/* * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds * these modifications are Copyright 2004-2009 Analog Devices Inc. * * Licensed under the GPL-2 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define TEXT_OFFSET 0 /* * does not yet catch signals sent when the child dies. * in exit.c or in signal.c. */ /* determines which bits in the SYSCFG reg the user has access to. */ /* 1 = access 0 = no access */ #define SYSCFG_MASK 0x0007 /* SYSCFG reg */ /* sets the trace bits. */ #define TRACE_BITS 0x0001 /* Find the stack offset for a register, relative to thread.esp0. */ #define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg) /* * Get the address of the live pt_regs for the specified task. * These are saved onto the top kernel stack when the process * is not running. * * Note: if a user thread is execve'd from kernel space, the * kernel stack will not be empty on entry to the kernel, so * ptracing these tasks will fail. */ static inline struct pt_regs *get_user_regs(struct task_struct *task) { return (struct pt_regs *) ((unsigned long)task_stack_page(task) + (THREAD_SIZE - sizeof(struct pt_regs))); } /* * Get all user integer registers. */ static inline int ptrace_getregs(struct task_struct *tsk, void __user *uregs) { struct pt_regs regs; memcpy(®s, get_user_regs(tsk), sizeof(regs)); regs.usp = tsk->thread.usp; return copy_to_user(uregs, ®s, sizeof(struct pt_regs)) ? -EFAULT : 0; } /* Mapping from PT_xxx to the stack offset at which the register is * saved. Notice that usp has no stack-slot and needs to be treated * specially (see get_reg/put_reg below). */ /* * Get contents of register REGNO in task TASK. */ static inline long get_reg(struct task_struct *task, int regno) { unsigned char *reg_ptr; struct pt_regs *regs = (struct pt_regs *)((unsigned long)task_stack_page(task) + (THREAD_SIZE - sizeof(struct pt_regs))); reg_ptr = (char *)regs; switch (regno) { case PT_USP: return task->thread.usp; default: if (regno <= 216) return *(long *)(reg_ptr + regno); } /* slight mystery ... never seems to come here but kernel misbehaves without this code! */ printk(KERN_WARNING "Request to get for unknown register %d\n", regno); return 0; } /* * Write contents of register REGNO in task TASK. */ static inline int put_reg(struct task_struct *task, int regno, unsigned long data) { char *reg_ptr; struct pt_regs *regs = (struct pt_regs *)((unsigned long)task_stack_page(task) + (THREAD_SIZE - sizeof(struct pt_regs))); reg_ptr = (char *)regs; switch (regno) { case PT_PC: /*********************************************************************/ /* At this point the kernel is most likely in exception. */ /* The RETX register will be used to populate the pc of the process. */ /*********************************************************************/ regs->retx = data; regs->pc = data; break; case PT_RETX: break; /* regs->retx = data; break; */ case PT_USP: regs->usp = data; task->thread.usp = data; break; default: if (regno <= 216) *(long *)(reg_ptr + regno) = data; } return 0; } /* * check that an address falls within the bounds of the target process's memory mappings */ static inline int is_user_addr_valid(struct task_struct *child, unsigned long start, unsigned long len) { struct vm_area_struct *vma; struct sram_list_struct *sraml; /* overflow */ if (start + len < start) return -EIO; vma = find_vma(child->mm, start); if (vma && start >= vma->vm_start && start + len <= vma->vm_end) return 0; for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next) if (start >= (unsigned long)sraml->addr && start + len < (unsigned long)sraml->addr + sraml->length) return 0; if (start >= FIXED_CODE_START && start + len < FIXED_CODE_END) return 0; return -EIO; } void ptrace_enable(struct task_struct *child) { unsigned long tmp; tmp = get_reg(child, PT_SYSCFG) | (TRACE_BITS); put_reg(child, PT_SYSCFG, tmp); } /* * Called by kernel/ptrace.c when detaching.. * * Make sure the single step bit is not set. */ void ptrace_disable(struct task_struct *child) { unsigned long tmp; /* make sure the single step bit is not set. */ tmp = get_reg(child, PT_SYSCFG) & ~TRACE_BITS; put_reg(child, PT_SYSCFG, tmp); } long arch_ptrace(struct task_struct *child, long request, long addr, long data) { int ret; unsigned long __user *datap = (unsigned long __user *)data; void *paddr = (void *)addr; switch (request) { /* when I and D space are separate, these will need to be fixed. */ case PTRACE_PEEKDATA: pr_debug("ptrace: PEEKDATA\n"); /* fall through */ case PTRACE_PEEKTEXT: /* read word at location addr. */ { unsigned long tmp = 0; int copied = 0, to_copy = sizeof(tmp); ret = -EIO; pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + %i\n", addr, to_copy); if (is_user_addr_valid(child, addr, to_copy) < 0) break; pr_debug("ptrace: user address is valid\n"); switch (bfin_mem_access_type(addr, to_copy)) { case BFIN_MEM_ACCESS_CORE: case