/* * linux/arch/x86_64/ia32/ia32_signal.c * * Copyright (C) 1991, 1992 Linus Torvalds * * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes * 2000-12-* x86-64 compatibility mode signal handling by Andi Kleen */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) #define FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \ X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \ X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \ X86_EFLAGS_CF) void signal_fault(struct pt_regs *regs, void __user *frame, char *where); int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from) { int err = 0; if (!access_ok(VERIFY_WRITE, to, sizeof(compat_siginfo_t))) return -EFAULT; put_user_try { /* If you change siginfo_t structure, please make sure that this code is fixed accordingly. It should never copy any pad contained in the structure to avoid security leaks, but must copy the generic 3 ints plus the relevant union member. */ put_user_ex(from->si_signo, &to->si_signo); put_user_ex(from->si_errno, &to->si_errno); put_user_ex((short)from->si_code, &to->si_code); if (from->si_code < 0) { put_user_ex(from->si_pid, &to->si_pid); put_user_ex(from->si_uid, &to->si_uid); put_user_ex(ptr_to_compat(from->si_ptr), &to->si_ptr); } else { /* * First 32bits of unions are always present: * si_pid === si_band === si_tid === si_addr(LS half) */ put_user_ex(from->_sifields._pad[0], &to->_sifields._pad[0]); switch (from->si_code >> 16) { case __SI_FAULT >> 16: break; case __SI_CHLD >> 16: put_user_ex(from->si_utime, &to->si_utime); put_user_ex(from->si_stime, &to->si_stime); put_user_ex(from->si_status, &to->si_status); /* FALL THROUGH */ default: case __SI_KILL >> 16: put_user_ex(from->si_uid, &to->si_uid); break; case __SI_POLL >> 16: put_user_ex(from->si_fd, &to->si_fd); break; case __SI_TIMER >> 16: put_user_ex(from->si_overrun, &to->si_overrun); put_user_ex(ptr_to_compat(from->si_ptr), &to->si_ptr); break; /* This is not generated by the kernel as of now. */ case __SI_RT >> 16: case __SI_MESGQ >> 16: put_user_ex(from->si_uid, &to->si_uid); put_user_ex(from->si_int, &to->si_int); break; } } } put_user_catch(err); return err; } int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from) { int err = 0; u32 ptr32; if (!access_ok(VERIFY_READ, from, sizeof(compat_siginfo_t))) return -EFAULT; get_user_try { get_user_ex(to->si_signo, &from->si_signo); get_user_ex(to->si_errno, &from->si_errno); get_user_ex(to->si_code, &from->si_code); get_user_ex(to->si_pid, &from->si_pid); get_user_ex(to->si_uid, &from->si_uid); get_user_ex(ptr32, &from->si_ptr); to->si_ptr = compat_ptr(ptr32); } get_user_catch(err); return err; } asmlinkage long sys32_sigsuspend(int history0, int history1, old_sigset_t mask) { mask &= _BLOCKABLE; spin_lock_irq(¤t->sighand->siglock); current->saved_sigmask = current->blocked; siginitset(¤t->blocked, mask); recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); current->state = TASK_INTERRUPTIBLE; schedule(); set_restore_sigmask(); return -ERESTARTNOHAND; } asmlinkage long sys32_sigaltstack(const stack_ia32_t __user *uss_ptr, stack_ia32_t __user *uoss_ptr, struct pt_regs *regs) { stack_t uss, uoss; int ret, err = 0; mm_segment_t seg; if (uss_ptr) { u32 ptr; memset(&uss, 0, sizeof(stack_t)); if (!access_ok(VERIFY_READ, uss_ptr, sizeof(stack_ia32_t))) return -EFAULT; get_user_try { get_user_ex(ptr, &uss_ptr->ss_sp); get_user_ex(uss.ss_flags, &uss_ptr->ss_flags); get_user_ex(uss.ss_size, &uss_ptr->ss_size); } get_user_catch(err); if (err) return -EFAULT; uss.ss_sp = compat_ptr(ptr); } seg = get_fs(); set_fs(KERNEL_DS); ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss, regs->sp); set_fs(seg); if (ret >= 0 && uoss_ptr) { if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(stack_ia32_t))) return -EFAULT; put_user_try { put_user_ex(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp); put_user_ex(uoss.ss_flags, &uoss_ptr->ss_flags); put_user_ex(uoss.ss_size, &uoss_ptr->ss_size); } put_user_catch(err); if (err) ret = -EFAULT; } return ret; } /* * Do a signal return; undo the signal stack. */ #define loadsegment_gs(v) load_gs_index(v) #define loadsegment_fs(v) loadsegment(fs, v) #define loadsegment_ds(v) loadsegment(ds, v) #define loadsegment_es(v) loadsegment(es, v) #define get_user_seg(seg) ({ unsigned