diff options
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r-- | arch/arm/kernel/Makefile | 1 | ||||
-rw-r--r-- | arch/arm/kernel/dma-isa.c | 2 | ||||
-rw-r--r-- | arch/arm/kernel/entry-armv.S | 63 | ||||
-rw-r--r-- | arch/arm/kernel/entry-common.S | 2 | ||||
-rw-r--r-- | arch/arm/kernel/kprobes-decode.c | 1529 | ||||
-rw-r--r-- | arch/arm/kernel/kprobes.c | 447 | ||||
-rw-r--r-- | arch/arm/kernel/time.c | 2 | ||||
-rw-r--r-- | arch/arm/kernel/traps.c | 21 | ||||
-rw-r--r-- | arch/arm/kernel/vmlinux.lds.S | 11 |
9 files changed, 2056 insertions, 22 deletions
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 593b56509f4f..faa761921153 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_ISA_DMA) += dma-isa.o obj-$(CONFIG_PCI) += bios32.o isa.o obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o +obj-$(CONFIG_KPROBES) += kprobes.o kprobes-decode.o obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o obj-$(CONFIG_CRUNCH) += crunch.o crunch-bits.o diff --git a/arch/arm/kernel/dma-isa.c b/arch/arm/kernel/dma-isa.c index 0a3e9ad297d8..2f080a35a2d9 100644 --- a/arch/arm/kernel/dma-isa.c +++ b/arch/arm/kernel/dma-isa.c @@ -216,7 +216,7 @@ void __init isa_init_dma(dma_t *dma) request_dma(DMA_ISA_CASCADE, "cascade"); - for (i = 0; i < sizeof(dma_resources) / sizeof(dma_resources[0]); i++) + for (i = 0; i < ARRAY_SIZE(dma_resources); i++) request_resource(&ioport_resource, dma_resources + i); } } diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 29dec080a604..a46d5b456765 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -11,8 +11,8 @@ * * Low-level vector interface routines * - * Note: there is a StrongARM bug in the STMIA rn, {regs}^ instruction that causes - * it to save wrong values... Be aware! + * Note: there is a StrongARM bug in the STMIA rn, {regs}^ instruction + * that causes it to save wrong values... Be aware! */ #include <asm/memory.h> @@ -58,6 +58,12 @@ .endm +#ifdef CONFIG_KPROBES + .section .kprobes.text,"ax",%progbits +#else + .text +#endif + /* * Invalid mode handlers */ @@ -112,8 +118,8 @@ common_invalid: #define SPFIX(code...) #endif - .macro svc_entry - sub sp, sp, #S_FRAME_SIZE + .macro svc_entry, stack_hole=0 + sub sp, sp, #(S_FRAME_SIZE + \stack_hole) SPFIX( tst sp, #4 ) SPFIX( bicne sp, sp, #4 ) stmib sp, {r1 - r12} @@ -121,7 +127,7 @@ common_invalid: ldmia r0, {r1 - r3} add r5, sp, #S_SP @ here for interlock avoidance mov r4, #-1 @ "" "" "" "" - add r0, sp, #S_FRAME_SIZE @ "" "" "" "" + add r0, sp, #(S_FRAME_SIZE + \stack_hole) SPFIX( addne r0, r0, #4 ) str r1, [sp] @ save the "real" r0 copied @ from the exception stack @@ -242,7 +248,14 @@ svc_preempt: .align 5 __und_svc: +#ifdef CONFIG_KPROBES + @ If a kprobe is about to simulate a "stmdb sp..." instruction, + @ it obviously needs free stack space which then will belong to + @ the saved context. + svc_entry 64 +#else svc_entry +#endif @ @ call emulation code, which returns using r9 if it has emulated @@ -480,6 +493,13 @@ __und_usr: * co-processor instructions. However, we have to watch out * for the ARM6/ARM7 SWI bug. * + * NEON is a special case that has to be handled here. Not all + * NEON instructions are co-processor instructions, so we have + * to make a special case of checking for them. Plus, there's + * five groups of them, so we have a table of mask/opcode pairs + * to check against, and if any match then we branch off into the + * NEON handler code. + * * Emulators may wish to make use of the following registers: * r0 = instruction opcode. * r2 = PC+4 @@ -488,6 +508,23 @@ __und_usr: * lr = unrecognised instruction return address */ call_fpe: +#ifdef CONFIG_NEON + adr r6, .LCneon_opcodes +2: + ldr r7, [r6], #4 @ mask value + cmp r7, #0 @ end mask? + beq 1f + and r8, r0, r7 + ldr r7, [r6], #4 @ opcode bits matching in mask + cmp r8, r7 @ NEON instruction? + bne 2b + get_thread_info r10 + mov r7, #1 + strb r7, [r10, #TI_USED_CP + 10] @ mark CP#10 as used + strb r7, [r10, #TI_USED_CP + 11] @ mark CP#11 as used + b do_vfp @ let VFP handler handle this +1: +#endif tst r0, #0x08000000 @ only CDP/CPRT/LDC/STC have bit 27 #if defined(CONFIG_CPU_ARM610) || defined(CONFIG_CPU_ARM710) and r8, r0, #0x0f000000 @ mask out op-code bits @@ -537,6 +574,20 @@ call_fpe: mov pc, lr @ CP#14 (Debug) mov pc, lr @ CP#15 (Control) +#ifdef CONFIG_NEON + .align 6 + +.LCneon_opcodes: + .word 0xfe000000 @ mask + .word 0xf2000000 @ opcode + + .word 0xff100000 @ mask + .word 0xf4000000 @ opcode + + .word 0x00000000 @ mask + .word 0x00000000 @ opcode +#endif + do_fpe: enable_irq ldr r4, .LCfp @@ -555,7 +606,7 @@ do_fpe: .data ENTRY(fp_enter) .word no_fp - .text + .previous no_fp: mov pc, lr diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 33e6cc2ffd3b..6c90c50a9ee3 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -72,7 +72,7 @@ no_work_pending: ldr r1, [sp, #S_PSR] @ get calling cpsr ldr lr, [sp, #S_PC]! @ get pc msr spsr_cxsf, r1 @ save in spsr_svc - ldmdb sp, {r0 - lr}^ @ get calling r1 - lr + ldmdb sp, {r0 - lr}^ @ get calling r0 - lr mov r0, r0 add sp, sp, #S_FRAME_SIZE - S_PC movs pc, lr @ return & move spsr_svc into cpsr diff --git a/arch/arm/kernel/kprobes-decode.c b/arch/arm/kernel/kprobes-decode.c new file mode 100644 index 000000000000..d51bc8b60557 --- /dev/null +++ b/arch/arm/kernel/kprobes-decode.c @@ -0,0 +1,1529 @@ +/* + * arch/arm/kernel/kprobes-decode.c + * + * Copyright (C) 2006, 2007 Motorola Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This 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. + */ + +/* + * 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 kprobe. + * (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. + * If it is a conditional instruction, the handler + * will use insn[0] to copy its condition code to + * set r0 to 1 and insn[1] to "mov pc, lr" to return. + * + * *) 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 kprobes must be reserved + * exclusively for kprobes use. + * + * TODO: ifdef out some instruction decoding based on architecture. + */ + +#include <linux/kernel.h> +#include <linux/kprobes.h> + +#define sign_extend(x, signbit) ((x) | (0 - ((x) & (1 << (signbit))))) + +#define branch_displacement(insn) sign_extend(((insn) & 0xffffff) << 2, 25) + +#define PSR_fs (PSR_f|PSR_s) + +#define KPROBE_RETURN_INSTRUCTION 0xe1a0f00e /* mov pc, lr */ +#define SET_R0_TRUE_INSTRUCTION 0xe3a00001 /* mov r0, #1 */ + +#define truecc_insn(insn) (((insn) & 0xf0000000) | \ + (SET_R0_TRUE_INSTRUCTION & 0x0fffffff)) + +typedef long (insn_0arg_fn_t)(void); +typedef long (insn_1arg_fn_t)(long); +typedef long (insn_2arg_fn_t)(long, long); +typedef long (insn_3arg_fn_t)(long, long, long); +typedef long (insn_4arg_fn_t)(long, long, long, long); +typedef long long (insn_llret_0arg_fn_t)(void); +typedef long long (insn_llret_3arg_fn_t)(long, long, long); +typedef long long (insn_llret_4arg_fn_t)(long, long, long, long); + +union reg_pair { + long long dr; +#ifdef __LITTLE_ENDIAN + struct { long r0, r1; }; +#else + struct { long r1, r0; }; +#endif +}; + +/* + * 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. + */ + +static int str_pc_offset; + +static void __init 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; +} + +/* + * The insnslot_?arg_r[w]flags() functions below are to keep the + * msr -> *fn -> mrs instruction sequences indivisible so that + * the state of the CPSR flags aren't