BFIN_MEM_ACCESS_CORE_ONLY: copied = access_process_vm(child, addr, &tmp, to_copy, 0); if (copied) break; /* hrm, why didn't that work ... maybe no mapping */ if (addr >= FIXED_CODE_START && addr + to_copy <= FIXED_CODE_END) { copy_from_user_page(0, 0, 0, &tmp, paddr, to_copy); copied = to_copy; } else if (addr >= BOOT_ROM_START) { memcpy(&tmp, paddr, to_copy); copied = to_copy; } break; case BFIN_MEM_ACCESS_DMA: if (safe_dma_memcpy(&tmp, paddr, to_copy)) copied = to_copy; break; case BFIN_MEM_ACCESS_ITEST: if (isram_memcpy(&tmp, paddr, to_copy)) copied = to_copy; break; default: copied = 0; break; } pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp); if (copied == to_copy) ret = put_user(tmp, datap); break; } /* read the word at location addr in the USER area. */ case PTRACE_PEEKUSR: { unsigned long tmp; ret = -EIO; tmp = 0; if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) { printk(KERN_WARNING "ptrace error : PEEKUSR : temporarily returning " "0 - %x sizeof(pt_regs) is %lx\n", (int)addr, sizeof(struct pt_regs)); break; } if (addr == sizeof(struct pt_regs)) { /* PT_TEXT_ADDR */ tmp = child->mm->start_code + TEXT_OFFSET; } else if (addr == (sizeof(struct pt_regs) + 4)) { /* PT_TEXT_END_ADDR */ tmp = child->mm->end_code; } else if (addr == (sizeof(struct pt_regs) + 8)) { /* PT_DATA_ADDR */ tmp = child->mm->start_data; #ifdef CONFIG_BINFMT_ELF_FDPIC } else if (addr == (sizeof(struct pt_regs) + 12)) { goto case_PTRACE_GETFDPIC_EXEC; } else if (addr == (sizeof(struct pt_regs) + 16)) { goto case_PTRACE_GETFDPIC_INTERP; #endif } else { tmp = get_reg(child, addr); } ret = put_user(tmp, datap); break; } #ifdef CONFIG_BINFMT_ELF_FDPIC case PTRACE_GETFDPIC: { unsigned long tmp = 0; switch (addr) { case_PTRACE_GETFDPIC_EXEC: case PTRACE_GETFDPIC_EXEC: tmp = child->mm->context.exec_fdpic_loadmap; break; case_PTRACE_GETFDPIC_INTERP: case PTRACE_GETFDPIC_INTERP: tmp = child->mm->context.interp_fdpic_loadmap; break; default: break; } ret = put_user(tmp, datap); break; } #endif /* when I and D space are separate, this will have to be fixed. */ case PTRACE_POKEDATA: pr_debug("ptrace: PTRACE_PEEKDATA\n"); /* fall through */ case PTRACE_POKETEXT: /* write the word at location addr. */ { int copied = 0, to_copy = sizeof(data); ret = -EIO; pr_debug("ptrace: POKETEXT at addr 0x%08lx + %i bytes %lx\n", addr, to_copy, data); if (is_user_addr_valid(child, addr, to_copy) < 0) break; pr_debug("ptrace: user address is valid\n"); switch (bfin_mem_access_type(addr, to_copy)) { case BFIN_MEM_ACCESS_CORE: case BFIN_MEM_ACCESS_CORE_ONLY: copied = access_process_vm(child, addr, &data, to_copy, 0); if (copied) break; /* hrm, why didn't that work ... maybe no mapping */ if (addr >= FIXED_CODE_START && addr + to_copy <= FIXED_CODE_END) { copy_to_user_page(0, 0, 0, paddr, &data, to_copy); copied = to_copy; } else if (addr >= BOOT_ROM_START) { memcpy(paddr, &data, to_copy); copied = to_copy; } break; case BFIN_MEM_ACCESS_DMA: if (safe_dma_memcpy(paddr, &data, to_copy)) copied = to_copy; break; case BFIN_MEM_ACCESS_ITEST: if (isram_memcpy(paddr, &data, to_copy)) copied = to_copy; break; default: copied = 0; break; } pr_debug("ptrace: copied size %d\n", copied); if (copied == to_copy) ret = 0; break; } case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ ret = -EIO; if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) { printk(KERN_WARNING "ptrace error : POKEUSR: temporarily returning 0\n"); break; } if (addr >= (sizeof(struct pt_regs))) { ret = 0; break; } if (addr == PT_SYSCFG) { data &= SYSCFG_MASK; data |= get_reg(child, PT_SYSCFG); } ret = put_reg(child, addr, data); break; case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ case PTRACE_CONT: /* restart after signal. */ pr_debug("ptrace: syscall/cont\n"); 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; ptrace_disable(child); pr_debug("ptrace: before wake_up_process\n"); 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: ret = 0; if (child->exit_state == EXIT_ZOMBIE) /* already dead */ break; child->exit_code = SIGKILL; ptrace_disable(child); wake_up_process(child); break; case PTRACE_SINGLESTEP: /* set the trap flag. */ pr_debug("ptrace: single step\n"); ret = -EIO; if (!valid_signal(data)) break; clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); ptrace_enable(child); child->exit_code = data; wake_up_process(child); ret = 0; break; case PTRACE_GETREGS: /* Get all gp regs from the child. */ ret = ptrace_getregs(child, datap); break; case PTRACE_SETREGS: printk(KERN_WARNING "ptrace: SETREGS: **** NOT IMPLEMENTED ***\n"); /* Set all gp regs in the child. */ ret = 0; break; default: ret = ptrace_request(child, request, addr, data); break; } return ret; } asmlinkage void syscall_trace(void) { if (!test_thread_flag(TIF_SYSCALL_TRACE)) return; if (!(current->ptrace & PT_PTRACED)) return; /* 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; } }