+++ /dev/null
-/*
- * linux/arch/arm26/kernel/ptrace.c
- *
- * By Ross Biro 1/23/92
- * edited by Linus Torvalds
- * ARM modifications Copyright (C) 2000 Russell King
- *
- * 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/user.h>
-#include <linux/security.h>
-#include <linux/signal.h>
-
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-#include <asm/system.h>
-//#include <asm/processor.h>
-
-#include "ptrace.h"
-
-#define REG_PC 15
-#define REG_PSR 15
-/*
- * does not yet catch signals sent when the child dies.
- * in exit.c or in signal.c.
- */
-
-/*
- * Breakpoint SWI instruction: SWI &9F0001
- */
-#define BREAKINST_ARM 0xef9f0001
-
-/*
- * 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;
- 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 = pc_pointer(val + 8); //FIXME - correct for arm26?
-
- 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 & 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;
- }
- if (read_u32(child, base, &alt) == 0)
- alt = pc_pointer(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);
-
- if (read_u32(child, base + nr_regs, &alt) == 0)
- alt = pc_pointer(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_ARM;
- 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. We copy what the hardware
- * does and use bit 0 of the address to indicate whether this is a Thumb
- * breakpoint or an ARM breakpoint.
- */
-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_ARM)
- printk(KERN_ERR "%s:%d: corrupted ARM breakpoint at "
- "0x%08lx (0x%08x)\n", task->comm, task->pid,
- 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]);
-}
-
-/*
- * Called by kernel/ptrace.c when detaching..
- *
- * Make sure the single step bit is not set.
- */
-void ptrace_disable(struct task_struct *child)
-{
- child->ptrace &= ~PT_SINGLESTEP;
- ptrace_cancel_bpt(child);
-}
-
-/*
- * Handle hitting a breakpoint.
- */
-void ptrace_break(struct task_struct *tsk, struct pt_regs *regs)
-{
- siginfo_t info;
-
- /*
- * The PC is always left pointing at the next instruction. Fix this.
- */
- regs->ARM_pc -= 4;
-
- if (tsk->thread.debug.nsaved == 0)
- printk(KERN_ERR "ptrace: bogus breakpoint trap\n");
-
- ptrace_cancel_bpt(tsk);
-
- info.si_signo = SIGTRAP;
- info.si_errno = 0;
- info.si_code = TRAP_BRKPT;
- info.si_addr = (void *)instruction_pointer(regs) - 4;
-
- force_sig_info(SIGTRAP, &info, tsk);
-}
-
-/*
- * Read the word at offset "off" into the "struct user". 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 *ret)
-{
- unsigned long tmp;
-
- if (off & 3 || off >= sizeof(struct user))
- return -EIO;
-
- tmp = 0;
- if (off < sizeof(struct pt_regs))
- tmp = get_user_reg(tsk, off >> 2);
-
- return put_user(tmp, ret);
-}
-
-/*
- * Write the word at offset "off" into "struct user". 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 & 3 || off >= sizeof(struct user))
- return -EIO;
-
- if (off >= sizeof(struct pt_regs))
- return 0;
-
- return put_user_reg(tsk, off >> 2, val);
-}
-
-/*
- * Get all user integer registers.
- */
-static int ptrace_getregs(struct task_struct *tsk, void *uregs)
-{
- struct pt_regs *regs = task_pt_regs(tsk);
-
- return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
-}
-
-/*
- * Set all user integer registers.
- */
-static int ptrace_setregs(struct task_struct *tsk, void *uregs)
-{
- struct pt_regs newregs;
- int ret;
-
- ret = -EFAULT;
- if (copy_from_user(&newregs, uregs, sizeof(struct pt_regs)) == 0) {
- struct pt_regs *regs = task_pt_regs(tsk);
-
- ret = -EINVAL;
- if (valid_user_regs(&newregs)) {
- *regs = newregs;
- ret = 0;
- }
- }
-
- return ret;
-}
-
-/*
- * Get the child FPU state.
