// SPDX-License-Identifier: GPL-2.0 /* * Copyright 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "compat_linux.h" #include "compat_ptrace.h" #include "entry.h" typedef struct { __u8 callee_used_stack[__SIGNAL_FRAMESIZE32]; struct sigcontext32 sc; _sigregs32 sregs; int signo; _sigregs_ext32 sregs_ext; __u16 svc_insn; /* Offset of svc_insn is NOT fixed! */ } sigframe32; typedef struct { __u8 callee_used_stack[__SIGNAL_FRAMESIZE32]; __u16 svc_insn; compat_siginfo_t info; struct ucontext32 uc; } rt_sigframe32; int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from) { int err; /* 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(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 (siginfo_layout(from->si_signo, from->si_code)) { case SIL_RT: err |= __put_user(from->si_int, &to->si_int); /* fallthrough */ case SIL_KILL: err |= __put_user(from->si_pid, &to->si_pid); err |= __put_user(from->si_uid, &to->si_uid); break; case SIL_CHLD: 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 SIL_FAULT: err |= __put_user((unsigned long) from->si_addr, &to->si_addr); break; case SIL_POLL: err |= __put_user(from->si_band, &to->si_band); err |= __put_user(from->si_fd, &to->si_fd); break; case SIL_TIMER: 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 ? -EFAULT : 0; } int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from) { int err; u32 tmp; 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 (siginfo_layout(to->si_signo, to->si_code)) { case SIL_RT: err |= __get_user(to->si_int, &from->si_int); /* fallthrough */ case SIL_KILL: err |= __get_user(to->si_pid, &from->si_pid); err |= __get_user(to->si_uid, &from->si_uid); break; case SIL_CHLD: 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 SIL_FAULT: err |= __get_user(tmp, &from->si_addr); to->si_addr = (void __force __user *) (u64) (tmp & PSW32_ADDR_INSN); break; case SIL_POLL: err |= __get_user(to->si_band, &from->si_band); err |= __get_user(to->si_fd, &from->si_fd); break; case SIL_TIMER: 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 ? -EFAULT : 0; } /* Store registers needed to create the signal frame */ static void store_sigregs(void) { save_access_regs(current->thread.acrs); save_fpu_regs(); } /* Load registers after signal return */ static void load_sigregs(void) { restore_access_regs(current->thread.acrs); } static int save_sigregs32(struct pt_regs *regs, _sigregs32 __user *sregs) { _sigregs32 user_sregs; int i; user_sregs.regs.psw.mask = (__u32)(regs->psw.mask >> 32); user_sregs.regs.psw.mask &= PSW32_MASK_USER | PSW32_MASK_RI; user_sregs.regs.psw.mask |= PSW32_USER_BITS; user_sregs.regs.psw.addr = (__u32) regs->psw.addr | (__u32)(regs->psw.mask & PSW_MASK_BA); for (i = 0; i < NUM_GPRS; i++) user_sregs.regs.gprs[i] = (__u32) regs->gprs[i]; memcpy(&user_sregs.regs.acrs, current->thread.acrs, sizeof(user_sregs.regs.acrs)); fpregs_store((_s390_fp_regs *) &user_sregs.fpregs, ¤t->thread.fpu); if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs32))) return -EFAULT; return 0; } static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs) { _sigregs32 user_sregs; int i; /* Alwys make any pending restarted system call return -EINTR */ current->restart_block.fn = do_no_restart_syscall; if (__copy_from_user(&user_sregs, &sregs->regs, sizeof(user_sregs))) return -EFAULT; if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW32_MASK_RI)) return -EINVAL; /* Test the floating-point-control word. */ if (test_fp_ctl(user_sregs.fpregs.fpc)) return -EINVAL; /* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */ regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) | (__u64)(user_sregs.regs.psw.mask & PSW32_MASK_USER) << 32 | (__u64)(user_sregs.regs.psw.mask & PSW32_MASK_RI) << 32 | (__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_AMODE); /* Check for invalid user address space control. */ if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME) regs->psw.mask = PSW_ASC_PRIMARY | (regs->psw.mask & ~PSW_MASK_ASC); regs->psw.addr = (__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_INSN); for (i = 0; i < NUM_GPRS; i++) regs->gprs[i] = (__u64) user_sregs.regs.gprs[i]; memcpy(¤t->thread.acrs, &user_sregs.regs.acrs, sizeof(current->thread.acrs)); fpregs_load((_s390_fp_regs *) &user_sregs.fpregs, ¤t->thread.fpu); clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */ return 0; } static int save_sigregs_ext32(struct pt_regs *regs, _sigregs_ext32 __user *sregs_ext) { __u32 gprs_high[NUM_GPRS]; __u64 vxrs[__NUM_VXRS_LOW]; int i; /* Save high gprs to signal stack */ for (i = 0; i < NUM_GPRS; i++) gprs_high[i] = regs->gprs[i] >> 32; if (__copy_to_user(&sregs_ext->gprs_high, &gprs_high, sizeof(sregs_ext->gprs_high))) return -EFAULT; /* Save vector registers to signal stack */ if (MACHINE_HAS_VX) { for (i = 0; i < __NUM_VXRS_LOW; i++) vxrs[i] = *((__u64 *)(current->thread.fpu.vxrs + i) + 1); if (__copy_to_user(&sregs_ext->vxrs_low, vxrs, sizeof(sregs_ext->vxrs_low)) || __copy_to_user(&sregs_ext->vxrs_high, current->thread.fpu.vxrs + __NUM_VXRS_LOW, sizeof(sregs_ext->vxrs_high))) return -EFAULT; } return 0; } static int restore_sigregs_ext32(struct pt_regs *regs, _sigregs_ext32 __user *sregs_ext) { __u32 gprs_high[NUM_GPRS]; __u64 vxrs[__NUM_VXRS_LOW]; int i; /* Restore high gprs from signal stack */ if (__copy_from_user(&gprs_high, &sregs_ext->gprs_high, sizeof(sregs_ext->gprs_high))) return -EFAULT; for (i = 0; i < NUM_GPRS; i++) *(__u32 *)®s->gprs[i] = gprs_high[i]; /* Restore vector registers from signal stack */ if (MACHINE_HAS_VX) { if (__copy_from_user(vxrs, &sregs_ext->vxrs_low, sizeof(sregs_ext->vxrs_low)) || __copy_from_user(current->thread.fpu.vxrs + __NUM_VXRS_LOW, &sregs_ext->vxrs_high, sizeof(sregs_ext->vxrs_high))) return -EFAULT; for (i = 0; i < __NUM_VXRS_LOW; i++) *((__u64 *)(current->thread.fpu.vxrs + i) + 1) = vxrs[i]; } return 0; } COMPAT_SYSCALL_DEFINE0(sigreturn) { struct pt_regs *regs = task_pt_regs(current); sigframe32 __user *frame = (sigframe32 __user *)regs->gprs[15]; sigset_t set; if (get_compat_sigset(&set, (compat_sigset_t __user *)frame->sc.oldmask)) goto badframe; set_current_blocked(&set); save_fpu_regs(); if (restore_sigregs32(regs, &frame->sregs)) goto badframe; if (restore_sigregs_ext32(regs, &frame->sregs_ext)) goto badframe; load_sigregs(); return regs->gprs[2]; badframe: force_sig(SIGSEGV, current); return 0; } COMPAT_SYSCALL_DEFINE0(rt_sigreturn) { struct pt_regs *regs = task_pt_regs(current); rt_sigframe32 __user *frame = (rt_sigframe32 __user *)regs->gprs[15]; sigset_t set; if (get_compat_sigset(&set, &frame->uc.uc_sigmask)) goto badframe; set_current_blocked(&set); if (compat_restore_altstack(&frame->uc.uc_stack)) goto badframe; save_fpu_regs(); if (restore_sigregs32(regs, &frame->uc.uc_mcontext)) goto badframe; if (restore_sigregs_ext32(regs, &frame->uc.uc_mcontext_ext)) goto badframe; load_sigregs(); 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; } return (void __user *)((sp - frame_size) & -8ul); } static int setup_frame32(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) { int sig = ksig->sig; sigframe32 __user *frame; unsigned long restorer; size_t frame_size; /* * gprs_high are always present for 31-bit compat tasks. * The space for vector registers is only allocated if * the machine supports it */ frame_size = sizeof(*frame) - sizeof(frame->sregs_ext.__reserved); if (!MACHINE_HAS_VX) frame_size -= sizeof(frame->sregs_ext.vxrs_low) + sizeof(frame->sregs_ext.vxrs_high); frame = get_sigframe(&ksig->ka, regs, frame_size); if (frame == (void __user *) -1UL) return -EFAULT; /* Set up backchain. */ if (__put_user(regs->gprs[15], (unsigned int __user *) frame)) return -EFAULT; /* Create struct sigcontext32 on the signal stack */ if (put_compat_sigset((compat_sigset_t __user *)frame->sc.oldmask, set, sizeof(compat_sigset_t))) return -EFAULT; if (__put_user(ptr_to_compat(&frame->sc), &frame->sc.sregs)) return -EFAULT; /* Store registers needed to create the signal frame */ store_sigregs(); /* Create _sigregs32 on the signal stack */ if (save_sigregs32(regs, &frame->sregs)) return -EFAULT; /* Place signal number on stack to allow backtrace from handler. */ if (__put_user(regs->gprs[2], (int __force __user *) &frame->signo)) return -EFAULT; /* Create _sigregs_ext32 on the signal stack */ if (save_sigregs_ext32(regs, &frame->sregs_ext)) return -EFAULT; /* Set up to return from userspace. If provided, use a stub already in userspace. */ if (ksig->ka.sa.sa_flags & SA_RESTORER) { restorer = (unsigned long __force) ksig->ka.sa.sa_restorer | PSW32_ADDR_AMODE; } else { /* Signal frames without vectors registers are short ! */ __u16 __user *svc = (void __user *) frame + frame_size - 2; if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn, svc)) return -EFAULT; restorer = (unsigned long __force) svc | PSW32_ADDR_AMODE; } /* Set up registers for signal handler */ regs->gprs[14] = restorer; regs->gprs[15] = (__force __u64) frame; /* Force 31 bit amode and default user address space control. */ regs->psw.mask = PSW_MASK_BA | (PSW_USER_BITS & PSW_MASK_ASC) | (regs->psw.mask & ~PSW_MASK_ASC); regs->psw.addr = (__force __u64) ksig->ka.sa.sa_handler; regs->gprs[2] = 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. */ if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL || sig == SIGTRAP || sig == SIGFPE) { /* set extra registers only for synchronous signals */ regs->gprs[4] = regs->int_code & 127; regs->gprs[5] = regs->int_parm_long; regs->gprs[6] = current->thread.last_break; } return 0; } static int setup_rt_frame32(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) { rt_sigframe32 __user *frame; unsigned long restorer; size_t frame_size; u32 uc_flags; frame_size = sizeof(*frame) - sizeof(frame->uc.uc_mcontext_ext.__reserved); /* * gprs_high are always present for 31-bit compat tasks. * The space for vector registers is only allocated if * the machine supports it */ uc_flags = UC_GPRS_HIGH; if (MACHINE_HAS_VX) { uc_flags |= UC_VXRS; } else frame_size -= sizeof(frame->uc.uc_mcontext_ext.vxrs_low) + sizeof(frame->uc.uc_mcontext_ext.vxrs_high); frame = get_sigframe(&ksig->ka, regs, frame_size); if (frame == (void __user *) -1UL) return -EFAULT; /* Set up backchain. */ if (__put_user(regs->gprs[15], (unsigned int __force __user *) frame)) return -EFAULT; /* Set up to return from userspace. If provided, use a stub already in userspace. */ if (ksig->ka.sa.sa_flags & SA_RESTORER) { restorer = (unsigned long __force) ksig->ka.sa.sa_restorer | PSW32_ADDR_AMODE; } else { __u16 __user *svc = &frame->svc_insn; if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn, svc)) return -EFAULT; restorer = (unsigned long __force) svc | PSW32_ADDR_AMODE; } /* Create siginfo on the signal stack */ if (copy_siginfo_to_user32(&frame->info, &ksig->info)) return -EFAULT; /* Store registers needed to create the signal frame */ store_sigregs(); /* Create ucontext on the signal stack. */ if (__put_user(uc_flags, &frame->uc.uc_flags) || __put_user(0, &frame->uc.uc_link) || __compat_save_altstack(&frame->uc.uc_stack, regs->gprs[15]) || save_sigregs32(regs, &frame->uc.uc_mcontext) || put_compat_sigset(&frame->uc.uc_sigmask, set, sizeof(compat_sigset_t)) || save_sigregs_ext32(regs, &frame->uc.uc_mcontext_ext)) return -EFAULT; /* Set up registers for signal handler */ regs->gprs[14] = restorer; regs->gprs[15] = (__force __u64) frame; /* Force 31 bit amode and default user address space control. */ regs->psw.mask = PSW_MASK_BA | (PSW_USER_BITS & PSW_MASK_ASC) | (regs->psw.mask & ~PSW_MASK_ASC); regs->psw.addr = (__u64 __force) ksig->ka.sa.sa_handler; regs->gprs[2] = ksig->sig; regs->gprs[3] = (__force __u64) &frame->info; regs->gprs[4] = (__force __u64) &frame->uc; regs->gprs[5] = current->thread.last_break; return 0; } /* * OK, we're invoking a handler */ void handle_signal32(struct ksignal *ksig, sigset_t *oldset, struct pt_regs *regs) { int ret; /* Set up the stack frame */ if (ksig->ka.sa.sa_flags & SA_SIGINFO) ret = setup_rt_frame32(ksig, oldset, regs); else ret = setup_frame32(ksig, oldset, regs); signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLE_STEP)); }