2 /* By Ross Biro 1/23/92 */
4 * Pentium III FXSR, SSE support
5 * Gareth Hughes <gareth@valinux.com>, May 2000
8 #include <linux/kernel.h>
9 #include <linux/sched.h>
11 #include <linux/smp.h>
12 #include <linux/smp_lock.h>
13 #include <linux/errno.h>
14 #include <linux/ptrace.h>
15 #include <linux/user.h>
16 #include <linux/security.h>
17 #include <linux/audit.h>
19 #include <asm/uaccess.h>
20 #include <asm/pgtable.h>
21 #include <asm/system.h>
22 #include <asm/processor.h>
24 #include <asm/debugreg.h>
29 * does not yet catch signals sent when the child dies.
30 * in exit.c or in signal.c.
33 /* determines which flags the user has access to. */
34 /* 1 = access 0 = no access */
35 #define FLAG_MASK 0x00044dd5
37 /* set's the trap flag. */
38 #define TRAP_FLAG 0x100
41 * Offset of eflags on child stack..
43 #define EFL_OFFSET ((EFL-2)*4-sizeof(struct pt_regs))
46 * this routine will get a word off of the processes privileged stack.
47 * the offset is how far from the base addr as stored in the TSS.
48 * this routine assumes that all the privileged stacks are in our
51 static inline int get_stack_long(struct task_struct *task, int offset)
55 stack = (unsigned char *)task->thread.esp0;
57 return (*((int *)stack));
61 * this routine will put a word on the processes privileged stack.
62 * the offset is how far from the base addr as stored in the TSS.
63 * this routine assumes that all the privileged stacks are in our
66 static inline int put_stack_long(struct task_struct *task, int offset,
69 unsigned char * stack;
71 stack = (unsigned char *) task->thread.esp0;
73 *(unsigned long *) stack = data;
77 static int putreg(struct task_struct *child,
78 unsigned long regno, unsigned long value)
82 if (value && (value & 3) != 3)
84 child->thread.fs = value;
87 if (value && (value & 3) != 3)
89 child->thread.gs = value;
93 if (value && (value & 3) != 3)
105 value |= get_stack_long(child, EFL_OFFSET) & ~FLAG_MASK;
110 put_stack_long(child, regno - sizeof(struct pt_regs), value);
114 static unsigned long getreg(struct task_struct *child,
117 unsigned long retval = ~0UL;
119 switch (regno >> 2) {
121 retval = child->thread.fs;
124 retval = child->thread.gs;
135 regno = regno - sizeof(struct pt_regs);
136 retval &= get_stack_long(child, regno);
142 * Called by kernel/ptrace.c when detaching..
144 * Make sure the single step bit is not set.
146 void ptrace_disable(struct task_struct *child)
150 tmp = get_stack_long(child, EFL_OFFSET) & ~TRAP_FLAG;
151 put_stack_long(child, EFL_OFFSET, tmp);
155 * Perform get_thread_area on behalf of the traced child.
158 ptrace_get_thread_area(struct task_struct *child,
159 int idx, struct user_desc __user *user_desc)
161 struct user_desc info;
162 struct desc_struct *desc;
165 * Get the current Thread-Local Storage area:
168 #define GET_BASE(desc) ( \
169 (((desc)->a >> 16) & 0x0000ffff) | \
170 (((desc)->b << 16) & 0x00ff0000) | \
171 ( (desc)->b & 0xff000000) )
173 #define GET_LIMIT(desc) ( \
174 ((desc)->a & 0x0ffff) | \
175 ((desc)->b & 0xf0000) )
177 #define GET_32BIT(desc) (((desc)->b >> 22) & 1)
178 #define GET_CONTENTS(desc) (((desc)->b >> 10) & 3)
179 #define GET_WRITABLE(desc) (((desc)->b >> 9) & 1)
180 #define GET_LIMIT_PAGES(desc) (((desc)->b >> 23) & 1)
181 #define GET_PRESENT(desc) (((desc)->b >> 15) & 1)
182 #define GET_USEABLE(desc) (((desc)->b >> 20) & 1)
184 if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
187 desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
189 info.entry_number = idx;
190 info.base_addr = GET_BASE(desc);
191 info.limit = GET_LIMIT(desc);
192 info.seg_32bit = GET_32BIT(desc);
193 info.contents = GET_CONTENTS(desc);
194 info.read_exec_only = !GET_WRITABLE(desc);
195 info.limit_in_pages = GET_LIMIT_PAGES(desc);
196 info.seg_not_present = !GET_PRESENT(desc);
197 info.useable = GET_USEABLE(desc);
199 if (copy_to_user(user_desc, &info, sizeof(info)))
206 * Perform set_thread_area on behalf of the traced child.