int v; savesegment(seg, v); v; }) #define set_user_seg(seg, v) loadsegment_##seg(v) #define COPY(x) { \ get_user_ex(regs->x, &sc->x); \ } #define GET_SEG(seg) ({ \ unsigned short tmp; \ get_user_ex(tmp, &sc->seg); \ tmp; \ }) #define COPY_SEG_CPL3(seg) do { \ regs->seg = GET_SEG(seg) | 3; \ } while (0) #define RELOAD_SEG(seg) { \ unsigned int pre = GET_SEG(seg); \ unsigned int cur = get_user_seg(seg); \ pre |= 3; \ if (pre != cur) \ set_user_seg(seg, pre); \ } static int ia32_restore_sigcontext(struct pt_regs *regs, struct sigcontext_ia32 __user *sc, unsigned int *pax) { unsigned int tmpflags, err = 0; void __user *buf; u32 tmp; /* Always make any pending restarted system calls return -EINTR */ current_thread_info()->restart_block.fn = do_no_restart_syscall; get_user_try { /* * Reload fs and gs if they have changed in the signal * handler. This does not handle long fs/gs base changes in * the handler, but does not clobber them at least in the * normal case. */ RELOAD_SEG(gs); RELOAD_SEG(fs); RELOAD_SEG(ds); RELOAD_SEG(es); COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); COPY(dx); COPY(cx); COPY(ip); /* Don't touch extended registers */ COPY_SEG_CPL3(cs); COPY_SEG_CPL3(ss); get_user_ex(tmpflags, &sc->flags); regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); /* disable syscall checks */ regs->orig_ax = -1; get_user_ex(tmp, &sc->fpstate); buf = compat_ptr(tmp); err |= restore_i387_xstate_ia32(buf); get_user_ex(*pax, &sc->ax); } get_user_catch(err); return err; } asmlinkage long sys32_sigreturn(struct pt_regs *regs) { struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8); sigset_t set; unsigned int ax; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) goto badframe; if (__get_user(set.sig[0], &frame->sc.oldmask) || (_COMPAT_NSIG_WORDS > 1 && __copy_from_user((((char *) &set.sig) + 4), &frame->extramask, sizeof(frame->extramask)))) goto badframe; sigdelsetmask(&set, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); current->blocked = set; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); if (ia32_restore_sigcontext(regs, &frame->sc, &ax)) goto badframe; return ax; badframe: signal_fault(regs, frame, "32bit sigreturn"); return 0; } asmlinkage long sys32_rt_sigreturn(struct pt_regs *regs) { struct rt_sigframe_ia32 __user *frame; sigset_t set; unsigned int ax; struct pt_regs tregs; frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4); if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) goto badframe; if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) goto badframe; sigdelsetmask(&set, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); current->blocked = set; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax)) goto badframe; tregs = *regs; if (sys32_sigaltstack(&frame->uc.uc_stack, NULL, &tregs) == -EFAULT) goto badframe; return ax; badframe: signal_fault(regs, frame, "32bit rt sigreturn"); return 0; } /* * Set up a signal frame. */ static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc, void __user *fpstate, struct pt_regs *regs, unsigned int mask) { int err = 0; put_user_try { put_user_ex(get_user_seg(gs), (unsigned int __user *)&sc->gs); put_user_ex(get_user_seg(fs), (unsigned int __user *)&sc->fs); put_user_ex(get_user_seg(ds), (unsigned int __user *)&sc->ds); put_user_ex(get_user_seg(es), (unsigned int __user *)&sc->es); put_user_ex(regs->di, &sc->di); put_user_ex(regs->si, &sc->si); put_user_ex(regs->bp, &sc->bp); put_user_ex(regs->sp, &sc->sp); put_user_ex(regs->bx, &sc->bx); put_user_ex(regs->dx, &sc->dx); put_user_ex(regs->cx, &sc->cx); put_user_ex(regs->ax, &sc->ax); put_user_ex(current->thread.trap_no, &sc->trapno); put_user_ex(current->thread.error_code, &sc->err); put_user_ex(regs->ip, &sc->ip); put_user_ex(regs->cs, (unsigned int __user *)&sc->cs); put_user_ex(regs->flags, &sc->flags); put_user_ex(regs->sp, &sc->sp_at_signal); put_user_ex(regs->ss, (unsigned int __user *)&sc->ss); put_user_ex(ptr_to_compat(fpstate), &sc->fpstate); /* non-iBCS2 extensions.. */ put_user_ex(mask, &sc->oldmask); put_user_ex(current->thread.cr2, &sc->cr2); } put_user_catch(err); return err; } /* * Determine which stack to use.. */ static void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size, void **fpstate) { unsigned long sp; /* Default to using normal stack */ sp = regs->sp; /* This is the X/Open sanctioned signal stack switching. */ if (ka->sa.sa_flags & SA_ONSTACK) { if (sas_ss_flags(sp) == 0) sp = current->sas_ss_sp + current->sas_ss_size; } /* This is the legacy signal stack switching. */ else if ((regs->ss & 0xffff) != __USER32_DS && !