/* * arch/s390/kernel/compat_signal.c * * Copyright (C) IBM Corp. 2000,2006 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com) * Gerhard Tonn (ton@de.ibm.com) * * Copyright (C) 1991, 1992 Linus Torvalds * * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson */ #include <linux/compat.h> #include <linux/sched.h> #include <linux/mm.h> #include <linux/smp.h> #include <linux/kernel.h> #include <linux/signal.h> #include <linux/errno.h> #include <linux/wait.h> #include <linux/ptrace.h> #include <linux/unistd.h> #include <linux/stddef.h> #include <linux/tty.h> #include <linux/personality.h> #include <linux/binfmts.h> #include <asm/ucontext.h> #include <asm/uaccess.h> #include <asm/lowcore.h> #include "compat_linux.h" #include "compat_ptrace.h" #include "entry.h" #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) typedef struct { __u8 callee_used_stack[__SIGNAL_FRAMESIZE32]; struct sigcontext32 sc; _sigregs32 sregs; int signo; __u32 gprs_high[NUM_GPRS]; __u8 retcode[S390_SYSCALL_SIZE]; } sigframe32; typedef struct { __u8 callee_used_stack[__SIGNAL_FRAMESIZE32]; __u8 retcode[S390_SYSCALL_SIZE]; compat_siginfo_t info; struct ucontext32 uc; __u32 gprs_high[NUM_GPRS]; } rt_sigframe32; int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from) { int err; if (!access_ok (VERIFY_WRITE, to, sizeof(compat_siginfo_t))) return -EFAULT; /* If you change siginfo_t structure, please be sure 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. This routine must convert siginfo from 64bit to 32bit as well at the same time. */ 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 |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE); else { switch (from->si_code >> 16) { case __SI_RT >> 16: /* This is not generated by the kernel as of now. */ case __SI_MESGQ >> 16: err |= __put_user(from->si_int, &to->si_int); /* fallthrough */ case __SI_KILL >> 16: err |= __put_user(from->si_pid, &to->si_pid); err |= __put_user(from->si_uid, &to->si_uid); break; case __SI_CHLD >> 16: err |= __put_user(from->si_pid, &to->si_pid); err |= __put_user(from->si_uid, &to->si_uid); 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); break; case __SI_FAULT >> 16: err |= __put_user((unsigned long) from->si_addr, &to->si_addr); break; case __SI_POLL >> 16: err |= __put_user(from->si_band, &to->si_band); err |= __put_user(from->si_fd, &to->si_fd); break; case __SI_TIMER >> 16: err |= __put_user(from->si_tid, &to->si_tid); err |= __put_user(from->si_overrun, &to->si_overrun); err |= __put_user(from->si_int, &to->si_int); break; default: break; } } return err; } int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from) { int err; u32 tmp; if (!access_ok (VERIFY_READ, from, sizeof(compat_siginfo_t))) 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); if (to->si_code < 0) err |= __copy_from_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE); else { switch (to->si_code >> 16) { case __SI_RT >> 16: /* This is not generated by the kernel as of now. */ case __SI_MESGQ >> 16: err |= __get_user(to->si_int, &from->si_int); /* fallthrough */ case __SI_KILL >> 16: err |= __get_user(to->si_pid, &from->si_pid); err |= __get_user(to->si_uid, &from->si_uid); break; case __SI_CHLD >> 16: err |= __get_user(to->si_pid, &from->si_pid); err |= __get_user(to->si_uid, &from->si_uid); err |= __get_user(to->si_utime, &from->si_utime); err |= __get_user(to->si_stime, &from->si_stime); err |= __get_user(to->si_status, &from->si_status); break; case __SI_FAULT >> 16: err |= __get_user(tmp, &from->si_addr); to->si_addr = (void __force __user *) (u64) (tmp & PSW32_ADDR_INSN); break; case __SI_POLL >> 16: err |= __get_user(to->si_band, &from->si_band); err |= __get_user(to->si_fd, &from->si_fd); break; case __SI_TIMER >> 16: err |= __get_user(to->si_tid, &from->si_tid); err |= __get_user(to->si_overrun, &from->si_overrun); err |= __get_user(to->si_int, &from->si_int); break; default: break; } } return err; } asmlinkage long sys32_sigaction(int sig, const struct old_sigaction32 __user *act, struct old_sigaction32 __user *oact) { struct k_sigaction new_ka, old_ka; unsigned long sa_handler, sa_restorer; int ret; if (act) { compat_old_sigset_t mask; if (!access_ok(VERIFY_READ, act, sizeof(*act)) || __get_user(sa_handler, &act->sa_handler) || __get_user(sa_restorer, &act->sa_restorer) || __get_user(new_ka.sa.sa_flags, &act->sa_flags) || __get_user(mask, &act->sa_mask)) return -EFAULT; new_ka.sa.sa_handler = (__sighandler_t) sa_handler; new_ka.sa.sa_restorer = (void (*)(void)) sa_restorer; siginitset(&new_ka.sa.sa_mask, mask); } ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); if (!ret && oact) { sa_handler = (unsigned long) old_ka.sa.sa_handler; sa_restorer = (unsigned long) old_ka.sa.sa_restorer; if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || __put_user(sa_handler, &oact->sa_handler) || __put_user(sa_restorer, &oact->sa_restorer) || __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) return -EFAULT; } return ret; } asmlinkage long sys32_rt_sigaction(int sig, const struct sigaction32 __user *act, struct sigaction32 __user *oact, size_t sigsetsize) { struct k_sigaction new_ka, old_ka; unsigned long sa_handler; int ret; compat_sigset_t set32; /* XXX: Don't preclude handling different sized sigset_t's. */ if (sigsetsize != sizeof(compat_sigset_t)) return -EINVAL; if (act) { ret = get_user(sa_handler, &act->sa_handler); ret |= __copy_from_user(&set32, &act->sa_mask, sizeof(compat_sigset_t)); new_ka.sa.sa_mask.sig[0] = set32.sig[0] | (((long)set32.sig[1]) << 32); ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags); if (ret) return -EFAULT; new_ka.sa.sa_handler = (__sighandler_t) sa_handler; } ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); if (!ret && oact) { set32.sig[1] = (old_ka.sa.sa_mask.sig[0] >> 32); set32.sig[0] = old_ka.sa.sa_mask.sig[0]; ret = put_user((unsigned long)old_ka.sa.sa_handler, &oact->sa_handler); ret |= __copy_to_user(&oact->sa_mask, &set32, sizeof(compat_sigset_t)); ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags); } return ret; } asmlinkage long sys32_sigaltstack(const stack_t32 __user *uss, stack_t32 __user *uoss) { struct pt_regs *regs = task_pt_regs(current); stack_t kss, koss; unsigned long ss_sp; int ret, err = 0; mm_segment_t old_fs = get_fs(); if (uss) { if (!access_ok(VERIFY_READ, uss, sizeof(*uss))) return -EFAULT; err |= __get_user(ss_sp, &uss->ss_sp); err |= __get_user(kss.ss_size, &uss->ss_size); err |= __get_user(kss.ss_flags, &uss->ss_flags); if (err) return -EFAULT; kss.ss_sp = (void __user *) ss_sp; } set_fs (KERNEL_DS); ret = do_sigaltstack((stack_t __force __user *) (uss ? &kss : NULL), (stack_t __force __user *) (uoss ? &koss : NULL), regs->gprs[15]); set_fs (old_fs); if (!ret && uoss) { if (!access_ok(VERIFY_WRITE, uoss, sizeof(*uoss))) return -EFAULT; ss_sp = (unsigned long) koss.ss_sp; err |= __put_user(ss_sp, &uoss->ss_sp); err |= __put_user(koss.ss_size, &uoss->ss_size); err |= __put_user(koss.ss_flags, &uoss->ss_flags); if (err) return -EFAULT; } return ret; } static int save_sigregs32(struct pt_regs *regs, _sigregs32 __user *sregs) { _s390_regs_common32 regs32; int err, i; regs32.psw.mask = psw32_user_bits | ((__u32)(regs->psw.mask >> 32) & PSW32_MASK_USER); regs32.psw.addr = (__u32) regs->psw.addr | (__u32)(regs->psw.mask & PSW_MASK_BA); for (i = 0; i < NUM_GPRS; i++) regs32.gprs[i] = (__u32) regs->gprs[i]; save_access_regs(current->thread.acrs); memcpy(regs32.acrs, current->thread.acrs, sizeof(regs32.acrs)); err = __copy_to_user(&sregs->regs, ®s32, sizeof(regs32)); if (err) return err; save_fp_regs(¤t->thread.fp_regs); /* s390_fp_regs and _s390_fp_regs32 are the same ! */ return __copy_to_user(&sregs->fpregs, ¤t->thread.fp_regs, sizeof(_s390_fp_regs32)); } static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs) { _s390_regs_common32 