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>
22 #include <asm/uaccess.h>
23 #include <asm/pgtable.h>
24 #include <asm/system.h>
25 #include <asm/processor.h>
27 #include <asm/debugreg.h>
30 #include <asm/proto.h>
34 * does not yet catch signals sent when the child dies.
35 * in exit.c or in signal.c.
38 /* determines which flags the user has access to. */
39 /* 1 = access 0 = no access */
40 #define FLAG_MASK 0x44dd5UL
42 /* set's the trap flag. */
43 #define TRAP_FLAG 0x100UL
46 * eflags and offset of eflags on child stack..
48 #define EFLAGS offsetof(struct pt_regs, eflags)
49 #define EFL_OFFSET ((int)(EFLAGS-sizeof(struct pt_regs)))
52 * this routine will get a word off of the processes privileged stack.
53 * the offset is how far from the base addr as stored in the TSS.
54 * this routine assumes that all the privileged stacks are in our
57 static inline unsigned long get_stack_long(struct task_struct *task, int offset)
61 stack = (unsigned char *)task->thread.rsp0;
63 return (*((unsigned long *)stack));
66 static inline struct pt_regs *get_child_regs(struct task_struct *task)
68 struct pt_regs *regs = (void *)task->thread.rsp0;
73 * this routine will put a word on the processes privileged stack.
74 * the offset is how far from the base addr as stored in the TSS.
75 * this routine assumes that all the privileged stacks are in our
78 static inline long put_stack_long(struct task_struct *task, int offset,
81 unsigned char * stack;
83 stack = (unsigned char *) task->thread.rsp0;
85 *(unsigned long *) stack = data;
91 unsigned long convert_rip_to_linear(struct task_struct *child, struct pt_regs *regs)
93 unsigned long addr, seg;
96 seg = regs->cs & 0xffff;
99 * We'll assume that the code segments in the GDT
100 * are all zero-based. That is largely true: the
101 * TLS segments are used for data, and the PNPBIOS
102 * and APM bios ones we just ignore here.
104 if (seg & LDT_SEGMENT) {
108 down(&child->mm->context.sem);
109 desc = child->mm->context.ldt + (seg & ~7);
110 base = (desc[0] >> 16) | ((desc[1] & 0xff) << 16) | (desc[1] & 0xff000000);
112 /* 16-bit code segment? */
113 if (!((desc[1] >> 22) & 1))
116 up(&child->mm->context.sem);
121 static int is_at_popf(struct task_struct *child, struct pt_regs *regs)
124 unsigned char opcode[16];
125 unsigned long addr = convert_rip_to_linear(child, regs);
127 copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0);
128 for (i = 0; i < copied; i++) {
136 /* opcode and address size prefixes */
137 case 0x66: case 0x67:
139 /* irrelevant prefixes (segment overrides and repeats) */
140 case 0x26: case 0x2e:
141 case 0x36: case 0x3e:
142 case 0x64: case 0x65:
143 case 0xf0: case 0xf2: case 0xf3:
150 /* CHECKME: f0, f2, f3 */
153 * pushf: NOTE! We should probably not let
154 * the user see the TF bit being set. But
155 * it's more pain than it's worth to avoid
156 * it, and a debugger could emulate this
157 * all in user space if it _really_ cares.
167 static void set_singlestep(struct task_struct *child)
169 struct pt_regs *regs = get_child_regs(child);
172 * Always set TIF_SINGLESTEP - this guarantees that
173 * we single-step system calls etc.. This will also
174 * cause us to set TF when returning to user mode.
176 set_tsk_thread_flag(child, TIF_SINGLESTEP);
179 * If TF was already set, don't do anything else
181 if (regs->eflags & TRAP_FLAG)
184 /* Set TF on the kernel stack.. */
185 regs->eflags |= TRAP_FLAG;
188 * ..but if TF is changed by the instruction we will trace,
189 * don't mark it as being "us" that set it, so that we
190 * won't clear it by hand later.
