| /* |
| * 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 <linux/sched.h> |
| #include <linux/mm.h> |
| #include <linux/smp.h> |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/wait.h> |
| #include <linux/unistd.h> |
| #include <linux/stddef.h> |
| #include <linux/personality.h> |
| #include <linux/compat.h> |
| #include <linux/binfmts.h> |
| #include <asm/ucontext.h> |
| #include <asm/uaccess.h> |
| #include <asm/i387.h> |
| #include <asm/fpu-internal.h> |
| #include <asm/ptrace.h> |
| #include <asm/ia32_unistd.h> |
| #include <asm/user32.h> |
| #include <asm/sigcontext32.h> |
| #include <asm/proto.h> |
| #include <asm/vdso.h> |
| #include <asm/sigframe.h> |
| #include <asm/sighandling.h> |
| #include <asm/sys_ia32.h> |
| #include <asm/smap.h> |
| |
| #define FIX_EFLAGS __FIX_EFLAGS |
| |
| int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from) |
| { |
| int err = 0; |
| bool ia32 = test_thread_flag(TIF_IA32); |
| |
| 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_SYS >> 16: |
| put_user_ex(from->si_syscall, &to->si_syscall); |
| put_user_ex(from->si_arch, &to->si_arch); |
| break; |
| case __SI_CHLD >> 16: |
| if (ia32) { |
| put_user_ex(from->si_utime, &to->si_utime); |
| put_user_ex(from->si_stime, &to->si_stime); |
| } else { |
| put_user_ex(from->si_utime, &to->_sifields._sigchld_x32._utime); |
| put_user_ex(from->si_stime, &to->_sifields._sigchld_x32._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; |
| } |
| |
| /* |
| * 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); |
| |
| get_user_ex(*pax, &sc->ax); |
| } get_user_catch(err); |
| |
| err |= restore_xstate_sig(buf, 1); |
| |
| return err; |
| } |
| |
| asmlinkage long sys32_sigreturn(void) |
| { |
| struct pt_regs *regs = current_pt_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; |
| |
| set_current_blocked(&set); |
| |
| 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(void) |
| { |
| struct pt_regs *regs = current_pt_regs(); |
| struct rt_sigframe_ia32 __user *frame; |
| sigset_t set; |
| unsigned int ax; |
| |
| 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; |
| |
| set_current_blocked(&set); |
| |
| if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax)) |
| goto badframe; |
| |
| if (compat_restore_altstack(&frame->uc.uc_stack)) |
| 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_nr, &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 ksignal *ksig, struct pt_regs *regs, |
| size_t frame_size, |
| void __user **fpstate) |
| { |
| unsigned long sp; |
| |
| /* Default to using normal stack */ |
| sp = regs->sp; |
| |
| /* This is the X/Open sanctioned signal stack switching. */ |
| if (ksig->ka.sa.sa_flags & SA_ONSTACK) |
| sp = sigsp(sp, ksig); |
| /* This is the legacy signal stack switching. */ |
| else if ((regs->ss & 0xffff) != __USER32_DS && |
| !(ksig->ka.sa.sa_flags & SA_RESTORER) && |
| ksig->ka.sa.sa_restorer) |
| sp = (unsigned long) ksig->ka.sa.sa_restorer; |
| |
| if (used_math()) { |
| unsigned long fx_aligned, math_size; |
| |
| sp = alloc_mathframe(sp, 1, &fx_aligned, &math_size); |
| *fpstate = (struct _fpstate_ia32 __user *) sp; |
| if (save_xstate_sig(*fpstate, (void __user *)fx_aligned, |
| math_size) < 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 ksignal *ksig, |
| 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(ksig, 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 (ksig->ka.sa.sa_flags & SA_RESTORER) { |
| restorer = ksig->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 __user *)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) ksig->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 ksignal *ksig, |
| 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(ksig, 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); |
| |
| /* 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); |
| compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
| |
| if (ksig->ka.sa.sa_flags & SA_RESTORER) |
| restorer = ksig->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 __user *)frame->retcode); |
| } put_user_catch(err); |
| |
| err |= copy_siginfo_to_user32(&frame->info, &ksig->info); |
| 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 (err) |
| return -EFAULT; |
| |
| /* Set up registers for signal handler */ |
| regs->sp = (unsigned long) frame; |
| regs->ip = (unsigned long) ksig->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; |
| } |