From: Guan Xuetao <guanxuetao@xxxxxxxxxxxxxxx> Patch 3 adds ptrace support. Signed-off-by: Guan Xuetao <guanxuetao@xxxxxxxxxxxxxxx> --- arch/unicore32/include/asm/ptrace.h | 184 +++++++++++ arch/unicore32/kernel/ptrace.c | 600 +++++++++++++++++++++++++++++++++++ arch/unicore32/kernel/ptrace.h | 53 +++ 3 files changed, 837 insertions(+), 0 deletions(-) diff --git a/arch/unicore32/include/asm/ptrace.h b/arch/unicore32/include/asm/ptrace.h new file mode 100644 index 0000000..57badd1 --- /dev/null +++ b/arch/unicore32/include/asm/ptrace.h @@ -0,0 +1,184 @@ +/* + * linux/arch/unicore32/include/asm/ptrace.h + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * 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. + */ +#ifndef __UNICORE_PTRACE_H__ +#define __UNICORE_PTRACE_H__ + +#include <asm/hwcap.h> + +#define PTRACE_GET_THREAD_AREA 22 + +/* + * PSR bits + */ +#define USER_MODE 0x00000010 +#define REAL_MODE 0x00000011 +#define INTR_MODE 0x00000012 +#define PRIV_MODE 0x00000013 +#define ABRT_MODE 0x00000017 +#define EXTN_MODE 0x0000001b +#define SUSR_MODE 0x0000001f +#define MODE_MASK 0x0000001f +#define PSR_R_BIT 0x00000040 +#define PSR_I_BIT 0x00000080 +#define PSR_V_BIT 0x10000000 +#define PSR_C_BIT 0x20000000 +#define PSR_Z_BIT 0x40000000 +#define PSR_S_BIT 0x80000000 + +/* + * Groups of PSR bits + */ +#define PSR_f 0xff000000 /* Flags */ +#define PSR_c 0x000000ff /* Control */ + +#ifndef __ASSEMBLY__ + +/* + * This struct defines the way the registers are stored on the + * stack during a system call. Note that sizeof(struct pt_regs) + * has to be a multiple of 8. + */ +#ifndef __KERNEL__ +struct pt_regs { + long uregs[34]; +}; +#else /* __KERNEL__ */ +struct pt_regs { + unsigned long uregs[34]; +}; +#endif /* __KERNEL__ */ + +#define UCreg_asr uregs[32] +#define UCreg_pc uregs[31] +#define UCreg_lr uregs[30] +#define UCreg_sp uregs[29] +#define UCreg_ip uregs[28] +#define UCreg_fp uregs[27] +#define UCreg_26 uregs[26] +#define UCreg_25 uregs[25] +#define UCreg_24 uregs[24] +#define UCreg_23 uregs[23] +#define UCreg_22 uregs[22] +#define UCreg_21 uregs[21] +#define UCreg_20 uregs[20] +#define UCreg_19 uregs[19] +#define UCreg_18 uregs[18] +#define UCreg_17 uregs[17] +#define UCreg_16 uregs[16] +#define UCreg_15 uregs[15] +#define UCreg_14 uregs[14] +#define UCreg_13 uregs[13] +#define UCreg_12 uregs[12] +#define UCreg_11 uregs[11] +#define UCreg_10 uregs[10] +#define UCreg_09 uregs[9] +#define UCreg_08 uregs[8] +#define UCreg_07 uregs[7] +#define UCreg_06 uregs[6] +#define UCreg_05 uregs[5] +#define UCreg_04 uregs[4] +#define UCreg_03 uregs[3] +#define UCreg_02 uregs[2] +#define UCreg_01 uregs[1] +#define UCreg_00 uregs[0] +#define UCreg_ORIG_00 uregs[33] + +#ifdef __KERNEL__ + +#define arch_has_single_step() (1) + +#define user_mode(regs) \ + (processor_mode(regs) == USER_MODE) + +#define processor_mode(regs) \ + ((regs)->UCreg_asr & MODE_MASK) + +#define interrupts_enabled(regs) \ + (!((regs)->UCreg_asr & PSR_I_BIT)) + +#define fast_interrupts_enabled(regs) \ + (!((regs)->UCreg_asr & PSR_R_BIT)) + +/* Are the current registers suitable for user mode? + * (used to maintain security in signal handlers) + */ +static inline int valid_user_regs(struct pt_regs *regs) +{ + unsigned long mode = regs->UCreg_asr & MODE_MASK; + + /* + * Always clear the R (REAL) bits + */ + regs->UCreg_asr &= ~(PSR_R_BIT); + + if ((regs->UCreg_asr & PSR_I_BIT) == 0) { + if (mode == USER_MODE) + return 1; + } + + /* + * Force ASR to something logical... + */ + regs->UCreg_asr &= PSR_f | USER_MODE; + + return 0; +} + +#define instruction_pointer(regs) ((regs)->UCreg_pc) + +#define profile_pc(regs) instruction_pointer(regs) + +#define predicate(x) ((x) & 0xf0000000) +#define PREDICATE_ALWAYS 0xe0000000 + +/* + * kprobe-based event tracer