTRUCTION(code) \
TESTCASE_END
#define TEST_SUPPORTED(code) \
TESTCASE_START(code) \
TEST_ARG_END("|"__stringify(ARG_FLAG_SUPPORTED)) \
TEST_INSTRUCTION(code) \
TESTCASE_END
#define TEST_R(code1, reg, val, code2) \
TESTCASE_START(code1 #reg code2) \
TEST_ARG_REG(reg, val) \
TEST_ARG_END("") \
TEST_INSTRUCTION(code1 #reg code2) \
TESTCASE_END
#define TEST_RR(code1, reg1, val1, code2, reg2, val2, code3) \
TESTCASE_START(code1 #reg1 code2 #reg2 code3) \
TEST_ARG_REG(reg1, val1) \
TEST_ARG_REG(reg2, val2) \
TEST_ARG_END("") \
TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3) \
TESTCASE_END
#define TEST_RRR(code1, reg1, val1, code2, reg2, val2, code3, reg3, val3, code4)\
TESTCASE_START(code1 #reg1 code2 #reg2 code3 #reg3 code4) \
TEST_ARG_REG(reg1, val1) \
TEST_ARG_REG(reg2, val2) \
TEST_ARG_REG(reg3, val3) \
TEST_ARG_END("") \
TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3 #reg3 code4) \
TESTCASE_END
#define TEST_RRRR(code1, reg1, val1, code2, reg2, val2, code3, reg3, val3, code4, reg4, val4) \
TESTCASE_START(code1 #reg1 code2 #reg2 code3 #reg3 code4 #reg4) \
TEST_ARG_REG(reg1, val1) \
TEST_ARG_REG(reg2, val2) \
TEST_ARG_REG(reg3, val3) \
TEST_ARG_REG(reg4, val4) \
TEST_ARG_END("") \
TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3 #reg3 code4 #reg4) \
TESTCASE_END
#define TEST_P(code1, reg1, val1, code2) \
TESTCASE_START(code1 #reg1 code2) \
TEST_ARG_PTR(reg1, val1) \
TEST_ARG_END("") \
TEST_INSTRUCTION(code1 #reg1 code2) \
TESTCASE_END
#define TEST_PR(code1, reg1, val1, code2, reg2, val2, code3) \
TESTCASE_START(code1 #reg1 code2 #reg2 code3) \
TEST_ARG_PTR(reg1, val1) \
TEST_ARG_REG(reg2, val2) \
TEST_ARG_END("") \
TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3) \
TESTCASE_END
#define TEST_RP(code1, reg1, val1, code2, reg2, val2, code3) \
TESTCASE_START(code1 #reg1 code2 #reg2 code3) \
TEST_ARG_REG(reg1, val1) \
TEST_ARG_PTR(reg2, val2) \
TEST_ARG_END("") \
TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3) \
TESTCASE_END
#define TEST_PRR(code1, reg1, val1, code2, reg2, val2, code3, reg3, val3, code4)\
TESTCASE_START(code1 #reg1 code2 #reg2 code3 #reg3 code4) \
TEST_ARG_PTR(reg1, val1) \
TEST_ARG_REG(reg2, val2) \
TEST_ARG_REG(reg3, val3) \
TEST_ARG_END("") \
TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3 #reg3 code4) \
TESTCASE_END
#define TEST_RPR(code1, reg1, val1, code2, reg2, val2, code3, reg3, val3, code4)\
TESTCASE_START(code1 #reg1 code2 #reg2 code3 #reg3 code4) \
TEST_ARG_REG(reg1, val1) \
TEST_ARG_PTR(reg2, val2) \
TEST_ARG_REG(reg3, val3) \
TEST_ARG_END("") \
TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3 #reg3 code4) \
TESTCASE_END
#define TEST_RRP(code1, reg1, val1, code2, reg2, val2, code3, reg3, val3, code4)\
TESTCASE_START(code1 #reg1 code2 #reg2 code3 #reg3 code4) \
TEST_ARG_REG(reg1, val1) \
TEST_ARG_REG(reg2, val2) \
TEST_ARG_PTR(reg3, val3) \
TEST_ARG_END("") \
TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3 #reg3 code4) \
TESTCASE_END
#define TEST_BF_P(code1, reg1, val1, code2) \
TESTCASE_START(code1 #reg1 code2) \
