|  | /* | 
|  | *  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 "user-internals.h" | 
|  | #include "signal-common.h" | 
|  | #include "linux-user/trace.h" | 
|  |  | 
|  | # if defined(TARGET_ABI_MIPSO32) | 
|  | struct target_sigcontext { | 
|  | uint32_t   sc_regmask;     /* Unused */ | 
|  | uint32_t   sc_status; | 
|  | uint64_t   sc_pc; | 
|  | uint64_t   sc_regs[32]; | 
|  | uint64_t   sc_fpregs[32]; | 
|  | uint32_t   sc_ownedfp;     /* Unused */ | 
|  | uint32_t   sc_fpc_csr; | 
|  | uint32_t   sc_fpc_eir;     /* Unused */ | 
|  | uint32_t   sc_used_math; | 
|  | uint32_t   sc_dsp;         /* dsp status, was sc_ssflags */ | 
|  | uint32_t   pad0; | 
|  | uint64_t   sc_mdhi; | 
|  | uint64_t   sc_mdlo; | 
|  | target_ulong   sc_hi1;         /* Was sc_cause */ | 
|  | target_ulong   sc_lo1;         /* Was sc_badvaddr */ | 
|  | target_ulong   sc_hi2;         /* Was sc_sigset[4] */ | 
|  | target_ulong   sc_lo2; | 
|  | target_ulong   sc_hi3; | 
|  | target_ulong   sc_lo3; | 
|  | }; | 
|  | # else /* N32 || N64 */ | 
|  | struct target_sigcontext { | 
|  | uint64_t sc_regs[32]; | 
|  | uint64_t sc_fpregs[32]; | 
|  | uint64_t sc_mdhi; | 
|  | uint64_t sc_hi1; | 
|  | uint64_t sc_hi2; | 
|  | uint64_t sc_hi3; | 
|  | uint64_t sc_mdlo; | 
|  | uint64_t sc_lo1; | 
|  | uint64_t sc_lo2; | 
|  | uint64_t sc_lo3; | 
|  | uint64_t sc_pc; | 
|  | uint32_t sc_fpc_csr; | 
|  | uint32_t sc_used_math; | 
|  | uint32_t sc_dsp; | 
|  | uint32_t sc_reserved; | 
|  | }; | 
|  | # endif /* O32 */ | 
|  |  | 
|  | struct sigframe { | 
|  | uint32_t sf_ass[4];                 /* argument save space for o32 */ | 
|  | uint32_t sf_code[2];                        /* signal trampoline */ | 
|  | struct target_sigcontext sf_sc; | 
|  | target_sigset_t sf_mask; | 
|  | }; | 
|  |  | 
|  | struct target_ucontext { | 
|  | abi_ulong tuc_flags; | 
|  | abi_ulong tuc_link; | 
|  | target_stack_t tuc_stack; | 
|  | struct target_sigcontext tuc_mcontext; | 
|  | target_sigset_t tuc_sigmask; | 
|  | }; | 
|  |  | 
|  | struct target_rt_sigframe { | 
|  | uint32_t rs_ass[4];               /* argument save space for o32 */ | 
|  | uint32_t rs_code[2];              /* signal trampoline */ | 
|  | struct target_siginfo rs_info; | 
|  | struct target_ucontext rs_uc; | 
|  | }; | 
|  |  | 
|  | /* Install trampoline to jump back from signal handler */ | 
|  | static void install_sigtramp(uint32_t *tramp, unsigned int syscall) | 
|  | { | 
|  | /* | 
|  | * Set up the return code ... | 
|  | * | 
|  | *         li      v0, __NR__foo_sigreturn | 
|  | *         syscall | 
|  | */ | 
|  |  | 
|  | __put_user(0x24020000 + syscall, tramp + 0); | 
|  | __put_user(0x0000000c          , tramp + 1); | 
|  | } | 
|  |  | 
|  | static inline void setup_sigcontext(CPUMIPSState *regs, | 
|  | struct target_sigcontext *sc) | 
|  | { | 
|  | int i; | 
|  |  | 
|  | __put_user(exception_resume_pc(regs), &sc->sc_pc); | 
|  | regs->hflags &= ~MIPS_HFLAG_BMASK; | 
|  |  | 
|  | __put_user(0, &sc->sc_regs[0]); | 
|  | for (i = 1; i < 32; ++i) { | 
|  | __put_user(regs->active_tc.gpr[i], &sc->sc_regs[i]); | 
|  | } | 
|  |  | 
