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338 lines
9.0 KiB
338 lines
9.0 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* ptrace.c */ |
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/* By Ross Biro 1/23/92 */ |
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/* edited by Linus Torvalds */ |
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/* mangled further by Bob Manson ([email protected]) */ |
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/* more mutilation by David Mosberger ([email protected]) */ |
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#include <linux/kernel.h> |
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#include <linux/sched.h> |
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#include <linux/sched/task_stack.h> |
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#include <linux/mm.h> |
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#include <linux/smp.h> |
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#include <linux/errno.h> |
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#include <linux/ptrace.h> |
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#include <linux/user.h> |
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#include <linux/security.h> |
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#include <linux/signal.h> |
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#include <linux/tracehook.h> |
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#include <linux/audit.h> |
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#include <linux/uaccess.h> |
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#include <asm/fpu.h> |
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#include "proto.h" |
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#define DEBUG DBG_MEM |
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#undef DEBUG |
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#ifdef DEBUG |
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enum { |
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DBG_MEM = (1<<0), |
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DBG_BPT = (1<<1), |
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DBG_MEM_ALL = (1<<2) |
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}; |
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#define DBG(fac,args) {if ((fac) & DEBUG) printk args;} |
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#else |
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#define DBG(fac,args) |
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#endif |
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#define BREAKINST 0x00000080 /* call_pal bpt */ |
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/* |
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* does not yet catch signals sent when the child dies. |
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* in exit.c or in signal.c. |
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*/ |
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/* |
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* Processes always block with the following stack-layout: |
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* |
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* +================================+ <---- task + 2*PAGE_SIZE |
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* | PALcode saved frame (ps, pc, | ^ |
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* | gp, a0, a1, a2) | | |
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* +================================+ | struct pt_regs |
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* | | | |
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* | frame generated by SAVE_ALL | | |
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* | | v |
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* +================================+ |
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* | | ^ |
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* | frame saved by do_switch_stack | | struct switch_stack |
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* | | v |
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* +================================+ |
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*/ |
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/* |
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* The following table maps a register index into the stack offset at |
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* which the register is saved. Register indices are 0-31 for integer |
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* regs, 32-63 for fp regs, and 64 for the pc. Notice that sp and |
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* zero have no stack-slot and need to be treated specially (see |
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* get_reg/put_reg below). |
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*/ |
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enum { |
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REG_R0 = 0, REG_F0 = 32, REG_FPCR = 63, REG_PC = 64 |
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}; |
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#define PT_REG(reg) \ |
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(PAGE_SIZE*2 - sizeof(struct pt_regs) + offsetof(struct pt_regs, reg)) |
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#define SW_REG(reg) \ |
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(PAGE_SIZE*2 - sizeof(struct pt_regs) - sizeof(struct switch_stack) \ |
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+ offsetof(struct switch_stack, reg)) |
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static int regoff[] = { |
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PT_REG( r0), PT_REG( r1), PT_REG( r2), PT_REG( r3), |
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PT_REG( r4), PT_REG( r5), PT_REG( r6), PT_REG( r7), |
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PT_REG( r8), SW_REG( r9), SW_REG( r10), SW_REG( r11), |
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SW_REG( r12), SW_REG( r13), SW_REG( r14), SW_REG( r15), |
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PT_REG( r16), PT_REG( r17), PT_REG( r18), PT_REG( r19), |
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PT_REG( r20), PT_REG( r21), PT_REG( r22), PT_REG( r23), |
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PT_REG( r24), PT_REG( r25), PT_REG( r26), PT_REG( r27), |
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PT_REG( r28), PT_REG( gp), -1, -1, |
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SW_REG(fp[ 0]), SW_REG(fp[ 1]), SW_REG(fp[ 2]), SW_REG(fp[ 3]), |
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SW_REG(fp[ 4]), SW_REG(fp[ 5]), SW_REG(fp[ 6]), SW_REG(fp[ 7]), |
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SW_REG(fp[ 8]), SW_REG(fp[ 9]), SW_REG(fp[10]), SW_REG(fp[11]), |
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SW_REG(fp[12]), SW_REG(fp[13]), SW_REG(fp[14]), SW_REG(fp[15]), |
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SW_REG(fp[16]), SW_REG(fp[17]), SW_REG(fp[18]), SW_REG(fp[19]), |
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SW_REG(fp[20]), SW_REG(fp[21]), SW_REG(fp[22]), SW_REG(fp[23]), |
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SW_REG(fp[24]), SW_REG(fp[25]), SW_REG(fp[26]), SW_REG(fp[27]), |
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SW_REG(fp[28]), SW_REG(fp[29]), SW_REG(fp[30]), SW_REG(fp[31]), |
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PT_REG( pc) |
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}; |
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static unsigned long zero; |
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/* |
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* Get address of register REGNO in task TASK. |
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*/ |
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static unsigned long * |
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get_reg_addr(struct task_struct * task, unsigned long regno) |
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{ |
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unsigned long *addr; |