TEST_ARG_PTR(reg1, val1) \
TEST_ARG_END("") \
TEST_BRANCH_F(code1 #reg1 code2) \
TESTCASE_END
#define TEST_BF(code) \
TESTCASE_START(code) \
TEST_ARG_END("") \
TEST_BRANCH_F(code) \
TESTCASE_END
#define TEST_BB(code) \
TESTCASE_START(code) \
TEST_ARG_END("") \
TEST_BRANCH_B(code) \
TESTCASE_END
#define TEST_BF_R(code1, reg, val, code2) \
TESTCASE_START(code1 #reg code2) \
TEST_ARG_REG(reg, val) \
TEST_ARG_END("") \
TEST_BRANCH_F(code1 #reg code2) \
TESTCASE_END
#define TEST_BB_R(code1, reg, val, code2) \
TESTCASE_START(code1 #reg code2) \
TEST_ARG_REG(reg, val) \
TEST_ARG_END("") \
TEST_BRANCH_B(code1 #reg code2) \
TESTCASE_END
#define TEST_BF_RR(code1, reg1, val1, code2, reg2, val2, code3) \
TESTCASE_START(code1 #reg1 code2 #reg2 code3) \
TEST_ARG_REG(reg1, val1) \
TEST_ARG_REG(reg2, val2) \
TEST_ARG_END("") \
TEST_BRANCH_F(code1 #reg1 code2 #reg2 code3) \
TESTCASE_END
#define TEST_BF_X(code, codex) \
TESTCASE_START(code) \
TEST_ARG_END("") \
TEST_BRANCH_FX(code, codex) \
TESTCASE_END
#define TEST_BB_X(code, codex) \
TESTCASE_START(code) \
TEST_ARG_END("") \
TEST_BRANCH_BX(code, codex) \
TESTCASE_END
#define TEST_BF_RX(code1, reg, val, code2, codex) \
TESTCASE_START(code1 #reg code2) \
TEST_ARG_REG(reg, val) \
TEST_ARG_END("") \
TEST_BRANCH_FX(code1 #reg code2, codex) \
TESTCASE_END
#define TEST_X(code, codex) \
TESTCASE_START(code) \
TEST_ARG_END("") \
TEST_INSTRUCTION(code) \
" b 99f \n\t" \
" "codex" \n\t" \
TESTCASE_END
#define TEST_RX(code1, reg, val, code2, codex) \
TESTCASE_START(code1 #reg code2) \
TEST_ARG_REG(reg, val) \
TEST_ARG_END("") \
TEST_INSTRUCTION(code1 __stringify(reg) code2) \
" b 99f \n\t" \
" "codex" \n\t" \
TESTCASE_END
#define TEST_RRX(code1, reg1, val1, code2, reg2, val2, code3, codex) \
TESTCASE_START(code1 #reg1 code2 #reg2 code3) \
TEST_ARG_REG(reg1, val1) \
TEST_ARG_REG(reg2, val2) \
TEST_ARG_END("") \
TEST_INSTRUCTION(code1 __stringify(reg1) code2 __stringify(reg2) code3) \
" b 99f \n\t" \
" "codex" \n\t" \
TESTCASE_END
/*
* Macros for defining space directives spread over multiple lines.
* These are required so the compiler guesses better the length of inline asm
* code and will spill the literal pool early enough to avoid generating PC
* relative loads with out of range offsets.
*/
#define TWICE(x) x x
#define SPACE_0x8 TWICE(".space 4\n\t")
#define SPACE_0x10 TWICE(SPACE_0x8)
#define SPACE_0x20 TWICE(SPACE_0x10)
#define SPACE_0x40 TWICE(SPACE_0x20)
#define SPACE_0x80 TWICE(SPACE_0x40)
#define SPACE_0x100 TWICE(SPACE_0x80)
#define SPACE_0x200 TWICE(SPACE_0x100)
#define SPACE_0x400 TWICE(SPACE_0x200)
#define SPACE_0x800 TWICE(SPACE_0x400)
#define SPACE_0x1000 TWICE(SPACE_0x800)
/* Various values used in test cases... */
#define N(val) (val ^ 0xffffffff)
#define VAL1 0x12345678
#define VAL2 N(VAL1)
#define VAL3 0xa5f801
#define VAL4 N(VAL3)
#define VALM 0x456789ab
#define VALR 0xdeaddead
#define HH1 0x0123fecb
#define HH2 0xa9874567
#ifdef CONFIG_THUMB2_KERNEL
void kprobe_thumb16_test_cases(void);
void kprobe_thumb32_test_cases(void);
#else
void kprobe_arm_test_cases(void);
#endif