|  | __put_user(regs->active_tc.HI[0], &sc->sc_mdhi); | 
|  | __put_user(regs->active_tc.LO[0], &sc->sc_mdlo); | 
|  |  | 
|  | /* Rather than checking for dsp existence, always copy.  The storage | 
|  | would just be garbage otherwise.  */ | 
|  | __put_user(regs->active_tc.HI[1], &sc->sc_hi1); | 
|  | __put_user(regs->active_tc.HI[2], &sc->sc_hi2); | 
|  | __put_user(regs->active_tc.HI[3], &sc->sc_hi3); | 
|  | __put_user(regs->active_tc.LO[1], &sc->sc_lo1); | 
|  | __put_user(regs->active_tc.LO[2], &sc->sc_lo2); | 
|  | __put_user(regs->active_tc.LO[3], &sc->sc_lo3); | 
|  | { | 
|  | uint32_t dsp = cpu_rddsp(0x3ff, regs); | 
|  | __put_user(dsp, &sc->sc_dsp); | 
|  | } | 
|  |  | 
|  | __put_user(1, &sc->sc_used_math); | 
|  |  | 
|  | for (i = 0; i < 32; ++i) { | 
|  | __put_user(regs->active_fpu.fpr[i].d, &sc->sc_fpregs[i]); | 
|  | } | 
|  | } | 
|  |  | 
|  | static inline void | 
|  | restore_sigcontext(CPUMIPSState *regs, struct target_sigcontext *sc) | 
|  | { | 
|  | int i; | 
|  |  | 
|  | __get_user(regs->CP0_EPC, &sc->sc_pc); | 
|  |  | 
|  | __get_user(regs->active_tc.HI[0], &sc->sc_mdhi); | 
|  | __get_user(regs->active_tc.LO[0], &sc->sc_mdlo); | 
|  |  | 
|  | for (i = 1; i < 32; ++i) { | 
|  | __get_user(regs->active_tc.gpr[i], &sc->sc_regs[i]); | 
|  | } | 
|  |  | 
|  | __get_user(regs->active_tc.HI[1], &sc->sc_hi1); | 
|  | __get_user(regs->active_tc.HI[2], &sc->sc_hi2); | 
|  | __get_user(regs->active_tc.HI[3], &sc->sc_hi3); | 
|  | __get_user(regs->active_tc.LO[1], &sc->sc_lo1); | 
|  | __get_user(regs->active_tc.LO[2], &sc->sc_lo2); | 
|  | __get_user(regs->active_tc.LO[3], &sc->sc_lo3); | 
|  | { | 
|  | uint32_t dsp; | 
|  | __get_user(dsp, &sc->sc_dsp); | 
|  | cpu_wrdsp(dsp, 0x3ff, regs); | 
|  | } | 
|  |  | 
|  | for (i = 0; i < 32; ++i) { | 
|  | __get_user(regs->active_fpu.fpr[i].d, &sc->sc_fpregs[i]); | 
|  | } | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Determine which stack to use.. | 
|  | */ | 
|  | static inline abi_ulong | 
|  | get_sigframe(struct target_sigaction *ka, CPUMIPSState *regs, size_t frame_size) | 
|  | { | 
|  | unsigned long sp; | 
|  |  | 
|  | /* | 
|  | * FPU emulator may have its own trampoline active just | 
|  | * above the user stack, 16-bytes before the next lowest | 
|  | * 16 byte boundary.  Try to avoid trashing it. | 
|  | */ | 
|  | sp = target_sigsp(get_sp_from_cpustate(regs) - 32, ka); | 
|  |  | 
|  | return (sp - frame_size) & ~7; | 
|  | } | 
|  |  | 
|  | static void mips_set_hflags_isa_mode_from_pc(CPUMIPSState *env) | 
|  | { | 
|  | if (env->insn_flags & (ASE_MIPS16 | ASE_MICROMIPS)) { | 
|  | env->hflags &= ~MIPS_HFLAG_M16; | 
|  | env->hflags |= (env->active_tc.PC & 1) << MIPS_HFLAG_M16_SHIFT; | 
|  | env->active_tc.PC &= ~(target_ulong) 1; | 
|  | } | 
|  | } | 
|  |  | 
|  | # if defined(TARGET_ABI_MIPSO32) | 
|  | /* compare linux/arch/mips/kernel/signal.c:setup_frame() */ | 
|  | void setup_frame(int sig, struct target_sigaction * ka, | 
|  | target_sigset_t *set, CPUMIPSState *regs) | 
|  | { | 
|  | struct sigframe *frame; | 
|  | abi_ulong frame_addr; | 
|  | int i; | 
|  |  | 