209 ptrace_set_thread_area(struct task_struct *child,
210 int idx, struct user_desc __user *user_desc)
212 struct user_desc info;
213 struct desc_struct *desc;
215 if (copy_from_user(&info, user_desc, sizeof(info)))
218 if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
221 desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
222 if (LDT_empty(&info)) {
226 desc->a = LDT_entry_a(&info);
227 desc->b = LDT_entry_b(&info);
233 asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
235 struct task_struct *child;
236 struct user * dummy = NULL;
238 unsigned long __user *datap = (unsigned long __user *)data;
242 if (request == PTRACE_TRACEME) {
243 /* are we already being traced? */
244 if (current->ptrace & PT_PTRACED)
246 ret = security_ptrace(current->parent, current);
249 /* set the ptrace bit in the process flags. */
250 current->ptrace |= PT_PTRACED;
255 read_lock(&tasklist_lock);
256 child = find_task_by_pid(pid);
258 get_task_struct(child);
259 read_unlock(&tasklist_lock);
262 if (!vx_check(vx_task_xid(child), VX_WATCH|VX_IDENT))
266 if (pid == 1) /* you may not mess with init */
269 if (request == PTRACE_ATTACH) {
270 ret = ptrace_attach(child);
274 ret = ptrace_check_attach(child, request == PTRACE_KILL);
279 /* when I and D space are separate, these will need to be fixed. */
280 case PTRACE_PEEKTEXT: /* read word at location addr. */
281 case PTRACE_PEEKDATA: {
285 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
287 if (copied != sizeof(tmp))
289 ret = put_user(tmp, datap);
293 /* read the word at location addr in the USER area. */
294 case PTRACE_PEEKUSR: {
298 if ((addr & 3) || addr < 0 ||
299 addr > sizeof(struct user) - 3)
302 tmp = 0; /* Default return condition */
303 if(addr < FRAME_SIZE*sizeof(long))
304 tmp = getreg(child, addr);
305 if(addr >= (long) &dummy->u_debugreg[0] &&
306 addr <= (long) &dummy->u_debugreg[7]){
307 addr -= (long) &dummy->u_debugreg[0];
309 tmp = child->thread.debugreg[addr];
311 ret = put_user(tmp, datap);
315 /* when I and D space are separate, this will have to be fixed. */
316 case PTRACE_POKETEXT: /* write the word at location addr. */
317 case PTRACE_POKEDATA:
319 if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
324 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
326 if ((addr & 3) || addr < 0 ||
327 addr > sizeof(struct user) - 3)
330 if (addr < FRAME_SIZE*sizeof(long)) {
331 ret = putreg(child, addr, data);
334 /* We need to be very careful here. We implicitly
335 want to modify a portion of the task_struct, and we
336 have to be selective about what portions we allow someone
340 if(addr >= (long) &dummy->u_debugreg[0] &&
341 addr <= (long) &dummy->u_debugreg[7]){
343 if(addr == (long) &dummy->u_debugreg[4]) break;
344 if(addr == (long) &dummy->u_debugreg[5]) break;
345 if(addr < (long) &dummy->u_debugreg[4] &&
346 ((unsigned long) data) >= TASK_SIZE-3) break;
348 if(addr == (long) &dummy->u_debugreg[7]) {
349 data &= ~DR_CONTROL_RESERVED;
351 if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
355 addr -= (long) &dummy->u_debugreg;
357 child->thread.debugreg[addr] = data;
362 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
363 case PTRACE_CONT: { /* restart after signal. */
367 if ((unsigned long) data > _NSIG)
369 if (request == PTRACE_SYSCALL) {
370 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
373 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
375 child->exit_code = data;
376 /* make sure the single step bit is not set. */
377 tmp = get_stack_long(child, EFL_OFFSET) & ~TRAP_FLAG;
378 put_stack_long(child, EFL_OFFSET,tmp);
379 wake_up_process(child);
385 * make the child exit. Best I can do is send it a sigkill.