regs32; int err, i; /* Alwys make any pending restarted system call return -EINTR */ current_thread_info()->restart_block.fn = do_no_restart_syscall; err = __copy_from_user(®s32, &sregs->regs, sizeof(regs32)); if (err) return err; regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) | (__u64)(regs32.psw.mask & PSW32_MASK_USER) << 32 | (__u64)(regs32.psw.addr & PSW32_ADDR_AMODE); regs->psw.addr = (__u64)(regs32.psw.addr & PSW32_ADDR_INSN); for (i = 0; i < NUM_GPRS; i++) regs->gprs[i] = (__u64) regs32.gprs[i]; memcpy(current->thread.acrs, regs32.acrs, sizeof(current->thread.acrs)); restore_access_regs(current->thread.acrs); err = __copy_from_user(¤t->thread.fp_regs, &sregs->fpregs, sizeof(_s390_fp_regs32)); current->thread.fp_regs.fpc &= FPC_VALID_MASK; if (err) return err; restore_fp_regs(¤t->thread.fp_regs); clear_thread_flag(TIF_SYSCALL); /* No longer in a system call */ return 0; } static int save_sigregs_gprs_high(struct pt_regs *regs, __u32 __user *uregs) { __u32 gprs_high[NUM_GPRS]; int i; for (i = 0; i < NUM_GPRS; i++) gprs_high[i] = regs->gprs[i] >> 32; return __copy_to_user(uregs, &gprs_high, sizeof(gprs_high)); } static int restore_sigregs_gprs_high(struct pt_regs *regs, __u32 __user *uregs) { __u32 gprs_high[NUM_GPRS]; int err, i; err = __copy_from_user(&gprs_high, uregs, sizeof(gprs_high)); if (err) return err; for (i = 0; i < NUM_GPRS; i++) *(__u32 *)®s->gprs[i] = gprs_high[i]; return 0; } asmlinkage long sys32_sigreturn(void) { struct pt_regs *regs = task_pt_regs(current); sigframe32 __user *frame = (sigframe32 __user *)regs->gprs[15]; sigset_t set; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) goto badframe; if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE32)) goto badframe; sigdelsetmask(&set, ~_BLOCKABLE); set_current_blocked(&set); if (restore_sigregs32(regs, &frame->sregs)) goto badframe; if (restore_sigregs_gprs_high(regs, frame->gprs_high)) goto badframe; return regs->gprs[2]; badframe: force_sig(SIGSEGV, current); return 0; } asmlinkage long sys32_rt_sigreturn(void) { struct pt_regs *regs = task_pt_regs(current); rt_sigframe32 __user *frame = (rt_sigframe32 __user *)regs->gprs[15]; sigset_t set; stack_t st; __u32 ss_sp; int err; mm_segment_t old_fs = get_fs(); 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); set_current_blocked(&set); if (restore_sigregs32(regs, &frame->uc.uc_mcontext)) goto badframe; if (restore_sigregs_gprs_high(regs, frame->gprs_high)) goto badframe; err = __get_user(ss_sp, &frame->uc.uc_stack.ss_sp); st.ss_sp = compat_ptr(ss_sp); err |= __get_user(st.ss_size, &frame->uc.uc_stack.ss_size); err |= __get_user(st.ss_flags, &frame->uc.uc_stack.ss_flags); if (err) goto badframe; set_fs (KERNEL_DS); do_sigaltstack((stack_t __force __user *)&st, NULL, regs->gprs[15]); set_fs (old_fs); return regs->gprs[2]; badframe: force_sig(SIGSEGV, current); return 0; } /* * Set up a signal frame. */ /* * Determine which stack to use.. */ static inline void __user * 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) A(regs->gprs[15]); /* Overflow on alternate signal stack gives SIGSEGV. */ if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL)) return (void __user *) -1UL; /* This is the X/Open sanctioned signal stack switching. */ if (ka->sa.sa_flags & SA_ONSTACK) { if (! sas_ss_flags(sp)) sp = current->sas_ss_sp + current->sas_ss_size; } /* This is the legacy signal stack switching. */ else if (!user_mode(regs) && !