From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11222 invoked by alias); 4 Nov 2011 19:35:49 -0000 Received: (qmail 8620 invoked by uid 22791); 4 Nov 2011 19:35:32 -0000 X-SWARE-Spam-Status: No, hits=-1.6 required=5.0 tests=AWL,BAYES_00,TW_XD X-Spam-Check-By: sourceware.org Received: from relay1.mentorg.com (HELO relay1.mentorg.com) (192.94.38.131) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Fri, 04 Nov 2011 19:35:09 +0000 Received: from svr-orw-fem-01.mgc.mentorg.com ([147.34.98.93]) by relay1.mentorg.com with esmtp id 1RMPXg-0003pY-HO from wade_farnsworth@mentor.com for systemtap@sourceware.org; Fri, 04 Nov 2011 12:35:08 -0700 Received: from SVR-ORW-FEM-03.mgc.mentorg.com ([147.34.97.39]) by svr-orw-fem-01.mgc.mentorg.com over TLS secured channel with Microsoft SMTPSVC(6.0.3790.4675); Fri, 4 Nov 2011 12:35:08 -0700 Received: from [172.30.5.135] (147.34.91.1) by svr-orw-fem-03.mgc.mentorg.com (147.34.97.39) with Microsoft SMTP Server id 14.1.289.1; Fri, 4 Nov 2011 12:35:07 -0700 Message-ID: <4EB43E69.40004@mentor.com> Date: Fri, 04 Nov 2011 19:35:00 -0000 From: Wade Farnsworth User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110424 Lightning/1.0b2 Thunderbird/3.1.10 MIME-Version: 1.0 To: Subject: [PATCH v2] ARM uprobes support References: <4EB2D832.60402@mentor.com> <4EB2D8B9.1000603@mentor.com> In-Reply-To: <4EB2D8B9.1000603@mentor.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-IsSubscribed: yes Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2011-q4/txt/msg00144.txt.bz2 Basic uprobes support for ARM. Signed-off-by: Wade Farnsworth --- v2: Add cpu_architecture() which is not exported from the kernel and is required for some configurations. runtime/uprobes2/uprobes_arch.c | 2 + runtime/uprobes2/uprobes_arch.h | 2 + runtime/uprobes2/uprobes_arm.c | 1947 +++++++++++++++++++++++++++++++++++++++ runtime/uprobes2/uprobes_arm.h | 114 +++ 4 files changed, 2065 insertions(+), 0 deletions(-) create mode 100644 runtime/uprobes2/uprobes_arm.c create mode 100644 runtime/uprobes2/uprobes_arm.h diff --git a/runtime/uprobes2/uprobes_arch.c b/runtime/uprobes2/uprobes_arch.c index a91d5b6..1df4fdd 100644 --- a/runtime/uprobes2/uprobes_arch.c +++ b/runtime/uprobes2/uprobes_arch.c @@ -1,5 +1,7 @@ #if defined (__x86_64__) || defined(__i386) #include "uprobes_x86.c" +#elif defined (__arm__) +#include "uprobes_arm.c" #elif defined (__powerpc__) #include "../uprobes/uprobes_ppc.c" #elif defined (__s390__) || defined (__s390x__) diff --git a/runtime/uprobes2/uprobes_arch.h b/runtime/uprobes2/uprobes_arch.h index cce5775..a499279 100644 --- a/runtime/uprobes2/uprobes_arch.h +++ b/runtime/uprobes2/uprobes_arch.h @@ -1,5 +1,7 @@ #if defined (__x86_64__) || defined(__i386) #include "uprobes_x86.h" +#elif defined (__arm__) +#include "uprobes_arm.h" #elif defined (__powerpc__) #include "../uprobes/uprobes_ppc.h" #elif defined (__s390__) || defined (__s390x__) diff --git a/runtime/uprobes2/uprobes_arm.c b/runtime/uprobes2/uprobes_arm.c new file mode 100644 index 0000000..25088e5 --- /dev/null +++ b/runtime/uprobes2/uprobes_arm.c @@ -0,0 +1,1947 @@ +/* + * Userspace Probes (UProbes) + * uprobes.c + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + * + * Copyright (C) 2011 Mentor Graphics Corporation + * + * Instruction validation and emulation code is based on + * ARM kprobes which is + * Copyright (C) 2011 Jon Medhurst . + * Copyright (C) 2006, 2007 Motorola Inc. + */ +/* + * In versions of uprobes built in the SystemTap runtime, this file + * is #included at the end of uprobes.c. + */ + +/* + * We do not have hardware single-stepping on ARM, This + * effort is further complicated by the ARM not having a + * "next PC" register. Instructions that change the PC + * can't be safely single-stepped in a MP environment, so + * we have a lot of work to do: + * + * In the prepare phase: + * *) If it is an instruction that does anything + * with the CPU mode, we reject it for a uprobe. + * (This is out of laziness rather than need. The + * instructions could be simulated.) + * + * *) Otherwise, decode the instruction rewriting its + * registers to take fixed, ordered registers and + * setting a handler for it to run the instruction. + * + * In the execution phase by an instruction's handler: + * + * *) If the PC is written to by the instruction, the + * instruction must be fully simulated in software. + * + * *) Otherwise, a modified form of the instruction is + * directly executed. Its handler calls the + * instruction in insn[0]. In insn[1] is a + * "mov pc, lr" to return. + * + * Before calling, load up the reordered registers + * from the original instruction's registers. If one + * of the original input registers is the PC, compute + * and adjust the appropriate input register. + * + * After call completes, copy the output registers to + * the original instruction's original registers. + * + * We don't use a real breakpoint instruction since that + * would have us in the kernel go from SVC mode to SVC + * mode losing the link register. Instead we use an + * undefined instruction. To simplify processing, the + * undefined instruction used for uprobes must be reserved + * exclusively for uprobes use. + * + * TODO: ifdef out some instruction decoding based on architecture. + */ + +#define APSR_MASK 0xf80f0000 /* N, Z, C, V, Q and GE flags */ + +int cpu_architecture(void) +{ + int cpu_arch; + + if ((read_cpuid_id() & 0x0008f000) == 0) { + cpu_arch = CPU_ARCH_UNKNOWN; + } else if ((read_cpuid_id() & 0x0008f000) == 0x00007000) { + cpu_arch = (read_cpuid_id() & (1 << 23)) ? CPU_ARCH_ARMv4T : CPU_ARCH_ARMv3; + } else if ((read_cpuid_id() & 0x00080000) == 0x00000000) { + cpu_arch = (read_cpuid_id() >> 16) & 7; + if (cpu_arch) + cpu_arch += CPU_ARCH_ARMv3; + } else if ((read_cpuid_id() & 0x000f0000) == 0x000f0000) { + unsigned int mmfr0; + + /* Revised CPUID format. Read the Memory Model Feature + * Register 0 and check for VMSAv7 or PMSAv7 */ + asm("mrc p15, 0, %0, c0, c1, 4" + : "=r" (mmfr0)); + if ((mmfr0 & 0x0000000f) >= 0x00000003 || + (mmfr0 & 0x000000f0) >= 0x00000030) + cpu_arch = CPU_ARCH_ARMv7; + else if ((mmfr0 & 0x0000000f) == 0x00000002 || + (mmfr0 & 0x000000f0) == 0x00000020) + cpu_arch = CPU_ARCH_ARMv6; + else + cpu_arch = CPU_ARCH_UNKNOWN; + } else + cpu_arch = CPU_ARCH_UNKNOWN; + + return cpu_arch; +} + +#if __LINUX_ARM_ARCH__ >= 7 + +/* str_pc_offset is architecturally defined from ARMv7 onwards */ +#define str_pc_offset 8 +#define find_str_pc_offset() + +#else /* __LINUX_ARM_ARCH__ < 7 */ + +/* We need a run-time check to determine str_pc_offset */ +extern int str_pc_offset; +void find_str_pc_offset(void); + +#endif + +static inline void bx_write_pc(long pcv, struct pt_regs *regs) +{ + long cpsr = regs->ARM_cpsr; + if (pcv & 0x1) { + cpsr |= PSR_T_BIT; + pcv &= ~0x1; + } else { + cpsr &= ~PSR_T_BIT; + pcv &= ~0x2; /* Avoid UNPREDICTABLE address allignment */ + } + regs->ARM_cpsr = cpsr; + regs->ARM_pc = pcv; +} + +#if __LINUX_ARM_ARCH__ >= 6 + +/* Kernels built for >= ARMv6 should never run on <= ARMv5 hardware, so... */ +#define load_write_pc_interworks true +#define test_load_write_pc_interworking() + +#else /* __LINUX_ARM_ARCH__ < 6 */ + +/* We need run-time testing to determine if load_write_pc() should interwork. + * */ +extern bool load_write_pc_interworks; +void test_load_write_pc_interworking(void); + +#endif + +static inline void load_write_pc(long pcv, struct pt_regs *regs) +{ + if (load_write_pc_interworks) + bx_write_pc(pcv, regs); + else + regs->ARM_pc = pcv; +} + +#if __LINUX_ARM_ARCH__ >= 7 + +#define alu_write_pc_interworks true +#define test_alu_write_pc_interworking() + +#elif __LINUX_ARM_ARCH__ <= 5 + +/* Kernels built for <= ARMv5 should never run on >= ARMv6 hardware, so... */ +#define alu_write_pc_interworks false +#define test_alu_write_pc_interworking() + +#else /* __LINUX_ARM_ARCH__ == 6 */ + +/* We could be an ARMv6 binary on ARMv7 hardware so we need a run-time check. + * */ +extern bool alu_write_pc_interworks; +void test_alu_write_pc_interworking(void); + +#endif /* __LINUX_ARM_ARCH__ == 6 */ + +static inline void alu_write_pc(long pcv, struct pt_regs *regs) +{ + if (alu_write_pc_interworks) + bx_write_pc(pcv, regs); + else + regs->ARM_pc = pcv; +} + +enum uprobe_insn { + INSN_REJECTED, + INSN_GOOD, + INSN_GOOD_NO_SLOT +}; + +typedef enum uprobe_insn (uprobe_decode_insn_t)(uprobe_opcode_t, + struct uprobe_probept_arch_info *); + +/* + * Test if load/store instructions