freebsd_machdep.c revision 1.1
1 /* $NetBSD: freebsd_machdep.c,v 1.1 2017/08/01 14:43:54 maxv Exp $ */ 2 3 /*- 4 * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Charles M. Hannum. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: freebsd_machdep.c,v 1.1 2017/08/01 14:43:54 maxv Exp $"); 34 35 #if defined(_KERNEL_OPT) 36 #include "opt_vm86.h" 37 #endif 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/signalvar.h> 42 #include <sys/proc.h> 43 #include <sys/exec.h> 44 #include <sys/mount.h> 45 46 #include <compat/sys/signal.h> 47 48 #include <machine/cpufunc.h> 49 #include <x86/fpu.h> 50 #include <machine/reg.h> 51 #include <machine/vm86.h> 52 #include <machine/vmparam.h> 53 #include <machine/freebsd_machdep.h> 54 55 56 #include <compat/freebsd/freebsd_syscallargs.h> 57 #include <compat/freebsd/freebsd_exec.h> 58 #include <compat/freebsd/freebsd_signal.h> 59 60 void 61 freebsd_setregs(struct lwp *l, struct exec_package *epp, vaddr_t stack) 62 { 63 64 setregs(l, epp, stack); 65 fpu_set_default_cw(l, __FreeBSD_NPXCW__); 66 } 67 68 /* 69 * signal support 70 */ 71 72 /* 73 * Send an interrupt to process. 74 * 75 * Stack is set up to allow sigcode stored 76 * in u. to call routine, followed by kcall 77 * to sigreturn routine below. After sigreturn 78 * resets the signal mask, the stack, and the 79 * frame pointer, it returns to the user 80 * specified pc, psl. 81 */ 82 void 83 freebsd_sendsig(const ksiginfo_t *ksi, const sigset_t *mask) 84 { 85 int sig = ksi->ksi_signo; 86 u_long code = KSI_TRAPCODE(ksi); 87 struct lwp *l = curlwp; 88 struct proc *p = l->l_proc; 89 int onstack, error; 90 struct freebsd_sigframe *fp = getframe(l, sig, &onstack), frame; 91 sig_t catcher = SIGACTION(p, sig).sa_handler; 92 struct trapframe *tf = l->l_md.md_regs; 93 94 fp--; 95 96 /* Build stack frame for signal trampoline. */ 97 frame.sf_signum = sig; 98 frame.sf_code = code; 99 frame.sf_scp = &fp->sf_sc; 100 frame.sf_addr = (char *)rcr2(); 101 frame.sf_handler = catcher; 102 103 /* Save context. */ 104 #ifdef VM86 105 if (tf->tf_eflags & PSL_VM) { 106 frame.sf_sc.sc_gs = tf->tf_vm86_gs; 107 frame.sf_sc.sc_fs = tf->tf_vm86_fs; 108 frame.sf_sc.sc_es = tf->tf_vm86_es; 109 frame.sf_sc.sc_ds = tf->tf_vm86_ds; 110 frame.sf_sc.sc_efl = get_vflags(l); 111 (*p->p_emul->e_syscall_intern)(p); 112 } else 113 #endif 114 { 115 frame.sf_sc.sc_gs = tf->tf_gs; 116 frame.sf_sc.sc_fs = tf->tf_fs; 117 frame.sf_sc.sc_es = tf->tf_es; 118 frame.sf_sc.sc_ds = tf->tf_ds; 119 frame.sf_sc.sc_efl = tf->tf_eflags; 120 } 121 frame.sf_sc.sc_edi = tf->tf_edi; 122 frame.sf_sc.sc_esi = tf->tf_esi; 123 frame.sf_sc.sc_ebp = tf->tf_ebp; 124 frame.sf_sc.sc_isp = 0; /* don't have to pass kernel sp to user. */ 125 frame.sf_sc.sc_ebx = tf->tf_ebx; 126 frame.sf_sc.sc_edx = tf->tf_edx; 127 frame.sf_sc.sc_ecx = tf->tf_ecx; 128 frame.sf_sc.sc_eax = tf->tf_eax; 129 frame.sf_sc.sc_eip = tf->tf_eip; 130 frame.sf_sc.sc_cs = tf->tf_cs; 131 frame.sf_sc.sc_esp = tf->tf_esp; 132 frame.sf_sc.sc_ss = tf->tf_ss; 133 134 /* Save signal stack. */ 135 frame.sf_sc.sc_onstack = l->l_sigstk.ss_flags & SS_ONSTACK; 136 137 /* Save signal mask. */ 138 /* XXX freebsd_osigcontext compat? */ 139 frame.sf_sc.sc_mask = *mask; 140 141 sendsig_reset(l, sig); 142 143 mutex_exit(p->p_lock); 144 error = copyout(&frame, fp, sizeof(frame)); 145 mutex_enter(p->p_lock); 146 147 if (error != 0) { 148 /* 149 * Process has trashed its stack; give it an illegal 150 * instruction to halt it in its tracks. 