2 /* By Ross Biro 1/23/92 */
4 * Pentium III FXSR, SSE support
5 * Gareth Hughes <gareth@valinux.com>, May 2000
7 * x86-64 port 2000-2002 Andi Kleen
10 #include <linux/kernel.h>
11 #include <linux/sched.h>
13 #include <linux/smp.h>
14 #include <linux/smp_lock.h>
15 #include <linux/errno.h>
16 #include <linux/ptrace.h>
17 #include <linux/user.h>
18 #include <linux/security.h>
19 #include <linux/audit.h>
20 #include <linux/seccomp.h>
21 #include <linux/signal.h>
23 #include <asm/uaccess.h>
24 #include <asm/pgtable.h>
25 #include <asm/system.h>
26 #include <asm/processor.h>
28 #include <asm/debugreg.h>
31 #include <asm/proto.h>
35 * does not yet catch signals sent when the child dies.
36 * in exit.c or in signal.c.
39 /* determines which flags the user has access to. */
40 /* 1 = access 0 = no access */
41 #define FLAG_MASK 0x44dd5UL
43 /* set's the trap flag. */
44 #define TRAP_FLAG 0x100UL
47 * eflags and offset of eflags on child stack..
49 #define EFLAGS offsetof(struct pt_regs, eflags)
50 #define EFL_OFFSET ((int)(EFLAGS-sizeof(struct pt_regs)))
53 * this routine will get a word off of the processes privileged stack.
54 * the offset is how far from the base addr as stored in the TSS.
55 * this routine assumes that all the privileged stacks are in our
58 static inline unsigned long get_stack_long(struct task_struct *task, int offset)
62 stack = (unsigned char *)task->thread.rsp0;
64 return (*((unsigned long *)stack));
67 static inline struct pt_regs *get_child_regs(struct task_struct *task)
69 struct pt_regs *regs = (void *)task->thread.rsp0;
74 * this routine will put a word on the processes privileged stack.
75 * the offset is how far from the base addr as stored in the TSS.
76 * this routine assumes that all the privileged stacks are in our
79 static inline long put_stack_long(struct task_struct *task, int offset,
82 unsigned char * stack;
84 stack = (unsigned char *) task->thread.rsp0;
86 *(unsigned long *) stack = data;
92 unsigned long convert_rip_to_linear(struct task_struct *child, struct pt_regs *regs)
94 unsigned long addr, seg;
97 seg = regs->cs & 0xffff;
100 * We'll assume that the code segments in the GDT
101 * are all zero-based. That is largely true: the
102 * TLS segments are used for data, and the PNPBIOS
103 * and APM bios ones we just ignore here.
105 if (seg & LDT_SEGMENT) {
109 down(&child->mm->context.sem);
110 desc = child->mm->context.ldt + (seg & ~7);
111 base = (desc[0] >> 16) | ((desc[1] & 0xff) << 16) | (desc[1] & 0xff000000);
113 /* 16-bit code segment? */
114 if (!((desc[1] >> 22) & 1))
117 up(&child->mm->context.sem);
122 static int is_at_popf(struct task_struct *child, struct pt_regs *regs)
125 unsigned char opcode[16];
126 unsigned long addr = convert_rip_to_linear(child, regs);
128 copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0);
129 for (i = 0; i < copied; i++) {
137 /* opcode and address size prefixes */
138 case 0x66: case 0x67:
140 /* irrelevant prefixes (segment overrides and repeats) */
141 case 0x26: case 0x2e:
142 case 0x36: case 0x3e:
143 case 0x64: case 0x65:
144 case 0xf0: case 0xf2: case 0xf3:
151 /* CHECKME: f0, f2, f3 */
154 * pushf: NOTE! We should probably not let
155 * the user see the TF bit being set. But
156 * it's more pain than it's worth to avoid
157 * it, and a debugger could emulate this
158 * all in user space if it _really_ cares.
168 static void set_singlestep(struct task_struct *child)
170 struct pt_regs *regs = get_child_regs(child);
173 * Always set TIF_SINGLESTEP - this guarantees that
174 * we single-step system calls etc.. This will also
175 * cause us to set TF when returning to user mode.
