1 /* By Ross Biro 1/23/92 */
3 * Pentium III FXSR, SSE support
4 * Gareth Hughes <gareth@valinux.com>, May 2000
7 #include <linux/kernel.h>
8 #include <linux/sched.h>
10 #include <linux/smp.h>
11 #include <linux/errno.h>
12 #include <linux/ptrace.h>
13 #include <linux/user.h>
14 #include <linux/security.h>
15 #include <linux/audit.h>
16 #include <linux/seccomp.h>
17 #include <linux/signal.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.
34 * Determines which flags the user has access to [1 = access, 0 = no access].
35 * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), NT(14), IOPL(12-13), IF(9).
36 * Also masks reserved bits (31-22, 15, 5, 3, 1).
38 #define FLAG_MASK 0x00050dd5
40 static long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
42 BUILD_BUG_ON(offsetof(struct pt_regs, ebx) != 0);
45 return ®s->ebx + regno;
48 static int putreg(struct task_struct *child,
49 unsigned long regno, unsigned long value)
51 struct pt_regs *regs = task_pt_regs(child);
55 if (value && (value & 3) != 3)
57 child->thread.gs = value;
62 if (value && (value & 3) != 3)
75 * If the user value contains TF, mark that
76 * it was not "us" (the debugger) that set it.
77 * If not, make sure it stays set if we had.
79 if (value & X86_EFLAGS_TF)
80 clear_tsk_thread_flag(child, TIF_FORCED_TF);
81 else if (test_tsk_thread_flag(child, TIF_FORCED_TF))
82 value |= X86_EFLAGS_TF;
83 value |= regs->eflags & ~FLAG_MASK;
86 *pt_regs_access(regs, regno) = value;
90 static unsigned long getreg(struct task_struct *child, unsigned long regno)
92 struct pt_regs *regs = task_pt_regs(child);
93 unsigned long retval = ~0UL;
99 * If the debugger set TF, hide it from the readout.
101 retval = regs->eflags;
102 if (test_tsk_thread_flag(child, TIF_FORCED_TF))
103 retval &= ~X86_EFLAGS_TF;
106 retval = child->thread.gs;
116 retval &= *pt_regs_access(regs, regno);
122 * Called by kernel/ptrace.c when detaching..
124 * Make sure the single step bit is not set.
126 void ptrace_disable(struct task_struct *child)
128 user_disable_single_step(child);
129 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
132 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
134 struct user * dummy = NULL;
136 unsigned long __user *datap = (unsigned long __user *)data;
139 /* when I and D space are separate, these will need to be fixed. */
140 case PTRACE_PEEKTEXT: /* read word at location addr. */
141 case PTRACE_PEEKDATA:
142 ret = generic_ptrace_peekdata(child, addr, data);
145 /* read the word at location addr in the USER area. */
146 case PTRACE_PEEKUSR: {
150 if ((addr & 3) || addr < 0 ||
151 addr > sizeof(struct user) - 3)
154 tmp = 0; /* Default return condition */
155 if(addr < FRAME_SIZE*sizeof(long))
156 tmp = getreg(child, addr);
157 if(addr >= (long) &dummy->u_debugreg[0] &&
158 addr <= (long) &dummy->u_debugreg[7]){
159 addr -= (long) &dummy->u_debugreg[0];
161 tmp = child->thread.debugreg[addr];
163 ret = put_user(tmp, datap);
167 /* when I and D space are separate, this will have to be fixed. */
168 case PTRACE_POKETEXT: /* write the word at location addr. */
169 case PTRACE_POKEDATA:
170 ret = generic_ptrace_pokedata(child, addr, data);
173 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
175 if ((addr & 3) || addr < 0 ||
176 addr > sizeof(struct user) - 3)
179 if (addr < FRAME_SIZE*sizeof(long)) {
180 ret = putreg(child, addr, data);
183 /* We need to be very careful here. We implicitly
184 want to modify a portion of the task_struct, and we
185 have to be selective about what portions we allow someone
189 if(addr >= (long) &dummy->u_debugreg[0] &&
190 addr <= (long) &dummy->u_debugreg[7]){
192 if(addr == (long) &dummy->u_debugreg[4]) break;
193 if(addr == (long) &dummy->u_debugreg[5]) break;
194 if(addr < (long) &dummy->u_debugreg[4] &&
195 ((unsigned long) data) >= TASK_SIZE-3) break;
197 /* Sanity-check data. Take one half-byte at once with
198 * check = (val >> (16 + 4*i)) & 0xf. It contains the
199 * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits
200 * 2 and 3 are LENi. Given a list of invalid values,
201 * we do mask |= 1 << invalid_value, so that
202 * (mask >> check) & 1 is a correct test for invalid
205 * R/Wi contains the type of the breakpoint /
206 * watchpoint, LENi contains the length of the watched
207 * data in the watchpoint case.
209 * The invalid values are:
210 * - LENi == 0x10 (undefined), so mask |= 0x0f00.
211 * - R/Wi == 0x10 (break on I/O reads or writes), so
213 * - R/Wi == 0x00 && LENi != 0x00, so we have mask |=
216 * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54.
218 * See the Intel Manual "System Programming Guide",
221 * Note that LENi == 0x10 is defined on x86_64 in long
222 * mode (i.e. even for 32-bit userspace software, but
223 * 64-bit kernel), so the x86_64 mask value is 0x5454.