writeback the address register. + * if P (bit 24) == 0 or W (bit 21) == 1 + */ +#define is_writeback(insn) ((insn ^ 0x01000000) & 0x01200000) + +/* + * The following definitions and macros are used to build instruction + * decoding tables for use by uprobe_decode_insn. + * + * These tables are a concatenation of entries each of which consist of one of + * the decode_* structs. All of the fields in every type of decode structure + * are of the union type decode_item, therefore the entire decode table can be + * viewed as an array of these and declared like: + * + * static const union decode_item table_name[] = {}; + * + * In order to construct each entry in the table, macros are used to + * initialise a number of sequential decode_item values in a layout which + * matches the relevant struct. E.g. DECODE_SIMULATE initialise a struct + * decode_simulate by initialising four decode_item objects like this... + * + * {.bits = _type}, + * {.bits = _mask}, + * {.bits = _value}, + * {.handler = _handler}, + * + * Initialising a specified member of the union means that the compiler + * will produce a warning if the argument is of an incorrect type. + * + * Below is a list of each of the macros used to initialise entries and a + * description of the action performed when that entry is matched to an + * instruction. A match is found when (instruction & mask) == value. + * + * DECODE_TABLE(mask, value, table) + * Instruction decoding jumps to parsing the new sub-table 'table'. + * + * DECODE_CUSTOM(mask, value, decoder) + * The custom function 'decoder' is called to the complete decoding + * of an instruction. + * + * DECODE_SIMULATE(mask, value, handler) + * Set the probes instruction handler to 'handler', this will be used + * to simulate the instruction when the probe is hit. Decoding returns + * with INSN_GOOD_NO_SLOT. + * + * DECODE_EMULATE(mask, value, handler) + * Set the probes instruction handler to 'handler', this will be used + * to emulate the instruction when the probe is hit. The modified + * instruction (see below) is placed in the probes instruction slot so it + * may be called by the emulation code. Decoding returns with INSN_GOOD. + * + * DECODE_REJECT(mask, value) + * Instruction decoding fails with INSN_REJECTED + * + * DECODE_OR(mask, value) + * This allows the mask/value test of multiple table entries to be + * logically ORed. Once an 'or' entry is matched the decoding action to + * be performed is that of the next entry which isn't an 'or'. E.g. + * + * DECODE_OR (mask1, value1) + * DECODE_OR (mask2, value2) + * DECODE_SIMULATE (mask3, value3, simulation_handler) + * + * This means that if any of the three mask/value pairs match the + * instruction being decoded, then 'simulation_handler' will be used + * for it. + * + * Both the SIMULATE and EMULATE macros have a second form which take an + * additional 'regs' argument. + * + * DECODE_SIMULATEX(mask, value, handler, regs) + * DECODE_EMULATEX (mask, value, handler, regs) + * + * These are used to specify what kind of CPU register is encoded in each of the + * least significant 5 nibbles of the instruction being decoded. The regs value + * is specified using the REGS macro, this takes any of the REG_TYPE_* values + * from enum decode_reg_type as arguments; only the '*' part of the name is + * given. E.g. + * + * REGS(0, ANY, NOPC, 0, ANY) + * + * This indicates an instruction is encoded like: + * + * bits 19..16 ignore + * bits 15..12 any register allowed here + * bits 11.. 8 any register except PC allowed here + * bits 7.. 4 ignore + * bits 3.. 0 any register allowed here + * + * This register specification is checked after a decode table entry is found to + * match an instruction (through the mask/value test). Any invalid register then + * found in the instruction will cause decoding to fail with INSN_REJECTED. In + * the above example this would happen if bits 11..8 of the instruction were + * 1111, indicating R15 or PC. + * + * As well as checking for legal combinations of registers, this data is also + * used to modify the registers encoded in the instructions so that an + * emulation routines can use it. (See decode_regs() and INSN_NEW_BITS.) + * + * Here is a real example which matches ARM instructions of the form + * "AND ,,, " + * + * DECODE_EMULATEX (0x0e000090, 0x00000010, emulate_rd12rn16rm0rs8_rwflags, + * REGS(ANY, ANY, NOPC, 0, ANY)), + * ^ ^ ^ ^ + * Rn Rd Rs Rm + * + * Decoding the instruction "AND R4, R5, R6, ASL R15" will be rejected because + * Rs == R15 + * + * Decoding the instruction "AND R4, R5, R6, ASL R7" will be accepted and the + * instruction will be modified to "AND R0, R2, R3, ASL R1" and then placed into + * the uprobes instruction slot. This can then be called later by the handler + * function emulate_rd12rn16rm0rs8_rwflags in order to simulate the instruction. + */ + +enum decode_type { + DECODE_TYPE_END, + DECODE_TYPE_TABLE, + DECODE_TYPE_CUSTOM, + DECODE_TYPE_SIMULATE, + DECODE_TYPE_EMULATE, + DECODE_TYPE_OR, + DECODE_TYPE_REJECT, + NUM_DECODE_TYPES /* Must be last enum */ +}; + +#define DECODE_TYPE_BITS 4 +#define DECODE_TYPE_MASK ((1 << DECODE_TYPE_BITS) - 1) + +enum decode_reg_type { + REG_TYPE_NONE = 0, /* Not a register, ignore */ + REG_TYPE_ANY, /* Any register allowed */ + REG_TYPE_SAMEAS16, /* Register should be same as that at bits 19..16 */ + REG_TYPE_SP, /* Register must be SP */ + REG_TYPE_PC, /* Register must be PC */ + REG_TYPE_NOSP, /* Register must not be SP */ + REG_TYPE_NOSPPC, /* Register must not be SP or PC */ + REG_TYPE_NOPC, /* Register must not be PC */ + REG_TYPE_NOPCWB, /* No PC if load/store write-back flag also set */ + + /* The following types are used when the encoding for PC indicates + * another instruction form. This distiction only matters for test + * case coverage checks. + */ + REG_TYPE_NOPCX, /* Register must not be PC */ + REG_TYPE_NOSPPCX, /* Register must not be SP or PC */ + + /* Alias to allow '0' arg to be used in REGS macro. */ + REG_TYPE_0 = REG_TYPE_NONE +}; + +#define REGS(r16, r12, r8, r4, r0) \ + ((REG_TYPE_##r16) << 16) + \ + ((REG_TYPE_##r12) << 12) + \ + ((REG_TYPE_##r8) << 8) + \ + ((REG_TYPE_##r4) << 4) + \ + (REG_TYPE_##r0) + +union decode_item { + u32 bits; + const union decode_item *table; + uprobe_insn_handler_t *handler; + uprobe_decode_insn_t *decoder; +}; + + +#define DECODE_END \ + {.bits = DECODE_TYPE_END} + + +struct decode_header { + union decode_item type_regs; + union decode_item mask; + union decode_item value; +}; + +#define DECODE_HEADER(_type, _mask, _value, _regs) \ + {.bits = (_type) | ((_regs) << DECODE_TYPE_BITS)}, \ + {.bits = (_mask)}, \ + {.bits = (_value)} + + +struct decode_table { + struct decode_header header; + union decode_item table; +}; + +#define DECODE_TABLE(_mask, _value, _table) \ + DECODE_HEADER(DECODE_TYPE_TABLE, _mask, _value, 0), \ + {.table = (_table)} + + +struct decode_custom { + struct decode_header header; + union decode_item decoder; +}; + +#define DECODE_CUSTOM(_mask, _value, _decoder) \ + DECODE_HEADER(DECODE_TYPE_CUSTOM, _mask, _value, 0), \ + {.decoder = (_decoder)} + + +struct decode_simulate { + struct decode_header header; + union decode_item handler; +}; + +#define DECODE_SIMULATEX(_mask, _value, _handler, _regs) \ + DECODE_HEADER(DECODE_TYPE_SIMULATE, _mask, _value, _regs), \ + {.handler = (_handler)} + +#define DECODE_SIMULATE(_mask, _value, _handler) \ + DECODE_SIMULATEX(_mask, _value, _handler, 0) + + +struct decode_emulate { + struct decode_header header; + union decode_item handler; +}; + +#define DECODE_EMULATEX(_mask, _value, _handler, _regs) \ + DECODE_HEADER(DECODE_TYPE_EMULATE, _mask, _value, _regs), \ + {.handler = (_handler)} + +#define DECODE_EMULATE(_mask, _value, _handler) \ + DECODE_EMULATEX(_mask, _value, _handler, 0) + + +struct decode_or { + struct decode_header header; +}; + +#define DECODE_OR(_mask, _value) \ + DECODE_HEADER(DECODE_TYPE_OR, _mask, _value, 0) + + +struct decode_reject { + struct decode_header header; +}; + +#define DECODE_REJECT(_mask, _value) \ + DECODE_HEADER(DECODE_TYPE_REJECT, _mask, _value, 0) + +#define sign_extend(x, signbit) ((x) | (0 - ((x) & (1 << (signbit))))) + +#define branch_displacement(insn) sign_extend(((insn) & 0xffffff) << 2, 25) + +#if __LINUX_ARM_ARCH__ >= 6 +#define BLX(reg) "blx "reg" \n\t" +#else +#define BLX(reg) "mov lr, pc \n\t" \ + "mov pc, "reg" \n\t" +#endif + +#ifndef find_str_pc_offset + +/* + * For STR and STM instructions, an ARM core may choose