177 set_tsk_thread_flag(child, TIF_SINGLESTEP);
180 * If TF was already set, don't do anything else
182 if (regs->eflags & TRAP_FLAG)
185 /* Set TF on the kernel stack.. */
186 regs->eflags |= TRAP_FLAG;
189 * ..but if TF is changed by the instruction we will trace,
190 * don't mark it as being "us" that set it, so that we
191 * won't clear it by hand later.
193 * AK: this is not enough, LAHF and IRET can change TF in user space too.
195 if (is_at_popf(child, regs))
198 child->ptrace |= PT_DTRACE;
201 static void clear_singlestep(struct task_struct *child)
203 /* Always clear TIF_SINGLESTEP... */
204 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
206 /* But touch TF only if it was set by us.. */
207 if (child->ptrace & PT_DTRACE) {
208 struct pt_regs *regs = get_child_regs(child);
209 regs->eflags &= ~TRAP_FLAG;
210 child->ptrace &= ~PT_DTRACE;
215 * Called by kernel/ptrace.c when detaching..
217 * Make sure the single step bit is not set.
219 void ptrace_disable(struct task_struct *child)
221 clear_singlestep(child);
224 static int putreg(struct task_struct *child,
225 unsigned long regno, unsigned long value)
229 /* Some code in the 64bit emulation may not be 64bit clean.
230 Don't take any chances. */
231 if (test_tsk_thread_flag(child, TIF_IA32))
234 case offsetof(struct user_regs_struct,fs):
235 if (value && (value & 3) != 3)
237 child->thread.fsindex = value & 0xffff;
239 case offsetof(struct user_regs_struct,gs):
240 if (value && (value & 3) != 3)
242 child->thread.gsindex = value & 0xffff;
244 case offsetof(struct user_regs_struct,ds):
245 if (value && (value & 3) != 3)
247 child->thread.ds = value & 0xffff;
249 case offsetof(struct user_regs_struct,es):
250 if (value && (value & 3) != 3)
252 child->thread.es = value & 0xffff;
254 case offsetof(struct user_regs_struct,ss):
255 if ((value & 3) != 3)
259 case offsetof(struct user_regs_struct,fs_base):
260 if (value >= TASK_SIZE)
262 child->thread.fs = value;
264 case offsetof(struct user_regs_struct,gs_base):
265 if (value >= TASK_SIZE)
267 child->thread.gs = value;
269 case offsetof(struct user_regs_struct, eflags):
271 tmp = get_stack_long(child, EFL_OFFSET);
275 case offsetof(struct user_regs_struct,cs):
276 if ((value & 3) != 3)
280 case offsetof(struct user_regs_struct, rip):
281 /* Check if the new RIP address is canonical */
282 if (value >= TASK_SIZE)
286 put_stack_long(child, regno - sizeof(struct pt_regs), value);
290 static unsigned long getreg(struct task_struct *child, unsigned long regno)
294 case offsetof(struct user_regs_struct, fs):
295 return child->thread.fsindex;
296 case offsetof(struct user_regs_struct, gs):
297 return child->thread.gsindex;
298 case offsetof(struct user_regs_struct, ds):
299 return child->thread.ds;
300 case offsetof(struct user_regs_struct, es):
301 return child->thread.es;
302 case offsetof(struct user_regs_struct, fs_base):
303 return child->thread.fs;
304 case offsetof(struct user_regs_struct, gs_base):
305 return child->thread.gs;
307 regno = regno - sizeof(struct pt_regs);
308 val = get_stack_long(child, regno);
309 if (test_tsk_thread_flag(child, TIF_IA32))
316 asmlinkage long sys_ptrace(long request, long pid, unsigned long addr, long data)
318 struct task_struct *child;
322 /* This lock_kernel fixes a subtle race with suid exec */
325 if (request == PTRACE_TRACEME) {
326 /* are we already being traced? */
327 if (current->ptrace & PT_PTRACED)
329 ret = security_ptrace(current->parent, current);
332 /* set the ptrace bit in the process flags. */
333 current->ptrace |= PT_PTRACED;
338 read_lock(&tasklist_lock);
339 child = find_task_by_pid(pid);
341 get_task_struct(child);
342 read_unlock(&tasklist_lock);
345 if (!vx_check(vx_task_xid(child), VX_WATCH|VX_IDENT))
349 if (pid == 1) /* you may not mess with init */
