diff options
Diffstat (limited to 'arch/blackfin/kernel/ptrace.c')
| -rw-r--r-- | arch/blackfin/kernel/ptrace.c | 430 |
1 files changed, 430 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/ptrace.c b/arch/blackfin/kernel/ptrace.c new file mode 100644 index 000000000000..d7c8e514cb92 --- /dev/null +++ b/arch/blackfin/kernel/ptrace.c @@ -0,0 +1,430 @@ +/* + * 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 <linux/kernel.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/smp.h> +#include <linux/smp_lock.h> +#include <linux/errno.h> +#include <linux/ptrace.h> +#include <linux/user.h> +#include <linux/signal.h> + +#include <asm/uaccess.h> +#include <asm/page.h> +#include <asm/pgtable.h> +#include <asm/system.h> +#include <asm/processor.h> +#include <asm/asm-offsets.h> +#include <asm/dma.h> + +#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->thread_info + + (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->thread_info + + (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->thread_info + + (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; + + 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 + 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 + 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; + } +} |