/* * Copyright 2010 Tilera Corporation. All Rights Reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation, version 2. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or * NON INFRINGEMENT. See the GNU General Public License for * more details. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include struct compat_sigaction { compat_uptr_t sa_handler; compat_ulong_t sa_flags; compat_uptr_t sa_restorer; sigset_t sa_mask __packed; }; struct compat_ucontext { compat_ulong_t uc_flags; compat_uptr_t uc_link; struct compat_sigaltstack uc_stack; struct sigcontext uc_mcontext; sigset_t uc_sigmask; /* mask last for extensibility */ }; struct compat_rt_sigframe { unsigned char save_area[C_ABI_SAVE_AREA_SIZE]; /* caller save area */ struct compat_siginfo info; struct compat_ucontext uc; }; long compat_sys_rt_sigaction(int sig, struct compat_sigaction __user *act, struct compat_sigaction __user *oact, size_t sigsetsize) { struct k_sigaction new_sa, old_sa; int ret = -EINVAL; /* XXX: Don't preclude handling different sized sigset_t's. */ if (sigsetsize != sizeof(sigset_t)) goto out; if (act) { compat_uptr_t handler, restorer; if (!access_ok(VERIFY_READ, act, sizeof(*act)) || __get_user(handler, &act->sa_handler) || __get_user(new_sa.sa.sa_flags, &act->sa_flags) || __get_user(restorer, &act->sa_restorer) || __copy_from_user(&new_sa.sa.sa_mask, &act->sa_mask, sizeof(sigset_t))) return -EFAULT; new_sa.sa.sa_handler = compat_ptr(handler); new_sa.sa.sa_restorer = compat_ptr(restorer); } ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL); if (!ret && oact) { if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || __put_user(ptr_to_compat(old_sa.sa.sa_handler), &oact->sa_handler) || __put_user(ptr_to_compat(old_sa.sa.sa_restorer), &oact->sa_restorer) || __put_user(old_sa.sa.sa_flags, &oact->sa_flags) || __copy_to_user(&oact->sa_mask, &old_sa.sa.sa_mask, sizeof(sigset_t))) return -EFAULT; } out: return ret; } int copy_siginfo_to_user32(struct compat_siginfo __user *to, siginfo_t *from) { int err; if (!access_ok(VERIFY_WRITE, to, sizeof(struct compat_siginfo))) return -EFAULT; /* 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. */ err = __put_user(from->si_signo, &to->si_signo); err |= __put_user(from->si_errno, &to->si_errno); err |= __put_user((short)from->si_code, &to->si_code); if (from->si_code < 0) { err |= __put_user(from->si_pid, &to->si_pid); err |= __put_user(from->si_uid, &to->si_uid); err |= __put_user(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) */ err |= __put_user(from->_sifields._pad[0], &to->_sifields._pad[0]); switch (from->si_code >> 16) { case __SI_FAULT >> 16: break; case __SI_CHLD >> 16: err |= __put_user(from->si_utime, &to->si_utime); err |= __put_user(from->si_stime, &to->si_stime); err |= __put_user(from->si_status, &to->si_status); /* FALL THROUGH */ default: case __SI_KILL >> 16: err |= __put_user(from->si_uid, &to->si_uid); break; case __SI_POLL >> 16: err |= __put_user(from->si_fd, &to->si_fd); break; case __SI_TIMER >> 16: err |= __put_user(from->si_overrun, &to->si_overrun); err |= __put_user(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: err |= __put_user(from->si_uid, &to->si_uid); err |= __put_user(from->si_int, &to->si_int); break; } } return err; } int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from) { int err; u32 ptr32; if (!access_ok(VERIFY_READ, from, sizeof(struct compat_siginfo))) return -EFAULT; err = __get_user(to->si_signo, &from->si_signo); err |= __get_user(to->si_errno, &from->si_errno); err |= __get_user(to->si_code, &from->si_code); err |= __get_user(to->si_pid, &from->si_pid); err |= __get_user(to->si_uid, &from->si_uid); err |= __get_user(ptr32, &from->si_ptr); to->si_ptr = compat_ptr(ptr32); return err; } /* The assembly shim for this function arranges to ignore the return value. */ long compat_sys_rt_sigreturn(void) { struct pt_regs *regs = current_pt_regs(); struct compat_rt_sigframe __user *frame = (struct compat_rt_sigframe __user *) compat_ptr(regs->sp); sigset_t set; 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 (restore_sigcontext(regs, &frame->uc.uc_mcontext)) goto badframe; if (compat_restore_altstack(&frame->uc.uc_stack)) goto badframe; return 0; badframe: signal_fault("bad sigreturn frame", regs, frame, 0); return 0; } /* * Determine which stack to use.. */ static inline void __user *compat_get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) { unsigned long sp; /* Default to using normal stack */ sp = (unsigned long)compat_ptr(regs->sp); /* * If we are on the alternate signal stack and would overflow * it, don't. Return an always-bogus address instead so we * will die with SIGSEGV. */ if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size))) return (void __user __force *)-1UL; /* 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; } sp -= frame_size; /* * Align the stack pointer according to the TILE ABI, * i.e. so that on function entry (sp & 15) == 0. */ sp &= -16UL; return (void __user *) sp; } int compat_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, struct pt_regs *regs) { unsigned long restorer; struct compat_rt_sigframe __user *frame; int err = 0; int usig; frame = compat_get_sigframe(ka, regs, sizeof(*frame)); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; usig = current_thread_info()->exec_domain && current_thread_info()->exec_domain->signal_invmap && sig < 32 ? current_thread_info()->exec_domain->signal_invmap[sig] : sig; /* Always write at least the signal number for the stack backtracer. */ if (ka->sa.sa_flags & SA_SIGINFO) { /* At sigreturn time, restore the callee-save registers too. */ err |= copy_siginfo_to_user32(&frame->info, info); regs->flags |= PT_FLAGS_RESTORE_REGS; } else { err |= __put_user(info->si_signo, &frame->info.si_signo); } /* Create the ucontext. */ err |= __clear_user(&frame->save_area, sizeof(frame->save_area)); err |= __put_user(0, &frame->uc.uc_flags); err |= __put_user(0, &frame->uc.uc_link); err |= __compat_save_altstack(&frame->uc.uc_stack, regs->sp); err |= setup_sigcontext(&frame->uc.uc_mcontext, regs); err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); if (err) goto give_sigsegv; restorer = VDSO_BASE; if (ka->sa.sa_flags & SA_RESTORER) restorer = ptr_to_compat_reg(ka->sa.sa_restorer); /* * Set up registers for signal handler. * Registers that we don't modify keep the value they had from * user-space at the time we took the signal. * We always pass siginfo and mcontext, regardless of SA_SIGINFO, * since some things rely on this (e.g. glibc's debug/segfault.c). */ regs->pc = ptr_to_compat_reg(ka->sa.sa_handler); regs->ex1 = PL_ICS_EX1(USER_PL, 1); /* set crit sec in handler */ regs->sp = ptr_to_compat_reg(frame); regs->lr = restorer; regs->regs[0] = (unsigned long) usig; regs->regs[1] = ptr_to_compat_reg(&frame->info); regs->regs[2] = ptr_to_compat_reg(&frame->uc); regs->flags |= PT_FLAGS_CALLER_SAVES; return 0; give_sigsegv: signal_fault("bad setup frame", regs, frame, sig); return -EFAULT; }