/* By Ross Biro 1/23/92 */ /* * Pentium III FXSR, SSE support * Gareth Hughes , May 2000 * * x86-64 port 2000-2002 Andi Kleen */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * does not yet catch signals sent when the child dies. * in exit.c or in signal.c. */ /* * Determines which flags the user has access to [1 = access, 0 = no access]. * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), IOPL(12-13), IF(9). * Also masks reserved bits (63-22, 15, 5, 3, 1). */ #define FLAG_MASK 0x54dd5UL /* * Called by kernel/ptrace.c when detaching.. * * Make sure the single step bit is not set. */ void ptrace_disable(struct task_struct *child) { user_disable_single_step(child); } static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset) { BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0); return ®s->r15 + (offset / sizeof(regs->r15)); } static int putreg(struct task_struct *child, unsigned long regno, unsigned long value) { struct pt_regs *regs = task_pt_regs(child); switch (regno) { case offsetof(struct user_regs_struct,fs): if (value && (value & 3) != 3) return -EIO; child->thread.fsindex = value & 0xffff; return 0; case offsetof(struct user_regs_struct,gs): if (value && (value & 3) != 3) return -EIO; child->thread.gsindex = value & 0xffff; return 0; case offsetof(struct user_regs_struct,ds): if (value && (value & 3) != 3) return -EIO; child->thread.ds = value & 0xffff; return 0; case offsetof(struct user_regs_struct,es): if (value && (value & 3) != 3) return -EIO; child->thread.es = value & 0xffff; return 0; case offsetof(struct user_regs_struct,ss): if ((value & 3) != 3) return -EIO; value &= 0xffff; return 0; case offsetof(struct user_regs_struct,fs_base): if (value >= TASK_SIZE_OF(child)) return -EIO; /* * When changing the segment base, use do_arch_prctl * to set either thread.fs or thread.fsindex and the * corresponding GDT slot. */ if (child->thread.fs != value) return do_arch_prctl(child, ARCH_SET_FS, value); return 0; case offsetof(struct user_regs_struct,gs_base): /* * Exactly the same here as the %fs handling above. */ if (value >= TASK_SIZE_OF(child)) return -EIO; if (child->thread.gs != value) return do_arch_prctl(child, ARCH_SET_GS, value); return 0; case offsetof(struct user_regs_struct, eflags): value &= FLAG_MASK; /* * If the user value contains TF, mark that * it was not "us" (the debugger) that set it. * If not, make sure it stays set if we had. */ if (value & X86_EFLAGS_TF) clear_tsk_thread_flag(child, TIF_FORCED_TF); else if (test_tsk_thread_flag(child, TIF_FORCED_TF)) value |= X86_EFLAGS_TF; value |= regs->eflags & ~FLAG_MASK; break; case offsetof(struct user_regs_struct,cs): if ((value & 3) != 3) return -EIO; value &= 0xffff; break; } *pt_regs_access(regs, regno) = value; return 0; } static unsigned long getreg(struct task_struct *child, unsigned long regno) { struct pt_regs *regs = task_pt_regs(child); unsigned long val; switch (regno) { case offsetof(struct user_regs_struct, fs): return child->thread.fsindex; case offsetof(struct user_regs_struct, gs): return child->thread.gsindex; case offsetof(struct user_regs_struct, ds): return child->thread.ds; case offsetof(struct user_regs_struct, es): return child->thread.es; case offsetof(struct user_regs_struct, fs_base): /* * do_arch_prctl may have used a GDT slot instead of * the MSR. To userland, it appears the same either * way, except the %fs segment selector might not be 0. */ if (child->thread.fs != 0) return child->thread.fs; if (child->thread.fsindex != FS_TLS_SEL) return 0; return get_desc_base(&child->thread.tls_array[FS_TLS]); case offsetof(struct user_regs_struct, gs_base): /* * Exactly the same here as the %fs handling above. */ if (child->thread.gs != 0) return child->thread.gs; if (child->thread.gsindex != GS_TLS_SEL) return 0; return get_desc_base(&child->thread.tls_array[GS_TLS]); case offsetof(struct user_regs_struct, eflags): /* * If the debugger set TF, hide it from the readout. */ val = regs->eflags; if (test_tsk_thread_flag(child, TIF_IA32)) val &= 0xffffffff; if (test_tsk_thread_flag(child, TIF_FORCED_TF)) val &= ~X86_EFLAGS_TF; return val; default: val = *pt_regs_access(regs, regno); if (test_tsk_thread_flag(child, TIF_IA32)) val &= 0xffffffff; return val; } } unsigned long ptrace_get_debugreg(struct task_struct *child, int n) { switch (n) { case 0: return child->thread.debugreg0; case 1: return child->thread.debugreg1; case 2: return child->thread.debugreg2; case 3: return child->thread.debugreg3; case 6: return child->thread.debugreg6; case 7: return child->thread.debugreg7; } return 0; } int ptrace_set_debugreg(struct task_struct *child, int n, unsigned long data) { int i; if (n < 4) { int dsize = test_tsk_thread_flag(child, TIF_IA32) ? 