inadvertently modified + * just before or just after the call. + */ + +static inline long __kprobes +insnslot_0arg_rflags(long cpsr, insn_0arg_fn_t *fn) +{ + register long ret asm("r0"); + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + : "=r" (ret) + : [cpsr] "r" (cpsr), [fn] "r" (fn) + : "lr", "cc" + ); + return ret; +} + +static inline long long __kprobes +insnslot_llret_0arg_rflags(long cpsr, insn_llret_0arg_fn_t *fn) +{ + register long ret0 asm("r0"); + register long ret1 asm("r1"); + union reg_pair fnr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + : "=r" (ret0), "=r" (ret1) + : [cpsr] "r" (cpsr), [fn] "r" (fn) + : "lr", "cc" + ); + fnr.r0 = ret0; + fnr.r1 = ret1; + return fnr.dr; +} + +static inline long __kprobes +insnslot_1arg_rflags(long r0, long cpsr, insn_1arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long ret asm("r0"); + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + : "=r" (ret) + : "0" (rr0), [cpsr] "r" (cpsr), [fn] "r" (fn) + : "lr", "cc" + ); + return ret; +} + +static inline long __kprobes +insnslot_2arg_rflags(long r0, long r1, long cpsr, insn_2arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long ret asm("r0"); + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + : "=r" (ret) + : "0" (rr0), "r" (rr1), + [cpsr] "r" (cpsr), [fn] "r" (fn) + : "lr", "cc" + ); + return ret; +} + +static inline long __kprobes +insnslot_3arg_rflags(long r0, long r1, long r2, long cpsr, insn_3arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long rr2 asm("r2") = r2; + register long ret asm("r0"); + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + : "=r" (ret) + : "0" (rr0), "r" (rr1), "r" (rr2), + [cpsr] "r" (cpsr), [fn] "r" (fn) + : "lr", "cc" + ); + return ret; +} + +static inline long long __kprobes +insnslot_llret_3arg_rflags(long r0, long r1, long r2, long cpsr, + insn_llret_3arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long rr2 asm("r2") = r2; + register long ret0 asm("r0"); + register long ret1 asm("r1"); + union reg_pair fnr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + : "=r" (ret0), "=r" (ret1) + : "0" (rr0), "r" (rr1), "r" (rr2), + [cpsr] "r" (cpsr), [fn] "r" (fn) + : "lr", "cc" + ); + fnr.r0 = ret0; + fnr.r1 = ret1; + return fnr.dr; +} + +static inline long __kprobes +insnslot_4arg_rflags(long r0, long r1, long r2, long r3, long cpsr, + insn_4arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long rr2 asm("r2") = r2; + register long rr3 asm("r3") = r3; + register long ret asm("r0"); + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + : "=r" (ret) + : "0" (rr0), "r" (rr1), "r" (rr2), "r" (rr3), + [cpsr] "r" (cpsr), [fn] "r" (fn) + : "lr", "cc" + ); + return ret; +} + +static inline long __kprobes +insnslot_1arg_rwflags(long r0, long *cpsr, insn_1arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long ret asm("r0"); + long oldcpsr = *cpsr; + long newcpsr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[oldcpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + "mrs %[newcpsr], cpsr \n\t" + : "=r" (ret), [newcpsr] "=r" (newcpsr) + : "0" (rr0), [oldcpsr] "r" (oldcpsr), [fn] "r" (fn) + : "lr", "cc" + ); + *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs); + return ret; +} + +static inline long __kprobes +insnslot_2arg_rwflags(long r0, long r1, long *cpsr, insn_2arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long ret asm("r0"); + long oldcpsr = *cpsr; + long newcpsr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[oldcpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + "mrs %[newcpsr], cpsr \n\t" + : "=r" (ret), [newcpsr] "=r" (newcpsr) + : "0" (rr0), "r" (rr1), [oldcpsr] "r" (oldcpsr), [fn] "r" (fn) + : "lr", "cc" + ); + *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs); + return ret; +} + +static inline long __kprobes +insnslot_3arg_rwflags(long r0, long r1, long r2, long *cpsr, + insn_3arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long rr2 asm("r2") = r2; + register long ret asm("r0"); + long oldcpsr = *cpsr; + long newcpsr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[oldcpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + "mrs %[newcpsr], cpsr \n\t" + : "=r" (ret), [newcpsr] "=r" (newcpsr) + : "0" (rr0), "r" (rr1), "r" (rr2), + [oldcpsr] "r" (oldcpsr), [fn] "r" (fn) + : "lr", "cc" + ); + *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs); + return ret; +} + +static inline long __kprobes +insnslot_4arg_rwflags(long r0, long r1, long r2, long r3, long *cpsr, + insn_4arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long rr2 asm("r2") = r2; + register long rr3 asm("r3") = r3; + register long ret asm("r0"); + long oldcpsr = *cpsr; + long newcpsr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[oldcpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + "mrs %[newcpsr], cpsr \n\t" + : "=r" (ret), [newcpsr] "=r" (newcpsr) + : "0" (rr0), "r" (rr1), "r" (rr2), "r" (rr3), + [oldcpsr] "r" (oldcpsr), [fn] "r" (fn) + : "lr", "cc" + ); + *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs); + return ret; +} + +static inline long long __kprobes +insnslot_llret_4arg_rwflags(long r0, long r1, long r2, long r3, long *cpsr, + insn_llret_4arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long rr2 asm("r2") = r2; + register long rr3 asm("r3") = r3; + register long ret0 asm("r0"); + register long ret1 asm("r1"); + long oldcpsr = *cpsr; + long newcpsr; + union reg_pair fnr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[oldcpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + "mrs %[newcpsr], cpsr \n\t" + : "=r" (ret0), "=r" (ret1), [newcpsr] "=r" (newcpsr) + : "0" (rr0), "r" (rr1), "r" (rr2), "r" (rr3), + [oldcpsr] "r" (oldcpsr), [fn] "r" (fn) + : "lr", "cc" + ); + *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs); + fnr.r0 = ret0; + fnr.r1 = ret1; + return fnr.dr; +} + +/* + * 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 kprobe'd instruction completed before + * returning from the kprobe_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. + */ + +static void __kprobes simulate_bbl(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + long iaddr = (long)p->addr; + int disp = branch_displacement(insn); + + if (!insnslot_1arg_rflags(0, regs->ARM_cpsr, i_fn)) + return; + + if (insn & (1 << 24)) + regs->ARM_lr = iaddr + 4; + + regs->ARM_pc = iaddr + 8 + disp; +} + +static void __kprobes simulate_blx1(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + long iaddr = (long)p->addr; + 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 __kprobes simulate_blx2bx(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rm = insn & 0xf; + long rmv = regs->uregs[rm]; + + if (!insnslot_1arg_rflags(0, regs->ARM_cpsr, i_fn)) + return; + + if (insn & (1 << 5)) + regs->ARM_lr = (long)p->addr + 4; + + regs->ARM_pc = rmv & ~0x1; + regs->ARM_cpsr &= ~PSR_T_BIT; + if (rmv & 0x1) + regs->ARM_cpsr |= PSR_T_BIT; +} + +static void __kprobes simulate_ldm1stm1(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_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; + + if (!insnslot_1arg_rflags(0, regs->ARM_cpsr, i_fn)) + return; + + 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 __kprobes simulate_stm1_pc(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + + if (!insnslot_1arg_rflags(0, regs->ARM_cpsr, i_fn)) + return; + + regs->ARM_pc = (long)p->addr + str_pc_offset; + simulate_ldm1stm1(p, regs); + regs->ARM_pc = (long)p->addr + 4; +} + +static void __kprobes simulate_mov_ipsp(struct kprobe *p, struct pt_regs *regs) +{ + regs->uregs[12] = regs->uregs[13]; +} + +static void __kprobes emulate_ldcstc(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rn = (insn >> 16) & 0xf; + long rnv = regs->uregs[rn]; + + /* Save Rn in case of writeback. */ + regs->uregs[rn] = insnslot_1arg_rflags(rnv, regs->ARM_cpsr, i_fn); +} + +static void __kprobes emulate_ldrd(struct kprobe *p, struct pt_regs *regs) +{ + insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; /* rm may be invalid, don't care. */ + + /* Not following the C calling convention here, so need asm(). */ + __asm__ __volatile__ ( + "ldr r0, %[rn] \n\t" + "ldr r1, %[rm] \n\t" + "msr cpsr_fs, %[cpsr]\n\t" + "mov lr, pc \n\t" + "mov pc, %[i_fn] \n\t" + "str r0, %[rn] \n\t" /* in case of writeback */ + "str r2, %[rd0] \n\t" + "str r3, %[rd1] \n\t" + : [rn] "+m" (regs->uregs[rn]), + [rd0] "=m" (regs->uregs[rd]), + [rd1] "=m" (regs->uregs[rd+1]) + : [rm] "m" (regs->uregs[rm]), + [cpsr] "r" (regs->ARM_cpsr), + [i_fn] "r" (i_fn) + : "r0", "r1", "r2", "r3", "lr", "cc" + ); +} + +static void __kprobes emulate_strd(struct kprobe *p, struct pt_regs *regs) +{ + insn_4arg_fn_t *i_fn = (insn_4arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + long rnv = regs->uregs[rn]; + long rmv = regs->uregs[rm]; /* rm/rmv may be invalid, don't care. */ + + regs->uregs[rn] = insnslot_4arg_rflags(rnv, rmv, regs->uregs[rd], + regs->uregs[rd+1], + regs->ARM_cpsr, i_fn); +} + +static void __kprobes emulate_ldr(struct kprobe *p, struct pt_regs *regs) +{ + insn_llret_3arg_fn_t *i_fn = (insn_llret_3arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + union reg_pair fnr; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + long rdv; + long rnv = regs->uregs[rn]; + long rmv = regs->uregs[rm]; /* rm/rmv may be invalid, don't care. */ + long cpsr = regs->ARM_cpsr; + + fnr.dr = insnslot_llret_3arg_rflags(rnv, 0, rmv, cpsr, i_fn); + regs->uregs[rn] = fnr.r0; /* Save Rn in case of writeback. */ + rdv = fnr.r1; + + if (rd == 15) { +#if __LINUX_ARM_ARCH__ >= 5 + cpsr &= ~PSR_T_BIT; + if (rdv & 0x1) + cpsr |= PSR_T_BIT; + regs->ARM_cpsr = cpsr; + rdv &= ~0x1; +#else + rdv &= ~0x2; +#endif + } + regs->uregs[rd] = rdv; +} + +static void __kprobes emulate_str(struct kprobe *p, struct pt_regs *regs) +{ + insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + long iaddr = (long)p->addr; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + long rdv = (rd == 15) ? iaddr + str_pc_offset : regs->uregs[rd]; + long rnv = (rn == 15) ? iaddr + 8 : regs->uregs[rn]; + long rmv = regs->uregs[rm]; /* rm/rmv may be invalid, don't care. */ + + /* Save Rn in case of writeback. */ + regs->uregs[rn] = + insnslot_3arg_rflags(rnv, rdv, rmv, regs->ARM_cpsr, i_fn); +} + +static void __kprobes emulate_mrrc(struct kprobe *p, struct pt_regs *regs) +{ + insn_llret_0arg_fn_t *i_fn = (insn_llret_0arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + union reg_pair fnr; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + + fnr.dr = insnslot_llret_0arg_rflags(regs->ARM_cpsr, i_fn); + regs->uregs[rn] = fnr.r0; + regs->uregs[rd] = fnr.r1; +} + +static void __kprobes emulate_mcrr(struct kprobe *p, struct pt_regs *regs) +{ + insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + long rnv = regs->uregs[rn]; + long rdv = regs->uregs[rd]; + + insnslot_2arg_rflags(rnv, rdv, regs->ARM_cpsr, i_fn); +} + +static void __kprobes emulate_sat(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rm = insn & 0xf; + long rmv = regs->uregs[rm]; + + /* Writes Q flag */ + regs->uregs[rd] = insnslot_1arg_rwflags(rmv, ®s->ARM_cpsr, i_fn); +} + +static void __kprobes emulate_sel(struct kprobe *p, struct pt_regs *regs) +{ + insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + long rnv = regs->uregs[rn]; + long rmv = regs->uregs[rm]; + + /* Reads GE bits */ + regs->uregs[rd] = insnslot_2arg_rflags(rnv, rmv, regs->ARM_cpsr, i_fn); +} + +static void __kprobes emulate_none(struct kprobe *p, struct pt_regs *regs) +{ + insn_0arg_fn_t *i_fn = (insn_0arg_fn_t *)&p->ainsn.insn[0]; + + insnslot_0arg_rflags(regs->ARM_cpsr, i_fn); +} + +static void __kprobes emulate_rd12(struct kprobe *p, struct pt_regs *regs) +{ + insn_0arg_fn_t *i_fn = (insn_0arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + + regs->uregs[rd] = insnslot_0arg_rflags(regs->ARM_cpsr, i_fn); +} + +static void __kprobes emulate_ird12(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int ird = (insn >> 12) & 0xf; + + insnslot_1arg_rflags(regs->uregs[ird], regs->ARM_cpsr, i_fn); +} + +static void __kprobes emulate_rn16(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rn = (insn >> 16) & 0xf; + long rnv = regs->uregs[rn]; + + insnslot_1arg_rflags(rnv, regs->ARM_cpsr, i_fn); +} + +static void __kprobes emulate_rd12rm0(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rm = insn & 0xf; + long rmv = regs->uregs[rm]; + + regs->uregs[rd] = insnslot_1arg_rflags(rmv, regs->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_rd12rn16rm0_rwflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + long rnv = regs->uregs[rn]; + long rmv = regs->uregs[rm]; + + regs->uregs[rd] = + insnslot_2arg_rwflags(rnv, rmv, ®s->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_rd16rn12rs8rm0_rwflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 16) & 0xf; + int rn = (insn >> 12) & 0xf; + int rs = (insn >> 8) & 0xf; + int rm = insn & 0xf; + long rnv = regs->uregs[rn]; + long rsv = regs->uregs[rs]; + long rmv = regs->uregs[rm]; + + regs->uregs[rd] = + insnslot_3arg_rwflags(rnv, rsv, rmv, ®s->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_rd16rs8rm0_rwflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 16) & 0xf; + int rs = (insn >> 8) & 0xf; + int rm = insn & 0xf; + long rsv = regs->uregs[rs]; + long rmv = regs->uregs[rm]; + + regs->uregs[rd] = + insnslot_2arg_rwflags(rsv, rmv, ®s->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_rdhi16rdlo12rs8rm0_rwflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_llret_4arg_fn_t *i_fn = (insn_llret_4arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + union reg_pair fnr; + int rdhi = (insn >> 16) & 0xf; + int rdlo = (insn >> 12) & 0xf; + int rs = (insn >> 8) & 0xf; + int rm = insn & 0xf; + long rsv = regs->uregs[rs]; + long rmv = regs->uregs[rm]; + + fnr.dr = insnslot_llret_4arg_rwflags(regs->uregs[rdhi], + regs->uregs[rdlo], rsv, rmv, + ®s->ARM_cpsr, i_fn); + regs->uregs[rdhi] = fnr.r0; + regs->uregs[rdlo] = fnr.r1; +} + +static void __kprobes +emulate_alu_imm_rflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + long rnv = (rn == 15) ? (long)p->addr + 8 : regs->uregs[rn]; + + regs->uregs[rd] = insnslot_1arg_rflags(rnv, regs->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_alu_imm_rwflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + long rnv = (rn == 15) ? (long)p->addr + 8 : regs->uregs[rn]; + + regs->uregs[rd] = insnslot_1arg_rwflags(rnv, ®s->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_alu_rflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + long ppc = (long)p->addr + 8; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; /* rn/rnv/rs/rsv may be */ + int rs = (insn >> 8) & 0xf; /* invalid, don't care. */ + int rm = insn & 0xf; + long rnv = (rn == 15) ? ppc : regs->uregs[rn]; + long rmv = (rm == 15) ? ppc : regs->uregs[rm]; + long rsv = regs->uregs[rs]; + + regs->uregs[rd] = + insnslot_3arg_rflags(rnv, rmv, rsv, regs->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_alu_rwflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + long ppc = (long)p->addr + 8; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; /* rn/rnv/rs/rsv may be */ + int rs = (insn >> 8) & 0xf; /* invalid, don't care. */ + int rm = insn & 0xf; + long rnv = (rn == 15) ? ppc : regs->uregs[rn]; + long rmv = (rm == 15) ? ppc : regs->uregs[rm]; + long rsv = regs->uregs[rs]; + + regs->uregs[rd] = + insnslot_3arg_rwflags(rnv, rmv, rsv, ®s->ARM_cpsr, i_fn); +} + +static enum kprobe_insn __kprobes +prep_emulate_ldr_str(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + int ibit = (insn & (1 << 26)) ? 