to use either + * a +8 or a +12 displacement from the current instruction's address. + * Whichever value is chosen for a given core, it must be the same for + * both instructions and may not change. This function measures it. + */ + +int str_pc_offset; + +void find_str_pc_offset(void) +{ + int addr, scratch, ret; + + __asm__ ( + "sub %[ret], pc, #4 \n\t" + "str pc, %[addr] \n\t" + "ldr %[scr], %[addr] \n\t" + "sub %[ret], %[scr], %[ret] \n\t" + : [ret] "=r" (ret), [scr] "=r" (scratch), [addr] "+m" (addr)); + + str_pc_offset = ret; +} + +#endif /* !find_str_pc_offset */ + + +#ifndef test_load_write_pc_interworking + +bool load_write_pc_interworks; + +void test_load_write_pc_interworking(void) +{ + int arch = cpu_architecture(); + BUG_ON(arch == CPU_ARCH_UNKNOWN); + load_write_pc_interworks = arch >= CPU_ARCH_ARMv5T; +} + +#endif /* !test_load_write_pc_interworking */ + + +#ifndef test_alu_write_pc_interworking + +bool alu_write_pc_interworks; + +void test_alu_write_pc_interworking(void) +{ + int arch = cpu_architecture(); + BUG_ON(arch == CPU_ARCH_UNKNOWN); + alu_write_pc_interworks = arch >= CPU_ARCH_ARMv7; +} + +#endif /* !test_alu_write_pc_interworking */ + + +void arm_uprobe_decode_init(void) +{ + find_str_pc_offset(); + test_load_write_pc_interworking(); + test_alu_write_pc_interworking(); +} + + +static unsigned long __check_eq(unsigned long cpsr) +{ + return cpsr & PSR_Z_BIT; +} + +static unsigned long __check_ne(unsigned long cpsr) +{ + return (~cpsr) & PSR_Z_BIT; +} + +static unsigned long __check_cs(unsigned long cpsr) +{ + return cpsr & PSR_C_BIT; +} + +static unsigned long __check_cc(unsigned long cpsr) +{ + return (~cpsr) & PSR_C_BIT; +} + +static unsigned long __check_mi(unsigned long cpsr) +{ + return cpsr & PSR_N_BIT; +} + +static unsigned long __check_pl(unsigned long cpsr) +{ + return (~cpsr) & PSR_N_BIT; +} + +static unsigned long __check_vs(unsigned long cpsr) +{ + return cpsr & PSR_V_BIT; +} + +static unsigned long __check_vc(unsigned long cpsr) +{ + return (~cpsr) & PSR_V_BIT; +} + +static unsigned long __check_hi(unsigned long cpsr) +{ + cpsr &= ~(cpsr >> 1); /* PSR_C_BIT &= ~PSR_Z_BIT */ + return cpsr & PSR_C_BIT; +} + +static unsigned long __check_ls(unsigned long cpsr) +{ + cpsr &= ~(cpsr >> 1); /* PSR_C_BIT &= ~PSR_Z_BIT */ + return (~cpsr) & PSR_C_BIT; +} + +static unsigned long __check_ge(unsigned long cpsr) +{ + cpsr ^= (cpsr << 3); /* PSR_N_BIT ^= PSR_V_BIT */ + return (~cpsr) & PSR_N_BIT; +} + +static unsigned long __check_lt(unsigned long cpsr) +{ + cpsr ^= (cpsr << 3); /* PSR_N_BIT ^= PSR_V_BIT */ + return cpsr & PSR_N_BIT; +} + +static unsigned long __check_gt(unsigned long cpsr) +{ + unsigned long temp = cpsr ^ (cpsr << 3); /* PSR_N_BIT ^= PSR_V_BIT */ + temp |= (cpsr << 1); /* PSR_N_BIT |= PSR_Z_BIT */ + return (~temp) & PSR_N_BIT; +} + +static unsigned long __check_le(unsigned long cpsr) +{ + unsigned long temp = cpsr ^ (cpsr << 3); /* PSR_N_BIT ^= PSR_V_BIT */ + temp |= (cpsr << 1); /* PSR_N_BIT |= PSR_Z_BIT */ + return temp & PSR_N_BIT; +} + +static unsigned long __check_al(unsigned long cpsr) +{ + return true; +} + +uprobe_check_cc * const uprobe_condition_checks[16] = { + &__check_eq, &__check_ne, &__check_cs, &__check_cc, + &__check_mi, &__check_pl, &__check_vs, &__check_vc, + &__check_hi, &__check_ls, &__check_ge, &__check_lt, + &__check_gt, &__check_le, &__check_al, &__check_al +}; + +/* + * To avoid the complications of mimicing single-stepping on a + * processor without a Next-PC or a single-step mode, and to + * avoid having to deal with the side-effects of boosting, we + * simulate or emulate (almost) all ARM instructions. + * + * "Simulation" is where the instruction's behavior is duplicated in + * C code. "Emulation" is where the original instruction is rewritten + * and executed, often by altering its registers. + * + * By having all behavior of the uprobe'd instruction completed before + * returning from the uprobe_handler(), all locks (scheduler and + * interrupt) can safely be released. There is no need for secondary + * breakpoints, no race with MP or preemptable kernels, nor having to + * clean up resources counts at a later time impacting overall system + * performance. By rewriting the instruction, only the minimum registers + * need to be loaded and saved back optimizing performance. + * + * Calling the insnslot_*_rwflags version of a function doesn't hurt + * anything even when the CPSR flags aren't updated by the + * instruction. It's just a little slower in return for saving + * a little space by not having a duplicate function that doesn't + * update the flags. (The same optimization can be said for + * instructions that do or don't perform register writeback) + * Also, instructions can either read the flags, only write the + * flags, or read and write the flags. To save combinations + * rather than for sheer performance, flag functions just assume + * read and write of flags. + */ + +void uprobe_simulate_nop(struct uprobe_probept *p, struct pt_regs *regs) +{ +} + +void uprobe_emulate_none(struct uprobe_probept *p, struct pt_regs *regs) +{ + p->arch_info.insn_fn(); +} + +static void simulate_ldm1stm1(struct uprobe_probept *p, struct pt_regs *regs) +{ + uprobe_opcode_t insn = p->opcode; + int rn = (insn >> 16) & 0xf; + int lbit = insn & (1 << 20); + int wbit = insn & (1 << 21); + int ubit = insn & (1 << 23); + int pbit = insn & (1 << 24); + long *addr = (long *)regs->uregs[rn]; + int reg_bit_vector; + int reg_count; + + reg_count = 0; + reg_bit_vector = insn & 0xffff; + while (reg_bit_vector) { + reg_bit_vector &= (reg_bit_vector - 1); + ++reg_count; + } + + if (!ubit) + addr -= reg_count; + addr += (!pbit == !ubit); + + reg_bit_vector = insn & 0xffff; + while (reg_bit_vector) { + int reg = __ffs(reg_bit_vector); + reg_bit_vector &= (reg_bit_vector - 1); + if (lbit) + regs->uregs[reg] = *addr++; + else + *addr++ = regs->uregs[reg]; + } + + if (wbit) { + if (!ubit) + addr -= reg_count; + addr -= (!pbit == !ubit); + regs->uregs[rn] = (long)addr; + } +} + +static void simulate_stm1_pc(struct uprobe_probept *p, struct pt_regs *regs) +{ + regs->ARM_pc = (long)p->vaddr + str_pc_offset; + simulate_ldm1stm1(p, regs); + regs->ARM_pc = (long)p->vaddr + 4; +} + +static void simulate_ldm1_pc(struct uprobe_probept *p, struct pt_regs *regs) +{ + simulate_ldm1stm1(p, regs); + load_write_pc(regs->ARM_pc, regs); +} + +static void +emulate_generic_r0_12_noflags(struct uprobe_probept *p, struct pt_regs *regs) +{ + register void *rregs asm("r1") = regs; + register void *rfn asm("lr") = p->arch_info.insn_fn; + + __asm__ __volatile__ ( + "stmdb sp!, {%[regs], r11} \n\t" + "ldmia %[regs], {r0-r12} \n\t" +#if __LINUX_ARM_ARCH__ >= 6 + "blx %[fn] \n\t" +#else + "str %[fn], [sp, #-4]! \n\t" + "adr lr, 1f \n\t" + "ldr pc, [sp], #4 \n\t" + "1: \n\t" +#endif + "ldr lr, [sp], #4 \n\t" /* lr = regs */ + "stmia lr, {r0-r12} \n\t" + "ldr r11, [sp], #4 \n\t" + : [regs] "=r" (rregs), [fn] "=r" (rfn) + : "0" (rregs), "1" (rfn) + : "r0", "r2", "r3", "r4", "r5", "r6", "r7", + "r8", "r9", "r10", "r12", "memory", "cc" + ); +} + +static void +emulate_generic_r2_14_noflags(struct uprobe_probept *p, struct pt_regs *regs) +{ + emulate_generic_r0_12_noflags(p, (struct pt_regs *)(regs->uregs+2)); +} + +static void +emulate_ldm_r3_15(struct uprobe_probept *p, struct pt_regs *regs) +{ + emulate_generic_r0_12_noflags(p, (struct pt_regs *)(regs->uregs+3)); + load_write_pc(regs->ARM_pc, regs); +} + +enum uprobe_insn +uprobe_decode_ldmstm(uprobe_opcode_t insn, struct uprobe_probept_arch_info *ai) +{ + uprobe_insn_handler_t *handler = 0; + unsigned reglist = insn & 0xffff; + int is_ldm = insn & 0x100000; + int rn = (insn >> 16) & 0xf; + + if (rn <= 12 && (reglist & 0xe000) == 0) { + /* Instruction only uses registers in the range R0..R12 */ + handler = emulate_generic_r0_12_noflags; + + } else if (rn >= 2 && (reglist & 0x8003) == 0) { + /* Instruction only uses registers in the range R2..R14 */ + rn -= 2; + reglist >>= 2; + handler = emulate_generic_r2_14_noflags; + + } else if (rn >= 3 && (reglist & 0x0007) == 0) { + /* Instruction only uses registers in the range R3..R15 */ + if (is_ldm && (reglist & 0x8000)) { + rn -= 3; + reglist >>= 3; + handler = emulate_ldm_r3_15; + } + } + + if (handler) { + /* We can emulate the instruction in (possibly) modified form */ + ai->insn[0] = (insn & 0xfff00000) | (rn << 16) | reglist; + ai->insn_handler = handler; + return INSN_GOOD; + } + + /* Fallback to slower