linux_machdep.c revision 1.4
1 /* $NetBSD: linux_machdep.c,v 1.4 1995/05/01 14:15:09 mycroft Exp $ */ 2 3 /* 4 * Copyright (c) 1995 Frank van der Linden 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed for the NetBSD Project 18 * by Frank van der Linden 19 * 4. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/signalvar.h> 37 #include <sys/kernel.h> 38 #include <sys/map.h> 39 #include <sys/proc.h> 40 #include <sys/user.h> 41 #include <sys/exec.h> 42 #include <sys/buf.h> 43 #include <sys/reboot.h> 44 #include <sys/conf.h> 45 #include <sys/file.h> 46 #include <sys/callout.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #include <sys/msgbuf.h> 50 #include <sys/mount.h> 51 #include <sys/vnode.h> 52 #include <sys/device.h> 53 #include <sys/sysctl.h> 54 #include <sys/syscallargs.h> 55 #include <compat/linux/linux_types.h> 56 #include <compat/linux/linux_syscallargs.h> 57 58 #include <machine/cpu.h> 59 #include <machine/cpufunc.h> 60 #include <machine/psl.h> 61 #include <machine/reg.h> 62 #include <machine/specialreg.h> 63 #include <machine/linux_machdep.h> 64 65 /* 66 * Deal with some i386-specific things in the Linux emulation code. 67 * This means just signals for now, will include stuff like 68 * I/O map permissions and V86 mode sometime. 69 */ 70 71 /* 72 * Send an interrupt to process. 73 * 74 * Stack is set up to allow sigcode stored 75 * in u. to call routine, followed by kcall 76 * to sigreturn routine below. After sigreturn 77 * resets the signal mask, the stack, and the 78 * frame pointer, it returns to the user 79 * specified pc, psl. 80 */ 81 82 void 83 linux_sendsig(catcher, sig, mask, code) 84 sig_t catcher; 85 int sig, mask; 86 u_long code; 87 { 88 register struct proc *p = curproc; 89 register struct trapframe *tf; 90 struct linux_sigframe *fp, frame; 91 struct sigacts *psp = p->p_sigacts; 92 int oonstack; 93 extern char linux_sigcode[], linux_esigcode[]; 94 95 tf = p->p_md.md_regs; 96 oonstack = psp->ps_sigstk.ss_flags & SA_ONSTACK; 97 98 /* 99 * Allocate space for the signal handler context. 100 */ 101 if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack && 102 (psp->ps_sigonstack & sigmask(sig))) { 103 fp = (struct linux_sigframe *)(psp->ps_sigstk.ss_base + 104 psp->ps_sigstk.ss_size - sizeof(struct linux_sigframe)); 105 psp->ps_sigstk.ss_flags |= SA_ONSTACK; 106 } else { 107 fp = (struct linux_sigframe *)tf->tf_esp - 1; 108 } 109 110 frame.ls_handler = catcher; 111 frame.ls_sig = bsd_to_linux_sig(sig); 112 113 /* 114 * Build the signal context to be used by sigreturn. 115 */ 116 frame.ls_sc.lsc_mask = mask; 117 #ifdef VM86 118 if (tf->tf_eflags & PSL_VM) { 119 frame.ls_sc.lsc_gs = tf->tf_vm86_gs; 120 frame.ls_sc.lsc_fs = tf->tf_vm86_fs; 121 frame.ls_sc.lsc_es = tf->tf_vm86_es; 122 frame.ls_sc.lsc_ds = tf->tf_vm86_ds; 123 } else 124 #else 125 { 126 __asm("movl %%gs,%w0" : "=r" (frame.ls_sc.sc_gs)); 127 __asm("movl %%fs,%w0" : "=r" (frame.ls_sc.sc_fs)); 128 frame.ls_sc.lsc_es = tf->tf_es; 129 frame.ls_sc.lsc_ds = tf->tf_ds; 130 } 131 #endif 132 frame.ls_sc.lsc_edi = tf->tf_edi; 133 frame.ls_sc.lsc_esi = tf->tf_esi; 134 frame.ls_sc.lsc_ebp = tf->tf_ebp; 135 frame.ls_sc.lsc_ebx = tf->tf_ebx; 136 