2 * Copyright (C) 2002- 2004 Jeff Dike (jdike@addtoit.com)
3 * Licensed under the GPL
13 #include "ptrace_user.h"
18 #include <asm/unistd.h>
19 #include <asm/types.h>
22 #include "sysdep/ptrace.h"
23 #include "user_util.h"
24 #include "kern_util.h"
26 #include "stub-data.h"
28 #include "sysdep/sigcontext.h"
29 #include "sysdep/stub.h"
32 #include "skas_ptrace.h"
33 #include "chan_user.h"
34 #include "registers.h"
36 #include "uml-config.h"
40 int is_skas_winch(int pid, int fd, void *data)
42 if(pid != os_getpgrp())
45 register_winch_irq(-1, fd, -1, data);
49 void wait_stub_done(int pid, int sig, char * fname)
55 err = ptrace(PTRACE_CONT, pid, 0, sig);
57 panic("%s : continue failed, errno = %d\n",
62 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
63 } while((n >= 0) && WIFSTOPPED(status) &&
64 ((WSTOPSIG(status) == SIGVTALRM) ||
65 /* running UML inside a detached screen can cause
68 (WSTOPSIG(status) == SIGWINCH)));
70 if((n < 0) || !WIFSTOPPED(status) ||
71 (WSTOPSIG(status) != SIGUSR1 && WSTOPSIG(status) != SIGTRAP)){
72 unsigned long regs[HOST_FRAME_SIZE];
74 if(ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
75 printk("Failed to get registers from stub, "
76 "errno = %d\n", errno);
80 printk("Stub registers -\n");
81 for(i = 0; i < HOST_FRAME_SIZE; i++)
82 printk("\t%d - %lx\n", i, regs[i]);
84 panic("%s : failed to wait for SIGUSR1/SIGTRAP, "
85 "pid = %d, n = %d, errno = %d, status = 0x%x\n",
86 fname, pid, n, errno, status);
90 extern unsigned long current_stub_stack(void);
92 void get_skas_faultinfo(int pid, struct faultinfo * fi)
97 err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
99 panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, "
100 "errno = %d\n", errno);
102 /* Special handling for i386, which has different structs */
103 if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo))
104 memset((char *)fi + sizeof(struct ptrace_faultinfo), 0,
105 sizeof(struct faultinfo) -
106 sizeof(struct ptrace_faultinfo));
109 wait_stub_done(pid, SIGSEGV, "get_skas_faultinfo");
111 /* faultinfo is prepared by the stub-segv-handler at start of
112 * the stub stack page. We just have to copy it.
114 memcpy(fi, (void *)current_stub_stack(), sizeof(*fi));
118 static void handle_segv(int pid, union uml_pt_regs * regs)
120 get_skas_faultinfo(pid, ®s->skas.faultinfo);
121 segv(regs->skas.faultinfo, 0, 1, NULL);
124 /*To use the same value of using_sysemu as the caller, ask it that value (in local_using_sysemu)*/
125 static void handle_trap(int pid, union uml_pt_regs *regs, int local_using_sysemu)
129 /* Mark this as a syscall */
130 UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->skas.regs);
132 if (!local_using_sysemu)
134 err = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
137 panic("handle_trap - nullifying syscall failed errno = %d\n",
140 err = ptrace(PTRACE_SYSCALL, pid, 0, 0);
142 panic("handle_trap - continuing to end of syscall failed, "
143 "errno = %d\n", errno);
145 CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
146 if((err < 0) || !WIFSTOPPED(status) ||
147 (WSTOPSIG(status) != SIGTRAP + 0x80))
148 panic("handle_trap - failed to wait at end of syscall, "
149 "errno = %d, status = %d\n", errno, status);
152 handle_syscall(regs);
155 extern int __syscall_stub_start;
157 static int userspace_tramp(void *stack)
161 ptrace(PTRACE_TRACEME, 0, 0, 0);
163 init_new_thread_signals(1);
167 /* This has a pte, but it can't be mapped in with the usual
168 * tlb_flush mechanism because this is part of that mechanism
172 fd = phys_mapping(to_phys(&__syscall_stub_start), &offset);
173 addr = mmap64((void *) UML_CONFIG_STUB_CODE, page_size(),
174 PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
175 if(addr == MAP_FAILED){
176 printk("mapping mmap stub failed, errno = %d\n",
182 fd = phys_mapping(to_phys(stack), &offset);
183 addr = mmap((void *) UML_CONFIG_STUB_DATA, page_size(),
184 PROT_READ | PROT_WRITE,
185 MAP_FIXED | MAP_SHARED, fd, offset);
186 if(addr == MAP_FAILED){
187 printk("mapping segfault stack failed, "
188 "errno = %d\n", errno);
193 if(!ptrace_faultinfo && (stack != NULL)){
194 unsigned long v = UML_CONFIG_STUB_CODE +
195 (unsigned long) stub_segv_handler -
196 (unsigned long) &__syscall_stub_start;
198 set_sigstack((void *) UML_CONFIG_STUB_DATA, page_size());
199 set_handler(SIGSEGV, (void *) v, SA_ONSTACK,
200 SIGIO, SIGWINCH, SIGALRM, SIGVTALRM,