simulation... */ + if (reglist & 0x8000) + handler = is_ldm ? simulate_ldm1_pc : simulate_stm1_pc; + else + handler = simulate_ldm1stm1; + ai->insn_handler = handler; + return INSN_GOOD_NO_SLOT; +} + +static void simulate_bbl(struct uprobe_probept *p, struct pt_regs *regs) +{ + uprobe_opcode_t insn = p->opcode; + long iaddr = (long)p->vaddr; + int disp = branch_displacement(insn); + + if (insn & (1 << 24)) + regs->ARM_lr = iaddr + 4; + + regs->ARM_pc = iaddr + 8 + disp; +} + +static void simulate_blx1(struct uprobe_probept *p, struct pt_regs *regs) +{ + uprobe_opcode_t insn = p->opcode; + long iaddr = (long)p->vaddr; + int disp = branch_displacement(insn); + + regs->ARM_lr = iaddr + 4; + regs->ARM_pc = iaddr + 8 + disp + ((insn >> 23) & 0x2); + regs->ARM_cpsr |= PSR_T_BIT; +} + +static void simulate_blx2bx(struct uprobe_probept *p, struct pt_regs *regs) +{ + uprobe_opcode_t insn = p->opcode; + int rm = insn & 0xf; + long rmv = regs->uregs[rm]; + + if (insn & (1 << 5)) + regs->ARM_lr = (long)p->vaddr + 4; + + regs->ARM_pc = rmv & ~0x1; + regs->ARM_cpsr &= ~PSR_T_BIT; + if (rmv & 0x1) + regs->ARM_cpsr |= PSR_T_BIT; +} + +static void simulate_mrs(struct uprobe_probept *p, struct pt_regs *regs) +{ + uprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + unsigned long mask = 0xf8ff03df; /* Mask out execution state */ + regs->uregs[rd] = regs->ARM_cpsr & mask; +} + +static void simulate_mov_ipsp(struct uprobe_probept *p, struct pt_regs *regs) +{ + regs->uregs[12] = regs->uregs[13]; +} + +static void +emulate_ldrdstrd(struct uprobe_probept *p, struct pt_regs *regs) +{ + uprobe_opcode_t insn = p->opcode; + unsigned long pc = (unsigned long)p->vaddr + 8; + int rt = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + + register unsigned long rtv asm("r0") = regs->uregs[rt]; + register unsigned long rt2v asm("r1") = regs->uregs[rt+1]; + register unsigned long rnv asm("r2") = (rn == 15) ? pc + : regs->uregs[rn]; + register unsigned long rmv asm("r3") = regs->uregs[rm]; + + __asm__ __volatile__ ( + BLX("%[fn]") + : "=r" (rtv), "=r" (rt2v), "=r" (rnv) + : "0" (rtv), "1" (rt2v), "2" (rnv), "r" (rmv), + [fn] "r" (p->arch_info.insn_fn) + : "lr", "memory", "cc" + ); + + regs->uregs[rt] = rtv; + regs->uregs[rt+1] = rt2v; + if (is_writeback(insn)) + regs->uregs[rn] = rnv; +} + +static void +emulate_ldr(struct uprobe_probept *p, struct pt_regs *regs) +{ + uprobe_opcode_t insn = p->opcode; + unsigned long pc = (unsigned long)p->vaddr + 8; + int rt = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + + register unsigned long rtv asm("r0"); + register unsigned long rnv asm("r2") = (rn == 15) ? pc + : regs->uregs[rn]; + register unsigned long rmv asm("r3") = regs->uregs[rm]; + + __asm__ __volatile__ ( + BLX("%[fn]") + : "=r" (rtv), "=r" (rnv) + : "1" (rnv), "r" (rmv), [fn] "r" (p->arch_info.insn_fn) + : "lr", "memory", "cc" + ); + + if (rt == 15) + load_write_pc(rtv, regs); + else + regs->uregs[rt] = rtv; + + if (is_writeback(insn)) + regs->uregs[rn] = rnv; +} + +static void +emulate_str(struct uprobe_probept *p, struct pt_regs *regs) +{ + uprobe_opcode_t insn = p->opcode; + unsigned long rtpc = (unsigned long)p->vaddr + str_pc_offset; + unsigned long rnpc = (unsigned long)p->vaddr + 8; + int rt = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + + register unsigned long rtv asm("r0") = (rt == 15) ? rtpc + : regs->uregs[rt]; + register unsigned long rnv asm("r2") = (rn == 15) ? rnpc + : regs->uregs[rn]; + register unsigned long rmv asm("r3") = regs->uregs[rm]; + + __asm__ __volatile__ ( + BLX("%[fn]") + : "=r" (rnv) + : "r" (rtv), "0" (rnv), "r" (rmv), [fn] "r" (p->arch_info.insn_fn) + : "lr", "memory", "cc" + ); + + if (is_writeback(insn)) + regs->uregs[rn] = rnv; +} + +static void +emulate_rd12rn16rm0rs8_rwflags(struct uprobe_probept *p, struct pt_regs *regs) +{ + uprobe_opcode_t insn = p->opcode; + unsigned long pc = (unsigned long)p->vaddr + 8; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + int rs = (insn >> 8) & 0xf; + + register unsigned long rdv asm("r0") = regs->uregs[rd]; + register unsigned long rnv asm("r2") = (rn == 15) ? pc + : regs->uregs[rn]; + register unsigned long rmv asm("r3") = (rm == 15) ? pc + : regs->uregs[rm]; + register unsigned long rsv asm("r1") = regs->uregs[rs]; + unsigned long cpsr = regs->ARM_cpsr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + BLX("%[fn]") + "mrs %[cpsr], cpsr \n\t" + : "=r" (rdv), [cpsr] "=r" (cpsr) + : "0" (rdv), "r" (rnv), "r" (rmv), "r" (rsv), + "1" (cpsr), [fn] "r" (p->arch_info.insn_fn) + : "lr", "memory", "cc" + ); + + if (rd == 15) + alu_write_pc(rdv, regs); + else + regs->uregs[rd] = rdv; + regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK); +} + +static void +emulate_rd12rn16rm0_rwflags_nopc(struct uprobe_probept *p, struct pt_regs *regs) +{ + uprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + + register unsigned long rdv asm("r0") = regs->uregs[rd]; + register unsigned long rnv asm("r2") = regs->uregs[rn]; + register unsigned long rmv asm("r3") = regs->uregs[rm]; + unsigned long cpsr = regs->ARM_cpsr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + BLX("%[fn]") + "mrs %[cpsr], cpsr \n\t" + : "=r" (rdv), [cpsr] "=r" (cpsr) + : "0" (rdv), "r" (rnv), "r" (rmv), + "1" (cpsr), [fn] "r" (p->arch_info.insn_fn) + : "lr", "memory", "cc" + ); + + regs->uregs[rd] = rdv; + regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK); +} + +static void +emulate_rd16rn12rm0rs8_rwflags_nopc(struct uprobe_probept *p, struct pt_regs *regs) +{ + uprobe_opcode_t insn = p->opcode; + int rd = (insn >> 16) & 0xf; + int rn = (insn >> 12) & 0xf; + int rm = insn & 0xf; + int rs = (insn >> 8) & 0xf; + + register unsigned long rdv asm("r2") = regs->uregs[rd]; + register unsigned long rnv asm("r0") = regs->uregs[rn]; + register unsigned long rmv asm("r3") = regs->uregs[rm]; + register unsigned long rsv asm("r1") = regs->uregs[rs]; + unsigned long cpsr = regs->ARM_cpsr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + BLX("%[fn]") + "mrs %[cpsr], cpsr \n\t" + : "=r" (rdv), [cpsr] "=r" (cpsr) + : "0" (rdv), "r" (rnv), "r" (rmv), "r" (rsv), + "1" (cpsr), [fn] "r" (p->arch_info.insn_fn) + : "lr", "memory", "cc" + ); + + regs->uregs[rd] = rdv; + regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK); +} + +static void +emulate_rd12rm0_noflags_nopc(struct uprobe_probept *p, struct pt_regs *regs) +{ + uprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rm = insn & 0xf; + + register unsigned long rdv asm("r0") = regs->uregs[rd]; + register unsigned long rmv asm("r3") = regs->uregs[rm]; + + __asm__ __volatile__ ( + BLX("%[fn]") + : "=r" (rdv) + : "0" (rdv), "r" (rmv), [fn] "r" (p->arch_info.insn_fn) + : "lr", "memory", "cc" + ); + + regs->uregs[rd] = rdv; +} + +static void +emulate_rdlo12rdhi16rn0rm8_rwflags_nopc(struct uprobe_probept *p, struct pt_regs *regs) +{ + uprobe_opcode_t insn = p->opcode; + int rdlo = (insn >> 12) & 0xf; + int rdhi = (insn >> 16) & 0xf; + int rn = insn & 0xf; + int rm = (insn >> 8) & 0xf; + + register unsigned long rdlov asm("r0") = regs->uregs[rdlo]; + register unsigned long rdhiv asm("r2") = regs->uregs[rdhi]; + register unsigned long rnv asm("r3") = regs->uregs[rn]; + register unsigned long rmv asm("r1") = regs->uregs[rm]; + unsigned long cpsr = regs->ARM_cpsr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + BLX("%[fn]") + "mrs %[cpsr], cpsr \n\t" + : "=r" (rdlov), "=r" (rdhiv), [cpsr] "=r" (cpsr) + : "0" (rdlov), "1" (rdhiv), "r" (rnv), "r" (rmv), + "2" (cpsr), [fn] "r" (p->arch_info.insn_fn) + : "lr", "memory", "cc" + ); + + regs->uregs[rdlo] = rdlov; + regs->uregs[rdhi] = rdhiv; + regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK); +} + +/* + * For the instruction masking and comparisons in all the "space_*" + * functions below, Do _not_ rearrange the order of tests unless + * you're very, very sure of what you are doing. For the sake of + * efficiency, the masks for some tests sometimes assume other test + * have been done prior to them so the number of patterns to test + * for an instruction set can be as broad as possible to reduce the + * number of tests needed. + */ + +static const union decode_item arm_1111_table[] = { + /* Unconditional instructions */ + + /* memory hint 1111 0100 x001 xxxx xxxx xxxx xxxx xxxx */ + /* PLDI (immediate) 1111 0100 x101 xxxx xxxx xxxx xxxx xxxx */ + /* PLDW (immediate) 1111 0101 x001 xxxx xxxx xxxx xxxx xxxx */ + /* PLD (immediate) 1111 0101 x101 xxxx xxxx xxxx xxxx xxxx */ + DECODE_SIMULATE (0xfe300000, 0xf4100000, uprobe_simulate_nop), + + /* memory hint 1111 0110 x001 xxxx xxxx xxxx xxx0 xxxx */ + /* PLDI (register) 1111 0110 x101 xxxx xxxx xxxx xxx0 xxxx */ + /* PLDW (register) 1111 0111 x001 xxxx xxxx xxxx xxx0 xxxx */ + /* PLD (register) 1111 0111 x101 xxxx xxxx xxxx xxx0 xxxx */ + DECODE_SIMULATE (0xfe300010, 0xf6100000, uprobe_simulate_nop), + + /* BLX (immediate) 1111 101x xxxx xxxx xxxx xxxx xxxx xxxx */ + DECODE_SIMULATE (0xfe000000, 0xfa000000, simulate_blx1), + + /* CPS 1111 0001 0000 xxx0 xxxx xxxx xx0x xxxx */ + /* SETEND 1111 0001 0000 0001 xxxx xxxx 0000 xxxx */ + /* SRS 1111 100x x1x0 xxxx xxxx xxxx xxxx xxxx */ + /* RFE 1111 100x x0x1 xxxx xxxx xxxx xxxx xxxx */ + + /* Coprocessor instructions... */ + /* MCRR2 1111 1100 0100 xxxx xxxx xxxx xxxx xxxx */ + /* MRRC2 1111 1100 0101 xxxx xxxx xxxx xxxx xxxx */ + /* LDC2 1111 110x xxx1 xxxx xxxx xxxx xxxx xxxx */ + /* STC2 1111 110x xxx0 xxxx xxxx xxxx xxxx xxxx */ + /* CDP2 1111 1110 xxxx xxxx xxxx xxxx xxx0 xxxx */ + /* MCR2 1111 1110 xxx0 xxxx xxxx xxxx xxx1 xxxx */ + /* MRC2 1111 1110 xxx1 xxxx xxxx xxxx xxx1 xxxx */ + + /* Other unallocated instructions... */ + DECODE_END +}; + +static const union decode_item arm_cccc_0001_0xx0____0xxx_table[] = { + /* Miscellaneous instructions */ + + /* MRS cpsr cccc 0001 0000 xxxx xxxx xxxx 0000 xxxx */ + DECODE_SIMULATEX(0x0ff000f0, 0x01000000, simulate_mrs, + REGS(0, NOPC, 0, 0, 0)), + + /* BX cccc 0001 0010 xxxx xxxx xxxx 0001 xxxx */ + DECODE_SIMULATE (0x0ff000f0, 0x01200010, simulate_blx2bx), + + /* BLX (register) cccc 0001 0010 xxxx xxxx xxxx 0011 xxxx */ + DECODE_SIMULATEX(0x0ff000f0, 0x01200030, simulate_blx2bx, + REGS(0, 0, 0, 0, NOPC)), + + /* CLZ cccc 0001 0110 xxxx xxxx xxxx 0001 xxxx */ + DECODE_EMULATEX (0x0ff000f0, 0x01600010, emulate_rd12rm0_noflags_nopc, + REGS(0, NOPC, 0, 0, NOPC)), + + /* QADD cccc 0001 0000 xxxx xxxx xxxx 0101 xxxx */ + /* QSUB cccc 0001 0010 xxxx xxxx xxxx 0101 xxxx */ + /* QDADD cccc 0001 0100 xxxx xxxx xxxx 0101 xxxx */ + /* QDSUB cccc 0001 0110 xxxx xxxx xxxx 0101 xxxx */ + DECODE_EMULATEX (0x0f9000f0, 0x01000050, emulate_rd12rn16rm0_rwflags_nopc, + REGS(NOPC, NOPC, 0, 0, NOPC)), + + /* BXJ cccc 0001 0010 xxxx xxxx xxxx 0010 xxxx */ + /* MSR cccc 0001 0x10 xxxx xxxx xxxx 0000 xxxx */ + /* MRS spsr cccc 0001 0100 xxxx xxxx xxxx 0000 xxxx */ + /* BKPT 1110 0001 0010 xxxx xxxx xxxx 0111 xxxx */ + /* SMC cccc 0001 0110 xxxx xxxx xxxx 0111 xxxx */ + /* And unallocated instructions... */ + DECODE_END +}; + +static const union decode_item arm_cccc_0001_0xx0____1xx0_table[] = { + /* Halfword multiply and multiply-accumulate */ + + /* SMLALxy cccc 0001 0100 xxxx xxxx xxxx 1xx0 xxxx */ + DECODE_EMULATEX (0x0ff00090, 0x01400080, emulate_rdlo12rdhi16rn0rm8_rwflags_nopc, + REGS(NOPC, NOPC, NOPC, 0, NOPC)), + + /* SMULWy cccc 0001 0010 xxxx xxxx xxxx 1x10 xxxx */ + DECODE_OR (0x0ff000b0, 0x012000a0), + /* SMULxy cccc 0001 0110 xxxx xxxx xxxx 1xx0 xxxx */ + DECODE_EMULATEX (0x0ff00090, 0x01600080, emulate_rd16rn12rm0rs8_rwflags_nopc, + REGS(NOPC, 0, NOPC, 0, NOPC)), + + /* SMLAxy cccc 0001 0000 xxxx xxxx xxxx 1xx0 xxxx */ + DECODE_OR (0x0ff00090, 0x01000080), + /* SMLAWy cccc 0001 0010 xxxx xxxx xxxx 1x00 xxxx */ + DECODE_EMULATEX (0x0ff000b0, 0x01200080, emulate_rd16rn12rm0rs8_rwflags_nopc, + REGS(NOPC, NOPC, NOPC, 0, NOPC)), + + DECODE_END +}; + +static const union decode_item arm_cccc_0000_____1001_table[] = { + /* Multiply and multiply-accumulate */ + + /* MUL cccc 0000 0000 xxxx xxxx xxxx 1001 xxxx */ + /* MULS cccc 0000 0001 xxxx xxxx xxxx 1001 xxxx */ + DECODE_EMULATEX (0x0fe000f0, 0x00000090, emulate_rd16rn12rm0rs8_rwflags_nopc, + REGS(NOPC, 0, NOPC, 0, NOPC)), + + /* MLA cccc 0000 0010 xxxx xxxx xxxx 1001 xxxx */ + /* MLAS cccc 0000 0011 xxxx xxxx xxxx 1001 xxxx */ + DECODE_OR (0x0fe000f0, 0x00200090), + /* MLS cccc 0000 0110 xxxx xxxx xxxx 1001 xxxx */ + DECODE_EMULATEX (0x0ff000f0, 0x00600090, emulate_rd16rn12rm0rs8_rwflags_nopc, + REGS(NOPC, NOPC, NOPC, 0, NOPC)), + + /* UMAAL cccc 0000 0100 xxxx xxxx xxxx 1001 xxxx */ + DECODE_OR (0x0ff000f0, 0x00400090), + /* UMULL cccc 0000 1000 xxxx xxxx xxxx 1001 xxxx */ + /* UMULLS cccc 0000 1001 xxxx xxxx xxxx 1001 xxxx */ + /* UMLAL cccc 0000 1010 xxxx xxxx xxxx 1001 xxxx */ + /* UMLALS cccc 0000 1011 xxxx xxxx xxxx 1001 xxxx */ + /* SMULL cccc 0000 1100 xxxx xxxx xxxx 1001 xxxx */ + /* SMULLS cccc 0000 1101 xxxx xxxx xxxx 1001 xxxx */ + /* SMLAL cccc 0000 1110 xxxx xxxx xxxx 1001 xxxx */ + /* SMLALS cccc 0000 1111 xxxx xxxx xxxx 1001 xxxx */ + DECODE_EMULATEX (0x0f8000f0, 0x00800090, emulate_rdlo12rdhi16rn0rm8_rwflags_nopc, + REGS(NOPC, NOPC, NOPC, 0, NOPC)), + + DECODE_END +}; + +static const union decode_item arm_cccc_0001_____1001_table[] = { + /* Synchronization primitives */ + + /* SMP/SWPB cccc 0001 0x00 xxxx xxxx xxxx 1001 xxxx */ + DECODE_EMULATEX (0x0fb000f0, 0x01000090, emulate_rd12rn16rm0_rwflags_nopc, + REGS(NOPC, NOPC, 0, 0, NOPC)), + + /* LDREX/STREX{,D,B,H} cccc 0001 1xxx xxxx xxxx xxxx 1001 xxxx */ + /* And unallocated instructions... */ + DECODE_END +}; + +static const union decode_item arm_cccc_000x_____1xx1_table[] = { + /* Extra load/store instructions */ + + /* STRHT cccc 0000 xx10 xxxx xxxx xxxx 1011 xxxx */ + /* ??? cccc 0000 xx10 xxxx xxxx xxxx 11x1 xxxx */ + /* LDRHT cccc 0000 xx11 xxxx xxxx xxxx 1011 xxxx */ + /* LDRSBT cccc 0000 xx11 xxxx xxxx xxxx 1101 xxxx */ + /* LDRSHT cccc 0000 xx11 xxxx xxxx xxxx 1111 xxxx */ + DECODE_REJECT (0x0f200090, 0x00200090), + + /* LDRD/STRD lr,pc,{... cccc 000x x0x0 xxxx 111x xxxx 1101 xxxx */ + DECODE_REJECT (0x0e10e0d0, 0x0000e0d0), + + /* LDRD (register) cccc 000x x0x0 xxxx xxxx xxxx 1101 xxxx */ + /* STRD (register) cccc 000x x0x0 xxxx xxxx xxxx 1111 xxxx */ + DECODE_EMULATEX (0x0e5000d0, 0x000000d0, emulate_ldrdstrd, + REGS(NOPCWB, NOPCX, 0, 0, NOPC)), + + /* LDRD (immediate) cccc 000x x1x0 xxxx xxxx xxxx 1101 xxxx */ + /* STRD (immediate) cccc 000x x1x0 xxxx xxxx xxxx 1111 xxxx */ + DECODE_EMULATEX (0x0e5000d0, 0x004000d0, emulate_ldrdstrd, + REGS(NOPCWB, NOPCX, 0, 0, 0)), + + /* STRH (register) cccc 000x x0x0 xxxx xxxx xxxx 1011 xxxx */ + DECODE_EMULATEX (0x0e5000f0, 0x000000b0, emulate_str, + REGS(NOPCWB, NOPC, 0, 0, NOPC)), + + /* LDRH (register) cccc 000x x0x1 xxxx xxxx xxxx 1011 xxxx */ + /* LDRSB (register) cccc 000x x0x1 xxxx xxxx xxxx 1101 xxxx */ + /* LDRSH (register) cccc 000x x0x1 xxxx xxxx xxxx 1111 xxxx */ + DECODE_EMULATEX (0x0e500090, 0x00100090, emulate_ldr, + REGS(NOPCWB, NOPC, 0, 0, NOPC)), + + /* STRH (immediate) cccc 000x x1x0 xxxx xxxx xxxx 1011 xxxx */ + DECODE_EMULATEX (0x0e5000f0, 0x004000b0, emulate_str, + REGS(NOPCWB, NOPC, 0, 0, 0)), + + /* LDRH (immediate) cccc 000x x1x1 xxxx xxxx xxxx 1011 xxxx */ + /* LDRSB (immediate) cccc 000x x1x1 xxxx xxxx xxxx 1101 xxxx */ + /* LDRSH (immediate) cccc 000x x1x1 xxxx xxxx xxxx 1111 xxxx */ + DECODE_EMULATEX (0x0e500090, 0x00500090, emulate_ldr, + REGS(NOPCWB, NOPC, 0, 0, 0)), + + DECODE_END +}; + +static const union decode_item arm_cccc_000x_table[] = { + /* Data-processing (register) */ + + /* S PC, ... cccc 000x xxx1 xxxx 1111 xxxx xxxx xxxx */ + DECODE_REJECT (0x0e10f000, 0x0010f000), + + /* MOV IP, SP 1110 0001 1010 0000 1100 0000 0000 1101 */ + DECODE_SIMULATE (0xffffffff, 0xe1a0c00d, simulate_mov_ipsp), + + /* TST (register) cccc 0001 0001 xxxx xxxx xxxx xxx0 xxxx */ + /* TEQ (register) cccc 0001 0011 xxxx xxxx xxxx xxx0 xxxx */ + /* CMP (register) cccc 0001 0101 xxxx xxxx xxxx xxx0 xxxx */ + /* CMN (register) cccc 0001 0111 xxxx xxxx xxxx xxx0 xxxx */ + DECODE_EMULATEX (0x0f900010, 0x01100000, emulate_rd12rn16rm0rs8_rwflags, + REGS(ANY, 0, 0, 0, ANY)), + + /* MOV (register) cccc 0001 101x xxxx xxxx xxxx xxx0 xxxx */ + /* MVN (register) cccc 0001 111x xxxx xxxx xxxx xxx0 xxxx */ + DECODE_EMULATEX (0x0fa00010, 0x01a00000, emulate_rd12rn16rm0rs8_rwflags, + REGS(0, ANY, 0, 0, ANY)), + + /* AND (register) cccc 0000 000x xxxx xxxx xxxx xxx0 xxxx */ + /* EOR (register) cccc 0000 001x xxxx xxxx xxxx xxx0 xxxx */ + /* SUB (register) cccc 0000 010x xxxx xxxx xxxx xxx0 xxxx */ + /* RSB (register) cccc 0000 011x xxxx xxxx xxxx xxx0 xxxx */ + /* ADD (register) cccc 0000 100x xxxx xxxx xxxx xxx0 xxxx */ + /* ADC (register) cccc 0000 101x xxxx xxxx xxxx xxx0 xxxx */ + /* SBC (register) cccc 0000 110x xxxx xxxx xxxx xxx0 xxxx */ + /* RSC (register) cccc 0000 111x xxxx xxxx xxxx xxx0 xxxx */ + /* ORR (register) cccc 0001 100x xxxx xxxx xxxx xxx0 xxxx */ + /* BIC (register) cccc 0001 