25 : 22; + + insn &= 0xfff00fff; + insn |= 0x00001000; /* Rn = r0, Rd = r1 */ + if (insn & (1 << ibit)) { + insn &= ~0xf; + insn |= 2; /* Rm = r2 */ + } + asi->insn[0] = insn; + asi->insn_handler = (insn & (1 << 20)) ? emulate_ldr : emulate_str; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +prep_emulate_rd12rm0(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + insn &= 0xffff0ff0; /* Rd = r0, Rm = r0 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_rd12rm0; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +prep_emulate_rd12(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + insn &= 0xffff0fff; /* Rd = r0 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_rd12; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +prep_emulate_rd12rn16rm0_wflags(kprobe_opcode_t insn, + struct arch_specific_insn *asi) +{ + insn &= 0xfff00ff0; /* Rd = r0, Rn = r0 */ + insn |= 0x00000001; /* Rm = r1 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_rd12rn16rm0_rwflags; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +prep_emulate_rd16rs8rm0_wflags(kprobe_opcode_t insn, + struct arch_specific_insn *asi) +{ + insn &= 0xfff0f0f0; /* Rd = r0, Rs = r0 */ + insn |= 0x00000001; /* Rm = r1 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_rd16rs8rm0_rwflags; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +prep_emulate_rd16rn12rs8rm0_wflags(kprobe_opcode_t insn, + struct arch_specific_insn *asi) +{ + insn &= 0xfff000f0; /* Rd = r0, Rn = r0 */ + insn |= 0x00000102; /* Rs = r1, Rm = r2 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_rd16rn12rs8rm0_rwflags; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +prep_emulate_rdhi16rdlo12rs8rm0_wflags(kprobe_opcode_t insn, + struct arch_specific_insn *asi) +{ + insn &= 0xfff000f0; /* RdHi = r0, RdLo = r1 */ + insn |= 0x00001203; /* Rs = r2, Rm = r3 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_rdhi16rdlo12rs8rm0_rwflags; + return INSN_GOOD; +} + +/* + * 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 enum kprobe_insn __kprobes +space_1111(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* CPS mmod == 1 : 1111 0001 0000 xx10 xxxx xxxx xx0x xxxx */ + /* RFE : 1111 100x x0x1 xxxx xxxx 1010 xxxx xxxx */ + /* SRS : 1111 100x x1x0 1101 xxxx 0101 xxxx xxxx */ + if ((insn & 0xfff30020) == 0xf1020000 || + (insn & 0xfe500f00) == 0xf8100a00 || + (insn & 0xfe5f0f00) == 0xf84d0500) + return INSN_REJECTED; + + /* PLD : 1111 01x1 x101 xxxx xxxx xxxx xxxx xxxx : */ + if ((insn & 0xfd700000) == 0xf4500000) { + insn &= 0xfff0ffff; /* Rn = r0 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_rn16; + return INSN_GOOD; + } + + /* BLX(1) : 1111 101x xxxx xxxx xxxx xxxx xxxx xxxx : */ + if ((insn & 0xfe000000) == 0xfa000000) { + asi->insn_handler = simulate_blx1; + return INSN_GOOD_NO_SLOT; + } + + /* SETEND : 1111 0001 0000 0001 xxxx xxxx 0000 xxxx */ + /* CDP2 : 1111 1110 xxxx xxxx xxxx xxxx xxx0 xxxx */ + if ((insn & 0xffff00f0) == 0xf1010000 || + (insn & 0xff000010) == 0xfe000000) { + asi->insn[0] = insn; + asi->insn_handler = emulate_none; + return INSN_GOOD; + } + + /* MCRR2 : 1111 1100 0100 xxxx xxxx xxxx xxxx xxxx : (Rd != Rn) */ + /* MRRC2 : 1111 1100 0101 xxxx xxxx xxxx xxxx xxxx : (Rd != Rn) */ + if ((insn & 0xffe00000) == 0xfc400000) { + insn &= 0xfff00fff; /* Rn = r0 */ + insn |= 0x00001000; /* Rd = r1 */ + asi->insn[0] = insn; + asi->insn_handler = + (insn & (1 << 20)) ? emulate_mrrc : emulate_mcrr; + return INSN_GOOD; + } + + /* LDC2 : 1111 110x xxx1 xxxx xxxx xxxx xxxx xxxx */ + /* STC2 : 1111 110x xxx0 xxxx xxxx xxxx xxxx xxxx */ + if ((insn & 0xfe000000) == 0xfc000000) { + insn &= 0xfff0ffff; /* Rn = r0 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_ldcstc; + return INSN_GOOD; + } + + /* MCR2 : 1111 1110 xxx0 xxxx xxxx xxxx xxx1 xxxx */ + /* MRC2 : 1111 1110 xxx1 xxxx xxxx xxxx xxx1 xxxx */ + insn &= 0xffff0fff; /* Rd = r0 */ + asi->insn[0] = insn; + asi->insn_handler = (insn & (1 << 20)) ? emulate_rd12 : emulate_ird12; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +space_cccc_000x(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* cccc 0001 0xx0 xxxx xxxx xxxx xxxx xxx0 xxxx */ + if ((insn & 0x0f900010) == 0x01000000) { + + /* BXJ : cccc 0001 0010 xxxx xxxx xxxx 0010 xxxx */ + /* MSR : cccc 0001 0x10 xxxx xxxx xxxx 0000 xxxx */ + if ((insn & 0x0ff000f0) == 0x01200020 || + (insn & 0x0fb000f0) == 0x01200000) + return INSN_REJECTED; + + /* MRS : cccc 0001 0x00 xxxx xxxx xxxx 0000 xxxx */ + if ((insn & 0x0fb00010) == 0x01000000) + return prep_emulate_rd12(insn, asi); + + /* SMLALxy : cccc 0001 0100 xxxx xxxx xxxx 1xx0 xxxx */ + if ((insn & 0x0ff00090) == 0x01400080) + return prep_emulate_rdhi16rdlo12rs8rm0_wflags(insn, asi); + + /* SMULWy : cccc 0001 0010 xxxx xxxx xxxx 1x10 xxxx */ + /* SMULxy : cccc 0001 0110 xxxx xxxx xxxx 1xx0 xxxx */ + if ((insn & 0x0ff000b0) == 0x012000a0 || + (insn & 0x0ff00090) == 0x01600080) + return prep_emulate_rd16rs8rm0_wflags(insn, asi); + + /* SMLAxy : cccc 0001 0000 xxxx xxxx xxxx 1xx0 xxxx : Q */ + /* SMLAWy : cccc 0001 0010 xxxx xxxx xxxx 0x00 xxxx : Q */ + return prep_emulate_rd16rn12rs8rm0_wflags(insn, asi); + + } + + /* cccc 0001 0xx0 xxxx xxxx xxxx xxxx 0xx1 xxxx */ + else if ((insn & 0x0f900090) == 0x01000010) { + + /* BKPT : 1110 0001 0010 xxxx xxxx xxxx 0111 xxxx */ + if ((insn & 0xfff000f0) == 0xe1200070) + return INSN_REJECTED; + + /* BLX(2) : cccc 0001 0010 xxxx xxxx xxxx 0011 xxxx */ + /* BX : cccc 0001 0010 xxxx xxxx xxxx 0001 xxxx */ + if ((insn & 0x0ff000d0) == 0x01200010) { + asi->insn[0] = truecc_insn(insn); + asi->insn_handler = simulate_blx2bx; + return INSN_GOOD; + } + + /* CLZ : cccc 0001 0110 xxxx xxxx xxxx 0001 xxxx */ + if ((insn & 0x0ff000f0) == 0x01600010) + return prep_emulate_rd12rm0(insn, asi); + + /* QADD : cccc 0001 0000 xxxx xxxx xxxx 0101 xxxx :Q */ + /* QSUB : cccc 0001 0010 xxxx xxxx xxxx 0101 xxxx :Q */ + /* QDADD : cccc 0001 0100 xxxx xxxx xxxx 0101 xxxx :Q */ + /* QDSUB : cccc 0001 0110 xxxx xxxx xxxx 0101 xxxx :Q */ + return prep_emulate_rd12rn16rm0_wflags(insn, asi); + } + + /* cccc 0000 xxxx xxxx xxxx xxxx xxxx 1001 xxxx */ + else if ((insn & 0x0f000090) == 0x00000090) { + + /* MUL : cccc 0000 0000 xxxx xxxx xxxx 1001 xxxx : */ + /* MULS : cccc 0000 0001 xxxx xxxx xxxx 1001 xxxx :cc */ + /* MLA : cccc 0000 0010 xxxx xxxx xxxx 1001 xxxx : */ + /* MLAS : cccc 0000 0011 xxxx xxxx xxxx 1001 xxxx :cc */ + /* UMAAL : cccc 0000 0100 xxxx xxxx xxxx 1001 xxxx : */ + /* UMULL : cccc 0000 1000 xxxx xxxx xxxx 1001 xxxx : */ + /* UMULLS : cccc 0000 1001 xxxx xxxx xxxx 1001 xxxx :cc */ + /* UMLAL : cccc 0000 1010 xxxx xxxx xxxx 1001 xxxx : */ + /* UMLALS : cccc 0000 1011 xxxx xxxx xxxx 1001 xxxx :cc */ + /* SMULL : cccc 0000 1100 xxxx xxxx xxxx 1001 xxxx : */ + /* SMULLS : cccc 0000 1101 xxxx xxxx xxxx 1001 xxxx :cc */ + /* SMLAL : cccc 0000 1110 xxxx xxxx xxxx 1001 xxxx : */ + /* SMLALS : cccc 0000 1111 xxxx xxxx xxxx 1001 xxxx :cc */ + if ((insn & 0x0fe000f0) == 0x00000090) { + return prep_emulate_rd16rs8rm0_wflags(insn, asi); + } else if ((insn & 0x0fe000f0) == 0x00200090) { + return prep_emulate_rd16rn12rs8rm0_wflags(insn, asi); + } else { + return prep_emulate_rdhi16rdlo12rs8rm0_wflags(insn, asi); + } + } + + /* cccc 000x xxxx xxxx xxxx xxxx xxxx 1xx1 xxxx */ + else if ((insn & 0x0e000090) == 0x00000090) { + + /* SWP : cccc 0001 0000 xxxx xxxx xxxx 1001 xxxx */ + /* SWPB : cccc 0001 0100 xxxx xxxx xxxx 1001 xxxx */ + /* LDRD : cccc 000x xxx0 xxxx xxxx xxxx 1101 xxxx */ + /* STRD : cccc 000x xxx0 xxxx xxxx xxxx 1111 xxxx */ + /* STREX : cccc 0001 1000 xxxx xxxx xxxx 1001 xxxx */ + /* LDREX : cccc 0001 1001 xxxx xxxx xxxx 1001 xxxx */ + /* LDRH : cccc 000x xxx1 xxxx xxxx xxxx 1011 xxxx */ + /* STRH : cccc 000x xxx0 xxxx xxxx xxxx 1011 xxxx */ + /* LDRSB : cccc 000x xxx1 xxxx xxxx xxxx 1101 xxxx */ + /* LDRSH : cccc 000x xxx1 xxxx xxxx xxxx 1111 xxxx */ + if ((insn & 0x0fb000f0) == 0x01000090) { + /* SWP/SWPB */ + return prep_emulate_rd12rn16rm0_wflags(insn, asi); + } else if ((insn & 0x0e1000d0) == 0x00000d0) { + /* STRD/LDRD */ + insn &= 0xfff00fff; + insn |= 0x00002000; /* Rn = r0, Rd = r2 */ + if (insn & (1 << 22)) { + /* I bit */ + insn &= ~0xf; + insn |= 1; /* Rm = r1 */ + } + asi->insn[0] = insn; + asi->insn_handler = + (insn & (1 << 5)) ? emulate_strd : emulate_ldrd; + return INSN_GOOD; + } + + return prep_emulate_ldr_str(insn, asi); + } + + /* cccc 000x xxxx xxxx xxxx xxxx xxxx xxxx xxxx */ + + /* + * ALU op with S bit and Rd == 15 : + * cccc 000x xxx1 xxxx 1111 xxxx xxxx xxxx + */ + if ((insn & 0x0e10f000) == 0x0010f000) + return INSN_REJECTED; + + /* + * "mov ip, sp" is the most common kprobe'd instruction by far. + * Check and optimize for it explicitly. + */ + if (insn == 0xe1a0c00d) { + asi->insn_handler = simulate_mov_ipsp; + return INSN_GOOD_NO_SLOT; + } + + /* + * Data processing: Immediate-shift / Register-shift + * ALU op : cccc 000x xxxx xxxx xxxx xxxx xxxx xxxx + * CPY : cccc 0001 1010 xxxx xxxx 0000 0000 xxxx + * MOV : cccc 0001 101x xxxx xxxx xxxx xxxx xxxx + * *S (bit 20) updates condition codes + * ADC/SBC/RSC reads the C flag + */ + insn &= 0xfff00ff0; /* Rn = r0, Rd = r0 */ + insn |= 0x00000001; /* Rm = r1 */ + if (insn & 0x010) { + insn &= 0xfffff0ff; /* register shift */ + insn |= 0x00000200; /* Rs = r2 */ + } + asi->insn[0] = insn; + asi->insn_handler = (insn & (1 << 20)) ? /* S-bit */ + emulate_alu_rwflags : emulate_alu_rflags; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +space_cccc_001x(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* + * MSR : cccc 0011 0x10 xxxx xxxx xxxx xxxx xxxx + * Undef : cccc 0011 0x00 xxxx xxxx xxxx xxxx xxxx + * ALU op with S bit and Rd == 15 : + * cccc 001x xxx1 xxxx 1111 xxxx xxxx xxxx + */ + if ((insn & 0x0f900000) == 0x03200000 || /* MSR & Undef */ + (insn & 0x0e10f000) == 0x0210f000) /* ALU s-bit, R15 */ + return INSN_REJECTED; + + /* + * Data processing: 32-bit Immediate + * ALU op : cccc 001x xxxx xxxx xxxx xxxx xxxx xxxx + * MOV : cccc 0011 101x xxxx xxxx xxxx xxxx xxxx + * *S (bit 20) updates condition codes + * ADC/SBC/RSC reads the C flag + */ + insn &= 0xfff00ff0; /* Rn = r0, Rd = r0 */ + asi->insn[0] = insn; + asi->insn_handler = (insn & (1 << 20)) ? /* S-bit */ + emulate_alu_imm_rwflags : emulate_alu_imm_rflags; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +space_cccc_0110__1(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* SEL : cccc 0110 1000 xxxx xxxx xxxx 1011 xxxx GE: !!! */ + if ((insn & 0x0ff000f0) == 0x068000b0) { + insn &= 0xfff00ff0; /* Rd = r0, Rn = r0 */ + insn |= 0x00000001; /* Rm = r1 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_sel; + return INSN_GOOD; + } + + /* SSAT : cccc 0110 101x xxxx xxxx xxxx xx01 xxxx :Q */ + /* USAT : cccc 0110 111x xxxx xxxx xxxx xx01 xxxx :Q */ + /* SSAT16 : cccc 0110 1010 xxxx xxxx xxxx 0011 xxxx :Q */ + /* USAT16 : cccc 0110 1110 xxxx xxxx xxxx 0011 xxxx :Q */ + if ((insn & 0x0fa00030) == 0x06a00010 || + (insn & 0x0fb000f0) == 0x06a00030) { + insn &= 0xffff0ff0; /* Rd = r0, Rm = r0 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_sat; + return INSN_GOOD; + } + + /* REV : cccc 0110 1011 xxxx xxxx xxxx 0011 xxxx */ + /* REV16 : cccc 0110 1011 xxxx xxxx xxxx 1011 xxxx */ + /* REVSH : cccc 0110 1111 xxxx xxxx xxxx 1011 xxxx */ + if ((insn & 0x0ff00070) == 0x06b00030 || + (insn & 0x0ff000f0) == 0x06f000b0) + return prep_emulate_rd12rm0(insn, asi); + + /* SADD16 : cccc 0110 0001 xxxx xxxx xxxx 0001 xxxx :GE */ + /* SADDSUBX : cccc 0110 0001 xxxx xxxx xxxx 0011 xxxx :GE */ + /* SSUBADDX : cccc 0110 0001 xxxx xxxx xxxx 0101 xxxx :GE */ + /* SSUB16 : cccc 0110 0001 xxxx xxxx xxxx 0111 xxxx :GE */ + /* SADD8 : cccc 0110 0001 xxxx xxxx xxxx 1001 xxxx :GE */ + /* SSUB8 : cccc 0110 0001 xxxx xxxx xxxx 1111 xxxx :GE */ + /* 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 :GE */ + /* UADDSUBX : cccc 0110 0101 xxxx xxxx xxxx 0011 xxxx :GE */ + /* USUBADDX : cccc 0110 0101 xxxx xxxx xxxx 0101 xxxx :GE */ + /* USUB16 : cccc 0110 0101 xxxx xxxx xxxx 0111 xxxx :GE */ + /* UADD8 : cccc 0110 0101 xxxx xxxx xxxx 1001 xxxx :GE */ + /* USUB8 : cccc 0110 0101 xxxx xxxx xxxx 1111 xxxx :GE */ + /* 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 : */ + /* PKHBT : cccc 0110 1000 xxxx xxxx xxxx x001 xxxx : */ + /* PKHTB : cccc 0110 1000 xxxx xxxx xxxx x101 xxxx : */ + /* SXTAB16 : cccc 0110 1000 xxxx xxxx xxxx 0111 xxxx : */ + /* SXTB : cccc 0110 1010 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 : */ + return prep_emulate_rd12rn16rm0_wflags(insn, asi); +} + +static enum kprobe_insn __kprobes +space_cccc_0111__1(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* Undef : cccc 0111 1111 xxxx xxxx xxxx 1111 xxxx */ + if ((insn & 0x0ff000f0) == 0x03f000f0) + return INSN_REJECTED; + + /* USADA8 : cccc 0111 1000 xxxx xxxx xxxx 0001 xxxx */ + /* USAD8 : cccc 0111 1000 xxxx 1111 xxxx 0001 xxxx */ + if ((insn & 0x0ff000f0) == 0x07800010) + return prep_emulate_rd16rn12rs8rm0_wflags(insn, asi); + + /* SMLALD : cccc 0111 0100 xxxx xxxx xxxx 00x1 xxxx */ + /* SMLSLD : cccc 0111 0100 xxxx xxxx xxxx 01x1 xxxx */ + if ((insn & 0x0ff00090) == 0x07400010) + return prep_emulate_rdhi16rdlo12rs8rm0_wflags(insn, asi); + + /* SMLAD : cccc 0111 0000 xxxx xxxx xxxx 00x1 xxxx :Q */ + /* SMLSD : cccc 0111 0000 xxxx xxxx xxxx 01x1 xxxx :Q */ + /* SMMLA : cccc 0111 0101 xxxx xxxx xxxx 00x1 xxxx : */ + /* SMMLS : cccc 0111 0101 xxxx xxxx xxxx 11x1 xxxx : */ + if ((insn & 0x0ff00090) == 0x07000010 || + (insn & 0x0ff000d0) == 0x07500010 || + (insn & 0x0ff000d0) == 0x075000d0) + return prep_emulate_rd16rn12rs8rm0_wflags(insn, asi); + + /* SMUSD : cccc 0111 0000 xxxx xxxx xxxx 01x1 xxxx : */ + /* SMUAD : cccc 0111 0000 xxxx 1111 xxxx 00x1 xxxx :Q */ + /* SMMUL : cccc 0111 0101 xxxx 1111 xxxx 00x1 xxxx : */ + return prep_emulate_rd16rs8rm0_wflags(insn, asi); +} + +static enum kprobe_insn __kprobes +space_cccc_01xx(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* LDR : cccc 01xx x0x1 xxxx xxxx