support + */ +#include <linux/stddef.h> +#include <linux/types.h> +#define MAX_REG_OFFSET (offsetof(struct pt_regs, UCreg_ORIG_00)) + +extern int regs_query_register_offset(const char *name); +extern const char *regs_query_register_name(unsigned int offset); +extern bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr); +extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, + unsigned int n); + +/** + * regs_get_register() - get register value from its offset + * @regs: pt_regs from which register value is gotten + * @offset: offset number of the register. + * + * regs_get_register returns the value of a register whose offset from @regs. + * The @offset is the offset of the register in struct pt_regs. + * If @offset is bigger than MAX_REG_OFFSET, this returns 0. + */ +static inline unsigned long regs_get_register(struct pt_regs *regs, + unsigned int offset) +{ + if (unlikely(offset > MAX_REG_OFFSET)) + return 0; + return *(unsigned long *)((unsigned long)regs + offset); +} + +/* Valid only for Kernel mode traps. */ +static inline unsigned long kernel_stack_pointer(struct pt_regs *regs) +{ + return regs->UCreg_sp; +} + +#endif /* __KERNEL__ */ + +#endif /* __ASSEMBLY__ */ + +#endif + diff --git a/arch/unicore32/kernel/ptrace.c b/arch/unicore32/kernel/ptrace.c new file mode 100644 index 0000000..53a9b63 --- /dev/null +++ b/arch/unicore32/kernel/ptrace.c @@ -0,0 +1,600 @@ +/* + * linux/arch/unicore32/kernel/ptrace.c + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * 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. + */ +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/smp.h> +#include <linux/ptrace.h> +#include <linux/security.h> +#include <linux/init.h> +#include <linux/signal.h> +#include <linux/uaccess.h> + +#include <asm/pgtable.h> +#include <asm/system.h> +#include <asm/traps.h> + +#include "ptrace.h" + +#define REG_PC 31 +#define REG_PSR 32 +/* + * does not yet catch signals sent when the child dies. + * in exit.c or in signal.c. + */ + +#if 0 +/* + * Breakpoint SWI instruction: SWI &9F0001 + */ +#define BREAKINST_UNICORE 0xff9f0001 +#else +/* + * New breakpoints - use an extended instruction. The UniCore architecture + * reference manual guarantees that the following instruction space + * will produce an extended instruction exception on all CPUs: + * + * 100x xxxx xxxx xxxx xxxx xxx1 xxxx xxxx + */ +#define BREAKINST_UNICORE 0x800001f1 +#endif + +/* + * this routine will get a word off of the processes privileged stack. + * the offset is how far from the base addr as stored in the THREAD. + * this routine assumes that all the privileged stacks are in our + * data space. + */ +static inline long get_user_reg(struct task_struct *task, int offset) +{ + return task_pt_regs(task)->uregs[offset]; +} + +/* + * this routine will put a word on the processes privileged stack. + * the offset is how far from the base addr as stored in the THREAD. + * this routine assumes that all the privileged stacks are in our + * data space. + */ +static inline int +put_user_reg(struct task_struct *task, int offset, long data) +{ + struct pt_regs newregs, *regs = task_pt_regs(task); + int ret = -EINVAL; + + newregs = *regs; + newregs.uregs[offset] = data; + + if (valid_user_regs(&newregs)) { + regs->uregs[offset] = data; + ret = 0; + } + + return ret; +} + +static inline int +read_u32(struct task_struct *task, unsigned long addr, u32 *res) +{ + int ret; + + ret = access_process_vm(task, addr, res, sizeof(*res), 0); + + return ret == sizeof(*res) ? 0 : -EIO; +} + +static inline int +read_instr(struct task_struct *task, unsigned long addr, u32 *res) +{ + int ret; + + if (addr & 1) { + u16 val; + ret = access_process_vm(task, addr & ~1, &val, sizeof(val), 0); + ret = ret == sizeof(val) ? 