/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_COMPAT #include "compat_ptrace.h" #endif static void FixPerRegisters(struct task_struct *task) { struct pt_regs *regs; per_struct *per_info; regs = task_pt_regs(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_COMPAT 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_64BIT # 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, mask; /* * Stupid gdb peeks/pokes the access registers in 64 bit with * an alignment of 4. Programmers from hell... */ mask = __ADDR_MASK; #ifdef CONFIG_64BIT if (addr >= (addr_t) &dummy->regs.acrs && addr < (addr_t) &dummy->regs.orig_gpr2) mask = 3; #endif if ((addr & mask) || 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) &task_pt_regs(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; #ifdef CONFIG_64BIT /* * Very special case: old & broken 64 bit gdb reading * from acrs[15]. Result is a 64 bit value. Read the * 32 bit acrs[15] value and shift it by 32. Sick... */ if (addr == (addr_t) &dummy->regs.acrs[15]) tmp = ((unsigned long) child->thread.acrs[15]) << 32; else #endif 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) task_pt_regs(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); if (addr == (addr_t) &dummy->regs.fp_regs.fpc) tmp &= (unsigned long) FPC_VALID_MASK << (BITS_PER_LONG - 32); } 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, mask; /* * Stupid gdb peeks/pokes the access registers in 64 bit with * an alignment of 4. Programmers from hell indeed... */ mask = __ADDR_MASK; #ifdef CONFIG_64BIT if (addr >= (addr_t) &dummy->regs.acrs && addr < (addr_t) &dummy->regs.orig_gpr2) mask = 3; #endif if ((addr & mask) || 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_COMPAT data != PSW_MASK_MERGE(PSW_USER32_BITS, data) && #endif data != PSW_MASK_MERGE(PSW_USER_BITS, data)) /* Invalid psw mask. */ return -EINVAL; #ifndef CONFIG_64BIT 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) &task_pt_regs(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; #ifdef CONFIG_64BIT /* * Very special case: old & broken 64 bit gdb writing * to acrs[15] with a 64 bit value. Ignore the lower * half of the value and write the upper 32 bit to * acrs[15]. Sick... */ if (addr == (addr_t) &dummy->regs.acrs[15]) child->thread.acrs[15] = (unsigned int) (data >> 32); else #endif *(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 */ task_pt_regs(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 & ~((unsigned long) FPC_VALID_MASK << (BITS_PER_LONG - 32))) != 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_COMPAT /* * 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)(task_pt_regs(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) task_pt_regs(child)->psw.addr | PSW32_ADDR_AMODE31; } else { /* gpr 0-15 */ tmp = *(__u32 *)((addr_t) &task_pt_regs(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) &task_pt_regs(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; task_pt_regs(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. */ task_pt_regs(child)->psw.addr = (__u64) tmp & PSW32_ADDR_INSN; } else { /* gpr 0-15 */ *(__u32*)((addr_t) &task_pt_regs(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) &task_pt_regs(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_COMPAT 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 (!valid_signal(data)) 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 (!valid_signal(data)) 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_COMPAT 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) { ret = ptrace_traceme(); goto out; } child = ptrace_get_task_struct(pid); if (IS_ERR(child)) { ret = PTR_ERR(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) && entryexit) audit_syscall_exit(current, AUDITSC_RESULT(regs->gprs[2]), regs->gprs[2]); if (!test_thread_flag(TIF_SYSCALL_TRACE)) goto out; if (!(current->ptrace & PT_PTRACED)) goto out; ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0)); /* * If the debuffer has set an invalid system call number, * we prepare to skip the system call restart handling. */ if (!entryexit && regs->gprs[2] >= NR_syscalls) regs->trap = -1; /* * 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; } out: if (unlikely(current->audit_context) && !entryexit) audit_syscall_entry(current, test_thread_flag(TIF_31BIT)?AUDIT_ARCH_S390:AUDIT_ARCH_S390X, regs->gprs[2], regs->orig_gpr2, regs->gprs[3], regs->gprs[4], regs->gprs[5]); }