224 * See the AMD manual no. 24593 (AMD64 System
227 if(addr == (long) &dummy->u_debugreg[7]) {
228 data &= ~DR_CONTROL_RESERVED;
230 if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
233 set_tsk_thread_flag(child, TIF_DEBUG);
235 clear_tsk_thread_flag(child, TIF_DEBUG);
237 addr -= (long) &dummy->u_debugreg;
239 child->thread.debugreg[addr] = data;
244 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
245 if (!access_ok(VERIFY_WRITE, datap, FRAME_SIZE*sizeof(long))) {
249 for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {
250 __put_user(getreg(child, i), datap);
257 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
259 if (!access_ok(VERIFY_READ, datap, FRAME_SIZE*sizeof(long))) {
263 for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {
264 __get_user(tmp, datap);
265 putreg(child, i, tmp);
272 case PTRACE_GETFPREGS: { /* Get the child FPU state. */
273 if (!access_ok(VERIFY_WRITE, datap,
274 sizeof(struct user_i387_struct))) {
279 if (!tsk_used_math(child))
281 get_fpregs((struct user_i387_struct __user *)data, child);
285 case PTRACE_SETFPREGS: { /* Set the child FPU state. */
286 if (!access_ok(VERIFY_READ, datap,
287 sizeof(struct user_i387_struct))) {
291 set_stopped_child_used_math(child);
292 set_fpregs(child, (struct user_i387_struct __user *)data);
297 case PTRACE_GETFPXREGS: { /* Get the child extended FPU state. */
298 if (!access_ok(VERIFY_WRITE, datap,
299 sizeof(struct user_fxsr_struct))) {
303 if (!tsk_used_math(child))
305 ret = get_fpxregs((struct user_fxsr_struct __user *)data, child);
309 case PTRACE_SETFPXREGS: { /* Set the child extended FPU state. */
310 if (!access_ok(VERIFY_READ, datap,
311 sizeof(struct user_fxsr_struct))) {
315 set_stopped_child_used_math(child);
316 ret = set_fpxregs(child, (struct user_fxsr_struct __user *)data);
320 case PTRACE_GET_THREAD_AREA:
323 ret = do_get_thread_area(child, addr,
324 (struct user_desc __user *) data);
327 case PTRACE_SET_THREAD_AREA:
330 ret = do_set_thread_area(child, addr,
331 (struct user_desc __user *) data, 0);
335 ret = ptrace_request(child, request, addr, data);
342 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)
346 tsk->thread.trap_no = 1;
347 tsk->thread.error_code = error_code;
349 memset(&info, 0, sizeof(info));
350 info.si_signo = SIGTRAP;
351 info.si_code = TRAP_BRKPT;
354 info.si_addr = user_mode_vm(regs) ? (void __user *) regs->eip : NULL;
356 /* Send us the fake SIGTRAP */
357 force_sig_info(SIGTRAP, &info, tsk);
360 /* notification of system call entry/exit
361 * - triggered by current->work.syscall_trace
363 __attribute__((regparm(3)))
364 int do_syscall_trace(struct pt_regs *regs, int entryexit)
366 int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU);
368 * With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall
371 int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP);
374 /* do the secure computing check first */
376 secure_computing(regs->orig_eax);
378 if (unlikely(current->audit_context)) {
380 audit_syscall_exit(AUDITSC_RESULT(regs->eax),
382 /* Debug traps, when using PTRACE_SINGLESTEP, must be sent only
383 * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is
384 * not used, entry.S will call us only on syscall exit, not
385 * entry; so when TIF_SYSCALL_AUDIT is used we must avoid
386 * calling send_sigtrap() on syscall entry.
388 * Note that when PTRACE_SYSEMU_SINGLESTEP is used,
389 * is_singlestep is false, despite his name, so we will still do
392 else if (is_singlestep)
396 if (!(current->ptrace & PT_PTRACED))
399 /* If a process stops on the 1st tracepoint with SYSCALL_TRACE
400 * and then is resumed with SYSEMU_SINGLESTEP, it will come in
401 * here. We have to check this and return */
402 if (is_sysemu && entryexit)
405 /* Fake a debug trap */
407 send_sigtrap(current, regs, 0);
409 if (!test_thread_flag(TIF_SYSCALL_TRACE) && !is_sysemu)
412 /* the 0x80 provides a way for the tracing parent to distinguish
413 between a syscall stop and SIGTRAP delivery */
414 /* Note that the debugger could change the result of test_thread_flag!*/
415 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80:0));
418 * this isn't the same as continuing with a signal, but it will do
419 * for normal use. strace only continues with a signal if the
420 * stopping signal is not SIGTRAP. -brl
422 if (current->exit_code) {
423 send_sig(current->exit_code, current, 1);
424 current->exit_code = 0;
428 if (unlikely(current->audit_context) && !entryexit)
429 audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_eax,
430 regs->ebx, regs->ecx, regs->edx, regs->esi);
434 regs->orig_eax = -1; /* force skip of syscall restarting */
435 if (unlikely(current->audit_context))
436 audit_syscall_exit(AUDITSC_RESULT(regs->eax), regs->eax);