151 */ 152 sigexit(l, SIGILL); 153 /* NOTREACHED */ 154 } 155 156 buildcontext(l, GUCODEBIG_SEL, p->p_sigctx.ps_sigcode, fp); 157 158 /* Remember that we're now on the signal stack. */ 159 if (onstack) 160 l->l_sigstk.ss_flags |= SS_ONSTACK; 161 } 162 163 /* 164 * System call to cleanup state after a signal 165 * has been taken. Reset signal mask and 166 * stack state from context left by sendsig (above). 167 * Return to previous pc and psl as specified by 168 * context left by sendsig. Check carefully to 169 * make sure that the user has not modified the 170 * psl to gain improper privileges or to cause 171 * a machine fault. 172 */ 173 int 174 freebsd_sys_sigreturn(struct lwp *l, const struct freebsd_sys_sigreturn_args *uap, register_t *retval) 175 { 176 /* { 177 syscallarg(struct freebsd_sigcontext *) scp; 178 } */ 179 struct proc *p = l->l_proc; 180 struct freebsd_sigcontext *scp, context; 181 struct trapframe *tf; 182 sigset_t mask; 183 184 /* 185 * The trampoline code hands us the context. 186 * It is unsafe to keep track of it ourselves, in the event that a 187 * program jumps out of a signal handler. 188 */ 189 scp = SCARG(uap, scp); 190 if (copyin((void *)scp, &context, sizeof(*scp)) != 0) 191 return (EFAULT); 192 193 /* Restore register context. */ 194 tf = l->l_md.md_regs; 195 #ifdef VM86 196 if (context.sc_efl & PSL_VM) { 197 void syscall_vm86(struct trapframe *); 198 199 tf->tf_vm86_gs = context.sc_gs; 200 tf->tf_vm86_fs = context.sc_fs; 201 tf->tf_vm86_es = context.sc_es; 202 tf->tf_vm86_ds = context.sc_ds; 203 set_vflags(l, context.sc_efl); 204 p->p_md.md_syscall = syscall_vm86; 205 } else 206 #endif 207 { 208 /* 209 * Check for security violations. If we're returning to 210 * protected mode, the CPU will validate the segment registers 211 * automatically and generate a trap on violations. We handle 212 * the trap, rather than doing all of the checking here. 213 */ 214 if (((context.sc_efl ^ tf->tf_eflags) & PSL_USERSTATIC) != 0 || 215 !USERMODE(context.sc_cs, context.sc_efl)) 216 return (EINVAL); 217 218 tf->tf_gs = context.sc_gs; 219 tf->tf_fs = context.sc_fs; 220 tf->tf_es = context.sc_es; 221 tf->tf_ds = context.sc_ds; 222 tf->tf_eflags &= ~PSL_USER; 223 tf->tf_eflags |= context.sc_efl & PSL_USER; 224 } 225 tf->tf_edi = context.sc_edi; 226 tf->tf_esi = context.sc_esi; 227 tf->tf_ebp = context.sc_ebp; 228 /* FreeBSD's context.sc_isp is useless. (`popal' ignores it.) */ 229 tf->tf_ebx = context.sc_ebx; 230 tf->tf_edx = context.sc_edx; 231 tf->tf_ecx = context.sc_ecx; 232 tf->tf_eax = context.sc_eax; 233 tf->tf_eip = context.sc_eip; 234 tf->tf_cs = context.sc_cs; 235 tf->tf_esp = context.sc_esp; 236 tf->tf_ss = context.sc_ss; 237 238 mutex_enter(p->p_lock); 239 /* Restore signal stack. */ 240 if (context.sc_onstack & SS_ONSTACK) 241 l->l_sigstk.ss_flags |= SS_ONSTACK; 242 else 243 l->l_sigstk.ss_flags &= ~SS_ONSTACK; 244 /* Restore signal mask. */ 245 /* XXX freebsd_osigcontext compat? */ 246 mask = context.sc_mask; 247 (void) sigprocmask1(l, SIG_SETMASK, &mask, 0); 248 mutex_exit(p->p_lock); 249 250 return (EJUSTRETURN); 251 } 252 253
Indexes created Wed Sep 24 14:09:57 GMT 2025