xxxx xxxx xxxx */ + /* LDRB : cccc 01xx x1x1 xxxx xxxx xxxx xxxx xxxx */ + /* LDRBT : cccc 01x0 x111 xxxx xxxx xxxx xxxx xxxx */ + /* LDRT : cccc 01x0 x011 xxxx xxxx xxxx xxxx xxxx */ + /* STR : cccc 01xx x0x0 xxxx xxxx xxxx xxxx xxxx */ + /* STRB : cccc 01xx x1x0 xxxx xxxx xxxx xxxx xxxx */ + /* STRBT : cccc 01x0 x110 xxxx xxxx xxxx xxxx xxxx */ + /* STRT : cccc 01x0 x010 xxxx xxxx xxxx xxxx xxxx */ + return prep_emulate_ldr_str(insn, asi); +} + +static enum kprobe_insn __kprobes +space_cccc_100x(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* LDM(2) : cccc 100x x101 xxxx 0xxx xxxx xxxx xxxx */ + /* LDM(3) : cccc 100x x1x1 xxxx 1xxx xxxx xxxx xxxx */ + if ((insn & 0x0e708000) == 0x85000000 || + (insn & 0x0e508000) == 0x85010000) + return INSN_REJECTED; + + /* LDM(1) : cccc 100x x0x1 xxxx xxxx xxxx xxxx xxxx */ + /* STM(1) : cccc 100x x0x0 xxxx xxxx xxxx xxxx xxxx */ + asi->insn[0] = truecc_insn(insn); + asi->insn_handler = ((insn & 0x108000) == 0x008000) ? /* STM & R15 */ + simulate_stm1_pc : simulate_ldm1stm1; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +space_cccc_101x(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* B : cccc 1010 xxxx xxxx xxxx xxxx xxxx xxxx */ + /* BL : cccc 1011 xxxx xxxx xxxx xxxx xxxx xxxx */ + asi->insn[0] = truecc_insn(insn); + asi->insn_handler = simulate_bbl; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +space_cccc_1100_010x(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* MCRR : cccc 1100 0100 xxxx xxxx xxxx xxxx xxxx : (Rd!=Rn) */ + /* MRRC : cccc 1100 0101 xxxx xxxx xxxx xxxx xxxx : (Rd!=Rn) */ + insn &= 0xfff00fff; + insn |= 0x00001000; /* Rn = r0, Rd = r1 */ + asi->insn[0] = insn; + asi->insn_handler = (insn & (1 << 20)) ? emulate_mrrc : emulate_mcrr; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +space_cccc_110x(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* LDC : cccc 110x xxx1 xxxx xxxx xxxx xxxx xxxx */ + /* STC : cccc 110x xxx0 xxxx xxxx xxxx xxxx xxxx */ + insn &= 0xfff0ffff; /* Rn = r0 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_ldcstc; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +space_cccc_111x(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* BKPT : 1110 0001 0010 xxxx xxxx xxxx 0111 xxxx */ + /* SWI : cccc 1111 xxxx xxxx xxxx xxxx xxxx xxxx */ + if ((insn & 0xfff000f0) == 0xe1200070 || + (insn & 0x0f000000) == 0x0f000000) + return INSN_REJECTED; + + /* CDP : cccc 1110 xxxx xxxx xxxx xxxx xxx0 xxxx */ + if ((insn & 0x0f000010) == 0x0e000000) { + asi->insn[0] = insn; + asi->insn_handler = emulate_none; + return INSN_GOOD; + } + + /* MCR : cccc 1110 xxx0 xxxx xxxx xxxx xxx1 xxxx */ + /* MRC : cccc 1110 xxx1 xxxx xxxx xxxx xxx1 xxxx */ + insn &= 0xffff0fff; /* Rd = r0 */ + asi->insn[0] = insn; + asi->insn_handler = (insn & (1 << 20)) ? emulate_rd12 : emulate_ird12; + return INSN_GOOD; +} + +/* Return: + * INSN_REJECTED If instruction is one not allowed to kprobe, + * 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 kprobe (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 kprobe_insn __kprobes +arm_kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + asi->insn[1] = KPROBE_RETURN_INSTRUCTION; + + if ((insn & 0xf0000000) == 0xf0000000) { + + return space_1111(insn, asi); + + } else if ((insn & 0x0e000000) == 0x00000000) { + + return space_cccc_000x(insn, asi); + + } else if ((insn & 0x0e000000) == 0x02000000) { + + return space_cccc_001x(insn, asi); + + } else if ((insn & 0x0f000010) == 0x06000010) { + + return space_cccc_0110__1(insn, asi); + + } else if ((insn & 0x0f000010) == 0x07000010) { + + return space_cccc_0111__1(insn, asi); + + } else if ((insn & 0x0c000000) == 0x04000000) { + + return space_cccc_01xx(insn, asi); + + } else if ((insn & 0x0e000000) == 0x08000000) { + + return space_cccc_100x(insn, asi); + + } else if ((insn & 0x0e000000) == 0x0a000000) { + + return space_cccc_101x(insn, asi); + + } else if ((insn & 0x0fe00000) == 0x0c400000) { + + return space_cccc_1100_010x(insn, asi); + + } else if ((insn & 0x0e000000) == 0x0c400000) { + + return space_cccc_110x(insn, asi); + + } + + return space_cccc_111x(insn, asi); +} + +void __init arm_kprobe_decode_init(void) +{ + find_str_pc_offset(); +} + + +/* + * All ARM instructions listed below. + * + * Instructions and their general purpose registers are given. + * If a particular register may not use R15, it is prefixed with a "!". + * If marked with a "*" means the value returned by reading R15 + * is implementation defined. + * + * ADC/ADD/AND/BIC/CMN/CMP/EOR/MOV/MVN/ORR/RSB/RSC/SBC/SUB/TEQ + * TST: Rd, Rn, Rm, !Rs + * BX: Rm + * BLX(2): !Rm + * BX: Rm (R15 legal, but discouraged) + * BXJ: !Rm, + * CLZ: !Rd, !Rm + * CPY: Rd, Rm + * LDC/2,STC/2 immediate offset & unindex: Rn + * LDC/2,STC/2 immediate pre/post-indexed: !Rn + * LDM(1/3): !Rn, register_list + * LDM(2): !Rn, !register_list + * LDR,STR,PLD immediate offset: Rd, Rn + * LDR,STR,PLD register offset: Rd, Rn, !Rm + * LDR,STR,PLD scaled register offset: Rd, !Rn, !Rm + * LDR,STR immediate pre/post-indexed: Rd, !Rn + * LDR,STR register pre/post-indexed: Rd, !Rn, !Rm + * LDR,STR scaled register pre/post-indexed: Rd, !Rn, !Rm + * LDRB,STRB immediate offset: !Rd, Rn + * LDRB,STRB register offset: !Rd, Rn, !Rm + * LDRB,STRB scaled register offset: !Rd, !Rn, !Rm + * LDRB,STRB immediate pre/post-indexed: !Rd, !Rn + * LDRB,STRB register pre/post-indexed: !Rd, !Rn, !Rm + * LDRB,STRB scaled register pre/post-indexed: !Rd, !Rn, !Rm + * LDRT,LDRBT,STRBT immediate pre/post-indexed: !Rd, !Rn + * LDRT,LDRBT,STRBT register pre/post-indexed: !Rd, !Rn, !Rm + * LDRT,LDRBT,STRBT scaled register pre/post-indexed: !Rd, !Rn, !Rm + * LDRH/SH/SB/D,STRH/SH/SB/D immediate offset: !Rd, Rn + * LDRH/SH/SB/D,STRH/SH/SB/D register offset: !Rd, Rn, !Rm + * LDRH/SH/SB/D,STRH/SH/SB/D immediate pre/post-indexed: !Rd, !Rn + * LDRH/SH/SB/D,STRH/SH/SB/D register pre/post-indexed: !Rd, !Rn, !Rm + * LDREX: !Rd, !Rn + * MCR/2: !Rd + * MCRR/2,MRRC/2: !Rd, !Rn + * MLA: !Rd, !Rn, !Rm, !Rs + * MOV: Rd + * MRC/2: !Rd (if Rd==15, only changes cond codes, not the register) + * MRS,MSR: !Rd + * MUL: !Rd, !Rm, !Rs + * PKH{BT,TB}: !Rd, !Rn, !Rm + * QDADD,[U]QADD/16/8/SUBX: !Rd, !Rm, !Rn + * QDSUB,[U]QSUB/16/8/ADDX: !Rd, !Rm, !Rn + * REV/16/SH: !Rd, !Rm + * RFE: !Rn + * {S,U}[H]ADD{16,8,SUBX},{S,U}[H]SUB{16,8,ADDX}: !Rd, !Rn, !Rm + * SEL: !Rd, !Rn, !Rm + * SMLA<x><y>,SMLA{D,W<y>},SMLSD,SMML{A,S}: !Rd, !Rn, !Rm, !Rs + * SMLAL<x><y>,SMLA{D,LD},SMLSLD,SMMULL,SMULW<y>: !RdHi, !RdLo, !Rm, !Rs + * SMMUL,SMUAD,SMUL<x><y>,SMUSD: !Rd, !Rm, !Rs + * SSAT/16: !Rd, !Rm + * STM(1/2): !Rn, register_list* (R15 in reg list not recommended) + * STRT immediate pre/post-indexed: Rd*, !Rn + * STRT register pre/post-indexed: Rd*, !Rn, !Rm + * STRT scaled register pre/post-indexed: Rd*, !Rn, !Rm + * STREX: !Rd, !Rn, !Rm + * SWP/B: !Rd, !Rn, !Rm + * {S,U}XTA{B,B16,H}: !Rd, !Rn, !Rm + * {S,U}XT{B,B16,H}: !Rd, !Rm + * UM{AA,LA,UL}L: !RdHi, !RdLo, !Rm, !Rs + * USA{D8,A8,T,T16}: !Rd, !Rm, !Rs + * + * May transfer control by writing R15 (possible mode changes or alternate + * mode accesses marked by "*"): + * ALU op (* with s-bit), B, BL, BKPT, BLX(1/2), BX, BXJ, CPS*, CPY, + * LDM(1), LDM(2/3)*, LDR, MOV, RFE*, SWI* + * + * Instructions that do not take general registers, nor transfer control: + * CDP/2, SETEND, SRS* + */ diff --git a/arch/arm/kernel/kprobes.c b/arch/arm/kernel/kprobes.c