352 if (request == PTRACE_ATTACH) {
353 ret = ptrace_attach(child);
356 ret = ptrace_check_attach(child, request == PTRACE_KILL);
361 /* when I and D space are separate, these will need to be fixed. */
362 case PTRACE_PEEKTEXT: /* read word at location addr. */
363 case PTRACE_PEEKDATA: {
367 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
369 if (copied != sizeof(tmp))
371 ret = put_user(tmp,(unsigned long __user *) data);
375 /* read the word at location addr in the USER area. */
376 case PTRACE_PEEKUSR: {
381 addr > sizeof(struct user) - 7)
385 case 0 ... sizeof(struct user_regs_struct) - sizeof(long):
386 tmp = getreg(child, addr);
388 case offsetof(struct user, u_debugreg[0]):
389 tmp = child->thread.debugreg0;
391 case offsetof(struct user, u_debugreg[1]):
392 tmp = child->thread.debugreg1;
394 case offsetof(struct user, u_debugreg[2]):
395 tmp = child->thread.debugreg2;
397 case offsetof(struct user, u_debugreg[3]):
398 tmp = child->thread.debugreg3;
400 case offsetof(struct user, u_debugreg[6]):
401 tmp = child->thread.debugreg6;
403 case offsetof(struct user, u_debugreg[7]):
404 tmp = child->thread.debugreg7;
410 ret = put_user(tmp,(unsigned long __user *) data);
414 /* when I and D space are separate, this will have to be fixed. */
415 case PTRACE_POKETEXT: /* write the word at location addr. */
416 case PTRACE_POKEDATA:
418 if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
423 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
426 addr > sizeof(struct user) - 7)
430 case 0 ... sizeof(struct user_regs_struct) - sizeof(long):
431 ret = putreg(child, addr, data);
433 /* Disallows to set a breakpoint into the vsyscall */
434 case offsetof(struct user, u_debugreg[0]):
435 if (data >= TASK_SIZE-7) break;
436 child->thread.debugreg0 = data;
439 case offsetof(struct user, u_debugreg[1]):
440 if (data >= TASK_SIZE-7) break;
441 child->thread.debugreg1 = data;
444 case offsetof(struct user, u_debugreg[2]):
445 if (data >= TASK_SIZE-7) break;
446 child->thread.debugreg2 = data;
449 case offsetof(struct user, u_debugreg[3]):
450 if (data >= TASK_SIZE-7) break;
451 child->thread.debugreg3 = data;
454 case offsetof(struct user, u_debugreg[6]):
457 child->thread.debugreg6 = data;
460 case offsetof(struct user, u_debugreg[7]):
461 /* See arch/i386/kernel/ptrace.c for an explanation of
462 * this awkward check.*/
463 data &= ~DR_CONTROL_RESERVED;
465 if ((0x5454 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
468 child->thread.debugreg7 = data;
474 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
475 case PTRACE_CONT: /* restart after signal. */
478 if (!valid_signal(data))
480 if (request == PTRACE_SYSCALL)
481 set_tsk_thread_flag(child,TIF_SYSCALL_TRACE);
483 clear_tsk_thread_flag(child,TIF_SYSCALL_TRACE);
484 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
485 child->exit_code = data;
486 /* make sure the single step bit is not set. */
487 clear_singlestep(child);
488 wake_up_process(child);
492 #ifdef CONFIG_IA32_EMULATION
493 /* This makes only sense with 32bit programs. Allow a
494 64bit debugger to fully examine them too. Better
495 don't use it against 64bit processes, use
496 PTRACE_ARCH_PRCTL instead. */
497 case PTRACE_SET_THREAD_AREA: {
498 struct user_desc __user *p;
500 p = (struct user_desc __user *)data;
501 get_user(old, &p->entry_number);
502 put_user(addr, &p->entry_number);
503 ret = do_set_thread_area(&child->thread, p);
504 put_user(old, &p->entry_number);
506 case PTRACE_GET_THREAD_AREA:
507 p = (struct user_desc __user *)data;
508 get_user(old, &p->entry_number);
509 put_user(addr, &p->entry_number);
510 ret = do_get_thread_area(&child->thread, p);
511 put_user(old, &p->entry_number);
515 /* normal 64bit interface to access TLS data.