110x xxxx xxxx xxxx xxx0 xxxx */ + DECODE_EMULATEX (0x0e000010, 0x00000000, emulate_rd12rn16rm0rs8_rwflags, + REGS(ANY, ANY, 0, 0, ANY)), + + /* TST (reg-shift reg) cccc 0001 0001 xxxx xxxx xxxx 0xx1 xxxx */ + /* TEQ (reg-shift reg) cccc 0001 0011 xxxx xxxx xxxx 0xx1 xxxx */ + /* CMP (reg-shift reg) cccc 0001 0101 xxxx xxxx xxxx 0xx1 xxxx */ + /* CMN (reg-shift reg) cccc 0001 0111 xxxx xxxx xxxx 0xx1 xxxx */ + DECODE_EMULATEX (0x0f900090, 0x01100010, emulate_rd12rn16rm0rs8_rwflags, + REGS(ANY, 0, NOPC, 0, ANY)), + + /* MOV (reg-shift reg) cccc 0001 101x xxxx xxxx xxxx 0xx1 xxxx */ + /* MVN (reg-shift reg) cccc 0001 111x xxxx xxxx xxxx 0xx1 xxxx */ + DECODE_EMULATEX (0x0fa00090, 0x01a00010, emulate_rd12rn16rm0rs8_rwflags, + REGS(0, ANY, NOPC, 0, ANY)), + + /* AND (reg-shift reg) cccc 0000 000x xxxx xxxx xxxx 0xx1 xxxx */ + /* EOR (reg-shift reg) cccc 0000 001x xxxx xxxx xxxx 0xx1 xxxx */ + /* SUB (reg-shift reg) cccc 0000 010x xxxx xxxx xxxx 0xx1 xxxx */ + /* RSB (reg-shift reg) cccc 0000 011x xxxx xxxx xxxx 0xx1 xxxx */ + /* ADD (reg-shift reg) cccc 0000 100x xxxx xxxx xxxx 0xx1 xxxx */ + /* ADC (reg-shift reg) cccc 0000 101x xxxx xxxx xxxx 0xx1 xxxx */ + /* SBC (reg-shift reg) cccc 0000 110x xxxx xxxx xxxx 0xx1 xxxx */ + /* RSC (reg-shift reg) cccc 0000 111x xxxx xxxx xxxx 0xx1 xxxx */ + /* ORR (reg-shift reg) cccc 0001 100x xxxx xxxx xxxx 0xx1 xxxx */ + /* BIC (reg-shift reg) cccc 0001 110x xxxx xxxx xxxx 0xx1 xxxx */ + DECODE_EMULATEX (0x0e000090, 0x00000010, emulate_rd12rn16rm0rs8_rwflags, + REGS(ANY, ANY, NOPC, 0, ANY)), + + DECODE_END +}; + +static const union decode_item arm_cccc_001x_table[] = { + /* Data-processing (immediate) */ + + /* MOVW cccc 0011 0000 xxxx xxxx xxxx xxxx xxxx */ + /* MOVT cccc 0011 0100 xxxx xxxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0x0fb00000, 0x03000000, emulate_rd12rm0_noflags_nopc, + REGS(0, NOPC, 0, 0, 0)), + + /* YIELD cccc 0011 0010 0000 xxxx xxxx 0000 0001 */ + DECODE_OR (0x0fff00ff, 0x03200001), + /* SEV cccc 0011 0010 0000 xxxx xxxx 0000 0100 */ + DECODE_EMULATE (0x0fff00ff, 0x03200004, uprobe_emulate_none), + /* NOP cccc 0011 0010 0000 xxxx xxxx 0000 0000 */ + /* WFE cccc 0011 0010 0000 xxxx xxxx 0000 0010 */ + /* WFI cccc 0011 0010 0000 xxxx xxxx 0000 0011 */ + DECODE_SIMULATE (0x0fff00fc, 0x03200000, uprobe_simulate_nop), + /* DBG cccc 0011 0010 0000 xxxx xxxx ffff xxxx */ + /* unallocated hints cccc 0011 0010 0000 xxxx xxxx xxxx xxxx */ + /* MSR (immediate) cccc 0011 0x10 xxxx xxxx xxxx xxxx xxxx */ + DECODE_REJECT (0x0fb00000, 0x03200000), + + /* S PC, ... cccc 001x xxx1 xxxx 1111 xxxx xxxx xxxx */ + DECODE_REJECT (0x0e10f000, 0x0210f000), + + /* TST (immediate) cccc 0011 0001 xxxx xxxx xxxx xxxx xxxx */ + /* TEQ (immediate) cccc 0011 0011 xxxx xxxx xxxx xxxx xxxx */ + /* CMP (immediate) cccc 0011 0101 xxxx xxxx xxxx xxxx xxxx */ + /* CMN (immediate) cccc 0011 0111 xxxx xxxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0x0f900000, 0x03100000, emulate_rd12rn16rm0rs8_rwflags, + REGS(ANY, 0, 0, 0, 0)), + + /* MOV (immediate) cccc 0011 101x xxxx xxxx xxxx xxxx xxxx */ + /* MVN (immediate) cccc 0011 111x xxxx xxxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0x0fa00000, 0x03a00000, emulate_rd12rn16rm0rs8_rwflags, + REGS(0, ANY, 0, 0, 0)), + + /* AND (immediate) cccc 0010 000x xxxx xxxx xxxx xxxx xxxx */ + /* EOR (immediate) cccc 0010 001x xxxx xxxx xxxx xxxx xxxx */ + /* SUB (immediate) cccc 0010 010x xxxx xxxx xxxx xxxx xxxx */ + /* RSB (immediate) cccc 0010 011x xxxx xxxx xxxx xxxx xxxx */ + /* ADD (immediate) cccc 0010 100x xxxx xxxx xxxx xxxx xxxx */ + /* ADC (immediate) cccc 0010 101x xxxx xxxx xxxx xxxx xxxx */ + /* SBC (immediate) cccc 0010 110x xxxx xxxx xxxx xxxx xxxx */ + /* RSC (immediate) cccc 0010 111x xxxx xxxx xxxx xxxx xxxx */ + /* ORR (immediate) cccc 0011 100x xxxx xxxx xxxx xxxx xxxx */ + /* BIC (immediate) cccc 0011 110x xxxx xxxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0x0e000000, 0x02000000, emulate_rd12rn16rm0rs8_rwflags, + REGS(ANY, ANY, 0, 0, 0)), + + DECODE_END +}; + +static const union decode_item arm_cccc_0110_____xxx1_table[] = { + /* Media instructions */ + + /* SEL cccc 0110 1000 xxxx xxxx xxxx 1011 xxxx */ + DECODE_EMULATEX (0x0ff000f0, 0x068000b0, emulate_rd12rn16rm0_rwflags_nopc, + REGS(NOPC, NOPC, 0, 0, NOPC)), + + /* SSAT cccc 0110 101x xxxx xxxx xxxx xx01 xxxx */ + /* USAT cccc 0110 111x xxxx xxxx xxxx xx01 xxxx */ + DECODE_OR(0x0fa00030, 0x06a00010), + /* SSAT16 cccc 0110 1010 xxxx xxxx xxxx 0011 xxxx */ + /* USAT16 cccc 0110 1110 xxxx xxxx xxxx 0011 xxxx */ + DECODE_EMULATEX (0x0fb000f0, 0x06a00030, emulate_rd12rn16rm0_rwflags_nopc, + REGS(0, NOPC, 0, 0, NOPC)), + + /* REV cccc 0110 1011 xxxx xxxx xxxx 0011 xxxx */ + /* REV16 cccc 0110 1011 xxxx xxxx xxxx 1011 xxxx */ + /* RBIT cccc 0110 1111 xxxx xxxx xxxx 0011 xxxx */ + /* REVSH cccc 0110 1111 xxxx xxxx xxxx 1011 xxxx */ + DECODE_EMULATEX (0x0fb00070, 0x06b00030, emulate_rd12rm0_noflags_nopc, + REGS(0, NOPC, 0, 0, NOPC)), + + /* ??? cccc 0110 0x00 xxxx xxxx xxxx xxx1 xxxx */ + DECODE_REJECT (0x0fb00010, 0x06000010), + /* ??? cccc 0110 0xxx xxxx xxxx xxxx 1011 xxxx */ + DECODE_REJECT (0x0f8000f0, 0x060000b0), + /* ??? cccc 0110 0xxx xxxx xxxx xxxx 1101 xxxx */ + DECODE_REJECT (0x0f8000f0, 0x060000d0), + /* SADD16 cccc 0110 0001 xxxx xxxx xxxx 0001 xxxx */ + /* SADDSUBX cccc 0110 0001 xxxx xxxx xxxx 0011 xxxx */ + /* SSUBADDX cccc 0110 0001 xxxx xxxx xxxx 0101 xxxx */ + /* SSUB16 cccc 0110 0001 xxxx xxxx xxxx 0111 xxxx */ + /* SADD8 cccc 0110 0001 xxxx xxxx xxxx 1001 xxxx */ + /* SSUB8 cccc 0110 0001 xxxx xxxx xxxx 1111 xxxx */ + /* QADD16 cccc 0110 0010 xxxx xxxx xxxx 0001 xxxx */ + /* QADDSUBX cccc 0110 0010 xxxx xxxx xxxx 0011 xxxx */ + /* QSUBADDX cccc 0110 0010 xxxx xxxx xxxx 0101 xxxx */ + /* QSUB16 cccc 0110 0010 xxxx xxxx xxxx 0111 xxxx */ + /* QADD8 cccc 0110 0010 xxxx xxxx xxxx 1001 xxxx */ + /* QSUB8 cccc 0110 0010 xxxx xxxx xxxx 1111 xxxx */ + /* SHADD16 cccc 0110 0011 xxxx xxxx xxxx 0001 xxxx */ + /* SHADDSUBX cccc 0110 0011 xxxx xxxx xxxx 0011 xxxx */ + /* SHSUBADDX cccc 0110 0011 xxxx xxxx xxxx 0101 xxxx */ + /* SHSUB16 cccc 0110 0011 xxxx xxxx xxxx 0111 xxxx */ + /* SHADD8 cccc 0110 0011 xxxx xxxx xxxx 1001 xxxx */ + /* SHSUB8 cccc 0110 0011 xxxx xxxx xxxx 1111 xxxx */ + /* UADD16 cccc 0110 0101 xxxx xxxx xxxx 0001 xxxx */ + /* UADDSUBX cccc 0110 0101 xxxx xxxx xxxx 0011 xxxx */ + /* USUBADDX cccc 0110 0101 xxxx xxxx xxxx 0101 xxxx */ + /* USUB16 cccc 0110 0101 xxxx xxxx xxxx 0111 xxxx */ + /* UADD8 cccc 0110 0101 xxxx xxxx xxxx 1001 xxxx */ + /* USUB8 cccc 0110 0101 xxxx xxxx xxxx 1111 xxxx */ + /* UQADD16 cccc 0110 0110 xxxx xxxx xxxx 0001 xxxx */ + /* UQADDSUBX cccc 0110 0110 xxxx xxxx xxxx 0011 xxxx */ + /* UQSUBADDX cccc 0110 0110 xxxx xxxx xxxx 0101 xxxx */ + /* UQSUB16 cccc 0110 0110 xxxx xxxx xxxx 0111 xxxx */ + /* UQADD8 cccc 0110 0110 xxxx xxxx xxxx 1001 xxxx */ + /* UQSUB8 cccc 0110 0110 xxxx xxxx xxxx 1111 xxxx */ + /* UHADD16 cccc 0110 0111 xxxx xxxx xxxx 0001 xxxx */ + /* UHADDSUBX cccc 0110 0111 xxxx xxxx xxxx 0011 xxxx */ + /* UHSUBADDX cccc 0110 0111 xxxx xxxx xxxx 0101 xxxx */ + /* UHSUB16 cccc 0110 0111 xxxx xxxx xxxx 0111 xxxx */ + /* UHADD8 cccc 0110 0111 xxxx xxxx xxxx 1001 xxxx */ + /* UHSUB8 cccc 0110 0111 xxxx xxxx xxxx 1111 xxxx */ + DECODE_EMULATEX (0x0f800010, 0x06000010, emulate_rd12rn16rm0_rwflags_nopc, + REGS(NOPC, NOPC, 0, 0, NOPC)), + + /* PKHBT cccc 0110 1000 xxxx xxxx xxxx x001 xxxx */ + /* PKHTB cccc 0110 1000 xxxx xxxx xxxx x101 xxxx */ + DECODE_EMULATEX (0x0ff00030, 0x06800010, emulate_rd12rn16rm0_rwflags_nopc, + REGS(NOPC, NOPC, 0, 0, NOPC)), + + /* ??? cccc 0110 1001 xxxx xxxx xxxx 0111 xxxx */ + /* ??? cccc 0110 1101 xxxx xxxx xxxx 0111 xxxx */ + DECODE_REJECT (0x0fb000f0, 0x06900070), + + /* SXTB16 cccc 0110 1000 1111 xxxx xxxx 0111 xxxx */ + /* SXTB cccc 0110 1010 1111 xxxx xxxx 0111 xxxx */ + /* SXTH cccc 0110 1011 1111 xxxx xxxx 0111 xxxx */ + /* UXTB16 cccc 0110 1100 1111 xxxx xxxx 0111 xxxx */ + /* UXTB cccc 0110 1110 1111 xxxx xxxx 0111 xxxx */ + /* UXTH cccc 0110 1111 1111 xxxx xxxx 0111 xxxx */ + DECODE_EMULATEX (0x0f8f00f0, 0x068f0070, emulate_rd12rm0_noflags_nopc, + REGS(0, NOPC, 0, 0, NOPC)), + + /* SXTAB16 cccc 0110 1000 xxxx xxxx xxxx 0111 xxxx */ + /* SXTAB cccc 0110 1010 xxxx xxxx xxxx 0111 xxxx */ + /* SXTAH cccc 0110 1011 xxxx xxxx xxxx 0111 xxxx */ + /* UXTAB16 cccc 0110 1100 xxxx xxxx xxxx 0111 xxxx */ + /* UXTAB cccc 0110 1110 xxxx xxxx xxxx 0111 xxxx */ + /* UXTAH cccc 0110 