new file mode 100644 index 000000000000..a22a98c43ca5 --- /dev/null +++ b/arch/arm/kernel/kprobes.c @@ -0,0 +1,447 @@ +/* + * arch/arm/kernel/kprobes.c + * + * Kprobes on ARM + * + * Abhishek Sagar <sagar.abhishek@gmail.com> + * Copyright (C) 2006, 2007 Motorola Inc. + * + * Nicolas Pitre <nico@marvell.com> + * Copyright (C) 2007 Marvell Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This 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. + */ + +#include <linux/kernel.h> +#include <linux/kprobes.h> +#include <linux/module.h> +#include <linux/stringify.h> +#include <asm/traps.h> +#include <asm/cacheflush.h> + +#define MIN_STACK_SIZE(addr) \ + min((unsigned long)MAX_STACK_SIZE, \ + (unsigned long)current_thread_info() + THREAD_START_SP - (addr)) + +#define flush_insns(addr, cnt) \ + flush_icache_range((unsigned long)(addr), \ + (unsigned long)(addr) + \ + sizeof(kprobe_opcode_t) * (cnt)) + +/* Used as a marker in ARM_pc to note when we're in a jprobe. */ +#define JPROBE_MAGIC_ADDR 0xffffffff + +DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; +DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); + + +int __kprobes arch_prepare_kprobe(struct kprobe *p) +{ + kprobe_opcode_t insn; + kprobe_opcode_t tmp_insn[MAX_INSN_SIZE]; + unsigned long addr = (unsigned long)p->addr; + int is; + + if (addr & 0x3 || in_exception_text(addr)) + return -EINVAL; + + insn = *p->addr; + p->opcode = insn; + p->ainsn.insn = tmp_insn; + + switch (arm_kprobe_decode_insn(insn, &p->ainsn)) { + case INSN_REJECTED: /* not supported */ + return -EINVAL; + + case INSN_GOOD: /* instruction uses slot */ + p->ainsn.insn = get_insn_slot(); + if (!p->ainsn.insn) + return -ENOMEM; + for (is = 0; is < MAX_INSN_SIZE; ++is) + p->ainsn.insn[is] = tmp_insn[is]; + flush_insns(&p->ainsn.insn, MAX_INSN_SIZE); + break; + + case INSN_GOOD_NO_SLOT: /* instruction doesn't need insn slot */ + p->ainsn.insn = NULL; + break; + } + + return 0; +} + +void __kprobes arch_arm_kprobe(struct kprobe *p) +{ + *p->addr = KPROBE_BREAKPOINT_INSTRUCTION; + flush_insns(p->addr, 1); +} + +void __kprobes arch_disarm_kprobe(struct kprobe *p) +{ + *p->addr = p->opcode; + flush_insns(p->addr, 1); +} + +void __kprobes arch_remove_kprobe(struct kprobe *p) +{ + if (p->ainsn.insn) { + mutex_lock(&kprobe_mutex); + free_insn_slot(p->ainsn.insn, 0); + mutex_unlock(&kprobe_mutex); + p->ainsn.insn = NULL; + } +} + +static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb) +{ + kcb->prev_kprobe.kp = kprobe_running(); + kcb->prev_kprobe.status = kcb->kprobe_status; +} + +static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb) +{ + __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp; + kcb->kprobe_status = kcb->prev_kprobe.status; +} + +static void __kprobes set_current_kprobe(struct kprobe *p) +{ + __get_cpu_var(current_kprobe) = p; +} + +static void __kprobes singlestep(struct kprobe *p, struct pt_regs *regs, + struct kprobe_ctlblk *kcb) +{ + regs->ARM_pc += 4; + p->ainsn.insn_handler(p, regs); +} + +/* + * Called with IRQs disabled. IRQs must remain disabled from that point + * all the way until processing this kprobe is complete. The current + * kprobes implementation cannot process more than one nested level of + * kprobe, and that level is reserved for user kprobe handlers, so we can't + * risk encountering a new kprobe in an interrupt handler. + */ +void __kprobes kprobe_handler(struct pt_regs *regs) +{ + struct kprobe *p, *cur; + struct kprobe_ctlblk *kcb; + kprobe_opcode_t *addr = (kprobe_opcode_t *)regs->ARM_pc; + + kcb = get_kprobe_ctlblk(); + cur = kprobe_running(); + p = get_kprobe(addr); + + if (p) { + if (cur) { + /* Kprobe is pending, so we're recursing. */ + switch (kcb->kprobe_status) { + case KPROBE_HIT_ACTIVE: + case KPROBE_HIT_SSDONE: + /* A pre- or post-handler probe got us here. */ + kprobes_inc_nmissed_count(p); + save_previous_kprobe(kcb); + set_current_kprobe(p); + kcb->kprobe_status = KPROBE_REENTER; + singlestep(p, regs, kcb); + restore_previous_kprobe(kcb); + break; + default: + /* impossible cases */ + BUG(); + } + } else { + set_current_kprobe(p); + kcb->kprobe_status = KPROBE_HIT_ACTIVE; + + /* + * If we have no pre-handler or it returned 0, we + * continue with normal processing. If we have a + * pre-handler and it returned non-zero, it prepped + * for calling the break_handler below on re-entry, + * so get out doing nothing more here. + */ + if (!p->pre_handler || !p->pre_handler(p, regs)) { + kcb->kprobe_status = KPROBE_HIT_SS; + singlestep(p, regs, kcb); + if (p->post_handler) { + kcb->kprobe_status = KPROBE_HIT_SSDONE; + p->post_handler(p, regs, 0); + } + reset_current_kprobe(); + } + } + } else if (cur) { + /* We probably hit a jprobe. Call its break handler. */ + if (cur->break_handler && cur->break_handler(cur, regs)) { + kcb->kprobe_status = KPROBE_HIT_SS; + singlestep(cur, regs, kcb); + if (cur->post_handler) { + kcb->kprobe_status = KPROBE_HIT_SSDONE; + cur->post_handler(cur, regs, 0); + } + } + reset_current_kprobe(); + } else { + /* + * The probe was removed and a race is in progress. + * There is nothing we can do about it. Let's restart + * the instruction. By the time we can restart, the + * real instruction will be there. + */ + } +} + +int kprobe_trap_handler(struct pt_regs *regs, unsigned int instr) +{ + kprobe_handler(regs); + return 0; +} + +int __kprobes kprobe_fault_handler(struct pt_regs *regs, unsigned int fsr) +{ + struct kprobe *cur = kprobe_running(); + struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + + switch (kcb->kprobe_status) { + case KPROBE_HIT_SS: + case KPROBE_REENTER: + /* + * We are here because the instruction being single + * stepped caused a page fault. We reset the current + * kprobe and the PC to point back to the probe address + * and allow the page fault handler to continue as a + * normal page fault. + */ + regs->ARM_pc = (long)cur->addr; + if (kcb->kprobe_status == KPROBE_REENTER) { + restore_previous_kprobe(kcb); + } else { + reset_current_kprobe(); + } + break; + + case KPROBE_HIT_ACTIVE: + case KPROBE_HIT_SSDONE: + /* + * We increment the nmissed count for accounting, + * we can also use npre/npostfault count for accounting + * these specific fault cases. + */ + kprobes_inc_nmissed_count(cur); + + /* + * We come here because instructions in the pre/post + * handler caused the page_fault, this could happen + * if handler tries to access user space by + * copy_from_user(), get_user() etc. Let the + * user-specified handler try to fix it. + */ + if (cur->fault_handler && cur->fault_handler(cur, regs, fsr)) + return 1; + break; + + default: + break; + } + + return 0; +} + +int __kprobes kprobe_exceptions_notify(struct notifier_block *self, + unsigned long val, void *data) +{ + /* + * notify_die() is currently never called on ARM, + * so this callback is currently empty. + */ + return NOTIFY_DONE; +} + +/* + * When a retprobed function returns, trampoline_handler() is called, + * calling the kretprobe's handler. We construct a struct pt_regs to + * give a view of registers r0-r11 to the user return-handler. This is + * not a complete pt_regs structure, but that should be plenty sufficient + * for kretprobe handlers which should normally be interested in r0 only + * anyway. + */ +static void __attribute__((naked)) __kprobes kretprobe_trampoline(void) +{ + __asm__ __volatile__ ( + "stmdb