/* * Emulation of Linux signals * * Copyright (c) 2003 Fabrice Bellard * * 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; either version 2 of the License, or * (at your option) any later version. * * 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. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see <http://www.gnu.org/licenses/>. */ #include "qemu/osdep.h" #include "qemu.h" #include "target_signal.h" #include "signal-common.h" #include "linux-user/trace.h" /* * code and data structures from linux kernel: * include/asm-sh/sigcontext.h * arch/sh/kernel/signal.c */ struct target_sigcontext { target_ulong oldmask; /* CPU registers */ target_ulong sc_gregs[16]; target_ulong sc_pc; target_ulong sc_pr; target_ulong sc_sr; target_ulong sc_gbr; target_ulong sc_mach; target_ulong sc_macl; /* FPU registers */ target_ulong sc_fpregs[16]; target_ulong sc_xfpregs[16]; unsigned int sc_fpscr; unsigned int sc_fpul; unsigned int sc_ownedfp; }; struct target_sigframe { struct target_sigcontext sc; target_ulong extramask[TARGET_NSIG_WORDS-1]; uint16_t retcode[3]; }; struct target_ucontext { target_ulong tuc_flags; struct target_ucontext *tuc_link; target_stack_t tuc_stack; struct target_sigcontext tuc_mcontext; target_sigset_t tuc_sigmask; /* mask last for extensibility */ }; struct target_rt_sigframe { struct target_siginfo info; struct target_ucontext uc; uint16_t retcode[3]; }; #define MOVW(n) (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */ #define TRAP_NOARG 0xc310 /* Syscall w/no args (NR in R3) SH3/4 */ static abi_ulong get_sigframe(struct target_sigaction *ka, unsigned long sp, size_t frame_size) { sp = target_sigsp(sp, ka); return (sp - frame_size) & -8ul; } /* Notice when we're in the middle of a gUSA region and reset. Note that this will only occur for !parallel_cpus, as we will translate such sequences differently in a parallel context. */ static void unwind_gusa(CPUSH4State *regs) { /* If the stack pointer is sufficiently negative, and we haven't completed the sequence, then reset to the entry to the region. */ /* ??? The SH4 kernel checks for and address above 0xC0000000. However, the page mappings in qemu linux-user aren't as restricted and we wind up with the normal stack mapped above 0xF0000000. That said, there is no reason why the kernel should be allowing a gUSA region that spans 1GB. Use a tighter check here, for what can actually be enabled by the immediate move. */ if (regs->gregs[15] >= -128u && regs->pc < regs->gregs[0]) { /* Reset the PC to before the gUSA region, as computed from R0 = region end, SP = -(region size), plus one more for the insn that actually initializes SP to the region size. */ regs->pc = regs->gregs[0] + regs->gregs[15] - 2; /* Reset the SP to the saved version in R1. */ regs->gregs[15] = regs->gregs[1]; } } static void setup_sigcontext(struct target_sigcontext *sc, CPUSH4State *regs, unsigned long mask) { int i; #define COPY(x) __put_user(regs->x, &sc->sc_##x) COPY(gregs[0]); COPY(gregs[1]); COPY(gregs[2]); COPY(gregs[3]); COPY(gregs[4]); COPY(gregs[5]); COPY(gregs[6]); COPY(gregs[7]); COPY(gregs[8]); COPY(gregs[9]); COPY(gregs[10]); COPY(gregs[11]); COPY(gregs[12]); COPY(gregs[13]); COPY(gregs[14]); COPY(gregs[15]); COPY(gbr); COPY(mach); COPY(macl); COPY(pr); COPY(sr); COPY(pc); #undef COPY for (i=0; i<16; i++) { __put_user(regs->fregs[i], &sc->sc_fpregs[i]); } __put_user(regs->fpscr, &sc->sc_fpscr); __put_user(regs->fpul, &sc->sc_fpul); /* non-iBCS2 extensions.. */ __put_user(mask, &sc->oldmask); } static void restore_sigcontext(CPUSH4State *regs, struct target_sigcontext *sc) { int i; #define COPY(x) __get_user(regs->x, &sc->sc_##x) COPY(gregs[0]); COPY(gregs[1]); COPY(gregs[2]); COPY(gregs[3]); COPY(gregs[4]); COPY(gregs[5]); COPY(gregs[6]); COPY(gregs[7]); COPY(gregs[8]); COPY(gregs[9]); COPY(gregs[10]); COPY(gregs[11]); COPY(gregs[12]); COPY(gregs[13]); COPY(gregs[14]); COPY(gregs[15]); COPY(gbr); COPY(mach); COPY(macl); COPY(pr); COPY(sr); COPY(pc); #undef COPY for (i=0; i<16; i++) { __get_user(regs->fregs[i], &sc->sc_fpregs[i]); } __get_user(regs->fpscr, &sc->sc_fpscr); __get_user(regs->fpul, &sc->sc_fpul); regs->tra = -1; /* disable syscall checks */ regs->flags &= ~(DELAY_SLOT_MASK | GUSA_MASK); } void setup_frame(int sig, struct target_sigaction *ka, target_sigset_t *set, CPUSH4State *regs) { struct target_sigframe *frame; abi_ulong frame_addr; int i; unwind_gusa(regs); frame_addr = get_sigframe(ka, regs->gregs[15], sizeof(*frame)); trace_user_setup_frame(regs, frame_addr); if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { goto give_sigsegv; } setup_sigcontext(&frame->sc, regs, set->sig[0]); for (i = 0; i < TARGET_NSIG_WORDS - 1; i++) { __put_user(set->sig[i + 1], &frame->extramask[i]); } /* Set up to return from userspace. If provided, use a stub already in userspace. */ if (ka->sa_flags & TARGET_SA_RESTORER) { regs->pr = (unsigned long) ka->sa_restorer; } else { /* Generate return code (system call to sigreturn) */ abi_ulong retcode_addr = frame_addr + offsetof(struct target_sigframe, retcode); __put_user(MOVW(2), &frame->retcode[0]); __put_user(TRAP_NOARG, &frame->retcode[1]); __put_user((TARGET_NR_sigreturn), &frame->retcode[2]); regs->pr = (unsigned long) retcode_addr; } /* Set up registers for signal handler */ regs->gregs[15] = frame_addr; regs->gregs[4] = sig; /* Arg for signal handler */ regs->gregs[5] = 0; regs->gregs[6] = frame_addr += offsetof(typeof(*frame), sc); regs->pc = (unsigned long) ka->_sa_handler; regs->flags &= ~(DELAY_SLOT_MASK | GUSA_MASK); unlock_user_struct(frame, frame_addr, 1); return; give_sigsegv: unlock_user_struct(frame, frame_addr, 1); force_sigsegv(sig); } void setup_rt_frame(int sig, struct target_sigaction *ka, target_siginfo_t *info, target_sigset_t *set, CPUSH4State *regs) { struct target_rt_sigframe *frame; abi_ulong frame_addr; int i; unwind_gusa(regs); frame_addr = get_sigframe(ka, regs->gregs[15], sizeof(*frame)); trace_user_setup_rt_frame(regs, frame_addr); if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { goto give_sigsegv; } tswap_siginfo(&frame->info, info); /* Create the ucontext. */ __put_user(0, &frame->uc.tuc_flags); __put_user(0, (unsigned long *)&frame->uc.tuc_link); target_save_altstack(&frame->uc.tuc_stack, regs); setup_sigcontext(&frame->uc.tuc_mcontext, regs, set->sig[0]); for(i = 0; i < TARGET_NSIG_WORDS; i++) { __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]); } /* Set up to return from userspace. If provided, use a stub already in userspace. */ if (ka->sa_flags & TARGET_SA_RESTORER) { regs->pr = (unsigned long) ka->sa_restorer; } else { /* Generate return code (system call to sigreturn) */ abi_ulong retcode_addr = frame_addr + offsetof(struct target_rt_sigframe, retcode); __put_user(MOVW(2), &frame->retcode[0]); __put_user(TRAP_NOARG, &frame->retcode[1]); __put_user((TARGET_NR_rt_sigreturn), &frame->retcode[2]); regs->pr = (unsigned long) retcode_addr; } /* Set up registers for signal handler */ regs->gregs[15] = frame_addr; regs->gregs[4] = sig; /* Arg for signal handler */ regs->gregs[5] = frame_addr + offsetof(typeof(*frame), info); regs->gregs[6] = frame_addr + offsetof(typeof(*frame), uc); regs->pc = (unsigned long) ka->_sa_handler; regs->flags &= ~(DELAY_SLOT_MASK | GUSA_MASK); unlock_user_struct(frame, frame_addr, 1); return; give_sigsegv: unlock_user_struct(frame, frame_addr, 1); force_sigsegv(sig); } long do_sigreturn(CPUSH4State *regs) { struct target_sigframe *frame; abi_ulong frame_addr; sigset_t blocked; target_sigset_t target_set; int i; int err = 0; frame_addr = regs->gregs[15]; trace_user_do_sigreturn(regs, frame_addr); if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { goto badframe; } __get_user(target_set.sig[0], &frame->sc.oldmask); for(i = 1; i < TARGET_NSIG_WORDS; i++) { __get_user(target_set.sig[i], &frame->extramask[i - 1]); } if (err) goto badframe; target_to_host_sigset_internal(&blocked, &target_set); set_sigmask(&blocked); restore_sigcontext(regs, &frame->sc); unlock_user_struct(frame, frame_addr, 0); return -TARGET_QEMU_ESIGRETURN; badframe: unlock_user_struct(frame, frame_addr, 0); force_sig(TARGET_SIGSEGV); return -TARGET_QEMU_ESIGRETURN; } long do_rt_sigreturn(CPUSH4State *regs) { struct target_rt_sigframe *frame; abi_ulong frame_addr; sigset_t blocked; frame_addr = regs->gregs[15]; trace_user_do_rt_sigreturn(regs, frame_addr); if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { goto badframe; } target_to_host_sigset(&blocked, &frame->uc.tuc_sigmask); set_sigmask(&blocked); restore_sigcontext(regs, &frame->uc.tuc_mcontext); if (do_sigaltstack(frame_addr + offsetof(struct target_rt_sigframe, uc.tuc_stack), 0, get_sp_from_cpustate(regs)) == -EFAULT) { goto badframe; } unlock_user_struct(frame, frame_addr, 0); return -TARGET_QEMU_ESIGRETURN; badframe: unlock_user_struct(frame, frame_addr, 0); force_sig(TARGET_SIGSEGV); return -TARGET_QEMU_ESIGRETURN; }