|  | frame_addr = get_sigframe(ka, regs, sizeof(*frame)); | 
|  | trace_user_setup_frame(regs, frame_addr); | 
|  | if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { | 
|  | goto give_sigsegv; | 
|  | } | 
|  |  | 
|  | setup_sigcontext(regs, &frame->sf_sc); | 
|  |  | 
|  | for(i = 0; i < TARGET_NSIG_WORDS; i++) { | 
|  | __put_user(set->sig[i], &frame->sf_mask.sig[i]); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Arguments to signal handler: | 
|  | * | 
|  | *   a0 = signal number | 
|  | *   a1 = 0 (should be cause) | 
|  | *   a2 = pointer to struct sigcontext | 
|  | * | 
|  | * $25 and PC point to the signal handler, $29 points to the | 
|  | * struct sigframe. | 
|  | */ | 
|  | regs->active_tc.gpr[ 4] = sig; | 
|  | regs->active_tc.gpr[ 5] = 0; | 
|  | regs->active_tc.gpr[ 6] = frame_addr + offsetof(struct sigframe, sf_sc); | 
|  | regs->active_tc.gpr[29] = frame_addr; | 
|  | regs->active_tc.gpr[31] = default_sigreturn; | 
|  | /* The original kernel code sets CP0_EPC to the handler | 
|  | * since it returns to userland using eret | 
|  | * we cannot do this here, and we must set PC directly */ | 
|  | regs->active_tc.PC = regs->active_tc.gpr[25] = ka->_sa_handler; | 
|  | mips_set_hflags_isa_mode_from_pc(regs); | 
|  | unlock_user_struct(frame, frame_addr, 1); | 
|  | return; | 
|  |  | 
|  | give_sigsegv: | 
|  | force_sigsegv(sig); | 
|  | } | 
|  |  | 
|  | long do_sigreturn(CPUMIPSState *regs) | 
|  | { | 
|  | struct sigframe *frame; | 
|  | abi_ulong frame_addr; | 
|  | sigset_t blocked; | 
|  | target_sigset_t target_set; | 
|  | int i; | 
|  |  | 
|  | frame_addr = regs->active_tc.gpr[29]; | 
|  | trace_user_do_sigreturn(regs, frame_addr); | 
|  | if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) | 
|  | goto badframe; | 
|  |  | 
|  | for(i = 0; i < TARGET_NSIG_WORDS; i++) { | 
|  | __get_user(target_set.sig[i], &frame->sf_mask.sig[i]); | 
|  | } | 
|  |  | 
|  | target_to_host_sigset_internal(&blocked, &target_set); | 
|  | set_sigmask(&blocked); | 
|  |  | 
|  | restore_sigcontext(regs, &frame->sf_sc); | 
|  |  | 
|  | #if 0 | 
|  | /* | 
|  | * Don't let your children do this ... | 
|  | */ | 
|  | __asm__ __volatile__( | 
|  | "move\t$29, %0\n\t" | 
|  | "j\tsyscall_exit" | 
|  | :/* no outputs */ | 
|  | :"r" (®s)); | 
|  | /* Unreached */ | 
|  | #endif | 
|  |  | 
|  | regs->active_tc.PC = regs->CP0_EPC; | 
|  | mips_set_hflags_isa_mode_from_pc(regs); | 
|  | /* I am not sure this is right, but it seems to work | 
|  | * maybe a problem with nested signals ? */ | 
|  | regs->CP0_EPC = 0; | 
|  | return -QEMU_ESIGRETURN; | 
|  |  | 
|  | badframe: | 
|  | force_sig(TARGET_SIGSEGV); | 
|  | return -QEMU_ESIGRETURN; | 
|  | } | 
|  | # endif /* O32 */ | 
|  |  | 
|  | void setup_rt_frame(int sig, struct target_sigaction *ka, | 
|  | target_siginfo_t *info, | 
|  | target_sigset_t *set, CPUMIPSState *env) | 
|  | { | 
|  | struct target_rt_sigframe *frame; | 
|  | abi_ulong frame_addr; | 
|  | int i; | 
|  |  | 
|  | frame_addr = get_sigframe(ka, env, sizeof(*frame)); | 
|  | trace_user_setup_rt_frame(env, frame_addr); | 