0 : -EIO; + *res = val; + } else { + u32 val; + ret = access_process_vm(task, addr & ~3, &val, sizeof(val), 0); + ret = ret == sizeof(val) ? 0 : -EIO; + *res = val; + } + return ret; +} + +/* + * Get value of register `rn' (in the instruction) + */ +static unsigned long +ptrace_getrn(struct task_struct *child, unsigned long insn) +{ + unsigned int reg = (insn >> 16) & 15; + unsigned long val; + + val = get_user_reg(child, reg); + if (reg == 15) + val += 8; + + return val; +} + +/* + * Get value of operand 2 (in an ALU instruction) + */ +static unsigned long +ptrace_getaluop2(struct task_struct *child, unsigned long insn) +{ + unsigned long val; + int shift; + int type; + + if (insn & 1 << 25) { + val = insn & 255; + shift = (insn >> 8) & 15; + type = 3; + } else { + val = get_user_reg(child, insn & 15); + + if (insn & (1 << 4)) + shift = (int)get_user_reg(child, (insn >> 8) & 15); + else + shift = (insn >> 7) & 31; + + type = (insn >> 5) & 3; + } + + switch (type) { + case 0: + val <<= shift; + break; + case 1: + val >>= shift; + break; + case 2: + val = (((signed long)val) >> shift); + break; + case 3: + val = (val >> shift) | (val << (32 - shift)); + break; + } + return val; +} + +/* + * Get value of operand 2 (in a LDR instruction) + */ +static unsigned long +ptrace_getldrop2(struct task_struct *child, unsigned long insn) +{ + unsigned long val; + int shift; + int type; + + val = get_user_reg(child, insn & 15); + shift = (insn >> 7) & 31; + type = (insn >> 5) & 3; + + switch (type) { + case 0: + val <<= shift; + break; + case 1: + val >>= shift; + break; + case 2: + val = (((signed long)val) >> shift); + break; + case 3: + val = (val >> shift) | (val << (32 - shift)); + break; + } + return val; +} + +#define OP_MASK 0x01e00000 +#define OP_AND 0x00000000 +#define OP_EOR 0x00200000 +#define OP_SUB 0x00400000 +#define OP_RSB 0x00600000 +#define OP_ADD 0x00800000 +#define OP_ADC 0x00a00000 +#define OP_SBC 0x00c00000 +#define OP_RSC 0x00e00000 +#define OP_ORR 0x01800000 +#define OP_MOV 0x01a00000 +#define OP_BIC 0x01c00000 +#define OP_MVN 0x01e00000 + +static unsigned long +get_branch_address(struct task_struct *child, + unsigned long pc, unsigned long insn) +{ + u32 alt = 0; + + switch (insn & 0x0e000000) { + case 0x00000000: + case 0x02000000: { + /* + * data processing + */ + long aluop1, aluop2, ccbit; + + if ((insn & 0x0fffffd0) == 0x012fff10) { + /* + * bx or blx + */ + alt = get_user_reg(child, insn & 15); + break; + } + + + if ((insn & 0xf000) != 0xf000) + break; + + aluop1 = ptrace_getrn(child, insn); + aluop2 = ptrace_getaluop2(child, insn); + ccbit = get_user_reg(child, REG_PSR) & PSR_C_BIT ? 1 : 0; + + switch (insn & OP_MASK) { + case OP_AND: + alt = aluop1 & aluop2; + break; + case OP_EOR: + alt = aluop1 ^ aluop2; + break; + case OP_SUB: + alt = aluop1 - aluop2; + break; + case OP_RSB: + alt = aluop2 - aluop1; + break; + case OP_ADD: + alt = aluop1 + aluop2; + break; + case OP_ADC: + alt = aluop1 + aluop2 + ccbit; + break; + case OP_SBC: + alt = aluop1 - aluop2 + ccbit; + break; + case OP_RSC: + alt = aluop2 - aluop1 + ccbit; + break; + case OP_ORR: + alt = aluop1 | aluop2; + break; + case OP_MOV: + alt = aluop2; + break; + case OP_BIC: + alt = aluop1 & ~aluop2; + break; + case OP_MVN: + alt = ~aluop2; + break; + } + break; + } + + case 0x04000000: + case 0x06000000: + /* + * ldr + */ + if ((insn & 0x0010f000) == 0x0010f000) { + unsigned long base; + + base = ptrace_getrn(child, insn); + if (insn & 1 << 24) { + long aluop2; + + if (insn & 0x02000000) + aluop2 = ptrace_getldrop2(child, insn); + else + aluop2 = insn & 0xfff; + + if (insn & 1 << 23) + base += aluop2; + else + base -= aluop2; + } + read_u32(child, base, &alt); + } + break; + + case 0x08000000: + /* + * ldm + */ + if ((insn & 0x00108000) == 0x00108000) { + unsigned long base; + unsigned int nr_regs; + + if (insn & (1 << 23)) { + nr_regs = hweight16(insn & 65535) << 2; + + if (!