frame.ls_sc.lsc_edx = tf->tf_edx; 137 frame.ls_sc.lsc_ecx = tf->tf_ecx; 138 frame.ls_sc.lsc_eax = tf->tf_eax; 139 frame.ls_sc.lsc_eip = tf->tf_eip; 140 frame.ls_sc.lsc_cs = tf->tf_cs; 141 frame.ls_sc.lsc_eflags = tf->tf_eflags; 142 frame.ls_sc.lsc_esp = tf->tf_esp; 143 frame.ls_sc.lsc_ss = tf->tf_ss; 144 frame.ls_sc.lsc_err = tf->tf_err; 145 frame.ls_sc.lsc_trapno = tf->tf_trapno; 146 147 if (copyout(&frame, fp, sizeof(frame)) != 0) { 148 /* 149 * Process has trashed its stack; give it an illegal 150 * instruction to halt it in its tracks. 151 */ 152 sigexit(p, SIGILL); 153 /* NOTREACHED */ 154 } 155 156 /* 157 * Build context to run handler in. 158 */ 159 tf->tf_esp = (int)fp; 160 tf->tf_eip = (int)(((char *)PS_STRINGS) - 161 (linux_esigcode - linux_sigcode)); 162 #ifdef VM86 163 tf->tf_eflags &= ~PSL_VM; 164 #endif 165 tf->tf_cs = LSEL(LUCODE_SEL, SEL_UPL); 166 tf->tf_ds = LSEL(LUDATA_SEL, SEL_UPL); 167 tf->tf_es = LSEL(LUDATA_SEL, SEL_UPL); 168 tf->tf_ss = LSEL(LUDATA_SEL, SEL_UPL); 169 } 170 171 /* 172 * System call to cleanup state after a signal 173 * has been taken. Reset signal mask and 174 * stack state from context left by sendsig (above). 175 * Return to previous pc and psl as specified by 176 * context left by sendsig. Check carefully to 177 * make sure that the user has not modified the 178 * psl to gain improper privileges or to cause 179 * a machine fault. 180 */ 181 int 182 linux_sigreturn(p, uap, retval) 183 struct proc *p; 184 struct linux_sigreturn_args /* { 185 syscallarg(struct linux_sigcontext *) scp; 186 } */ *uap; 187 register_t *retval; 188 { 189 struct linux_sigcontext *scp, context; 190 register struct trapframe *tf; 191 192 tf = p->p_md.md_regs; 193 194 /* 195 * The trampoline code hands us the context. 196 * It is unsafe to keep track of it ourselves, in the event that a 197 * program jumps out of a signal handler. 198 */ 199 scp = SCARG(uap, scp); 200 if (copyin((caddr_t)scp, &context, sizeof(*scp)) != 0) 201 return (EFAULT); 202 203 /* 204 * Check for security violations. 205 */ 206 if (((context.lsc_eflags ^ tf->tf_eflags) & PSL_USERSTATIC) != 0 || 207 ISPL(context.lsc_cs) != SEL_UPL) 208 return (EINVAL); 209 210 p->p_sigacts->ps_sigstk.ss_flags &= ~SA_ONSTACK; 211 p->p_sigmask = context.lsc_mask & ~sigcantmask; 212 213 /* 214 * Restore signal context. 215 */ 216 #ifdef VM86 217 if (context.lsc_eflags & PSL_VM) { 218 tf->tf_vm86_gs = context.lsc_gs; 219 tf->tf_vm86_fs = context.lsc_fs; 220 tf->tf_vm86_es = context.lsc_es; 221 tf->tf_vm86_ds = context.lsc_ds; 222 } else 223 #endif 224 { 225 /* %fs and %gs were restored by the trampoline. */ 226 tf->tf_es = context.lsc_es; 227 tf->tf_ds = context.lsc_ds; 228 } 229 tf->tf_edi = context.lsc_edi; 230 tf->tf_esi = context.lsc_esi; 231 tf->tf_ebp = context.lsc_ebp; 232 tf->tf_ebx = context.lsc_ebx; 233 tf->tf_edx = context.lsc_edx; 234 tf->tf_ecx = context.lsc_ecx; 235 tf->tf_eax = context.lsc_eax; 236 tf->tf_eip = context.lsc_eip; 237 tf->tf_cs = context.lsc_cs; 238 tf->tf_eflags = context.lsc_eflags; 239 tf->tf_esp = context.lsc_esp; 240 tf->tf_ss = context.lsc_ss; 241 242 return (EJUSTRETURN); 243 } 244
Indexes created Sun Sep 28 12:09:53 GMT 2025