- */
-static int ptrace_getfpregs(struct task_struct *tsk, void *ufp)
-{
- return copy_to_user(ufp, &task_thread_info(tsk)->fpstate,
- sizeof(struct user_fp)) ? -EFAULT : 0;
-}
-
-/*
- * Set the child FPU state.
- */
-static int ptrace_setfpregs(struct task_struct *tsk, void *ufp)
-{
- set_stopped_child_used_math(tsk);
- return copy_from_user(&task_thread_info(tsk)->fpstate, ufp,
- sizeof(struct user_fp)) ? -EFAULT : 0;
-}
-
-long arch_ptrace(struct task_struct *child, long request, long addr, long data)
-{
- int ret;
-
- switch (request) {
- /*
- * read word at location "addr" in the child process.
- */
- case PTRACE_PEEKTEXT:
- case PTRACE_PEEKDATA:
- ret = generic_ptrace_peekdata(child, addr, data);
- break;
-
- case PTRACE_PEEKUSR:
- ret = ptrace_read_user(child, addr, (unsigned long *)data);
- break;
-
- /*
- * write the word at location addr.
- */
- case PTRACE_POKETEXT:
- case PTRACE_POKEDATA:
- ret = generic_ptrace_pokedata(child, addr, data);
- break;
-
- case PTRACE_POKEUSR:
- ret = ptrace_write_user(child, addr, data);
- break;
-
- /*
- * continue/restart and stop at next (return from) syscall
- */
- case PTRACE_SYSCALL:
- case PTRACE_CONT:
- ret = -EIO;
- if (!valid_signal(data))
- break;
- if (request == PTRACE_SYSCALL)
- set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- else
- clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- child->exit_code = data;
- /* make sure single-step breakpoint is gone. */
- child->ptrace &= ~PT_SINGLESTEP;
- ptrace_cancel_bpt(child);
- wake_up_process(child);
- ret = 0;
- break;
-
- /*
- * make the child exit. Best I can do is send it a sigkill.
- * perhaps it should be put in the status that it wants to
- * exit.
- */
- case PTRACE_KILL:
- /* make sure single-step breakpoint is gone. */
- child->ptrace &= ~PT_SINGLESTEP;
- ptrace_cancel_bpt(child);
- if (child->exit_state != EXIT_ZOMBIE) {
- child->exit_code = SIGKILL;
- wake_up_process(child);
- }
- ret = 0;
- break;
-
- /*
- * execute single instruction.
- */
- case PTRACE_SINGLESTEP:
- ret = -EIO;
- if (!valid_signal(data))
- break;
- child->ptrace |= PT_SINGLESTEP;
- clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- child->exit_code = data;
- /* give it a chance to run. */
- wake_up_process(child);
- ret = 0;
- break;
-
- case PTRACE_DETACH:
- ret = ptrace_detach(child, data);
- break;
-
- case PTRACE_GETREGS:
- ret = ptrace_getregs(child, (void *)data);
- break;
-
- case PTRACE_SETREGS:
- ret = ptrace_setregs(child, (void *)data);
- break;
-
- case PTRACE_GETFPREGS:
- ret = ptrace_getfpregs(child, (void *)data);
- break;
-
- case PTRACE_SETFPREGS:
- ret = ptrace_setfpregs(child, (void *)data);
- break;
-
- default:
- ret = ptrace_request(child, request, addr, data);
- break;
- }
-
- return ret;
-}
-
-asmlinkage void syscall_trace(int why, struct pt_regs *regs)
-{
- unsigned long ip;
-
- if (!test_thread_flag(TIF_SYSCALL_TRACE))
- return;
- if (!(current->ptrace & PT_PTRACED))
- return;
-
- /*
- * Save IP. IP is used to denote syscall entry/exit:
- * IP = 0 -> entry, = 1 -> exit
- */
- ip = regs->ARM_ip;
- regs->ARM_ip = why;
-
- /* 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->ARM_ip = ip;
-}
git.openpandora.org / pandora-kernel.git / blobdiff