386 * perhaps it should be put in the status that it wants to
393 if (child->state == TASK_ZOMBIE) /* already dead */
395 child->exit_code = SIGKILL;
396 /* make sure the single step bit is not set. */
397 tmp = get_stack_long(child, EFL_OFFSET) & ~TRAP_FLAG;
398 put_stack_long(child, EFL_OFFSET, tmp);
399 wake_up_process(child);
403 case PTRACE_SINGLESTEP: { /* set the trap flag. */
407 if ((unsigned long) data > _NSIG)
409 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
410 if ((child->ptrace & PT_DTRACE) == 0) {
411 /* Spurious delayed TF traps may occur */
412 child->ptrace |= PT_DTRACE;
414 tmp = get_stack_long(child, EFL_OFFSET) | TRAP_FLAG;
415 put_stack_long(child, EFL_OFFSET, tmp);
416 child->exit_code = data;
417 /* give it a chance to run. */
418 wake_up_process(child);
424 /* detach a process that was attached. */
425 ret = ptrace_detach(child, data);
428 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
429 if (!access_ok(VERIFY_WRITE, datap, FRAME_SIZE*sizeof(long))) {
433 for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {
434 __put_user(getreg(child, i), datap);
441 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
443 if (!access_ok(VERIFY_READ, datap, FRAME_SIZE*sizeof(long))) {
447 for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {
448 __get_user(tmp, datap);
449 putreg(child, i, tmp);
456 case PTRACE_GETFPREGS: { /* Get the child FPU state. */
457 if (!access_ok(VERIFY_WRITE, datap,
458 sizeof(struct user_i387_struct))) {
463 if (!child->used_math)
465 get_fpregs((struct user_i387_struct __user *)data, child);
469 case PTRACE_SETFPREGS: { /* Set the child FPU state. */
470 if (!access_ok(VERIFY_READ, datap,
471 sizeof(struct user_i387_struct))) {
475 child->used_math = 1;
476 set_fpregs(child, (struct user_i387_struct __user *)data);
481 case PTRACE_GETFPXREGS: { /* Get the child extended FPU state. */
482 if (!access_ok(VERIFY_WRITE, datap,
483 sizeof(struct user_fxsr_struct))) {
487 if (!child->used_math)
489 ret = get_fpxregs((struct user_fxsr_struct __user *)data, child);
493 case PTRACE_SETFPXREGS: { /* Set the child extended FPU state. */
494 if (!access_ok(VERIFY_READ, datap,
495 sizeof(struct user_fxsr_struct))) {
499 child->used_math = 1;
500 ret = set_fpxregs(child, (struct user_fxsr_struct __user *)data);
504 case PTRACE_GET_THREAD_AREA:
505 ret = ptrace_get_thread_area(child, addr,
506 (struct user_desc __user *) data);
509 case PTRACE_SET_THREAD_AREA:
510 ret = ptrace_set_thread_area(child, addr,
511 (struct user_desc __user *) data);
515 ret = ptrace_request(child, request, addr, data);
519 put_task_struct(child);
525 /* notification of system call entry/exit
526 * - triggered by current->work.syscall_trace
528 __attribute__((regparm(3)))
529 void do_syscall_trace(struct pt_regs *regs, int entryexit)
531 if (unlikely(current->audit_context)) {
533 audit_syscall_entry(current, regs->orig_eax,
534 regs->ebx, regs->ecx,
535 regs->edx, regs->esi);
537 audit_syscall_exit(current, regs->eax);
540 if (!test_thread_flag(TIF_SYSCALL_TRACE))
542 if (!(current->ptrace & PT_PTRACED))
544 /* the 0x80 provides a way for the tracing parent to distinguish
545 between a syscall stop and SIGTRAP delivery */
546 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
550 * this isn't the same as continuing with a signal, but it will do
551 * for normal use. strace only continues with a signal if the
552 * stopping signal is not SIGTRAP. -brl
554 if (current->exit_code) {
555 send_sig(current->exit_code, current, 1);
556 current->exit_code = 0;