1111 xxxx xxxx xxxx 0111 xxxx */ + DECODE_EMULATEX (0x0f8000f0, 0x06800070, emulate_rd12rn16rm0_rwflags_nopc, + REGS(NOPCX, NOPC, 0, 0, NOPC)), + + DECODE_END +}; + +static const union decode_item arm_cccc_0111_____xxx1_table[] = { + /* Media instructions */ + + /* UNDEFINED cccc 0111 1111 xxxx xxxx xxxx 1111 xxxx */ + DECODE_REJECT (0x0ff000f0, 0x07f000f0), + + /* SMLALD cccc 0111 0100 xxxx xxxx xxxx 00x1 xxxx */ + /* SMLSLD cccc 0111 0100 xxxx xxxx xxxx 01x1 xxxx */ + DECODE_EMULATEX (0x0ff00090, 0x07400010, emulate_rdlo12rdhi16rn0rm8_rwflags_nopc, + REGS(NOPC, NOPC, NOPC, 0, NOPC)), + + /* SMUAD cccc 0111 0000 xxxx 1111 xxxx 00x1 xxxx */ + /* SMUSD cccc 0111 0000 xxxx 1111 xxxx 01x1 xxxx */ + DECODE_OR (0x0ff0f090, 0x0700f010), + /* SMMUL cccc 0111 0101 xxxx 1111 xxxx 00x1 xxxx */ + DECODE_OR (0x0ff0f0d0, 0x0750f010), + /* USAD8 cccc 0111 1000 xxxx 1111 xxxx 0001 xxxx */ + DECODE_EMULATEX (0x0ff0f0f0, 0x0780f010, emulate_rd16rn12rm0rs8_rwflags_nopc, + REGS(NOPC, 0, NOPC, 0, NOPC)), + + /* SMLAD cccc 0111 0000 xxxx xxxx xxxx 00x1 xxxx */ + /* SMLSD cccc 0111 0000 xxxx xxxx xxxx 01x1 xxxx */ + DECODE_OR (0x0ff00090, 0x07000010), + /* SMMLA cccc 0111 0101 xxxx xxxx xxxx 00x1 xxxx */ + DECODE_OR (0x0ff000d0, 0x07500010), + /* USADA8 cccc 0111 1000 xxxx xxxx xxxx 0001 xxxx */ + DECODE_EMULATEX (0x0ff000f0, 0x07800010, emulate_rd16rn12rm0rs8_rwflags_nopc, + REGS(NOPC, NOPCX, NOPC, 0, NOPC)), + + /* SMMLS cccc 0111 0101 xxxx xxxx xxxx 11x1 xxxx */ + DECODE_EMULATEX (0x0ff000d0, 0x075000d0, emulate_rd16rn12rm0rs8_rwflags_nopc, + REGS(NOPC, NOPC, NOPC, 0, NOPC)), + + /* SBFX cccc 0111 101x xxxx xxxx xxxx x101 xxxx */ + /* UBFX cccc 0111 111x xxxx xxxx xxxx x101 xxxx */ + DECODE_EMULATEX (0x0fa00070, 0x07a00050, emulate_rd12rm0_noflags_nopc, + REGS(0, NOPC, 0, 0, NOPC)), + + /* BFC cccc 0111 110x xxxx xxxx xxxx x001 1111 */ + DECODE_EMULATEX (0x0fe0007f, 0x07c0001f, emulate_rd12rm0_noflags_nopc, + REGS(0, NOPC, 0, 0, 0)), + + /* BFI cccc 0111 110x xxxx xxxx xxxx x001 xxxx */ + DECODE_EMULATEX (0x0fe00070, 0x07c00010, emulate_rd12rm0_noflags_nopc, + REGS(0, NOPC, 0, 0, NOPCX)), + + DECODE_END +}; + +static const union decode_item arm_cccc_01xx_table[] = { + /* Load/store word and unsigned byte */ + + /* LDRB/STRB pc,[...] cccc 01xx x0xx xxxx xxxx xxxx xxxx xxxx */ + DECODE_REJECT (0x0c40f000, 0x0440f000), + + /* STRT cccc 01x0 x010 xxxx xxxx xxxx xxxx xxxx */ + /* LDRT cccc 01x0 x011 xxxx xxxx xxxx xxxx xxxx */ + /* STRBT cccc 01x0 x110 xxxx xxxx xxxx xxxx xxxx */ + /* LDRBT cccc 01x0 x111 xxxx xxxx xxxx xxxx xxxx */ + DECODE_REJECT (0x0d200000, 0x04200000), + + /* STR (immediate) cccc 010x x0x0 xxxx xxxx xxxx xxxx xxxx */ + /* STRB (immediate) cccc 010x x1x0 xxxx xxxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0x0e100000, 0x04000000, emulate_str, + REGS(NOPCWB, ANY, 0, 0, 0)), + + /* LDR (immediate) cccc 010x x0x1 xxxx xxxx xxxx xxxx xxxx */ + /* LDRB (immediate) cccc 010x x1x1 xxxx xxxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0x0e100000, 0x04100000, emulate_ldr, + REGS(NOPCWB, ANY, 0, 0, 0)), + + /* STR (register) cccc 011x x0x0 xxxx xxxx xxxx xxxx xxxx */ + /* STRB (register) cccc 011x x1x0 xxxx xxxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0x0e100000, 0x06000000, emulate_str, + REGS(NOPCWB, ANY, 0, 0, NOPC)), + + /* LDR (register) cccc 011x x0x1 xxxx xxxx xxxx xxxx xxxx */ + /* LDRB (register) cccc 011x x1x1 xxxx xxxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0x0e100000, 0x06100000, emulate_ldr, + REGS(NOPCWB, ANY, 0, 0, NOPC)), + + DECODE_END +}; + +static const union decode_item arm_cccc_100x_table[] = { + /* Block data transfer instructions */ + + /* LDM cccc 100x x0x1 xxxx xxxx xxxx xxxx xxxx */ + /* STM cccc 100x x0x0 xxxx xxxx xxxx xxxx xxxx */ + DECODE_CUSTOM (0x0e400000, 0x08000000, uprobe_decode_ldmstm), + + /* STM (user registers) cccc 100x x1x0 xxxx xxxx xxxx xxxx xxxx */ + /* LDM (user registers) cccc 100x x1x1 xxxx 0xxx xxxx xxxx xxxx */ + /* LDM (exception ret) cccc 100x x1x1 xxxx 1xxx xxxx xxxx xxxx */ + DECODE_END +}; + +const union decode_item uprobe_decode_arm_table[] = { + /* + * Unconditional instructions + * 1111 xxxx xxxx xxxx xxxx xxxx xxxx xxxx + */ + DECODE_TABLE (0xf0000000, 0xf0000000, arm_1111_table), + + /* + * Miscellaneous instructions + * cccc 0001 0xx0 xxxx xxxx xxxx 0xxx xxxx + */ + DECODE_TABLE (0x0f900080, 0x01000000, arm_cccc_0001_0xx0____0xxx_table), + + /* + * Halfword multiply and multiply-accumulate + * cccc 0001 0xx0 xxxx xxxx xxxx 1xx0 xxxx + */ + DECODE_TABLE (0x0f900090, 0x01000080, arm_cccc_0001_0xx0____1xx0_table), + + /* + * Multiply and multiply-accumulate + * cccc 0000 xxxx xxxx xxxx xxxx 1001 xxxx + */ + DECODE_TABLE (0x0f0000f0, 0x00000090, arm_cccc_0000_____1001_table), + + /* + * Synchronization primitives + * cccc 0001 xxxx xxxx xxxx xxxx 1001 xxxx + */ + DECODE_TABLE (0x0f0000f0, 0x01000090, arm_cccc_0001_____1001_table), + + /* + * Extra load/store instructions + * cccc 000x xxxx xxxx xxxx xxxx 1xx1 xxxx + */ + DECODE_TABLE (0x0e000090, 0x00000090, arm_cccc_000x_____1xx1_table), + + /* + * Data-processing (register) + * cccc 000x xxxx xxxx xxxx xxxx xxx0 xxxx + * Data-processing (register-shifted register) + * cccc 000x xxxx xxxx xxxx xxxx 0xx1 xxxx + */ + DECODE_TABLE (0x0e000000, 0x00000000, arm_cccc_000x_table), + + /* + * Data-processing (immediate) + * cccc 001x xxxx xxxx xxxx xxxx xxxx xxxx + */ + DECODE_TABLE (0x0e000000, 0x02000000, arm_cccc_001x_table), + + /* + * Media instructions + * cccc 011x xxxx xxxx xxxx xxxx xxx1 xxxx + */ + DECODE_TABLE (0x0f000010, 0x06000010, arm_cccc_0110_____xxx1_table), + DECODE_TABLE (0x0f000010, 0x07000010, arm_cccc_0111_____xxx1_table), + + /* + * Load/store word and unsigned byte + * cccc 01xx xxxx xxxx xxxx xxxx xxxx xxxx + */ + DECODE_TABLE (0x0c000000, 0x04000000, arm_cccc_01xx_table), + + /* + * Block data transfer instructions + * cccc 100x xxxx xxxx xxxx xxxx xxxx xxxx + */ + DECODE_TABLE (0x0e000000, 0x08000000, arm_cccc_100x_table), + + /* B cccc 1010 xxxx xxxx xxxx xxxx xxxx xxxx */ + /* BL cccc 1011 xxxx xxxx xxxx xxxx xxxx xxxx */ + DECODE_SIMULATE (0x0e000000, 0x0a000000, simulate_bbl), + + /* + * Supervisor Call, and coprocessor instructions + */ + + /* MCRR cccc 1100 0100 xxxx xxxx xxxx xxxx xxxx */ + /* MRRC cccc 1100 0101 xxxx xxxx xxxx xxxx xxxx */ + /* LDC cccc 110x xxx1 xxxx xxxx xxxx xxxx xxxx */ + /* STC cccc 110x xxx0 xxxx xxxx xxxx xxxx xxxx */ + /* CDP cccc 1110 xxxx xxxx xxxx xxxx xxx0 xxxx */ + /* MCR cccc 1110 xxx0 xxxx xxxx xxxx xxx1 xxxx */ + /* MRC cccc 1110 xxx1 xxxx xxxx xxxx xxx1 xxxx */ + /* SVC cccc 1111 xxxx xxxx xxxx xxxx xxxx xxxx */ + DECODE_REJECT (0x0c000000, 0x0c000000), + + DECODE_END +}; + +/* + * Prepare an instruction slot to receive an instruction for emulating. + * This is done by placing a subroutine return after the location where the + * instruction will be placed. We also modify ARM instructions to be + * unconditional as the condition code will already be checked before any + * emulation handler is called. + */ +static uprobe_opcode_t +prepare_emulated_insn(uprobe_opcode_t insn, struct uprobe_probept_arch_info *ai) +{ + ai->insn[1] = 0xe1a0f00e; /* mov pc, lr */ + + /* Make an ARM instruction unconditional */ + if (insn < 0xe0000000) + insn = (insn | 0xe0000000) & ~0x10000000; + return insn; +} + +/* + * Write a (probably modified) instruction into the slot previously prepared by + * prepare_emulated_insn + */ +static void +set_emulated_insn(uprobe_opcode_t insn, struct uprobe_probept_arch_info *ai) +{ + ai->insn[0] = insn; +} + +/* + * When we modify the register numbers encoded in an instruction to be emulated, + * the new values come from this define. For ARM and 32-bit Thumb instructions + * this gives... + * + * bit position 16 12 8 4 0 + * ---------------+---+---+---+---+---+ + * register r2 r0 r1 -- r3 + */ +#define INSN_NEW_BITS 0x00020103 + +/* Each nibble has same value as that at INSN_NEW_BITS bit 16 */ +#define INSN_SAMEAS16_BITS 0x22222222 + +/* + * Validate and modify each of the registers encoded in an instruction. + * + * Each nibble in regs contains a value from enum decode_reg_type. For each + * non-zero value, the corresponding nibble in pinsn is validated and modified + * according to the type. + */ +static bool decode_regs(uprobe_opcode_t* pinsn, u32 regs) +{ + uprobe_opcode_t insn = *pinsn; + uprobe_opcode_t mask = 0xf; /* Start at least significant nibble */ + + for (; regs != 0; regs >>= 4, mask <<= 