(insn & (1 << 24))) + nr_regs -= 4; + } else { + if (insn & (1 << 24)) + nr_regs = -4; + else + nr_regs = 0; + } + + base = ptrace_getrn(child, insn); + + read_u32(child, base + nr_regs, &alt); + break; + } + break; + + case 0x0a000000: { + /* + * bl or b + */ + signed long displ; + /* It's a branch/branch link: instead of trying to + * figure out whether the branch will be taken or not, + * we'll put a breakpoint at both locations. This is + * simpler, more reliable, and probably not a whole lot + * slower than the alternative approach of emulating the + * branch. + */ + displ = (insn & 0x00ffffff) << 8; + displ = (displ >> 6) + 8; + if (displ != 0 && displ != 4) + alt = pc + displ; + } + break; + } + + return alt; +} + +static int +swap_insn(struct task_struct *task, unsigned long addr, + void *old_insn, void *new_insn, int size) +{ + int ret; + + ret = access_process_vm(task, addr, old_insn, size, 0); + if (ret == size) + ret = access_process_vm(task, addr, new_insn, size, 1); + return ret; +} + +static void +add_breakpoint(struct task_struct *task, + struct debug_info *dbg, unsigned long addr) +{ + int nr = dbg->nsaved; + + if (nr < 2) { + u32 new_insn = BREAKINST_UNICORE; + int res; + + res = swap_insn(task, addr, &dbg->bp[nr].insn, &new_insn, 4); + + if (res == 4) { + dbg->bp[nr].address = addr; + dbg->nsaved += 1; + } + } else + printk(KERN_ERR "ptrace: too many breakpoints\n"); +} + +/* + * Clear one breakpoint in the user program. + */ +static void clear_breakpoint(struct task_struct *task, struct debug_entry *bp) +{ + unsigned long addr = bp->address; + u32 old_insn; + int ret; + + ret = swap_insn(task, addr & ~3, &old_insn, + &bp->insn, 4); + + if (ret != 4 || old_insn != BREAKINST_UNICORE) + printk(KERN_ERR "%s:%d: corrupted UniCore breakpoint at " + "0x%08lx (0x%08x)\n", task->comm, + task_pid_nr(task), addr, old_insn); +} + +void ptrace_set_bpt(struct task_struct *child) +{ + struct pt_regs *regs; + unsigned long pc; + u32 insn; + int res; + + regs = task_pt_regs(child); + pc = instruction_pointer(regs); + + res = read_instr(child, pc, &insn); + if (!res) { + struct debug_info *dbg = &child->thread.debug; + unsigned long alt; + + dbg->nsaved = 0; + + alt = get_branch_address(child, pc, insn); + if (alt) + add_breakpoint(child, dbg, alt); + + /* + * Note that we ignore the result of setting the above + * breakpoint since it may fail. When it does, this is + * not so much an error, but a forewarning that we may + * be receiving a prefetch abort shortly. + * + * If we don't set this breakpoint here, then we can + * lose control of the thread during single stepping. + */ + if (!alt || predicate(insn) != PREDICATE_ALWAYS) + add_breakpoint(child, dbg, pc + 4); + } +} + +/* + * Ensure no single-step breakpoint is pending. Returns non-zero + * value if child was being single-stepped. + */ +void ptrace_cancel_bpt(struct task_struct *child) +{ + int i, nsaved = child->thread.debug.nsaved; + + child->thread.debug.nsaved = 0; + + if (nsaved > 2) { + printk("ptrace_cancel_bpt: bogus nsaved: %d!\n", nsaved); + nsaved = 2; + } + + for (i = 0; i < nsaved; i++) + clear_breakpoint(child, &child->thread.debug.bp[i]); +} + +void user_disable_single_step(struct task_struct *task) +{ + task->ptrace &= ~PT_SINGLESTEP; + ptrace_cancel_bpt(task); +} + +void user_enable_single_step(struct task_struct *task) +{ + task->ptrace |= PT_SINGLESTEP; +} + +/* + * Called by kernel/ptrace.c when detaching.. + */ +void ptrace_disable(struct task_struct *child) +{ + user_disable_single_step(child); +} + +/* + * Handle hitting a breakpoint. + */ +void ptrace_break(struct task_struct *tsk, struct pt_regs *regs) +{ + siginfo_t