|  | if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { | 
|  | goto give_sigsegv; | 
|  | } | 
|  |  | 
|  | frame->rs_info = *info; | 
|  |  | 
|  | __put_user(0, &frame->rs_uc.tuc_flags); | 
|  | __put_user(0, &frame->rs_uc.tuc_link); | 
|  | target_save_altstack(&frame->rs_uc.tuc_stack, env); | 
|  |  | 
|  | setup_sigcontext(env, &frame->rs_uc.tuc_mcontext); | 
|  |  | 
|  | for (i = 0; i < TARGET_NSIG_WORDS; i++) { | 
|  | __put_user(set->sig[i], &frame->rs_uc.tuc_sigmask.sig[i]); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Arguments to signal handler: | 
|  | * | 
|  | *   a0 = signal number | 
|  | *   a1 = pointer to siginfo_t | 
|  | *   a2 = pointer to ucontext_t | 
|  | * | 
|  | * $25 and PC point to the signal handler, $29 points to the | 
|  | * struct sigframe. | 
|  | */ | 
|  | env->active_tc.gpr[ 4] = sig; | 
|  | env->active_tc.gpr[ 5] = frame_addr | 
|  | + offsetof(struct target_rt_sigframe, rs_info); | 
|  | env->active_tc.gpr[ 6] = frame_addr | 
|  | + offsetof(struct target_rt_sigframe, rs_uc); | 
|  | env->active_tc.gpr[29] = frame_addr; | 
|  | env->active_tc.gpr[31] = default_rt_sigreturn; | 
|  |  | 
|  | /* | 
|  | * The original kernel code sets CP0_EPC to the handler | 
|  | * since it returns to userland using eret | 
|  | * we cannot do this here, and we must set PC directly | 
|  | */ | 
|  | env->active_tc.PC = env->active_tc.gpr[25] = ka->_sa_handler; | 
|  | mips_set_hflags_isa_mode_from_pc(env); | 
|  | unlock_user_struct(frame, frame_addr, 1); | 
|  | return; | 
|  |  | 
|  | give_sigsegv: | 
|  | unlock_user_struct(frame, frame_addr, 1); | 
|  | force_sigsegv(sig); | 
|  | } | 
|  |  | 
|  | long do_rt_sigreturn(CPUMIPSState *env) | 
|  | { | 
|  | struct target_rt_sigframe *frame; | 
|  | abi_ulong frame_addr; | 
|  | sigset_t blocked; | 
|  |  | 
|  | frame_addr = env->active_tc.gpr[29]; | 
|  | trace_user_do_rt_sigreturn(env, frame_addr); | 
|  | if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { | 
|  | goto badframe; | 
|  | } | 
|  |  | 
|  | target_to_host_sigset(&blocked, &frame->rs_uc.tuc_sigmask); | 
|  | set_sigmask(&blocked); | 
|  |  | 
|  | restore_sigcontext(env, &frame->rs_uc.tuc_mcontext); | 
|  | target_restore_altstack(&frame->rs_uc.tuc_stack, env); | 
|  |  | 
|  | env->active_tc.PC = env->CP0_EPC; | 
|  | mips_set_hflags_isa_mode_from_pc(env); | 
|  | /* I am not sure this is right, but it seems to work | 
|  | * maybe a problem with nested signals ? */ | 
|  | env->CP0_EPC = 0; | 
|  | return -QEMU_ESIGRETURN; | 
|  |  | 
|  | badframe: | 
|  | force_sig(TARGET_SIGSEGV); | 
|  | return -QEMU_ESIGRETURN; | 
|  | } | 
|  |  | 
|  | void setup_sigtramp(abi_ulong sigtramp_page) | 
|  | { | 
|  | uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 8, 0); | 
|  | assert(tramp != NULL); | 
|  |  | 
|  | #ifdef TARGET_ARCH_HAS_SETUP_FRAME | 
|  | default_sigreturn = sigtramp_page; | 
|  | install_sigtramp(tramp, TARGET_NR_sigreturn); | 
|  | #endif | 
|  |  | 
|  | default_rt_sigreturn = sigtramp_page + 8; | 
|  | install_sigtramp(tramp + 2, TARGET_NR_rt_sigreturn); | 
|  |  | 
|  | unlock_user(tramp, sigtramp_page, 2 * 8); | 
|  | } |