sp!, {r0 - r11} \n\t" + "mov r0, sp \n\t" + "bl trampoline_handler \n\t" + "mov lr, r0 \n\t" + "ldmia sp!, {r0 - r11} \n\t" + "mov pc, lr \n\t" + : : : "memory"); +} + +/* Called from kretprobe_trampoline */ +static __used __kprobes void *trampoline_handler(struct pt_regs *regs) +{ + struct kretprobe_instance *ri = NULL; + struct hlist_head *head, empty_rp; + struct hlist_node *node, *tmp; + unsigned long flags, orig_ret_address = 0; + unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline; + + INIT_HLIST_HEAD(&empty_rp); + spin_lock_irqsave(&kretprobe_lock, flags); + head = kretprobe_inst_table_head(current); + + /* + * It is possible to have multiple instances associated with a given + * task either because multiple functions in the call path have + * a return probe installed on them, and/or more than one return + * probe was registered for a target function. + * + * We can handle this because: + * - instances are always inserted at the head of the list + * - when multiple return probes are registered for the same + * function, the first instance's ret_addr will point to the + * real return address, and all the rest will point to + * kretprobe_trampoline + */ + hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { + if (ri->task != current) + /* another task is sharing our hash bucket */ + continue; + + if (ri->rp && ri->rp->handler) { + __get_cpu_var(current_kprobe) = &ri->rp->kp; + get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE; + ri->rp->handler(ri, regs); + __get_cpu_var(current_kprobe) = NULL; + } + + orig_ret_address = (unsigned long)ri->ret_addr; + recycle_rp_inst(ri, &empty_rp); + + if (orig_ret_address != trampoline_address) + /* + * This is the real return address. Any other + * instances associated with this task are for + * other calls deeper on the call stack + */ + break; + } + + kretprobe_assert(ri, orig_ret_address, trampoline_address); + spin_unlock_irqrestore(&kretprobe_lock, flags); + + hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { + hlist_del(&ri->hlist); + kfree(ri); + } + + return (void *)orig_ret_address; +} + +/* Called with kretprobe_lock held. */ +void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, + struct pt_regs *regs) +{ + ri->ret_addr = (kprobe_opcode_t *)regs->ARM_lr; + + /* Replace the return addr with trampoline addr. */ + regs->ARM_lr = (unsigned long)&kretprobe_trampoline; +} + +int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) +{ + struct jprobe *jp = container_of(p, struct jprobe, kp); + struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + long sp_addr = regs->ARM_sp; + + kcb->jprobe_saved_regs = *regs; + memcpy(kcb->jprobes_stack, (void *)sp_addr, MIN_STACK_SIZE(sp_addr)); + regs->ARM_pc = (long)jp->entry; + regs->ARM_cpsr |= PSR_I_BIT; + preempt_disable(); + return 1; +} + +void __kprobes jprobe_return(void) +{ + struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + + __asm__ __volatile__ ( + /* + * Setup an empty pt_regs. Fill SP and PC fields as + * they're needed by longjmp_break_handler. + */ + "sub sp, %0, %1 \n\t" + "ldr r0, ="__stringify(JPROBE_MAGIC_ADDR)"\n\t" + "str %0, [sp, %2] \n\t" + "str r0, [sp, %3] \n\t" + "mov r0, sp \n\t" + "bl kprobe_handler \n\t" + + /* + * Return to the context saved by setjmp_pre_handler + * and restored by longjmp_break_handler. + */ + "ldr r0, [sp, %4] \n\t" + "msr cpsr_cxsf, r0 \n\t" + "ldmia sp, {r0 - pc} \n\t" + : + : "r" (kcb->jprobe_saved_regs.ARM_sp), + "I" (sizeof(struct pt_regs)), + "J" (offsetof(struct pt_regs, ARM_sp)), + "J" (offsetof(struct pt_regs, ARM_pc)), + "J" (offsetof(struct pt_regs, ARM_cpsr)) + : "memory", "cc"); +} + +int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) +{ + struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + long stack_addr = kcb->jprobe_saved_regs.ARM_sp; + long orig_sp = regs->ARM_sp; + struct jprobe *jp = container_of(p, struct jprobe, kp); + + if (regs->ARM_pc == JPROBE_MAGIC_ADDR) { + if (orig_sp != stack_addr) { + struct pt_regs *saved_regs = + (struct pt_regs *)kcb->jprobe_saved_regs.ARM_sp; + printk("current sp %lx does not match saved sp %lx\n", + orig_sp, stack_addr); + printk("Saved registers for jprobe %p\n", jp); + show_regs(saved_regs); + printk("Current registers\n"); + show_regs(regs); + BUG(); + } + *regs = kcb->jprobe_saved_regs; + memcpy((void *)stack_addr, kcb->jprobes_stack, + MIN_STACK_SIZE(stack_addr)); + preempt_enable_no_resched(); + return 1; + } + return 0; +} + +static struct undef_hook kprobes_break_hook = { + .instr_mask = 0xffffffff, + .instr_val = KPROBE_BREAKPOINT_INSTRUCTION, + .cpsr_mask = MODE_MASK, + .cpsr_val = SVC_MODE, + .fn = kprobe_trap_handler, +}; + +int __init arch_init_kprobes() +{ + arm_kprobe_decode_init(); + register_undef_hook(&kprobes_break_hook); + return 0; +} diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c index e59b5b84168d..b5867eca1d0b 100644 --- a/arch/arm/kernel/time.c +++ b/arch/arm/kernel/time.c @@ -325,7 +325,9 @@ void timer_tick(void) profile_tick(CPU_PROFILING); do_leds(); do_set_rtc(); + write_seqlock(&xtime_lock); do_timer(1); + write_sequnlock(&xtime_lock); #ifndef CONFIG_SMP update_process_times(user_mode(get_irq_regs())); #endif diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index c34db4e868fa..5595fdd75e82 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -19,6 +19,7 @@ #include <linux/kallsyms.h> #include <linux/delay.h> #include <linux/init.h> +#include <linux/kprobes.h> #include <asm/atomic.h> #include <asm/cacheflush.h> @@ -46,15 +47,6 @@ __setup("user_debug=", user_debug_setup); static void dump_mem(const char *str, unsigned long bottom, unsigned long top); -static inline int in_exception_text(unsigned long ptr) -{ - extern char __exception_text_start[]; - extern char __exception_text_end[]; - - return ptr >= (unsigned long)&__exception_text_start && - ptr < (unsigned long)&__exception_text_end; -} - void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame) { #ifdef CONFIG_KALLSYMS @@ -322,6 +314,17 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs) get_user(instr, (u32 __user *)pc); } +#ifdef CONFIG_KPROBES + /* + * It is possible to have recursive kprobes, so we can't call + * the kprobe trap handler with the undef_lock held. + */ + if (instr == KPROBE_BREAKPOINT_INSTRUCTION && !user_mode(regs)) { + kprobe_trap_handler(regs, instr); + return; + } +#endif + spin_lock_irqsave(&undef_lock, flags); list_for_each_entry(hook, &undef_hook, node) { if ((instr & hook->instr_mask) == hook->instr_val && diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index 5ff5406666b4..4898bdcfe7dd 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -30,7 +30,7 @@ SECTIONS } .init : { /* Init code and data */ - *(.init.text) + INIT_TEXT _einittext = .; __proc_info_begin = .; *(.proc.info.init) @@ -70,15 +70,15 @@ SECTIONS __per_cpu_end = .; #ifndef CONFIG_XIP_KERNEL __init_begin = _stext; - *(.init.data) + INIT_DATA . = ALIGN(4096); __init_end = .; #endif } /DISCARD/ : { /* Exit code and data */ - *(.exit.text) - *(.exit.data) + EXIT_TEXT + EXIT_DATA *(.exitcall.exit) #ifndef CONFIG_MMU *(.fixup) @@ -94,6 +94,7 @@ SECTIONS TEXT_TEXT SCHED_TEXT LOCK_TEXT + KPROBES_TEXT #ifdef CONFIG_MMU *(.fixup) #endif @@ -129,7 +130,7 @@ SECTIONS #ifdef CONFIG_XIP_KERNEL . = ALIGN(4096); __init_begin = .; - *(.init.data) + INIT_DATA . = ALIGN(4096); __init_end = .; #endif |