/* * File: arch/blackfin/kernel/ptrace.c * Based on: Taken from linux/kernel/ptrace.c * Author: linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds * * Created: 1/23/92 * Description: * * Modified: * Copyright 2004-2006 Analog Devices Inc. * * Bugs: Enter bugs at http://blackfin.uclinux.org/ * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see the file COPYING, or write * to the Free Software Foundation, Inc., * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define MAX_SHARED_LIBS 3 #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 = get_user_regs(tsk); return copy_to_user(uregs, regs, 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_list_struct *vml; struct sram_list_struct *sraml; for (vml = child->mm->context.vmlist; vml; vml = vml->next) if (start >= vml->vma->vm_start && start + len <= vml->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; } /* * 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_SR) & ~(TRACE_BITS << 16); put_reg(child, PT_SR, tmp); } long arch_ptrace(struct task_struct *child, long request, long addr, long data) { int ret; int add = 0; switch (request) { /* when I and D space are separate, these will need to be fixed. */ case PTRACE_PEEKDATA: pr_debug("ptrace: PEEKDATA\n"); add = MAX_SHARED_LIBS * 4; /* space between text and data */ /* fall through */ case PTRACE_PEEKTEXT: /* read word at location addr. */ { unsigned long tmp = 0; int copied; ret = -EIO; pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + add %d %ld\n", addr, add, sizeof(data)); if (is_user_addr_valid(child, addr + add, sizeof(tmp)) < 0) break; pr_debug("ptrace: user address is valid\n"); #if L1_CODE_LENGTH != 0 if (addr + add >= L1_CODE_START && addr + add + sizeof(tmp) <= L1_CODE_START + L1_CODE_LENGTH) { safe_dma_memcpy (&tmp, (const void *)(addr + add), sizeof(tmp)); copied = sizeof(tmp); } else #endif if (addr + add >= FIXED_CODE_START && addr + add + sizeof(tmp) <= FIXED_CODE_END) { memcpy(&tmp, (const void *)(addr + add), sizeof(tmp)); copied = sizeof(tmp); } else copied = access_process_vm(child, addr + add, &tmp, sizeof(tmp), 0); pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp); if (copied != sizeof(tmp)) break; ret = put_user(tmp, (unsigned long *)data); 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)) { tmp = child->mm->context.exec_fdpic_loadmap; } else if (addr == (sizeof(struct pt_regs) + 16)) { tmp = child->mm->context.interp_fdpic_loadmap; #endif } else { tmp = get_reg(child, addr); } ret = put_user(tmp, (unsigned long *)data); break; } /* when I and D space are separate, this will have to be fixed. */ case PTRACE_POKEDATA: printk(KERN_NOTICE "ptrace: PTRACE_PEEKDATA\n"); /* fall through */ case PTRACE_POKETEXT: /* write the word at location addr. */ { int copied; ret = -EIO; pr_debug("ptrace: POKETEXT at addr 0x%08lx + add %d %ld bytes %lx\n", addr, add, sizeof(data), data); if (is_user_addr_valid(child, addr + add, sizeof(data)) < 0) break; pr_debug("ptrace: user address is valid\n"); #if L1_CODE_LENGTH != 0 if (addr + add >= L1_CODE_START && addr + add + sizeof(data) <= L1_CODE_START + L1_CODE_LENGTH) { safe_dma_memcpy ((void *)(addr + add), &data, sizeof(data)); copied = sizeof(data); } else #endif if (addr + add >= FIXED_CODE_START && addr + add + sizeof(data) <= FIXED_CODE_END) { memcpy((void *)(addr + add), &data, sizeof(data)); copied = sizeof(data); } else copied = access_process_vm(child, addr + add, &data, sizeof(data), 1); pr_debug("ptrace: copied size %d\n", copied); if (copied != sizeof(data)) break; 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. */ long tmp; pr_debug("ptrace_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; /* make sure the single step bit is not set. */ tmp = get_reg(child, PT_SYSCFG) & ~(TRACE_BITS); put_reg(child, PT_SYSCFG, tmp); pr_debug("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: { long tmp; ret = 0; if (child->exit_state == EXIT_ZOMBIE) /* already dead */ break; child->exit_code = SIGKILL; /* make sure the single step bit is not set. */ tmp = get_reg(child, PT_SYSCFG) & ~(TRACE_BITS); put_reg(child, PT_SYSCFG, tmp); wake_up_process(child); break; } case PTRACE_SINGLESTEP: { /* set the trap flag. */ long tmp; pr_debug("single step\n"); ret = -EIO; if (!valid_signal(data)) break; clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); tmp = get_reg(child, PT_SYSCFG) | (TRACE_BITS); put_reg(child, PT_SYSCFG, tmp); child->exit_code = data; /* give it a chance to run. */ wake_up_process(child); ret = 0; break; } case PTRACE_DETACH: { /* detach a process that was attached. */ ret = ptrace_detach(child, data); break; } case PTRACE_GETREGS: { /* Get all gp regs from the child. */ ret = ptrace_getregs(child, (void __user *)data); break; } case PTRACE_SETREGS: { printk(KERN_NOTICE "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; } }