192 * AK: this is not enough, LAHF and IRET can change TF in user space too.
194 if (is_at_popf(child, regs))
197 child->ptrace |= PT_DTRACE;
200 static void clear_singlestep(struct task_struct *child)
202 /* Always clear TIF_SINGLESTEP... */
203 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
205 /* But touch TF only if it was set by us.. */
206 if (child->ptrace & PT_DTRACE) {
207 struct pt_regs *regs = get_child_regs(child);
208 regs->eflags &= ~TRAP_FLAG;
209 child->ptrace &= ~PT_DTRACE;
214 * Called by kernel/ptrace.c when detaching..
216 * Make sure the single step bit is not set.
218 void ptrace_disable(struct task_struct *child)
220 clear_singlestep(child);
223 static int putreg(struct task_struct *child,
224 unsigned long regno, unsigned long value)
228 /* Some code in the 64bit emulation may not be 64bit clean.
229 Don't take any chances. */
230 if (test_tsk_thread_flag(child, TIF_IA32))
233 case offsetof(struct user_regs_struct,fs):
234 if (value && (value & 3) != 3)
236 child->thread.fsindex = value & 0xffff;
238 case offsetof(struct user_regs_struct,gs):
239 if (value && (value & 3) != 3)
241 child->thread.gsindex = value & 0xffff;
243 case offsetof(struct user_regs_struct,ds):
244 if (value && (value & 3) != 3)
246 child->thread.ds = value & 0xffff;
248 case offsetof(struct user_regs_struct,es):
249 if (value && (value & 3) != 3)
251 child->thread.es = value & 0xffff;
253 case offsetof(struct user_regs_struct,ss):
254 if ((value & 3) != 3)
258 case offsetof(struct user_regs_struct,fs_base):
259 if (!((value >> 48) == 0 || (value >> 48) == 0xffff))
261 child->thread.fs = value;
263 case offsetof(struct user_regs_struct,gs_base):
264 if (!((value >> 48) == 0 || (value >> 48) == 0xffff))
266 child->thread.gs = value;
268 case offsetof(struct user_regs_struct, eflags):
270 tmp = get_stack_long(child, EFL_OFFSET);
274 case offsetof(struct user_regs_struct,cs):
275 if ((value & 3) != 3)
280 put_stack_long(child, regno - sizeof(struct pt_regs), value);
284 static unsigned long getreg(struct task_struct *child, unsigned long regno)
288 case offsetof(struct user_regs_struct, fs):
289 return child->thread.fsindex;
290 case offsetof(struct user_regs_struct, gs):
291 return child->thread.gsindex;
292 case offsetof(struct user_regs_struct, ds):
293 return child->thread.ds;
294 case offsetof(struct user_regs_struct, es):
295 return child->thread.es;
296 case offsetof(struct user_regs_struct, fs_base):
297 return child->thread.fs;
298 case offsetof(struct user_regs_struct, gs_base):
299 return child->thread.gs;
301 regno = regno - sizeof(struct pt_regs);
302 val = get_stack_long(child, regno);
303 if (test_tsk_thread_flag(child, TIF_IA32))
310 asmlinkage long sys_ptrace(long request, long pid, unsigned long addr, long data)
312 struct task_struct *child;
316 /* This lock_kernel fixes a subtle race with suid exec */
319 if (request == PTRACE_TRACEME) {
320 /* are we already being traced? */
321 if (current->ptrace & PT_PTRACED)
323 ret = security_ptrace(current->parent, current);
326 /* set the ptrace bit in the process flags. */
327 current->ptrace |= PT_PTRACED;
332 read_lock(&tasklist_lock);
333 child = find_task_by_pid(pid);
335 get_task_struct(child);
336 read_unlock(&tasklist_lock);
341 if (pid == 1) /* you may not mess with init */
344 if (request == PTRACE_ATTACH) {
345 ret = ptrace_attach(child);
348 ret = ptrace_check_attach(child, request == PTRACE_KILL);
353 /* when I and D space are separate, these will need to be fixed. */
