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Diffstat (limited to 'arch/s390/kernel/ptrace.c')
| -rw-r--r-- | arch/s390/kernel/ptrace.c | 738 |
1 files changed, 738 insertions, 0 deletions
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c new file mode 100644 index 000000000000..647233c02fc8 --- /dev/null +++ b/arch/s390/kernel/ptrace.c @@ -0,0 +1,738 @@ +/* + * arch/s390/kernel/ptrace.c + * + * S390 version + * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation + * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), + * Martin Schwidefsky (schwidefsky@de.ibm.com) + * + * Based on PowerPC version + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * + * Derived from "arch/m68k/kernel/ptrace.c" + * Copyright (C) 1994 by Hamish Macdonald + * Taken from linux/kernel/ptrace.c and modified for M680x0. + * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds + * + * Modified by Cort Dougan (cort@cs.nmt.edu) + * + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file README.legal in the main directory of + * this archive for more details. + */ + +#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/security.h> +#include <linux/audit.h> + +#include <asm/segment.h> +#include <asm/page.h> +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/system.h> +#include <asm/uaccess.h> + +#ifdef CONFIG_S390_SUPPORT +#include "compat_ptrace.h" +#endif + +static void +FixPerRegisters(struct task_struct *task) +{ + struct pt_regs *regs; + per_struct *per_info; + + regs = __KSTK_PTREGS(task); + per_info = (per_struct *) &task->thread.per_info; + per_info->control_regs.bits.em_instruction_fetch = + per_info->single_step | per_info->instruction_fetch; + + if (per_info->single_step) { + per_info->control_regs.bits.starting_addr = 0; +#ifdef CONFIG_S390_SUPPORT + if (test_thread_flag(TIF_31BIT)) + per_info->control_regs.bits.ending_addr = 0x7fffffffUL; + else +#endif + per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN; + } else { + per_info->control_regs.bits.starting_addr = + per_info->starting_addr; + per_info->control_regs.bits.ending_addr = + per_info->ending_addr; + } + /* + * if any of the control reg tracing bits are on + * we switch on per in the psw + */ + if (per_info->control_regs.words.cr[0] & PER_EM_MASK) + regs->psw.mask |= PSW_MASK_PER; + else + regs->psw.mask &= ~PSW_MASK_PER; + + if (per_info->control_regs.bits.em_storage_alteration) + per_info->control_regs.bits.storage_alt_space_ctl = 1; + else + per_info->control_regs.bits.storage_alt_space_ctl = 0; +} + +void +set_single_step(struct task_struct *task) +{ + task->thread.per_info.single_step = 1; + FixPerRegisters(task); +} + +void +clear_single_step(struct task_struct *task) +{ + task->thread.per_info.single_step = 0; + FixPerRegisters(task); +} + +/* + * Called by kernel/ptrace.c when detaching.. + * + * Make sure single step bits etc are not set. + */ +void +ptrace_disable(struct task_struct *child) +{ + /* make sure the single step bit is not set. */ + clear_single_step(child); +} + +#ifndef CONFIG_ARCH_S390X +# define __ADDR_MASK 3 +#else +# define __ADDR_MASK 7 +#endif + +/* + * Read the word at offset addr from the user area of a process. The + * trouble here is that the information is littered over different + * locations. The process registers are found on the kernel stack, + * the floating point stuff and the trace settings are stored in + * the task structure. In addition the different structures in + * struct user contain pad bytes that should be read as zeroes. + * Lovely... + */ +static int +peek_user(struct task_struct *child, addr_t addr, addr_t data) +{ + struct user *dummy = NULL; + addr_t offset, tmp; + + /* + * Stupid gdb peeks/pokes the access registers in 64 bit with + * an alignment of 4. Programmers from hell... + */ + if ((addr & 3) || addr > sizeof(struct user) - __ADDR_MASK) + return -EIO; + + if (addr < (addr_t) &dummy->regs.acrs) { + /* + * psw and gprs are stored on the stack + */ + tmp = *(addr_t *)((addr_t) &__KSTK_PTREGS(child)->psw + addr); + if (addr == (addr_t) &dummy->regs.psw.mask) + /* Remove per bit from user psw. */ + tmp &= ~PSW_MASK_PER; + + } else if (addr < (addr_t) &dummy->regs.orig_gpr2) { + /* + * access registers are stored in the thread structure + */ + offset = addr - (addr_t) &dummy->regs.acrs; + tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset); + + } else if (addr == (addr_t) &dummy->regs.orig_gpr2) { + /* + * orig_gpr2 is stored on the kernel stack + */ + tmp = (addr_t) __KSTK_PTREGS(child)->orig_gpr2; + + } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) { + /* + * floating point regs. are stored in the thread structure + */ + offset = addr - (addr_t) &dummy->regs.fp_regs; + tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset); + + } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) { + /* + * per_info is found in the thread structure + */ + offset = addr - (addr_t) &dummy->regs.per_info; + tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset); + + } else + tmp = 0; + + return put_user(tmp, (addr_t __user *) data); +} + +/* + * Write a word to the user area of a process at location addr. This + * operation does have an additional problem compared to peek_user. + * Stores to the program status word and on the floating point + * control register needs to get checked for validity. + */ +static int +poke_user(struct task_struct *child, addr_t addr, addr_t data) +{ + struct user *dummy = NULL; + addr_t offset; + + /* + * Stupid gdb peeks/pokes the access registers in 64 bit with + * an alignment of 4. Programmers from hell indeed... + */ + if ((addr & 3) || addr > sizeof(struct user) - __ADDR_MASK) + return -EIO; + + if (addr < (addr_t) &dummy->regs.acrs) { + /* + * psw and gprs are stored on the stack + */ + if (addr == (addr_t) &dummy->regs.psw.mask && +#ifdef CONFIG_S390_SUPPORT + data != PSW_MASK_MERGE(PSW_USER32_BITS, data) && +#endif + data != PSW_MASK_MERGE(PSW_USER_BITS, data)) + /* Invalid psw mask. */ + return -EINVAL; +#ifndef CONFIG_ARCH_S390X + if (addr == (addr_t) &dummy->regs.psw.addr) + /* I'd like to reject addresses without the + high order bit but older gdb's rely on it */ + data |= PSW_ADDR_AMODE; +#endif + *(addr_t *)((addr_t) &__KSTK_PTREGS(child)->psw + addr) = data; + + } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) { + /* + * access registers are stored in the thread structure + */ + offset = addr - (addr_t) &dummy->regs.acrs; + *(addr_t *)((addr_t) &child->thread.acrs + offset) = data; + + } else if (addr == (addr_t) &dummy->regs.orig_gpr2) { + /* + * orig_gpr2 is stored on the kernel stack + */ + __KSTK_PTREGS(child)->orig_gpr2 = data; + + } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) { + /* + * floating point regs. are stored in the thread structure + */ + if (addr == (addr_t) &dummy->regs.fp_regs.fpc && + (data & ~FPC_VALID_MASK) != 0) + return -EINVAL; + offset = addr - (addr_t) &dummy->regs.fp_regs; + *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data; + + } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) { + /* + * per_info is found in the thread structure + */ + offset = addr - (addr_t) &dummy->regs.per_info; + *(addr_t *)((addr_t) &child->thread.per_info + offset) = data; + + } + + FixPerRegisters(child); + return 0; +} + +static int +do_ptrace_normal(struct task_struct *child, long request, long addr, long data) +{ + unsigned long tmp; + ptrace_area parea; + int copied, ret; + + switch (request) { + case PTRACE_PEEKTEXT: + case PTRACE_PEEKDATA: + /* Remove high order bit from address (only for 31 bit). */ + addr &= PSW_ADDR_INSN; + /* read word at location addr. */ + copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); + if (copied != sizeof(tmp)) + return -EIO; + return put_user(tmp, (unsigned long __user *) data); + + case PTRACE_PEEKUSR: + /* read the word at location addr in the USER area. */ + return peek_user(child, addr, data); + + case PTRACE_POKETEXT: + case PTRACE_POKEDATA: + /* Remove high order bit from address (only for 31 bit). */ + addr &= PSW_ADDR_INSN; + /* write the word at location addr. */ + copied = access_process_vm(child, addr, &data, sizeof(data),1); + if (copied != sizeof(data)) + return -EIO; + return 0; + + case PTRACE_POKEUSR: + /* write the word at location addr in the USER area */ + return poke_user(child, addr, data); + + case PTRACE_PEEKUSR_AREA: + case PTRACE_POKEUSR_AREA: + if (copy_from_user(&parea, (void __user *) addr, + sizeof(parea))) + return -EFAULT; + addr = parea.kernel_addr; + data = parea.process_addr; + copied = 0; + while (copied < parea.len) { + if (request == PTRACE_PEEKUSR_AREA) + ret = peek_user(child, addr, data); + else { + addr_t tmp; + if (get_user (tmp, (addr_t __user *) data)) + return -EFAULT; + ret = poke_user(child, addr, tmp); + } + if (ret) + return ret; + addr += sizeof(unsigned long); + data += sizeof(unsigned long); + copied += sizeof(unsigned long); + } + return 0; + } + return ptrace_request(child, request, addr, data); +} + +#ifdef CONFIG_S390_SUPPORT +/* + * Now the fun part starts... a 31 bit program running in the + * 31 bit emulation tracing another program. PTRACE_PEEKTEXT, + * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy + * to handle, the difference to the 64 bit versions of the requests + * is that the access is done in multiples of 4 byte instead of + * 8 bytes (sizeof(unsigned long) on 31/64 bit). + * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA, + * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program + * is a 31 bit program too, the content of struct user can be + * emulated. A 31 bit program peeking into the struct user of + * a 64 bit program is a no-no. + */ + +/* + * Same as peek_user but for a 31 bit program. + */ +static int +peek_user_emu31(struct task_struct *child, addr_t addr, addr_t data) +{ + struct user32 *dummy32 = NULL; + per_struct32 *dummy_per32 = NULL; + addr_t offset; + __u32 tmp; + + if (!test_thread_flag(TIF_31BIT) || + (addr & 3) || addr > sizeof(struct user) - 3) + return -EIO; + + if (addr < (addr_t) &dummy32->regs.acrs) { + /* + * psw and gprs are stored on the stack + */ + if (addr == (addr_t) &dummy32->regs.psw.mask) { + /* Fake a 31 bit psw mask. */ + tmp = (__u32)(__KSTK_PTREGS(child)->psw.mask >> 32); + tmp = PSW32_MASK_MERGE(PSW32_USER_BITS, tmp); + } else if (addr == (addr_t) &dummy32->regs.psw.addr) { + /* Fake a 31 bit psw address. */ + tmp = (__u32) __KSTK_PTREGS(child)->psw.addr | + PSW32_ADDR_AMODE31; + } else { + /* gpr 0-15 */ + tmp = *(__u32 *)((addr_t) &__KSTK_PTREGS(child)->psw + + addr*2 + 4); + } + } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) { + /* + * access registers are stored in the thread structure + */ + offset = addr - (addr_t) &dummy32->regs.acrs; + tmp = *(__u32*)((addr_t) &child->thread.acrs + offset); + + } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) { + /* + * orig_gpr2 is stored on the kernel stack + */ + tmp = *(__u32*)((addr_t) &__KSTK_PTREGS(child)->orig_gpr2 + 4); + + } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) { + /* + * floating point regs. are stored in the thread structure + */ + offset = addr - (addr_t) &dummy32->regs.fp_regs; + tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset); + + } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) { + /* + * per_info is found in the thread structure + */ + offset = addr - (addr_t) &dummy32->regs.per_info; + /* This is magic. See per_struct and per_struct32. */ + if ((offset >= (addr_t) &dummy_per32->control_regs && + offset < (addr_t) (&dummy_per32->control_regs + 1)) || + (offset >= (addr_t) &dummy_per32->starting_addr && + offset <= (addr_t) &dummy_per32->ending_addr) || + offset == (addr_t) &dummy_per32->lowcore.words.address) + offset = offset*2 + 4; + else + offset = offset*2; + tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset); + + } else + tmp = 0; + + return put_user(tmp, (__u32 __user *) data); +} + +/* + * Same as poke_user but for a 31 bit program. + */ +static int +poke_user_emu31(struct task_struct *child, addr_t addr, addr_t data) +{ + struct user32 *dummy32 = NULL; + per_struct32 *dummy_per32 = NULL; + addr_t offset; + __u32 tmp; + + if (!test_thread_flag(TIF_31BIT) || + (addr & 3) || addr > sizeof(struct user32) - 3) + return -EIO; + + tmp = (__u32) data; + + if (addr < (addr_t) &dummy32->regs.acrs) { + /* + * psw, gprs, acrs and orig_gpr2 are stored on the stack + */ + if (addr == (addr_t) &dummy32->regs.psw.mask) { + /* Build a 64 bit psw mask from 31 bit mask. */ + if (tmp != PSW32_MASK_MERGE(PSW32_USER_BITS, tmp)) + /* Invalid psw mask. */ + return -EINVAL; + __KSTK_PTREGS(child)->psw.mask = + PSW_MASK_MERGE(PSW_USER32_BITS, (__u64) tmp << 32); + } else if (addr == (addr_t) &dummy32->regs.psw.addr) { + /* Build a 64 bit psw address from 31 bit address. */ + __KSTK_PTREGS(child)->psw.addr = + (__u64) tmp & PSW32_ADDR_INSN; + } else { + /* gpr 0-15 */ + *(__u32*)((addr_t) &__KSTK_PTREGS(child)->psw + + addr*2 + 4) = tmp; + } + } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) { + /* + * access registers are stored in the thread structure + */ + offset = addr - (addr_t) &dummy32->regs.acrs; + *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp; + + } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) { + /* + * orig_gpr2 is stored on the kernel stack + */ + *(__u32*)((addr_t) &__KSTK_PTREGS(child)->orig_gpr2 + 4) = tmp; + + } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) { + /* + * floating point regs. are stored in the thread structure + */ + if (addr == (addr_t) &dummy32->regs.fp_regs.fpc && + (tmp & ~FPC_VALID_MASK) != 0) + /* Invalid floating point control. */ + return -EINVAL; + offset = addr - (addr_t) &dummy32->regs.fp_regs; + *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp; + + } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) { + /* + * per_info is found in the thread structure. + */ + offset = addr - (addr_t) &dummy32->regs.per_info; + /* + * This is magic. See per_struct and per_struct32. + * By incident the offsets in per_struct are exactly + * twice the offsets in per_struct32 for all fields. + * The 8 byte fields need special handling though, + * because the second half (bytes 4-7) is needed and + * not the first half. + */ + if ((offset >= (addr_t) &dummy_per32->control_regs && + offset < (addr_t) (&dummy_per32->control_regs + 1)) || + (offset >= (addr_t) &dummy_per32->starting_addr && + offset <= (addr_t) &dummy_per32->ending_addr) || + offset == (addr_t) &dummy_per32->lowcore.words.address) + offset = offset*2 + 4; + else + offset = offset*2; + *(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp; + + } + + FixPerRegisters(child); + return 0; +} + +static int +do_ptrace_emu31(struct task_struct *child, long request, long addr, long data) +{ + unsigned int tmp; /* 4 bytes !! */ + ptrace_area_emu31 parea; + int copied, ret; + + switch (request) { + case PTRACE_PEEKTEXT: + case PTRACE_PEEKDATA: + /* read word at location addr. */ + copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); + if (copied != sizeof(tmp)) + return -EIO; + return put_user(tmp, (unsigned int __user *) data); + + case PTRACE_PEEKUSR: + /* read the word at location addr in the USER area. */ + return peek_user_emu31(child, addr, data); + + case PTRACE_POKETEXT: + case PTRACE_POKEDATA: + /* write the word at location addr. */ + tmp = data; + copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 1); + if (copied != sizeof(tmp)) + return -EIO; + return 0; + + case PTRACE_POKEUSR: + /* write the word at location addr in the USER area */ + return poke_user_emu31(child, addr, data); + + case PTRACE_PEEKUSR_AREA: + case PTRACE_POKEUSR_AREA: + if (copy_from_user(&parea, (void __user *) addr, + sizeof(parea))) + return -EFAULT; + addr = parea.kernel_addr; + data = parea.process_addr; + copied = 0; + while (copied < parea.len) { + if (request == PTRACE_PEEKUSR_AREA) + ret = peek_user_emu31(child, addr, data); + else { + __u32 tmp; + if (get_user (tmp, (__u32 __user *) data)) + return -EFAULT; + ret = poke_user_emu31(child, addr, tmp); + } + if (ret) + return ret; + addr += sizeof(unsigned int); + data += sizeof(unsigned int); + copied += sizeof(unsigned int); + } + return 0; + case PTRACE_GETEVENTMSG: + return put_user((__u32) child->ptrace_message, + (unsigned int __user *) data); + case PTRACE_GETSIGINFO: + if (child->last_siginfo == NULL) + return -EINVAL; + return copy_siginfo_to_user32((compat_siginfo_t __user *) data, + child->last_siginfo); + case PTRACE_SETSIGINFO: + if (child->last_siginfo == NULL) + return -EINVAL; + return copy_siginfo_from_user32(child->last_siginfo, + (compat_siginfo_t __user *) data); + } + return ptrace_request(child, request, addr, data); +} +#endif + +#define PT32_IEEE_IP 0x13c + +static int +do_ptrace(struct task_struct *child, long request, long addr, long data) +{ + int ret; + + if (request == PTRACE_ATTACH) + return ptrace_attach(child); + + /* + * Special cases to get/store the ieee instructions pointer. + */ + if (child == current) { + if (request == PTRACE_PEEKUSR && addr == PT_IEEE_IP) + return peek_user(child, addr, data); + if (request == PTRACE_POKEUSR && addr == PT_IEEE_IP) + return poke_user(child, addr, data); +#ifdef CONFIG_S390_SUPPORT + if (request == PTRACE_PEEKUSR && + addr == PT32_IEEE_IP && test_thread_flag(TIF_31BIT)) + return peek_user_emu31(child, addr, data); + if (request == PTRACE_POKEUSR && + addr == PT32_IEEE_IP && test_thread_flag(TIF_31BIT)) + return poke_user_emu31(child, addr, data); +#endif + } + + ret = ptrace_check_attach(child, request == PTRACE_KILL); + if (ret < 0) + return ret; + + switch (request) { + case PTRACE_SYSCALL: + /* continue and stop at next (return from) syscall */ + case PTRACE_CONT: + /* restart after signal. */ + if ((unsigned long) data >= _NSIG) + return -EIO; + 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. */ + clear_single_step(child); + wake_up_process(child); + return 0; + + case PTRACE_KILL: + /* + * 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. + */ + if (child->exit_state == EXIT_ZOMBIE) /* already dead */ + return 0; + child->exit_code = SIGKILL; + /* make sure the single step bit is not set. */ + clear_single_step(child); + wake_up_process(child); + return 0; + + case PTRACE_SINGLESTEP: + /* set the trap flag. */ + if ((unsigned long) data >= _NSIG) + return -EIO; + clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); + child->exit_code = data; + if (data) + set_tsk_thread_flag(child, TIF_SINGLE_STEP); + else + set_single_step(child); + /* give it a chance to run. */ + wake_up_process(child); + return 0; + + case PTRACE_DETACH: + /* detach a process that was attached. */ + return ptrace_detach(child, data); + + + /* Do requests that differ for 31/64 bit */ + default: +#ifdef CONFIG_S390_SUPPORT + if (test_thread_flag(TIF_31BIT)) + return do_ptrace_emu31(child, request, addr, data); +#endif + return do_ptrace_normal(child, request, addr, data); + } + /* Not reached. */ + return -EIO; +} + +asmlinkage long +sys_ptrace(long request, long pid, long addr, long data) +{ + struct task_struct *child; + int ret; + + lock_kernel(); + + if (request == PTRACE_TRACEME) { + /* are we already being traced? */ + ret = -EPERM; + if (current->ptrace & PT_PTRACED) + goto out; + ret = security_ptrace(current->parent, current); + if (ret) + goto out; + /* set the ptrace bit in the process flags. */ + current->ptrace |= PT_PTRACED; + goto out; + } + + ret = -EPERM; + if (pid == 1) /* you may not mess with init */ + goto out; + + ret = -ESRCH; + read_lock(&tasklist_lock); + child = find_task_by_pid(pid); + if (child) + get_task_struct(child); + read_unlock(&tasklist_lock); + if (!child) + goto out; + + ret = do_ptrace(child, request, addr, data); + + put_task_struct(child); +out: + unlock_kernel(); + return ret; +} + +asmlinkage void +syscall_trace(struct pt_regs *regs, int entryexit) +{ + if (unlikely(current->audit_context)) { + if (!entryexit) + audit_syscall_entry(current, regs->gprs[2], + regs->orig_gpr2, regs->gprs[3], + regs->gprs[4], regs->gprs[5]); + else + audit_syscall_exit(current, regs->gprs[2]); + } + if (!test_thread_flag(TIF_SYSCALL_TRACE)) + return; + if (!(current->ptrace & PT_PTRACED)) + return; + 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; + } +} |