vkernel - Fix corrupt tailq (vkernel64 only)
[dragonfly.git] / sys / platform / vkernel64 / x86_64 / vm_machdep.c
CommitLineData
da673940
JG
1/*-
2 * Copyright (c) 1982, 1986 The Regents of the University of California.
3 * Copyright (c) 1989, 1990 William Jolitz
4 * Copyright (c) 1994 John Dyson
5 * Copyright (c) 2008 The DragonFly Project.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * the Systems Programming Group of the University of Utah Computer
10 * Science Department, and William Jolitz.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by the University of
23 * California, Berkeley and its contributors.
24 * 4. Neither the name of the University nor the names of its contributors
25 * may be used to endorse or promote products derived from this software
26 * without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
39 *
40 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91
41 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
42 * $FreeBSD: src/sys/i386/i386/vm_machdep.c,v 1.132.2.9 2003/01/25 19:02:23 dillon Exp $
43 * $DragonFly: src/sys/platform/pc64/amd64/vm_machdep.c,v 1.3 2008/08/29 17:07:10 dillon Exp $
44 */
45
46#include <sys/param.h>
47#include <sys/systm.h>
48#include <sys/malloc.h>
49#include <sys/proc.h>
50#include <sys/buf.h>
51#include <sys/interrupt.h>
52#include <sys/vnode.h>
53#include <sys/vmmeter.h>
54#include <sys/kernel.h>
55#include <sys/sysctl.h>
56#include <sys/unistd.h>
57
58#include <machine/clock.h>
59#include <machine/cpu.h>
60#include <machine/md_var.h>
61#include <machine/smp.h>
62#include <machine/pcb.h>
63#include <machine/pcb_ext.h>
64#include <machine/segments.h>
65#include <machine/globaldata.h> /* npxthread */
66
67#include <vm/vm.h>
68#include <vm/vm_param.h>
69#include <sys/lock.h>
70#include <vm/vm_kern.h>
71#include <vm/vm_page.h>
72#include <vm/vm_map.h>
73#include <vm/vm_extern.h>
74
75#include <sys/thread2.h>
76
77#include <bus/isa/isa.h>
78
79char machine[] = MACHINE;
80SYSCTL_STRING(_hw, HW_MACHINE, machine, CTLFLAG_RD,
81 machine, 0, "Machine class");
82
83/*
84 * Finish a fork operation, with lwp lp2 nearly set up.
85 * Copy and update the pcb, set up the stack so that the child
86 * ready to run and return to user mode.
87 */
88void
89cpu_fork(struct lwp *lp1, struct lwp *lp2, int flags)
90{
91 struct pcb *pcb2;
92
93 if ((flags & RFPROC) == 0) {
94 if ((flags & RFMEM) == 0) {
95 /* unshare user LDT */
96 struct pcb *pcb1 = lp1->lwp_thread->td_pcb;
97 struct pcb_ldt *pcb_ldt = pcb1->pcb_ldt;
98 if (pcb_ldt && pcb_ldt->ldt_refcnt > 1) {
99 pcb_ldt = user_ldt_alloc(pcb1,pcb_ldt->ldt_len);
100 user_ldt_free(pcb1);
101 pcb1->pcb_ldt = pcb_ldt;
102 set_user_ldt(pcb1);
103 }
104 }
105 return;
106 }
107
108 /* Ensure that lp1's pcb is up to date. */
109 if (mdcpu->gd_npxthread == lp1->lwp_thread)
110 npxsave(lp1->lwp_thread->td_savefpu);
111
112 /*
113 * Copy lp1's PCB. This really only applies to the
114 * debug registers and FP state, but its faster to just copy the
115 * whole thing. Because we only save the PCB at switchout time,
116 * the register state may not be current.
117 */
118 pcb2 = lp2->lwp_thread->td_pcb;
119 *pcb2 = *lp1->lwp_thread->td_pcb;
120
121 /*
122 * Create a new fresh stack for the new process.
123 * Copy the trap frame for the return to user mode as if from a
124 * syscall. This copies the user mode register values.
125 *
126 * pcb_rsp must allocate an additional call-return pointer below
127 * the trap frame which will be restored by cpu_heavy_restore from
128 * PCB_RIP, and the thread's td_sp pointer must allocate an
129 * additonal two quadwords below the pcb_rsp call-return pointer to
130 * hold the LWKT restore function pointer and rflags.