(ka->sa.sa_flags & SA_RESTORER) && ka->sa.sa_restorer) { sp = (unsigned long) ka->sa.sa_restorer; } return (void __user *)((sp - frame_size) & -8ul); } static inline int map_signal(int sig) { if (current_thread_info()->exec_domain && current_thread_info()->exec_domain->signal_invmap && sig < 32) return current_thread_info()->exec_domain->signal_invmap[sig]; else return sig; } static int setup_frame32(int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs * regs) { sigframe32 __user *frame = get_sigframe(ka, regs, sizeof(sigframe32)); if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe32))) goto give_sigsegv; if (frame == (void __user *) -1UL) goto give_sigsegv; if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE32)) goto give_sigsegv; if (save_sigregs32(regs, &frame->sregs)) goto give_sigsegv; if (save_sigregs_gprs_high(regs, frame->gprs_high)) goto give_sigsegv; if (__put_user((unsigned long) &frame->sregs, &frame->sc.sregs)) goto give_sigsegv; /* Set up to return from userspace. If provided, use a stub already in userspace. */ if (ka->sa.sa_flags & SA_RESTORER) { regs->gprs[14] = (__u64) ka->sa.sa_restorer | PSW32_ADDR_AMODE; } else { regs->gprs[14] = (__u64) frame->retcode | PSW32_ADDR_AMODE; if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn, (u16 __force __user *)(frame->retcode))) goto give_sigsegv; } /* Set up backchain. */ if (__put_user(regs->gprs[15], (unsigned int __user *) frame)) goto give_sigsegv; /* Set up registers for signal handler */ regs->gprs[15] = (__force __u64) frame; regs->psw.mask |= PSW_MASK_BA; /* force amode 31 */ regs->psw.addr = (__force __u64) ka->sa.sa_handler; regs->gprs[2] = map_signal(sig); regs->gprs[3] = (__force __u64) &frame->sc; /* We forgot to include these in the sigcontext. To avoid breaking binary compatibility, they are passed as args. */ regs->gprs[4] = current->thread.trap_no; regs->gprs[5] = current->thread.prot_addr; /* Place signal number on stack to allow backtrace from handler. */ if (__put_user(regs->gprs[2], (int __force __user *) &frame->signo)) goto give_sigsegv; return 0; give_sigsegv: force_sigsegv(sig, current); return -EFAULT; } static int setup_rt_frame32(int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, struct pt_regs * regs) { int err = 0; rt_sigframe32 __user *frame = get_sigframe(ka, regs, sizeof(rt_sigframe32)); if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe32))) goto give_sigsegv; if (frame == (void __user *) -1UL) goto give_sigsegv; if (copy_siginfo_to_user32(&frame->info, info)) goto give_sigsegv; /* Create the ucontext. */ err |= __put_user(UC_EXTENDED, &frame->uc.uc_flags); err |= __put_user(0, &frame->uc.uc_link); err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); err |= __put_user(sas_ss_flags(regs->gprs[15]), &frame->uc.uc_stack.ss_flags); err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); err |= save_sigregs32(regs, &frame->uc.uc_mcontext); err |= save_sigregs_gprs_high(regs, frame->gprs_high); err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); if (err) goto give_sigsegv; /* Set up to return from userspace. If provided, use a stub already in userspace. */ if (ka->sa.sa_flags & SA_RESTORER) { regs->gprs[14] = (__u64) ka->sa.sa_restorer; } else { regs->gprs[14] = (__u64) frame->retcode; err |= __put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn, (u16 __force __user *)(frame->retcode)); } /* Set up backchain. */ if (__put_user(regs->gprs[15], (unsigned int __force __user *) frame)) goto give_sigsegv; /* Set up registers for signal handler */ regs->gprs[15] = (__force __u64) frame; regs->psw.mask |= PSW_MASK_BA; /* force amode 31 */ regs->psw.addr = (__u64) ka->sa.sa_handler; regs->gprs[2] = map_signal(sig); regs->gprs[3] = (__force __u64) &frame->info; regs->gprs[4] = (__force __u64) &frame->uc; return 0; give_sigsegv: force_sigsegv(sig, current); return -EFAULT; } /* * OK, we're invoking a handler */ int handle_signal32(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *oldset, struct pt_regs *regs) { sigset_t blocked; int ret; /* Set up the stack frame */ if (ka->sa.sa_flags & SA_SIGINFO) ret = setup_rt_frame32(sig, ka, info, oldset, regs); else ret = setup_frame32(sig, ka, oldset, regs); if (ret) return ret; sigorsets(&blocked, ¤t->blocked, &ka->sa.sa_mask); if (!(ka->sa.sa_flags & SA_NODEFER)) sigaddset(&blocked, sig); set_current_blocked(&blocked); return 0; }