diff options
Diffstat (limited to 'arch/arm/kernel/ptrace.c')
-rw-r--r-- | arch/arm/kernel/ptrace.c | 383 |
1 files changed, 1 insertions, 382 deletions
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index b13e70f..2bf27f3 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -26,8 +26,6 @@ #include <asm/system.h> #include <asm/traps.h> -#include "ptrace.h" - #define REG_PC 15 #define REG_PSR 16 /* @@ -184,389 +182,12 @@ put_user_reg(struct task_struct *task, int offset, long data) 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_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; - union debug_insn old_insn; - int ret; - - if (addr & 1) { - ret = swap_insn(task, addr & ~1, &old_insn.thumb, - &bp->insn.thumb, 2); - - if (ret != 2 || old_insn.thumb != BREAKINST_THUMB) - printk(KERN_ERR "%s:%d: corrupted Thumb breakpoint at " - "0x%08lx (0x%04x)\n", task->comm, - task_pid_nr(task), addr, old_insn.thumb); - } else { - ret = swap_insn(task, addr & ~3, &old_insn.arm, - &bp->insn.arm, 4); - - if (ret != 4 || old_insn.arm != BREAKINST_ARM) - printk(KERN_ERR "%s:%d: corrupted ARM breakpoint at " - "0x%08lx (0x%08x)\n", task->comm, - task_pid_nr(task), addr, old_insn.arm); - } -} - -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); - - if (thumb_mode(regs)) { - printk(KERN_WARNING "ptrace: can't handle thumb mode\n"); - return; - } - - 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); + /* Nothing to do. */ } /* @@ -576,8 +197,6 @@ 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; |