131 *
132 * The LWKT restore function pointer must be set to cpu_heavy_restore,
133 * which is our standard heavy-weight process switch-in function.
134 * YYY eventually we should shortcut fork_return and fork_trampoline
135 * to use the LWKT restore function directly so we can get rid of
136 * all the extra crap we are setting up.
137 */
138 lp2->lwp_md.md_regs = (struct trapframe *)pcb2 - 1;
139 bcopy(lp1->lwp_md.md_regs, lp2->lwp_md.md_regs, sizeof(*lp2->lwp_md.md_regs));
140
141 /*
142 * Set registers for trampoline to user mode. Leave space for the
143 * return address on stack. These are the kernel mode register values.
144 */
145 pcb2->pcb_unused01 = 0;
146 pcb2->pcb_rbx = (unsigned long)fork_return; /* fork_trampoline argument */
147 pcb2->pcb_rbp = 0;
148 pcb2->pcb_rsp = (unsigned long)lp2->lwp_md.md_regs - sizeof(void *);
149 pcb2->pcb_r12 = (unsigned long)lp2; /* fork_trampoline argument */
150 pcb2->pcb_r13 = 0;
151 pcb2->pcb_r14 = 0;
152 pcb2->pcb_r15 = 0;
153 pcb2->pcb_rip = (unsigned long)fork_trampoline;
154 lp2->lwp_thread->td_sp = (char *)(pcb2->pcb_rsp - sizeof(void *));
155 *(u_int64_t *)lp2->lwp_thread->td_sp = PSL_USER;
156 lp2->lwp_thread->td_sp -= sizeof(void *);
157 *(void **)lp2->lwp_thread->td_sp = (void *)cpu_heavy_restore;
158
159 /*
160 * pcb2->pcb_ldt: duplicated below, if necessary.
161 * pcb2->pcb_savefpu: cloned above.
162 * pcb2->pcb_flags: cloned above (always 0 here?).
163 * pcb2->pcb_onfault: cloned above (always NULL here?).
164 */
165
166 /*
167 * XXX don't copy the i/o pages. this should probably be fixed.
168 */
169 pcb2->pcb_ext = 0;
170
171 /* Copy the LDT, if necessary. */
172 if (pcb2->pcb_ldt != 0) {
173 if (flags & RFMEM) {
174 pcb2->pcb_ldt->ldt_refcnt++;
175 } else {
176 pcb2->pcb_ldt = user_ldt_alloc(pcb2,
177 pcb2->pcb_ldt->ldt_len);
178 }
179 }
180 bcopy(&lp1->lwp_thread->td_tls, &lp2->lwp_thread->td_tls,
181 sizeof(lp2->lwp_thread->td_tls));
182 /*
183 * Now, cpu_switch() can schedule the new lwp.
184 * pcb_rsp is loaded pointing to the cpu_switch() stack frame
185 * containing the return address when exiting cpu_switch.
186 * This will normally be to fork_trampoline(), which will have
187 * %rbx loaded with the new lwp's pointer. fork_trampoline()
188 * will set up a stack to call fork_return(lp, frame); to complete
189 * the return to user-mode.
190 */
191}
192
193/*
194 * Prepare new lwp to return to the address specified in params.
195 */
196int
197cpu_prepare_lwp(struct lwp *lp, struct lwp_params *params)
198{
199 struct trapframe *regs = lp->lwp_md.md_regs;
200 void *bad_return = NULL;
201 int error;
202
203 regs->tf_rip = (long)params->func;
204 regs->tf_rsp = (long)params->stack;
205 /* Set up argument for function call */
206 regs->tf_rdi = (long)params->arg; /* JG Can this be in userspace addresses? */
207 /*
208 * Set up fake return address. As the lwp function may never return,
209 * we simply copy out a NULL pointer and force the lwp to receive
210 * a SIGSEGV if it returns anyways.
211 */
212 regs->tf_rsp -= sizeof(void *);
213 error = copyout(&bad_return, (void *)regs->tf_rsp, sizeof(bad_return));
214 if (error)
215 return (error);
216
217 cpu_set_fork_handler(lp,
218 (void (*)(void *, struct trapframe *))generic_lwp_return, lp);
219 return (0);
220}
221
222/*
223 * Intercept the return address from a freshly forked process that has NOT
224 * been scheduled yet.
225 *
226 * This is needed to make kernel threads stay in kernel mode.