354 case PTRACE_PEEKTEXT: /* read word at location addr. */
355 case PTRACE_PEEKDATA: {
359 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
361 if (copied != sizeof(tmp))
363 ret = put_user(tmp,(unsigned long __user *) data);
367 /* read the word at location addr in the USER area. */
368 case PTRACE_PEEKUSR: {
373 addr > sizeof(struct user) - 7)
377 case 0 ... sizeof(struct user_regs_struct):
378 tmp = getreg(child, addr);
380 case offsetof(struct user, u_debugreg[0]):
381 tmp = child->thread.debugreg0;
383 case offsetof(struct user, u_debugreg[1]):
384 tmp = child->thread.debugreg1;
386 case offsetof(struct user, u_debugreg[2]):
387 tmp = child->thread.debugreg2;
389 case offsetof(struct user, u_debugreg[3]):
390 tmp = child->thread.debugreg3;
392 case offsetof(struct user, u_debugreg[6]):
393 tmp = child->thread.debugreg6;
395 case offsetof(struct user, u_debugreg[7]):
396 tmp = child->thread.debugreg7;
402 ret = put_user(tmp,(unsigned long __user *) data);
406 /* when I and D space are separate, this will have to be fixed. */
407 case PTRACE_POKETEXT: /* write the word at location addr. */
408 case PTRACE_POKEDATA:
410 if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
415 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
418 addr > sizeof(struct user) - 7)
422 case 0 ... sizeof(struct user_regs_struct):
423 ret = putreg(child, addr, data);
425 /* Disallows to set a breakpoint into the vsyscall */
426 case offsetof(struct user, u_debugreg[0]):
427 if (data >= TASK_SIZE-7) break;
428 child->thread.debugreg0 = data;
431 case offsetof(struct user, u_debugreg[1]):
432 if (data >= TASK_SIZE-7) break;
433 child->thread.debugreg1 = data;
436 case offsetof(struct user, u_debugreg[2]):
437 if (data >= TASK_SIZE-7) break;
438 child->thread.debugreg2 = data;
441 case offsetof(struct user, u_debugreg[3]):
442 if (data >= TASK_SIZE-7) break;
443 child->thread.debugreg3 = data;
446 case offsetof(struct user, u_debugreg[6]):
449 child->thread.debugreg6 = data;
452 case offsetof(struct user, u_debugreg[7]):
453 /* See arch/i386/kernel/ptrace.c for an explanation of
454 * this awkward check.*/
455 data &= ~DR_CONTROL_RESERVED;
457 if ((0x5454 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
460 child->thread.debugreg7 = data;
466 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
467 case PTRACE_CONT: /* restart after signal. */
470 if ((unsigned long) data > _NSIG)
472 if (request == PTRACE_SYSCALL)
473 set_tsk_thread_flag(child,TIF_SYSCALL_TRACE);
475 clear_tsk_thread_flag(child,TIF_SYSCALL_TRACE);
476 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
477 child->exit_code = data;
478 /* make sure the single step bit is not set. */
479 clear_singlestep(child);
480 wake_up_process(child);
484 #ifdef CONFIG_IA32_EMULATION
485 /* This makes only sense with 32bit programs. Allow a
486 64bit debugger to fully examine them too. Better
487 don't use it against 64bit processes, use
488 PTRACE_ARCH_PRCTL instead. */
489 case PTRACE_SET_THREAD_AREA: {
490 struct user_desc __user *p;
492 p = (struct user_desc __user *)data;
493 get_user(old, &p->entry_number);
494 put_user(addr, &p->entry_number);
495 ret = do_set_thread_area(&child->thread, p);
496 put_user(old, &p->entry_number);
498 case PTRACE_GET_THREAD_AREA:
499 p = (struct user_desc __user *)data;
500 get_user(old, &p->entry_number);
501 put_user(addr, &p->entry_number);
502 ret = do_get_thread_area(&child->thread, p);
503 put_user(old, &p->entry_number);
507 /* normal 64bit interface to access TLS data.