info; + + ptrace_cancel_bpt(tsk); + + info.si_signo = SIGTRAP; + info.si_errno = 0; + info.si_code = TRAP_BRKPT; + info.si_addr = (void __user *)instruction_pointer(regs); + + force_sig_info(SIGTRAP, &info, tsk); +} + +static int __init ptrace_break_init(void) +{ + return 0; +} + +core_initcall(ptrace_break_init); + +/* + * We actually access the pt_regs stored on the kernel stack. + */ +static int ptrace_read_user(struct task_struct *tsk, unsigned long off, + unsigned long __user *ret) +{ + unsigned long tmp; + + tmp = 0; + if (off < sizeof(struct pt_regs)) + tmp = get_user_reg(tsk, off >> 2); + + return put_user(tmp, ret); +} + +/* + * We actually access the pt_regs stored on the kernel stack. + */ +static int ptrace_write_user(struct task_struct *tsk, unsigned long off, + unsigned long val) +{ + if (off >= sizeof(struct pt_regs)) + return 0; + + return put_user_reg(tsk, off >> 2, val); +} + +long arch_ptrace(struct task_struct *child, long request, + unsigned long addr, unsigned long data) +{ + int ret; + unsigned long __user *datap = (unsigned long __user *) data; + + switch (request) { + case PTRACE_PEEKUSR: + ret = ptrace_read_user(child, addr, datap); + break; + + case PTRACE_POKEUSR: + ret = ptrace_write_user(child, addr, data); + break; + + case PTRACE_GET_THREAD_AREA: + ret = put_user(task_pt_regs(child)->UCreg_16, + datap); + break; + + default: + ret = ptrace_request(child, request, addr, data); + break; + } + + return ret; +} + +asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno) +{ + unsigned long ip; + + if (!test_thread_flag(TIF_SYSCALL_TRACE)) + return scno; + if (!(current->ptrace & PT_PTRACED)) + return scno; + + /* + * Save IP. IP is used to denote syscall entry/exit: + * IP = 0 -> entry, = 1 -> exit + */ + ip = regs->UCreg_ip; + regs->UCreg_ip = why; + + current_thread_info()->syscall = scno; + + /* the 0x80 provides a way for the tracing parent to distinguish + between a syscall stop and SIGTRAP delivery */ + ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) + ? 0x80 : 0)); + /* + * this isn't the same as continuing with a signal, but it will do + * for normal use. strace only continues with a signal if the + * stopping signal is not SIGTRAP. -brl + */ + if (current->exit_code) { + send_sig(current->exit_code, current, 1); + current->exit_code = 0; + } + regs->UCreg_ip = ip; + + return current_thread_info()->syscall; +} diff --git a/arch/unicore32/kernel/ptrace.h b/arch/unicore32/kernel/ptrace.h new file mode 100644 index 0000000..bfea983 --- /dev/null +++ b/arch/unicore32/kernel/ptrace.h @@ -0,0 +1,53 @@ +/* + * linux/arch/unicore32/kernel/ptrace.h + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * 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. + */ +#include <linux/ptrace.h> + +extern void ptrace_cancel_bpt(struct task_struct *); +extern void ptrace_set_bpt(struct task_struct *); +extern void ptrace_break(struct task_struct *, struct pt_regs *); + +/* + * make sure single-step breakpoint is gone. + */ +static inline void single_step_disable(struct task_struct *task) +{ + task->ptrace &= ~PT_SINGLESTEP; + ptrace_cancel_bpt(task); +} + +static inline void single_step_enable(struct task_struct *task) +{ + task->ptrace |= PT_SINGLESTEP; +} + +/* + * Send SIGTRAP if we're single-stepping + */ +static inline void single_step_trap(struct task_struct *task) +{ + if (task->ptrace & PT_SINGLESTEP) { + ptrace_cancel_bpt(task); + send_sig(SIGTRAP, task, 1); + } +} + +static inline void single_step_clear(struct task_struct *task) +{ + if (task->ptrace & PT_SINGLESTEP) + ptrace_cancel_bpt(task); +} + +static inline void single_step_set(struct task_struct *task) +{ + if (task->ptrace & PT_SINGLESTEP) + ptrace_set_bpt(task); +} -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html