(ka->sa.sa_flags & SA_RESTORER) && ka->sa.sa_restorer) sp = (unsigned long) ka->sa.sa_restorer; if (used_math()) { sp = sp - sig_xstate_ia32_size; *fpstate = (struct _fpstate_ia32 *) sp; if (save_i387_xstate_ia32(*fpstate) < 0) return (void __user *) -1L; } sp -= frame_size; /* Align the stack pointer according to the i386 ABI, * i.e. so that on function entry ((sp + 4) & 15) == 0. */ sp = ((sp + 4) & -16ul) - 4; return (void __user *) sp; } int ia32_setup_frame(int sig, struct k_sigaction *ka, compat_sigset_t *set, struct pt_regs *regs) { struct sigframe_ia32 __user *frame; void __user *restorer; int err = 0; void __user *fpstate = NULL; /* copy_to_user optimizes that into a single 8 byte store */ static const struct { u16 poplmovl; u32 val; u16 int80; } __attribute__((packed)) code = { 0xb858, /* popl %eax ; movl $...,%eax */ __NR_ia32_sigreturn, 0x80cd, /* int $0x80 */ }; frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) return -EFAULT; if (__put_user(sig, &frame->sig)) return -EFAULT; if (ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0])) return -EFAULT; if (_COMPAT_NSIG_WORDS > 1) { if (__copy_to_user(frame->extramask, &set->sig[1], sizeof(frame->extramask))) return -EFAULT; } if (ka->sa.sa_flags & SA_RESTORER) { restorer = ka->sa.sa_restorer; } else { /* Return stub is in 32bit vsyscall page */ if (current->mm->context.vdso) restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn); else restorer = &frame->retcode; } put_user_try { put_user_ex(ptr_to_compat(restorer), &frame->pretcode); /* * These are actually not used anymore, but left because some * gdb versions depend on them as a marker. */ put_user_ex(*((u64 *)&code), (u64 *)frame->retcode); } put_user_catch(err); if (err) return -EFAULT; /* Set up registers for signal handler */ regs->sp = (unsigned long) frame; regs->ip = (unsigned long) ka->sa.sa_handler; /* Make -mregparm=3 work */ regs->ax = sig; regs->dx = 0; regs->cx = 0; loadsegment(ds, __USER32_DS); loadsegment(es, __USER32_DS); regs->cs = __USER32_CS; regs->ss = __USER32_DS; return 0; } int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, compat_sigset_t *set, struct pt_regs *regs) { struct rt_sigframe_ia32 __user *frame; void __user *restorer; int err = 0; void __user *fpstate = NULL; /* __copy_to_user optimizes that into a single 8 byte store */ static const struct { u8 movl; u32 val; u16 int80; u8 pad; } __attribute__((packed)) code = { 0xb8, __NR_ia32_rt_sigreturn, 0x80cd, 0, }; frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) return -EFAULT; put_user_try { put_user_ex(sig, &frame->sig); put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo); put_user_ex(ptr_to_compat(&frame->uc), &frame->puc); err |= copy_siginfo_to_user32(&frame->info, info); /* Create the ucontext. */ if (cpu_has_xsave) put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); else put_user_ex(0, &frame->uc.uc_flags); put_user_ex(0, &frame->uc.uc_link); put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); put_user_ex(sas_ss_flags(regs->sp), &frame->uc.uc_stack.ss_flags); put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size); err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate, regs, set->sig[0]); err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); if (ka->sa.sa_flags & SA_RESTORER) restorer = ka->sa.sa_restorer; else restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn); put_user_ex(ptr_to_compat(restorer), &frame->pretcode); /* * Not actually used anymore, but left because some gdb * versions need it. */ put_user_ex(*((u64 *)&code), (u64 *)frame->retcode); } put_user_catch(err); if (err) return -EFAULT; /* Set up registers for signal handler */ regs->sp = (unsigned long) frame; regs->ip = (unsigned long) ka->sa.sa_handler; /* Make -mregparm=3 work */ regs->ax = sig; regs->dx = (unsigned long) &frame->info; regs->cx = (unsigned long) &frame->uc; loadsegment(ds, __USER32_DS); loadsegment(es, __USER32_DS); regs->cs = __USER32_CS; regs->ss = __USER32_DS; return 0; }