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if (regno == 30) { |
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addr = &task_thread_info(task)->pcb.usp; |
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} else if (regno == 65) { |
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addr = &task_thread_info(task)->pcb.unique; |
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} else if (regno == 31 || regno > 65) { |
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zero = 0; |
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addr = &zero; |
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} else { |
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addr = task_stack_page(task) + regoff[regno]; |
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} |
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return addr; |
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} |
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/* |
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* Get contents of register REGNO in task TASK. |
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*/ |
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static unsigned long |
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get_reg(struct task_struct * task, unsigned long regno) |
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{ |
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/* Special hack for fpcr -- combine hardware and software bits. */ |
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if (regno == 63) { |
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unsigned long fpcr = *get_reg_addr(task, regno); |
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unsigned long swcr |
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= task_thread_info(task)->ieee_state & IEEE_SW_MASK; |
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swcr = swcr_update_status(swcr, fpcr); |
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return fpcr | swcr; |
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} |
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return *get_reg_addr(task, regno); |
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} |
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/* |
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* Write contents of register REGNO in task TASK. |
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*/ |
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static int |
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put_reg(struct task_struct *task, unsigned long regno, unsigned long data) |
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{ |
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if (regno == 63) { |
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task_thread_info(task)->ieee_state |
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= ((task_thread_info(task)->ieee_state & ~IEEE_SW_MASK) |
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| (data & IEEE_SW_MASK)); |
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data = (data & FPCR_DYN_MASK) | ieee_swcr_to_fpcr(data); |
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} |
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*get_reg_addr(task, regno) = data; |
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return 0; |
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} |
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static inline int |
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read_int(struct task_struct *task, unsigned long addr, int * data) |
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{ |
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int copied = access_process_vm(task, addr, data, sizeof(int), |
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FOLL_FORCE); |
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return (copied == sizeof(int)) ? 0 : -EIO; |
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} |
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static inline int |
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write_int(struct task_struct *task, unsigned long addr, int data) |
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{ |
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int copied = access_process_vm(task, addr, &data, sizeof(int), |
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FOLL_FORCE | FOLL_WRITE); |
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return (copied == sizeof(int)) ? 0 : -EIO; |
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} |
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/* |
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* Set breakpoint. |
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*/ |
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int |
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ptrace_set_bpt(struct task_struct * child) |
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{ |
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int displ, i, res, reg_b, nsaved = 0; |
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unsigned int insn, op_code; |
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unsigned long pc; |
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pc = get_reg(child, REG_PC); |
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res = read_int(child, pc, (int *) &insn); |
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if (res < 0) |
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return res; |
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op_code = insn >> 26; |
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if (op_code >= 0x30) { |
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/* |
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* It's a branch: instead of trying to figure out |
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* whether the branch will be taken or not, we'll put |
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* a breakpoint at either location. This is simpler, |
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* more reliable, and probably not a whole lot slower |
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* than the alternative approach of emulating the |
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* branch (emulation can be tricky for fp branches). |
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*/ |
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displ = ((s32)(insn << 11)) >> 9; |
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task_thread_info(child)->bpt_addr[nsaved++] = pc + 4; |
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if (displ) /* guard against unoptimized code */ |
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task_thread_info(child)->bpt_addr[nsaved++] |
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= pc + 4 + displ; |
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DBG(DBG_BPT, ("execing branch\n")); |
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} else if (op_code == 0x1a) { |
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reg_b = (insn >> 16) & 0x1f; |
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task_thread_info(child)->bpt_addr[nsaved++] = get_reg(child, reg_b); |
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DBG(DBG_BPT, ("execing jump\n")); |
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} else { |
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task_thread_info(child)->bpt_addr[nsaved++] = pc + 4; |
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DBG(DBG_BPT, ("execing normal insn\n")); |
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} |
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/* install breakpoints: */ |
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for (i = 0; i < nsaved; ++i) { |
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res = read_int(child, task_thread_info(child)->bpt_addr[i], |
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(int *) &insn); |
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if (res < 0) |
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return res; |
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task_thread_info(child)->bpt_insn[i] = insn; |
