1 /* $NetBSD: netbsd32_machdep_16.c,v 1.8 2023/12/20 06:36:01 thorpej Exp $ */
2
3 /*
4 * Copyright (c) 2001 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Frank van der Linden for Wasabi Systems, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed for the NetBSD Project by
20 * Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 * or promote products derived from this software without specific prior
23 * written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 #include <sys/cdefs.h>
39 __KERNEL_RCSID(0, "$NetBSD: netbsd32_machdep_16.c,v 1.8 2023/12/20 06:36:01 thorpej Exp $");
40
41 #ifdef _KERNEL_OPT
42 #include "opt_compat_netbsd.h"
43 #include "opt_execfmt.h"
44 #endif
45
46 #include <sys/param.h>
47 #include <sys/exec.h>
48 #include <sys/exec_aout.h>
49 #include <sys/kmem.h>
50 #include <sys/proc.h>
51 #include <sys/signalvar.h>
52 #include <sys/systm.h>
53 #include <sys/core.h>
54 #include <sys/mount.h>
55 #include <sys/buf.h>
56 #include <sys/vnode.h>
57 #include <sys/ras.h>
58 #include <sys/ptrace.h>
59 #include <sys/kauth.h>
60 #include <sys/module_hook.h>
61
62 #include <x86/fpu.h>
63 #include <x86/dbregs.h>
64 #include <machine/frame.h>
65 #include <machine/reg.h>
66 #include <machine/vmparam.h>
67 #include <machine/netbsd32_machdep.h>
68 #include <machine/sysarch.h>
69 #include <machine/userret.h>
70
71 #include <compat/netbsd32/netbsd32.h>
72 #include <compat/netbsd32/netbsd32_exec.h>
73 #include <compat/netbsd32/netbsd32_syscallargs.h>
74
75 #include <compat/sys/signal.h>
76 #include <compat/sys/signalvar.h>
77
78 void netbsd32_buildcontext(struct lwp *, struct trapframe *, void *,
79 sig_t, int);
80
81 int check_sigcontext32(struct lwp *, const struct netbsd32_sigcontext *);
82
83 static void
netbsd32_sendsig_sigcontext(const ksiginfo_t * ksi,const sigset_t * mask)84 netbsd32_sendsig_sigcontext(const ksiginfo_t *ksi, const sigset_t *mask)
85 {
86 struct lwp *l = curlwp;
87 struct proc *p = l->l_proc;
88 struct trapframe *tf;
89 int sig = ksi->ksi_signo;
90 sig_t catcher = SIGACTION(p, sig).sa_handler;
91 struct netbsd32_sigframe_sigcontext *fp, frame;
92 int onstack, error;
93 struct sigacts *ps = p->p_sigacts;
94
95 tf = l->l_md.md_regs;
96
97 /* Do we need to jump onto the signal stack? */
98 onstack =
99 (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 &&
100 (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0;
101
102 /* Allocate space for the signal handler context. */
103 if (onstack)
104 fp = (struct netbsd32_sigframe_sigcontext *)
105 ((char *)l->l_sigstk.ss_sp + l->l_sigstk.ss_size);
106 else
107 fp = (struct netbsd32_sigframe_sigcontext *)tf->tf_rsp;
108 fp--;
109
110 memset(&frame, 0, sizeof(frame));
111
112 /* Build stack frame for signal trampoline. */
113 switch (ps->sa_sigdesc[sig].sd_vers) {
114 case __SIGTRAMP_SIGCODE_VERSION:
115 frame.sf_ra = (uint32_t)(u_long)p->p_sigctx.ps_sigcode;
116 break;
117 case __SIGTRAMP_SIGCONTEXT_VERSION:
118 frame.sf_ra = (uint32_t)(u_long)ps->sa_sigdesc[sig].sd_tramp;
119 break;
120 default:
121 /* Don't know what trampoline version; kill it. */
122 sigexit(l, SIGILL);
123 }
124 frame.sf_signum = sig;
125 frame.sf_code = ksi->ksi_trap;
126 frame.sf_scp = (uint32_t)(u_long)&fp->sf_sc;
127
128 frame.sf_sc.sc_ds = tf->tf_ds & 0xFFFF;
129 frame.sf_sc.sc_es = tf->tf_es & 0xFFFF;
130 frame.sf_sc.sc_fs = tf->tf_fs & 0xFFFF;
131 frame.sf_sc.sc_gs = tf->tf_gs & 0xFFFF;
132
133 frame.sf_sc.sc_eflags = tf->tf_rflags;
134 frame.sf_sc.sc_edi = tf->tf_rdi;
135 frame.sf_sc.sc_esi = tf->tf_rsi;
136 frame.sf_sc.sc_ebp = tf->tf_rbp;
137 frame.sf_sc.sc_ebx = tf->tf_rbx;
138 frame.sf_sc.sc_edx = tf->tf_rdx;
139 frame.sf_sc.sc_ecx = tf->tf_rcx;
140 frame.sf_sc.sc_eax = tf->tf_rax;
141 frame.sf_sc.sc_eip = tf->tf_rip;
142 frame.sf_sc.sc_cs = tf->tf_cs & 0xFFFF;
143 frame.sf_sc.sc_esp = tf->tf_rsp;
144 frame.sf_sc.sc_ss = tf->tf_ss & 0xFFFF;
145 frame.sf_sc.sc_trapno = tf->tf_trapno;
146 frame.sf_sc.sc_err = tf->tf_err;
147
148 /* Save signal stack. */
149 frame.sf_sc.sc_onstack = l->l_sigstk.ss_flags & SS_ONSTACK;
150
151 /* Save signal mask. */
152 frame.sf_sc.sc_mask = *mask;
153
154 sendsig_reset(l, sig);
155
156 mutex_exit(p->p_lock);
157 error = copyout(&frame, fp, sizeof(frame));
158 mutex_enter(p->p_lock);
159
160 if (error != 0) {
161 /*
162 * Process has trashed its stack; give it an illegal
163 * instruction to halt it in its tracks.
