/* * Reset registers to default values on exec. */ static void linux_exec_setregs(struct thread *td, struct image_params *imgp, u_long stack) { struct trapframe *regs = td->td_frame; struct pcb *pcb = td->td_pcb; mtx_lock(&dt_lock); if (td->td_proc->p_md.md_ldt != NULL) user_ldt_free(td); else mtx_unlock(&dt_lock); pcb->pcb_fsbase = 0; pcb->pcb_gsbase = 0; clear_pcb_flags(pcb, PCB_32BIT); pcb->pcb_initial_fpucw = __LINUX_NPXCW__; set_pcb_flags(pcb, PCB_FULL_IRET); bzero((char *)regs, sizeof(struct trapframe)); regs->tf_rip = imgp->entry_addr; regs->tf_rsp = stack; regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T); regs->tf_ss = _udatasel; regs->tf_cs = _ucodesel; regs->tf_ds = _udatasel; regs->tf_es = _udatasel; regs->tf_fs = _ufssel; regs->tf_gs = _ugssel; regs->tf_flags = TF_HASSEGS; /* * Reset the hardware debug registers if they were in use. * They won't have any meaning for the newly exec'd process. */ if (pcb->pcb_flags & PCB_DBREGS) { pcb->pcb_dr0 = 0; pcb->pcb_dr1 = 0; pcb->pcb_dr2 = 0; pcb->pcb_dr3 = 0; pcb->pcb_dr6 = 0; pcb->pcb_dr7 = 0; if (pcb == curpcb) { /* * Clear the debug registers on the running * CPU, otherwise they will end up affecting * the next process we switch to. */ reset_dbregs(); } clear_pcb_flags(pcb, PCB_DBREGS); } /* * Drop the FP state if we hold it, so that the process gets a * clean FP state if it uses the FPU again. */ fpstate_drop(td); }
static int ia32_set_fpcontext(struct thread *td, const struct ia32_mcontext *mcp) { if (mcp->mc_fpformat == _MC_FPFMT_NODEV) return (0); else if (mcp->mc_fpformat != _MC_FPFMT_XMM) return (EINVAL); else if (mcp->mc_ownedfp == _MC_FPOWNED_NONE) /* We don't care what state is left in the FPU or PCB. */ fpstate_drop(td); else if (mcp->mc_ownedfp == _MC_FPOWNED_FPU || mcp->mc_ownedfp == _MC_FPOWNED_PCB) { fpusetregs(td, (struct savefpu *)&mcp->mc_fpstate); } else return (EINVAL); return (0); }
/* * Clear registers on exec * XXX copied from ia32_signal.c. */ static void exec_linux_setregs(struct thread *td, struct image_params *imgp, u_long stack) { struct trapframe *regs = td->td_frame; struct pcb *pcb = td->td_pcb; mtx_lock(&dt_lock); if (td->td_proc->p_md.md_ldt != NULL) user_ldt_free(td); else mtx_unlock(&dt_lock); critical_enter(); wrmsr(MSR_FSBASE, 0); wrmsr(MSR_KGSBASE, 0); /* User value while we're in the kernel */ pcb->pcb_fsbase = 0; pcb->pcb_gsbase = 0; critical_exit(); pcb->pcb_initial_fpucw = __LINUX_NPXCW__; bzero((char *)regs, sizeof(struct trapframe)); regs->tf_rip = imgp->entry_addr; regs->tf_rsp = stack; regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T); regs->tf_gs = _ugssel; regs->tf_fs = _ufssel; regs->tf_es = _udatasel; regs->tf_ds = _udatasel; regs->tf_ss = _udatasel; regs->tf_flags = TF_HASSEGS; regs->tf_cs = _ucode32sel; regs->tf_rbx = imgp->ps_strings; fpstate_drop(td); /* Do full restore on return so that we can change to a different %cs */ set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET); td->td_retval[1] = 0; }
static int ia32_set_fpcontext(struct thread *td, const struct ia32_mcontext *mcp, char *xfpustate, size_t xfpustate_len) { int error; if (mcp->mc_fpformat == _MC_FPFMT_NODEV) return (0); else if (mcp->mc_fpformat != _MC_FPFMT_XMM) return (EINVAL); else if (mcp->mc_ownedfp == _MC_FPOWNED_NONE) { /* We don't care what state is left in the FPU or PCB. */ fpstate_drop(td); error = 0; } else if (mcp->mc_ownedfp == _MC_FPOWNED_FPU || mcp->mc_ownedfp == _MC_FPOWNED_PCB) { error = fpusetregs(td, (struct savefpu *)&mcp->mc_fpstate, xfpustate, xfpustate_len); } else return (EINVAL); return (error); }
void ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) { struct ia32_sigframe sf, *sfp; struct siginfo32 siginfo; struct proc *p; struct thread *td; struct sigacts *psp; char *sp; struct trapframe *regs; char *xfpusave; size_t xfpusave_len; int oonstack; int sig; siginfo_to_siginfo32(&ksi->ksi_info, &siginfo); td = curthread; p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); sig = siginfo.si_signo; psp = p->p_sigacts; #ifdef COMPAT_FREEBSD4 if (SIGISMEMBER(psp->ps_freebsd4, sig)) { freebsd4_ia32_sendsig(catcher, ksi, mask); return; } #endif #ifdef COMPAT_43 if (SIGISMEMBER(psp->ps_osigset, sig)) { ia32_osendsig(catcher, ksi, mask); return; } #endif mtx_assert(&psp->ps_mtx, MA_OWNED); regs = td->td_frame; oonstack = sigonstack(regs->tf_rsp); if (cpu_max_ext_state_size > sizeof(struct savefpu) && use_xsave) { xfpusave_len = cpu_max_ext_state_size - sizeof(struct savefpu); xfpusave = __builtin_alloca(xfpusave_len); } else { xfpusave_len = 0; xfpusave = NULL; } /* Save user context. */ bzero(&sf, sizeof(sf)); sf.sf_uc.uc_sigmask = *mask; sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp; sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0; sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi; sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi; sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp; sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */ sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx; sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx; sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx; sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax; sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno; sf.sf_uc.uc_mcontext.mc_err = regs->tf_err; sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip; sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs; sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags; sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp; sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss; sf.sf_uc.uc_mcontext.mc_ds = regs->tf_ds; sf.sf_uc.uc_mcontext.mc_es = regs->tf_es; sf.sf_uc.uc_mcontext.mc_fs = regs->tf_fs; sf.sf_uc.uc_mcontext.mc_gs = regs->tf_gs; sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */ ia32_get_fpcontext(td, &sf.sf_uc.uc_mcontext, xfpusave, xfpusave_len); fpstate_drop(td); sf.sf_uc.uc_mcontext.mc_fsbase = td->td_pcb->pcb_fsbase; sf.sf_uc.uc_mcontext.mc_gsbase = td->td_pcb->pcb_gsbase; bzero(sf.sf_uc.__spare__, sizeof(sf.sf_uc.__spare__)); /* Allocate space for the signal handler context. */ if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && SIGISMEMBER(psp->ps_sigonstack, sig)) sp = td->td_sigstk.ss_sp + td->td_sigstk.ss_size; else sp = (char *)regs->tf_rsp; if (xfpusave != NULL) { sp -= xfpusave_len; sp = (char *)((unsigned long)sp & ~0x3Ful); sf.sf_uc.uc_mcontext.mc_xfpustate = (register_t)sp; } sp -= sizeof(sf); /* Align to 16 bytes. */ sfp = (struct ia32_sigframe *)((uintptr_t)sp & ~0xF); PROC_UNLOCK(p); /* Translate the signal if appropriate. */ if (p->p_sysent->sv_sigtbl && sig <= p->p_sysent->sv_sigsize) sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)]; /* Build the argument list for the signal handler. */ sf.sf_signum = sig; sf.sf_ucontext = (register_t)&sfp->sf_uc; bzero(&sf.sf_si, sizeof(sf.sf_si)); if (SIGISMEMBER(psp->ps_siginfo, sig)) { /* Signal handler installed with SA_SIGINFO. */ sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si; sf.sf_ah = (u_int32_t)(uintptr_t)catcher; /* Fill in POSIX parts */ sf.sf_si = siginfo; sf.sf_si.si_signo = sig; } else { /* Old FreeBSD-style arguments. */ sf.sf_siginfo = siginfo.si_code; sf.sf_addr = (u_int32_t)siginfo.si_addr; sf.sf_ah = (u_int32_t)(uintptr_t)catcher; } mtx_unlock(&psp->ps_mtx); /* * Copy the sigframe out to the user's stack. */ if (copyout(&sf, sfp, sizeof(*sfp)) != 0 || (xfpusave != NULL && copyout(xfpusave, PTRIN(sf.sf_uc.uc_mcontext.mc_xfpustate), xfpusave_len) != 0)) { #ifdef DEBUG printf("process %ld has trashed its stack\n", (long)p->p_pid); #endif PROC_LOCK(p); sigexit(td, SIGILL); } regs->tf_rsp = (uintptr_t)sfp; regs->tf_rip = p->p_sysent->sv_sigcode_base; regs->tf_rflags &= ~(PSL_T | PSL_D); regs->tf_cs = _ucode32sel; regs->tf_ss = _udatasel; regs->tf_ds = _udatasel; regs->tf_es = _udatasel; set_pcb_flags(td->td_pcb, PCB_FULL_IRET); /* XXXKIB leave user %fs and %gs untouched */ PROC_LOCK(p); mtx_lock(&psp->ps_mtx); }