227 */
228void
229cpu_set_fork_handler(struct lwp *lp, void (*func)(void *, struct trapframe *),
230 void *arg)
231{
232 /*
233 * Note that the trap frame follows the args, so the function
234 * is really called like this: func(arg, frame);
235 */
236 lp->lwp_thread->td_pcb->pcb_rbx = (long)func; /* function */
237 lp->lwp_thread->td_pcb->pcb_r12 = (long)arg; /* first arg */
238}
239
240void
241cpu_set_thread_handler(thread_t td, void (*rfunc)(void), void *func, void *arg)
242{
243 td->td_pcb->pcb_rbx = (long)func;
244 td->td_pcb->pcb_r12 = (long)arg;
245 td->td_switch = cpu_lwkt_switch;
246 td->td_sp -= sizeof(void *);
247 *(void **)td->td_sp = rfunc; /* exit function on return */
248 td->td_sp -= sizeof(void *);
249 *(void **)td->td_sp = cpu_kthread_restore;
250}
251
252void
253cpu_lwp_exit(void)
254{
255 struct thread *td = curthread;
256 struct pcb *pcb;
257 npxexit();
258 pcb = td->td_pcb;
2883d2d8
MD
259
260 /* Some i386 functionality was dropped */
261 KKASSERT(pcb->pcb_ext == NULL);
262
263 /*
264 * disable all hardware breakpoints
265 */
da673940 266 if (pcb->pcb_flags & PCB_DBREGS) {
da673940
JG
267 reset_dbregs();
268 pcb->pcb_flags &= ~PCB_DBREGS;
269 }
270 td->td_gd->gd_cnt.v_swtch++;
271
272 crit_enter_quick(td);
74c9628e
MD
273 if (td->td_flags & TDF_TSLEEPQ)
274 tsleep_remove(td);
da673940
JG
275 lwkt_deschedule_self(td);
276 lwkt_remove_tdallq(td);
277 cpu_thread_exit();
278}
279
280/*
281 * Terminate the current thread. The caller must have already acquired
282 * the thread's rwlock and placed it on a reap list or otherwise notified
283 * a reaper of its existance. We set a special assembly switch function which
284 * releases td_rwlock after it has cleaned up the MMU state and switched
285 * out the stack.
286 *
287 * Must be caller from a critical section and with the thread descheduled.
288 */
289void
290cpu_thread_exit(void)
291{
292 curthread->td_switch = cpu_exit_switch;
293 curthread->td_flags |= TDF_EXITING;
294 lwkt_switch();
295 panic("cpu_thread_exit: lwkt_switch() unexpectedly returned");
296}
297
298/*
299 * Process Reaper. Called after the caller has acquired the thread's
300 * rwlock and removed it from the reap list.
301 */
302void
303cpu_proc_wait(struct proc *p)
304{
305 /* drop per-process resources */
306 pmap_dispose_proc(p);
307}
308
309int
310grow_stack(struct proc *p, u_long sp)
311{
312 int rv;
313
314 rv = vm_map_growstack (p, sp);
315 if (rv != KERN_SUCCESS)
316 return (0);
317
318 return (1);
319}
320
321/*
322 * Tell whether this address is in some physical memory region.
323 * Currently used by the kernel coredump code in order to avoid
324 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
325 * or other unpredictable behaviour.
326 */
327
328int
329is_physical_memory(vm_offset_t addr)
330{
331 return 1;
332}
333
334/*
335 * Used by /dev/kmem to determine if we can safely read or write
336 * the requested KVA range. Some portions of kernel memory are
337 * not governed by our virtual page table.
338 */
339extern int64_t _end;
340extern void _start(void);
341
342int
343kvm_access_check(vm_offset_t saddr, vm_offset_t eaddr, int prot)
344{
345 vm_offset_t addr;
346
347 if (saddr >= trunc_page((vm_offset_t)&_start) && eaddr <= round_page((vm_offset_t)&_end))
348 return 0;
349 if (saddr < KvaStart)
350 return EFAULT;
351 if (eaddr >= KvaEnd)
352 return EFAULT;
353 for (addr = saddr; addr < eaddr; addr += PAGE_SIZE) {
354 if (pmap_extract(&kernel_pmap, addr) == 0)
355 return EFAULT;
356 }
357 if (!kernacc((caddr_t)saddr, eaddr - saddr, prot))
358 return EFAULT;
359 return 0;
360}