204 os_stop_process(os_getpid());
208 /* Each element set once, and only accessed by a single processor anyway */
211 int userspace_pid[NR_CPUS];
213 int start_userspace(unsigned long stub_stack)
217 int pid, status, n, flags;
219 stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
220 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
221 if(stack == MAP_FAILED)
222 panic("start_userspace : mmap failed, errno = %d", errno);
223 sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
225 flags = CLONE_FILES | SIGCHLD;
226 if(proc_mm) flags |= CLONE_VM;
227 pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
229 panic("start_userspace : clone failed, errno = %d", errno);
232 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
234 panic("start_userspace : wait failed, errno = %d",
236 } while(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM));
238 if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
239 panic("start_userspace : expected SIGSTOP, got status = %d",
242 if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, (void *)PTRACE_O_TRACESYSGOOD) < 0)
243 panic("start_userspace : PTRACE_OLDSETOPTIONS failed, errno=%d\n",
246 if(munmap(stack, PAGE_SIZE) < 0)
247 panic("start_userspace : munmap failed, errno = %d\n", errno);
252 void userspace(union uml_pt_regs *regs)
254 int err, status, op, pid = userspace_pid[0];
255 int local_using_sysemu; /*To prevent races if using_sysemu changes under us.*/
258 restore_registers(pid, regs);
260 /* Now we set local_using_sysemu to be used for one loop */
261 local_using_sysemu = get_using_sysemu();
263 op = SELECT_PTRACE_OPERATION(local_using_sysemu, singlestepping(NULL));
265 err = ptrace(op, pid, 0, 0);
267 panic("userspace - could not resume userspace process, "
268 "pid=%d, ptrace operation = %d, errno = %d\n",
271 CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
273 panic("userspace - waitpid failed, errno = %d\n",
276 regs->skas.is_user = 1;
277 save_registers(pid, regs);
278 UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */
280 if(WIFSTOPPED(status)){
281 switch(WSTOPSIG(status)){
283 if(PTRACE_FULL_FAULTINFO || !ptrace_faultinfo)
284 user_signal(SIGSEGV, regs, pid);
285 else handle_segv(pid, regs);
288 handle_trap(pid, regs, local_using_sysemu);
291 relay_signal(SIGTRAP, regs);
299 user_signal(WSTOPSIG(status), regs, pid);
302 printk("userspace - child stopped with signal "
303 "%d\n", WSTOPSIG(status));
305 pid = userspace_pid[0];
308 /* Avoid -ERESTARTSYS handling in host */
309 if(PT_SYSCALL_NR_OFFSET != PT_SYSCALL_RET_OFFSET)
310 PT_SYSCALL_NR(regs->skas.regs) = -1;
315 int copy_context_skas0(unsigned long new_stack, int pid)
318 unsigned long regs[HOST_FRAME_SIZE];
319 unsigned long fp_regs[HOST_FP_SIZE];
320 unsigned long current_stack = current_stub_stack();
321 struct stub_data *data = (struct stub_data *) current_stack;
322 struct stub_data *child_data = (struct stub_data *) new_stack;
324 int new_fd = phys_mapping(to_phys((void *)new_stack), &new_offset);
326 /* prepare offset and fd of child's stack as argument for parent's
327 * and child's mmap2 calls
329 *data = ((struct stub_data) { .offset = MMAP_OFFSET(new_offset),
331 .timer = ((struct itimerval)
332 { { 0, 1000000 / hz() },
333 { 0, 1000000 / hz() }})});
334 get_safe_registers(regs, fp_regs);
336 /* Set parent's instruction pointer to start of clone-stub */
337 regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
338 (unsigned long) stub_clone_handler -
339 (unsigned long) &__syscall_stub_start;
340 regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + PAGE_SIZE -
342 #ifdef __SIGNAL_FRAMESIZE
343 regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
345 err = ptrace_setregs(pid, regs);
347 panic("copy_context_skas0 : PTRACE_SETREGS failed, "
348 "pid = %d, errno = %d\n", pid, errno);
350 err = ptrace_setfpregs(pid, fp_regs);
352 panic("copy_context_skas0 : PTRACE_SETFPREGS failed, "
353 "pid = %d, errno = %d\n", pid, errno);
355 /* set a well known return code for detection of child write failure */
356 child_data->err = 12345678;
358 /* Wait, until parent has finished its work: read child's pid from
359 * parent's stack, and check, if bad result.
361 wait_stub_done(pid, 0, "copy_context_skas0");
365 panic("copy_context_skas0 - stub-parent reports error %d\n",
368 /* Wait, until child has finished too: read child's result from
369 * child's stack and check it.