4) { + + uprobe_opcode_t new_bits = INSN_NEW_BITS; + + switch (regs & 0xf) { + + case REG_TYPE_NONE: + /* Nibble not a register, skip to next */ + continue; + + case REG_TYPE_ANY: + /* Any register is allowed */ + break; + + case REG_TYPE_SAMEAS16: + /* Replace register with same as at bit position 16 */ + new_bits = INSN_SAMEAS16_BITS; + break; + + case REG_TYPE_SP: + /* Only allow SP (R13) */ + if ((insn ^ 0xdddddddd) & mask) + goto reject; + break; + + case REG_TYPE_PC: + /* Only allow PC (R15) */ + if ((insn ^ 0xffffffff) & mask) + goto reject; + break; + + case REG_TYPE_NOSP: + /* Reject SP (R13) */ + if (((insn ^ 0xdddddddd) & mask) == 0) + goto reject; + break; + + case REG_TYPE_NOSPPC: + case REG_TYPE_NOSPPCX: + /* Reject SP and PC (R13 and R15) */ + if (((insn ^ 0xdddddddd) & 0xdddddddd & mask) == 0) + goto reject; + break; + + case REG_TYPE_NOPCWB: + if (!is_writeback(insn)) + break; /* No writeback, so any register is OK */ + /* fall through... */ + case REG_TYPE_NOPC: + case REG_TYPE_NOPCX: + /* Reject PC (R15) */ + if (((insn ^ 0xffffffff) & mask) == 0) + goto reject; + break; + } + + /* Replace value of nibble with new register number... */ + insn &= ~mask; + insn |= new_bits & mask; + } + + *pinsn = insn; + return true; + +reject: + return false; +} + +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) +}; + +/* + * uprobe_decode_insn operates on data tables in order to decode an ARM + * architecture instruction onto which a uprobe has been placed. + * + * These instruction decoding tables are a concatenation of entries each + * of which consist of one of the following structs: + * + * decode_table + * decode_custom + * decode_simulate + * decode_emulate + * decode_or + * decode_reject + * + * Each of these starts with a struct decode_header which has the following + * fields: + * + * type_regs + * mask + * value + * + * The least significant DECODE_TYPE_BITS of type_regs contains a value + * from enum decode_type, this indicates which of the decode_* structs + * the entry contains. The value DECODE_TYPE_END indicates the end of the + * table. + * + * When the table is parsed, each entry is checked in turn to see if it + * matches the instruction to be decoded using the test: + * + * (insn & mask) == value + * + * If no match is found before the end of the table is reached then decoding + * fails with INSN_REJECTED. + * + * When a match is found, decode_regs() is called to validate and modify each + * of the registers encoded in the instruction; the data it uses to do this + * is (type_regs >> DECODE_TYPE_BITS). A validation failure will cause decoding + * to fail with INSN_REJECTED. + * + * Once the instruction has passed the above tests, further processing + * depends on the type of the table entry's decode struct. + * + */ +int +uprobe_decode_insn(uprobe_opcode_t insn, struct uprobe_probept_arch_info *ai, + const union decode_item *table) +{ + const struct decode_header *h = (struct decode_header *)table; + const struct decode_header *next; + bool matched = false; + + insn = prepare_emulated_insn(insn, ai); + + for (;; h = next) { + enum decode_type type = h->type_regs.bits & DECODE_TYPE_MASK; + u32 regs = h->type_regs.bits >> DECODE_TYPE_BITS; + + if (type == DECODE_TYPE_END) + return INSN_REJECTED; + + next = (struct decode_header *) + ((uintptr_t)h + decode_struct_sizes[type]); + + if (!matched && (insn & h->mask.bits) != h->value.bits) + continue; + + if (!decode_regs(&insn, regs)) + return INSN_REJECTED; + + switch (type) { + + case DECODE_TYPE_TABLE: { + struct decode_table *d = (struct decode_table *)h; + next = (struct decode_header *)d->table.table; + break; + } + + case DECODE_TYPE_CUSTOM: { + struct decode_custom *d = (struct decode_custom *)h; + return (*d->decoder.decoder)(insn, ai); + } + + case DECODE_TYPE_SIMULATE: { + struct decode_simulate *d = (struct decode_simulate *)h; + ai->insn_handler = d->handler.handler; + return INSN_GOOD_NO_SLOT; + } + + case DECODE_TYPE_EMULATE: { + struct decode_emulate *d = (struct decode_emulate *)h; + ai->insn_handler = d->handler.handler; + set_emulated_insn(insn, ai); + return INSN_GOOD; + } + + case DECODE_TYPE_OR: + matched = true; + break; + + case DECODE_TYPE_REJECT: + default: + return INSN_REJECTED; + } + } + } +/* Return: + * INSN_REJECTED If instruction is one not allowed to uprobe, + * INSN_GOOD If instruction is supported and uses instruction slot, + * INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot. + * + * For instructions we don't want to uprobe (INSN_REJECTED return result): + * These are generally ones that modify the processor state making + * them "hard" to simulate such as switches processor modes or + * make accesses in alternate modes. Any of these could be simulated + * if the work was put into it, but low return considering they + * should also be very rare. + */ +enum uprobe_insn +arm_uprobe_decode_insn(uprobe_opcode_t insn, + struct uprobe_probept_arch_info *ai) +{ + ai->insn_check_cc = uprobe_condition_checks[insn>>28]; + return uprobe_decode_insn(insn, ai, uprobe_decode_arm_table); +} + +static int arch_validate_probed_insn(struct uprobe_probept *ppt, + struct task_struct *tsk) +{ + uprobe_opcode_t insn = *ppt->insn; + + if (ppt->vaddr & 0x3) + return -EINVAL; + + arm_uprobe_decode_init(); + switch (arm_uprobe_decode_insn(insn, &ppt->arch_info)) { + case INSN_REJECTED: + return -EINVAL; + + case INSN_GOOD: + ppt->arch_info.insn_fn = (uprobe_insn_fn_t *) + ppt->arch_info.insn; + flush_icache_range((unsigned long)ppt->arch_info.insn, + (unsigned long)ppt->arch_info.insn + + sizeof(ppt->arch_info.insn[0]) * + MAX_INSN_SIZE); + break; + + case INSN_GOOD_NO_SLOT: + break; + } + + return 0; +} + +static int uprobe_emulate_insn(struct pt_regs *regs, + struct uprobe_probept *ppt) +{ + if (ppt->arch_info.insn_handler) { + regs->ARM_pc += 4; + ppt->arch_info.insn_handler(ppt, regs); + return 1; + } + return 0; +} + diff --git a/runtime/uprobes2/uprobes_arm.h b/runtime/uprobes2/uprobes_arm.h new file mode 100644 index 0000000..a71c73c --- /dev/null +++ b/runtime/uprobes2/uprobes_arm.h @@ -0,0 +1,114 @@ +#ifndef _ASM_UPROBES_H +#define _ASM_UPROBES_H +/* + * Userspace Probes (UProbes) + * uprobes.h + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + * + * Copyright 2011 (C) Mentor Graphics Corporation + */ +#include +#include +#include +#include +#include +#include +#include +#include + +/* Normally defined in Kconfig */ +#define CONFIG_URETPROBES 1 + +typedef u32 uprobe_opcode_t; +#define BREAKPOINT_INSTRUCTION 0xe7ffdefe +#define BP_INSN_SIZE 4 +#define MAX_UINSN_BYTES 4 + +#define BREAKPOINT_SIGNAL SIGILL +#define SSTEP_SIGNAL SIGILL + +/* Architecture specific switch for where the IP points after a bp hit */ +#define ARCH_BP_INST_PTR(inst_ptr) (inst_ptr) + +struct uprobe_probept; + +typedef void (uprobe_insn_handler_t)(struct uprobe_probept *, struct pt_regs *); +typedef unsigned long (uprobe_check_cc)(unsigned long); +typedef void (uprobe_insn_fn_t)(void); + +#define MAX_INSN_SIZE 2 +struct uprobe_probept_arch_info { + uprobe_opcode_t insn[MAX_INSN_SIZE]; + uprobe_insn_handler_t *insn_handler; + uprobe_check_cc *insn_check_cc; + uprobe_insn_fn_t *insn_fn; +}; + +struct uprobe_task_arch_info {}; + +struct uprobe_probept; +struct uprobe_task; + +static int arch_validate_probed_insn(struct uprobe_probept *ppt, + struct task_struct *tsk); + +static inline unsigned long arch_get_probept(struct pt_regs *regs) +{ + return regs->ARM_pc; +} + + +static inline void arch_reset_ip_for_sstep(struct pt_regs *regs) +{ +} + + +static long arch_hijack_uret_addr(unsigned long trampoline_addr, + struct pt_regs *regs, struct uprobe_task *utask) +{ + unsigned long orig_ret_addr = regs->ARM_lr; + + regs->ARM_lr = trampoline_addr; + return orig_ret_addr; +} + +static inline void arch_restore_uret_addr(unsigned long ret_addr, + struct pt_regs *regs) +{ + regs->ARM_pc = ret_addr; +} + +static inline unsigned long arch_get_cur_sp(struct pt_regs *regs) +{ + return regs->ARM_sp; +} + +static inline unsigned long arch_predict_sp_at_ret(struct pt_regs *regs, + struct task_struct *tsk) +{ + return regs->ARM_sp; +} + +/* copy_to_user_page() is not exported. Implement our own version.*/ +#ifndef copy_to_user_page +#define copy_to_user_page(vma, page, vaddr, dst, src, len) \ + do { \ + memcpy(dst, src, len); \ + flush_icache_range((unsigned long)dst, \ + (unsigned long)dst + len); \ + } while (0) +#endif + +#endif /* _ASM_UPROBES_H */ -- 1.7.0.4