516 Works just like arch_prctl, except that the arguments
518 case PTRACE_ARCH_PRCTL:
519 ret = do_arch_prctl(child, data, addr);
523 * make the child exit. Best I can do is send it a sigkill.
524 * perhaps it should be put in the status that it wants to
529 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
531 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
532 child->exit_code = SIGKILL;
533 /* make sure the single step bit is not set. */
534 clear_singlestep(child);
535 wake_up_process(child);
538 case PTRACE_SINGLESTEP: /* set the trap flag. */
540 if (!valid_signal(data))
542 clear_tsk_thread_flag(child,TIF_SYSCALL_TRACE);
543 set_singlestep(child);
544 child->exit_code = data;
545 /* give it a chance to run. */
546 wake_up_process(child);
551 /* detach a process that was attached. */
552 ret = ptrace_detach(child, data);
555 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
556 if (!access_ok(VERIFY_WRITE, (unsigned __user *)data,
557 sizeof(struct user_regs_struct))) {
562 for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
563 ret |= __put_user(getreg(child, ui),(unsigned long __user *) data);
564 data += sizeof(long);
569 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
571 if (!access_ok(VERIFY_READ, (unsigned __user *)data,
572 sizeof(struct user_regs_struct))) {
577 for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
578 ret |= __get_user(tmp, (unsigned long __user *) data);
579 putreg(child, ui, tmp);
580 data += sizeof(long);
585 case PTRACE_GETFPREGS: { /* Get the child extended FPU state. */
586 if (!access_ok(VERIFY_WRITE, (unsigned __user *)data,
587 sizeof(struct user_i387_struct))) {
591 ret = get_fpregs((struct user_i387_struct __user *)data, child);
595 case PTRACE_SETFPREGS: { /* Set the child extended FPU state. */
596 if (!access_ok(VERIFY_READ, (unsigned __user *)data,
597 sizeof(struct user_i387_struct))) {
601 set_stopped_child_used_math(child);
602 ret = set_fpregs(child, (struct user_i387_struct __user *)data);
607 ret = ptrace_request(child, request, addr, data);
611 put_task_struct(child);
617 static void syscall_trace(struct pt_regs *regs)
621 printk("trace %s rip %lx rsp %lx rax %d origrax %d caller %lx tiflags %x ptrace %x\n",
623 regs->rip, regs->rsp, regs->rax, regs->orig_rax, __builtin_return_address(0),
624 current_thread_info()->flags, current->ptrace);
627 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
630 * this isn't the same as continuing with a signal, but it will do
631 * for normal use. strace only continues with a signal if the
632 * stopping signal is not SIGTRAP. -brl
634 if (current->exit_code) {
635 send_sig(current->exit_code, current, 1);
636 current->exit_code = 0;
640 asmlinkage void syscall_trace_enter(struct pt_regs *regs)
642 /* do the secure computing check first */
643 secure_computing(regs->orig_rax);
645 if (test_thread_flag(TIF_SYSCALL_TRACE)
646 && (current->ptrace & PT_PTRACED))
649 if (unlikely(current->audit_context)) {
650 if (test_thread_flag(TIF_IA32)) {
651 audit_syscall_entry(current, AUDIT_ARCH_I386,
653 regs->rbx, regs->rcx,
654 regs->rdx, regs->rsi);
656 audit_syscall_entry(current, AUDIT_ARCH_X86_64,
658 regs->rdi, regs->rsi,
659 regs->rdx, regs->r10);
664 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
666 if (unlikely(current->audit_context))
667 audit_syscall_exit(current, AUDITSC_RESULT(regs->rax), regs->rax);
669 if ((test_thread_flag(TIF_SYSCALL_TRACE)
670 || test_thread_flag(TIF_SINGLESTEP))
671 && (current->ptrace & PT_PTRACED))