371 wait_stub_done(pid, -1, "copy_context_skas0");
372 if (child_data->err != UML_CONFIG_STUB_DATA)
373 panic("copy_context_skas0 - stub-child reports error %d\n",
376 if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
377 (void *)PTRACE_O_TRACESYSGOOD) < 0)
378 panic("copy_context_skas0 : PTRACE_OLDSETOPTIONS failed, "
379 "errno = %d\n", errno);
385 * This is used only, if stub pages are needed, while proc_mm is
386 * availabl. Opening /proc/mm creates a new mm_context, which lacks
387 * the stub-pages. Thus, we map them using /proc/mm-fd
389 void map_stub_pages(int fd, unsigned long code,
390 unsigned long data, unsigned long stack)
392 struct proc_mm_op mmop;
395 int code_fd = phys_mapping(to_phys((void *) &__syscall_stub_start),
398 mmop = ((struct proc_mm_op) { .op = MM_MMAP,
404 .flags = MAP_FIXED | MAP_PRIVATE,
406 .offset = code_offset
408 n = os_write_file(fd, &mmop, sizeof(mmop));
409 if(n != sizeof(mmop))
410 panic("map_stub_pages : /proc/mm map for code failed, "
415 int map_fd = phys_mapping(to_phys((void *)stack), &map_offset);
416 mmop = ((struct proc_mm_op)
422 .prot = PROT_READ | PROT_WRITE,
423 .flags = MAP_FIXED | MAP_SHARED,
427 n = os_write_file(fd, &mmop, sizeof(mmop));
428 if(n != sizeof(mmop))
429 panic("map_stub_pages : /proc/mm map for data failed, "
434 void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
435 void (*handler)(int))
438 sigjmp_buf switch_buf, fork_buf;
441 *switch_buf_ptr = &switch_buf;
442 *fork_buf_ptr = &fork_buf;
444 /* Somewhat subtle - siglongjmp restores the signal mask before doing
445 * the longjmp. This means that when jumping from one stack to another
446 * when the target stack has interrupts enabled, an interrupt may occur
447 * on the source stack. This is bad when starting up a process because
448 * it's not supposed to get timer ticks until it has been scheduled.
449 * So, we disable interrupts around the sigsetjmp to ensure that
450 * they can't happen until we get back here where they are safe.
452 flags = get_signals();
454 if(UML_SIGSETJMP(&fork_buf, enable) == 0)
455 new_thread_proc(stack, handler);
462 #define INIT_JMP_NEW_THREAD 0
463 #define INIT_JMP_REMOVE_SIGSTACK 1
464 #define INIT_JMP_CALLBACK 2
465 #define INIT_JMP_HALT 3
466 #define INIT_JMP_REBOOT 4
468 void thread_wait(void *sw, void *fb)
470 sigjmp_buf buf, **switch_buf = sw, *fork_buf;
475 if(UML_SIGSETJMP(&buf, enable) == 0)
476 siglongjmp(*fork_buf, INIT_JMP_REMOVE_SIGSTACK);
479 void switch_threads(void *me, void *next)
481 sigjmp_buf my_buf, **me_ptr = me, *next_buf = next;
485 if(UML_SIGSETJMP(&my_buf, enable) == 0)
486 UML_SIGLONGJMP(next_buf, 1);
489 static sigjmp_buf initial_jmpbuf;
491 /* XXX Make these percpu */
492 static void (*cb_proc)(void *arg);
494 static sigjmp_buf *cb_back;
496 int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
498 sigjmp_buf **switch_buf = switch_buf_ptr;
501 set_handler(SIGWINCH, (__sighandler_t) sig_handler,
502 SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGALRM,
505 *fork_buf_ptr = &initial_jmpbuf;
506 n = UML_SIGSETJMP(&initial_jmpbuf, enable);
508 case INIT_JMP_NEW_THREAD:
509 new_thread_proc((void *) stack, new_thread_handler);
511 case INIT_JMP_REMOVE_SIGSTACK:
514 case INIT_JMP_CALLBACK:
516 UML_SIGLONGJMP(cb_back, 1);
521 case INIT_JMP_REBOOT:
525 panic("Bad sigsetjmp return in start_idle_thread - %d\n", n);
527 UML_SIGLONGJMP(*switch_buf, 1);
530 void initial_thread_cb_skas(void (*proc)(void *), void *arg)
540 if(UML_SIGSETJMP(&here, enable) == 0)
541 UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_CALLBACK);
552 UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_HALT);
555 void reboot_skas(void)
558 UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_REBOOT);
561 void switch_mm_skas(struct mm_id *mm_idp)
565 #warning need cpu pid in switch_mm_skas
567 err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0,
570 panic("switch_mm_skas - PTRACE_SWITCH_MM failed, "
571 "errno = %d\n", errno);
573 else userspace_pid[0] = mm_idp->u.pid;