164 */
165 sigexit(l, SIGILL);
166 /* NOTREACHED */
167 }
168
169 netbsd32_buildcontext(l, tf, fp, catcher, onstack);
170 }
171
172 int
compat_16_netbsd32___sigreturn14(struct lwp * l,const struct compat_16_netbsd32___sigreturn14_args * uap,register_t * retval)173 compat_16_netbsd32___sigreturn14(struct lwp *l,
174 const struct compat_16_netbsd32___sigreturn14_args *uap,
175 register_t *retval)
176 {
177 /* {
178 syscallarg(netbsd32_sigcontextp_t) sigcntxp;
179 } */
180 struct netbsd32_sigcontext *scp, context;
181 struct proc *p = l->l_proc;
182 struct trapframe *tf;
183 int error;
184
185 /*
186 * The trampoline code hands us the context.
187 * It is unsafe to keep track of it ourselves, in the event that a
188 * program jumps out of a signal handler.
189 */
190 scp = NETBSD32PTR64(SCARG(uap, sigcntxp));
191 if (copyin(scp, &context, sizeof(*scp)) != 0)
192 return (EFAULT);
193
194 /*
195 * Check for security violations.
196 */
197 error = check_sigcontext32(l, &context);
198 if (error != 0)
199 return error;
200
201 /* Restore register context. */
202 tf = l->l_md.md_regs;
203 tf->tf_ds = context.sc_ds & 0xFFFF;
204 tf->tf_es = context.sc_es & 0xFFFF;
205 cpu_fsgs_reload(l, context.sc_fs, context.sc_gs);
206 tf->tf_rflags = context.sc_eflags;
207 tf->tf_rdi = context.sc_edi;
208 tf->tf_rsi = context.sc_esi;
209 tf->tf_rbp = context.sc_ebp;
210 tf->tf_rbx = context.sc_ebx;
211 tf->tf_rdx = context.sc_edx;
212 tf->tf_rcx = context.sc_ecx;
213 tf->tf_rax = context.sc_eax;
214
215 tf->tf_rip = context.sc_eip;
216 tf->tf_cs = context.sc_cs & 0xFFFF;
217 tf->tf_rsp = context.sc_esp;
218 tf->tf_ss = context.sc_ss & 0xFFFF;
219
220 mutex_enter(p->p_lock);
221 /* Restore signal stack. */
222 if (context.sc_onstack & SS_ONSTACK)
223 l->l_sigstk.ss_flags |= SS_ONSTACK;
224 else
225 l->l_sigstk.ss_flags &= ~SS_ONSTACK;
226 /* Restore signal mask. */
227 (void) sigprocmask1(l, SIG_SETMASK, &context.sc_mask, 0);
228 mutex_exit(p->p_lock);
229
230 return (EJUSTRETURN);
231 }
232
233 void
netbsd32_machdep_md_16_init(void)234 netbsd32_machdep_md_16_init(void)
235 {
236
237 MODULE_HOOK_SET(netbsd32_sendsig_sigcontext_16_hook,
238 netbsd32_sendsig_sigcontext);
239 }
240
241 void
netbsd32_machdep_md_16_fini(void)242 netbsd32_machdep_md_16_fini(void)
243 {
244
245 MODULE_HOOK_UNSET(netbsd32_sendsig_sigcontext_16_hook);
246 }
247