508 Works just like arch_prctl, except that the arguments
510 case PTRACE_ARCH_PRCTL:
511 ret = do_arch_prctl(child, data, addr);
515 * make the child exit. Best I can do is send it a sigkill.
516 * perhaps it should be put in the status that it wants to
521 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
523 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
524 child->exit_code = SIGKILL;
525 /* make sure the single step bit is not set. */
526 clear_singlestep(child);
527 wake_up_process(child);
530 case PTRACE_SINGLESTEP: /* set the trap flag. */
532 if ((unsigned long) data > _NSIG)
534 clear_tsk_thread_flag(child,TIF_SYSCALL_TRACE);
535 set_singlestep(child);
536 child->exit_code = data;
537 /* give it a chance to run. */
538 wake_up_process(child);
543 /* detach a process that was attached. */
544 ret = ptrace_detach(child, data);
547 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
548 if (!access_ok(VERIFY_WRITE, (unsigned __user *)data,
549 sizeof(struct user_regs_struct))) {
554 for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
555 ret |= __put_user(getreg(child, ui),(unsigned long __user *) data);
556 data += sizeof(long);
561 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
563 if (!access_ok(VERIFY_READ, (unsigned __user *)data,
564 sizeof(struct user_regs_struct))) {
569 for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
570 ret |= __get_user(tmp, (unsigned long __user *) data);
571 putreg(child, ui, tmp);
572 data += sizeof(long);
577 case PTRACE_GETFPREGS: { /* Get the child extended FPU state. */
578 if (!access_ok(VERIFY_WRITE, (unsigned __user *)data,
579 sizeof(struct user_i387_struct))) {
583 ret = get_fpregs((struct user_i387_struct __user *)data, child);
587 case PTRACE_SETFPREGS: { /* Set the child extended FPU state. */
588 if (!access_ok(VERIFY_READ, (unsigned __user *)data,
589 sizeof(struct user_i387_struct))) {
593 set_stopped_child_used_math(child);
594 ret = set_fpregs(child, (struct user_i387_struct __user *)data);
599 ret = ptrace_request(child, request, addr, data);
603 put_task_struct(child);
609 static void syscall_trace(struct pt_regs *regs)
613 printk("trace %s rip %lx rsp %lx rax %d origrax %d caller %lx tiflags %x ptrace %x\n",
615 regs->rip, regs->rsp, regs->rax, regs->orig_rax, __builtin_return_address(0),
616 current_thread_info()->flags, current->ptrace);
619 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
622 * this isn't the same as continuing with a signal, but it will do
623 * for normal use. strace only continues with a signal if the
624 * stopping signal is not SIGTRAP. -brl
626 if (current->exit_code) {
627 send_sig(current->exit_code, current, 1);
628 current->exit_code = 0;
632 asmlinkage void syscall_trace_enter(struct pt_regs *regs)
634 /* do the secure computing check first */
635 secure_computing(regs->orig_rax);
637 if (unlikely(current->audit_context))
638 audit_syscall_entry(current, regs->orig_rax,
639 regs->rdi, regs->rsi,
640 regs->rdx, regs->r10);
642 if (test_thread_flag(TIF_SYSCALL_TRACE)
643 && (current->ptrace & PT_PTRACED))
647 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
649 if (unlikely(current->audit_context))
650 audit_syscall_exit(current, regs->rax);
652 if ((test_thread_flag(TIF_SYSCALL_TRACE)
653 || test_thread_flag(TIF_SINGLESTEP))
654 && (current->ptrace & PT_PTRACED))