3 : 7; if (unlikely(data >= TASK_SIZE_OF(child) - dsize)) return -EIO; } switch (n) { case 0: child->thread.debugreg0 = data; break; case 1: child->thread.debugreg1 = data; break; case 2: child->thread.debugreg2 = data; break; case 3: child->thread.debugreg3 = data; break; case 6: if (data >> 32) return -EIO; child->thread.debugreg6 = data; break; case 7: /* * See ptrace_32.c for an explanation of this awkward check. */ data &= ~DR_CONTROL_RESERVED; for (i = 0; i < 4; i++) if ((0x5554 >> ((data >> (16 + 4*i)) & 0xf)) & 1) return -EIO; child->thread.debugreg7 = data; if (data) set_tsk_thread_flag(child, TIF_DEBUG); else clear_tsk_thread_flag(child, TIF_DEBUG); break; } return 0; } long arch_ptrace(struct task_struct *child, long request, long addr, long data) { long ret; unsigned ui; switch (request) { /* when I and D space are separate, these will need to be fixed. */ case PTRACE_PEEKTEXT: /* read word at location addr. */ case PTRACE_PEEKDATA: ret = generic_ptrace_peekdata(child, addr, data); break; /* read the word at location addr in the USER area. */ case PTRACE_PEEKUSR: { unsigned long tmp; ret = -EIO; if ((addr & 7) || addr > sizeof(struct user) - 7) break; tmp = 0; if (addr < sizeof(struct user_regs_struct)) tmp = getreg(child, addr); else if (addr >= offsetof(struct user, u_debugreg[0])) { addr -= offsetof(struct user, u_debugreg[0]); tmp = ptrace_get_debugreg(child, addr / sizeof(long)); } ret = put_user(tmp,(unsigned long __user *) data); break; } /* when I and D space are separate, this will have to be fixed. */ case PTRACE_POKETEXT: /* write the word at location addr. */ case PTRACE_POKEDATA: ret = generic_ptrace_pokedata(child, addr, data); break; case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ ret = -EIO; if ((addr & 7) || addr > sizeof(struct user) - 7) break; if (addr < sizeof(struct user_regs_struct)) ret = putreg(child, addr, data); else if (addr >= offsetof(struct user, u_debugreg[0])) { addr -= offsetof(struct user, u_debugreg[0]); ret = ptrace_set_debugreg(child, addr / sizeof(long), data); } break; #ifdef CONFIG_IA32_EMULATION /* This makes only sense with 32bit programs. Allow a 64bit debugger to fully examine them too. Better don't use it against 64bit processes, use PTRACE_ARCH_PRCTL instead. */ case PTRACE_GET_THREAD_AREA: if (addr < 0) return -EIO; ret = do_get_thread_area(child, addr, (struct user_desc __user *) data); break; case PTRACE_SET_THREAD_AREA: if (addr < 0) return -EIO; ret = do_set_thread_area(child, addr, (struct user_desc __user *) data, 0); break; #endif /* normal 64bit interface to access TLS data. Works just like arch_prctl, except that the arguments are reversed. */ case PTRACE_ARCH_PRCTL: ret = do_arch_prctl(child, data, addr); break; case PTRACE_GETREGS: { /* Get all gp regs from the child. */ if (!access_ok(VERIFY_WRITE, (unsigned __user *)data, sizeof(struct user_regs_struct))) { ret = -EIO; break; } ret = 0; for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) { ret |= __put_user(getreg(child, ui),(unsigned long __user *) data); data += sizeof(long); } break; } case PTRACE_SETREGS: { /* Set all gp regs in the child. */ unsigned long tmp; if (!access_ok(VERIFY_READ, (unsigned __user *)data, sizeof(struct user_regs_struct))) { ret = -EIO; break; } ret = 0; for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) { ret = __get_user(tmp, (unsigned long __user *) data); if (ret) break; ret = putreg(child, ui, tmp); if (ret) break; data += sizeof(long); } break; } case PTRACE_GETFPREGS: { /* Get the child extended FPU state. */ if (!access_ok(VERIFY_WRITE, (unsigned __user *)data, sizeof(struct user_i387_struct))) { ret = -EIO; break; } ret = get_fpregs((struct user_i387_struct __user *)data, child); break; } case PTRACE_SETFPREGS: { /* Set the child extended FPU state. */ if (!access_ok(VERIFY_READ, (unsigned __user *)data, sizeof(struct user_i387_struct))) { ret = -EIO; break; } set_stopped_child_used_math(child); ret = set_fpregs(child, (struct user_i387_struct __user *)data); break; } default: ret = ptrace_request(child, request, addr, data); break; } return ret; } static void syscall_trace(struct pt_regs *regs) { #if 0 printk("trace %s rip %lx rsp %lx rax %d origrax %d caller %lx tiflags %x ptrace %x\n", current->comm, regs->rip, regs->rsp, regs->rax, regs->orig_rax, __builtin_return_address(0), current_thread_info()->flags, current->ptrace); #endif 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; } } asmlinkage void syscall_trace_enter(struct pt_regs *regs) { /* do the secure computing check first */ secure_computing(regs->orig_rax); if (test_thread_flag(TIF_SYSCALL_TRACE) && (current->ptrace & PT_PTRACED)) syscall_trace(regs); if (unlikely(current->audit_context)) { if (test_thread_flag(TIF_IA32)) { audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_rax, regs->rbx, regs->rcx, regs->rdx, regs->rsi); } else { audit_syscall_entry(AUDIT_ARCH_X86_64, regs->orig_rax, regs->rdi, regs->rsi, regs->rdx, regs->r10); } } } asmlinkage void syscall_trace_leave(struct pt_regs *regs) { if (unlikely(current->audit_context)) audit_syscall_exit(AUDITSC_RESULT(regs->rax), regs->rax); if ((test_thread_flag(TIF_SYSCALL_TRACE) || test_thread_flag(TIF_SINGLESTEP)) && (current->ptrace & PT_PTRACED)) syscall_trace(regs); }