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DBG(DBG_BPT, (" -> next_pc=%lx\n", |
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task_thread_info(child)->bpt_addr[i])); |
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res = write_int(child, task_thread_info(child)->bpt_addr[i], |
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BREAKINST); |
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if (res < 0) |
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return res; |
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} |
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task_thread_info(child)->bpt_nsaved = nsaved; |
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return 0; |
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} |
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/* |
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* Ensure no single-step breakpoint is pending. Returns non-zero |
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* value if child was being single-stepped. |
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*/ |
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int |
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ptrace_cancel_bpt(struct task_struct * child) |
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{ |
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int i, nsaved = task_thread_info(child)->bpt_nsaved; |
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task_thread_info(child)->bpt_nsaved = 0; |
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if (nsaved > 2) { |
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printk("ptrace_cancel_bpt: bogus nsaved: %d!\n", nsaved); |
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nsaved = 2; |
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} |
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for (i = 0; i < nsaved; ++i) { |
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write_int(child, task_thread_info(child)->bpt_addr[i], |
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task_thread_info(child)->bpt_insn[i]); |
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} |
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return (nsaved != 0); |
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} |
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void user_enable_single_step(struct task_struct *child) |
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{ |
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/* Mark single stepping. */ |
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task_thread_info(child)->bpt_nsaved = -1; |
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} |
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void user_disable_single_step(struct task_struct *child) |
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{ |
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ptrace_cancel_bpt(child); |
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} |
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/* |
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* Called by kernel/ptrace.c when detaching.. |
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* |
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* Make sure the single step bit is not set. |
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*/ |
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void ptrace_disable(struct task_struct *child) |
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{ |
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user_disable_single_step(child); |
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} |
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long arch_ptrace(struct task_struct *child, long request, |
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unsigned long addr, unsigned long data) |
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{ |
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unsigned long tmp; |
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size_t copied; |
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long ret; |
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switch (request) { |
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/* When I and D space are separate, these will need to be fixed. */ |
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case PTRACE_PEEKTEXT: /* read word at location addr. */ |
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case PTRACE_PEEKDATA: |
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copied = ptrace_access_vm(child, addr, &tmp, sizeof(tmp), |
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FOLL_FORCE); |
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ret = -EIO; |
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if (copied != sizeof(tmp)) |
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break; |
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force_successful_syscall_return(); |
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ret = tmp; |
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break; |
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/* Read register number ADDR. */ |
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case PTRACE_PEEKUSR: |
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force_successful_syscall_return(); |
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ret = get_reg(child, addr); |
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DBG(DBG_MEM, ("peek $%lu->%#lx\n", addr, ret)); |
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break; |
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/* When I and D space are separate, this will have to be fixed. */ |
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case PTRACE_POKETEXT: /* write the word at location addr. */ |
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case PTRACE_POKEDATA: |
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ret = generic_ptrace_pokedata(child, addr, data); |
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break; |
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case PTRACE_POKEUSR: /* write the specified register */ |
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DBG(DBG_MEM, ("poke $%lu<-%#lx\n", addr, data)); |
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ret = put_reg(child, addr, data); |
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break; |
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default: |
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ret = ptrace_request(child, request, addr, data); |
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break; |
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} |
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return ret; |
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} |
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asmlinkage unsigned long syscall_trace_enter(void) |
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{ |
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unsigned long ret = 0; |
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struct pt_regs *regs = current_pt_regs(); |
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if (test_thread_flag(TIF_SYSCALL_TRACE) && |
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tracehook_report_syscall_entry(current_pt_regs())) |
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ret = -1UL; |
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audit_syscall_entry(regs->r0, regs->r16, regs->r17, regs->r18, regs->r19); |
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return ret ?: current_pt_regs()->r0; |
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} |
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asmlinkage void |
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syscall_trace_leave(void) |
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{ |
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audit_syscall_exit(current_pt_regs()); |
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if (test_thread_flag(TIF_SYSCALL_TRACE)) |
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tracehook_report_syscall_exit(current_pt_regs(), 0); |
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}
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