ptrace_64.c 8.9 KB
Newer Older
L
Linus Torvalds 已提交
1
/*
P
Paul Mundt 已提交
2
 * arch/sh/kernel/ptrace_64.c
L
Linus Torvalds 已提交
3 4
 *
 * Copyright (C) 2000, 2001  Paolo Alberelli
P
Paul Mundt 已提交
5
 * Copyright (C) 2003 - 2007  Paul Mundt
L
Linus Torvalds 已提交
6 7 8 9 10 11 12 13
 *
 * Started from SH3/4 version:
 *   SuperH version:   Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
 *
 *   Original x86 implementation:
 *	By Ross Biro 1/23/92
 *	edited by Linus Torvalds
 *
P
Paul Mundt 已提交
14 15 16
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
L
Linus Torvalds 已提交
17 18 19 20 21 22 23 24 25 26
 */
#include <linux/kernel.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
27
#include <linux/signal.h>
28
#include <linux/syscalls.h>
P
Paul Mundt 已提交
29
#include <linux/audit.h>
P
Paul Mundt 已提交
30
#include <linux/seccomp.h>
L
Linus Torvalds 已提交
31 32 33 34 35 36
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/mmu_context.h>
37
#include <asm/fpu.h>
L
Linus Torvalds 已提交
38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76

/* This mask defines the bits of the SR which the user is not allowed to
   change, which are everything except S, Q, M, PR, SZ, FR. */
#define SR_MASK      (0xffff8cfd)

/*
 * does not yet catch signals sent when the child dies.
 * in exit.c or in signal.c.
 */

/*
 * This routine will get a word from the user area in the process kernel stack.
 */
static inline int get_stack_long(struct task_struct *task, int offset)
{
	unsigned char *stack;

	stack = (unsigned char *)(task->thread.uregs);
	stack += offset;
	return (*((int *)stack));
}

static inline unsigned long
get_fpu_long(struct task_struct *task, unsigned long addr)
{
	unsigned long tmp;
	struct pt_regs *regs;
	regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1;

	if (!tsk_used_math(task)) {
		if (addr == offsetof(struct user_fpu_struct, fpscr)) {
			tmp = FPSCR_INIT;
		} else {
			tmp = 0xffffffffUL; /* matches initial value in fpu.c */
		}
		return tmp;
	}

	if (last_task_used_math == task) {
77
		enable_fpu();
78
		save_fpu(task, regs);
79
		disable_fpu();
L
Linus Torvalds 已提交
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112
		last_task_used_math = 0;
		regs->sr |= SR_FD;
	}

	tmp = ((long *)&task->thread.fpu)[addr / sizeof(unsigned long)];
	return tmp;
}

/*
 * This routine will put a word into the user area in the process kernel stack.
 */
static inline int put_stack_long(struct task_struct *task, int offset,
				 unsigned long data)
{
	unsigned char *stack;

	stack = (unsigned char *)(task->thread.uregs);
	stack += offset;
	*(unsigned long *) stack = data;
	return 0;
}

static inline int
put_fpu_long(struct task_struct *task, unsigned long addr, unsigned long data)
{
	struct pt_regs *regs;

	regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1;

	if (!tsk_used_math(task)) {
		fpinit(&task->thread.fpu.hard);
		set_stopped_child_used_math(task);
	} else if (last_task_used_math == task) {
113
		enable_fpu();
114
		save_fpu(task, regs);
115
		disable_fpu();
L
Linus Torvalds 已提交
116 117 118 119 120 121 122 123
		last_task_used_math = 0;
		regs->sr |= SR_FD;
	}

	((long *)&task->thread.fpu)[addr / sizeof(unsigned long)] = data;
	return 0;
}

124 125

long arch_ptrace(struct task_struct *child, long request, long addr, long data)
L
Linus Torvalds 已提交
126 127 128 129 130 131
{
	int ret;

	switch (request) {
	/* when I and D space are separate, these will need to be fixed. */
	case PTRACE_PEEKTEXT: /* read word at location addr. */
A
Alexey Dobriyan 已提交
132 133
	case PTRACE_PEEKDATA:
		ret = generic_ptrace_peekdata(child, addr, data);
L
Linus Torvalds 已提交
134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160
		break;

	/* read the word at location addr in the USER area. */
	case PTRACE_PEEKUSR: {
		unsigned long tmp;

		ret = -EIO;
		if ((addr & 3) || addr < 0)
			break;

		if (addr < sizeof(struct pt_regs))
			tmp = get_stack_long(child, addr);
		else if ((addr >= offsetof(struct user, fpu)) &&
			 (addr <  offsetof(struct user, u_fpvalid))) {
			tmp = get_fpu_long(child, addr - offsetof(struct user, fpu));
		} else if (addr == offsetof(struct user, u_fpvalid)) {
			tmp = !!tsk_used_math(child);
		} else {
			break;
		}
		ret = put_user(tmp, (unsigned long *)data);
		break;
	}

	/* when I and D space are separate, this will have to be fixed. */
	case PTRACE_POKETEXT: /* write the word at location addr. */
	case PTRACE_POKEDATA:
A
Alexey Dobriyan 已提交
161
		ret = generic_ptrace_pokedata(child, addr, data);
L
Linus Torvalds 已提交
162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197
		break;

	case PTRACE_POKEUSR:
                /* write the word at location addr in the USER area. We must
                   disallow any changes to certain SR bits or u_fpvalid, since
                   this could crash the kernel or result in a security
                   loophole. */
		ret = -EIO;
		if ((addr & 3) || addr < 0)
			break;

		if (addr < sizeof(struct pt_regs)) {
			/* Ignore change of top 32 bits of SR */
			if (addr == offsetof (struct pt_regs, sr)+4)
			{
				ret = 0;
				break;
			}
			/* If lower 32 bits of SR, ignore non-user bits */
			if (addr == offsetof (struct pt_regs, sr))
			{
				long cursr = get_stack_long(child, addr);
				data &= ~(SR_MASK);
				data |= (cursr & SR_MASK);
			}
			ret = put_stack_long(child, addr, data);
		}
		else if ((addr >= offsetof(struct user, fpu)) &&
			 (addr <  offsetof(struct user, u_fpvalid))) {
			ret = put_fpu_long(child, addr - offsetof(struct user, fpu), data);
		}
		break;

	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
	case PTRACE_CONT: { /* restart after signal. */
		ret = -EIO;
198
		if (!valid_signal(data))
L
Linus Torvalds 已提交
199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227
			break;
		if (request == PTRACE_SYSCALL)
			set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		else
			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		child->exit_code = data;
		wake_up_process(child);
		ret = 0;
		break;
	}

/*
 * make the child exit.  Best I can do is send it a sigkill.
 * perhaps it should be put in the status that it wants to
 * exit.
 */
	case PTRACE_KILL: {
		ret = 0;
		if (child->exit_state == EXIT_ZOMBIE)	/* already dead */
			break;
		child->exit_code = SIGKILL;
		wake_up_process(child);
		break;
	}

	case PTRACE_SINGLESTEP: {  /* set the trap flag. */
		struct pt_regs *regs;

		ret = -EIO;
228
		if (!valid_signal(data))
L
Linus Torvalds 已提交
229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253
			break;
		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		if ((child->ptrace & PT_DTRACE) == 0) {
			/* Spurious delayed TF traps may occur */
			child->ptrace |= PT_DTRACE;
		}

		regs = child->thread.uregs;

		regs->sr |= SR_SSTEP;	/* auto-resetting upon exception */

		child->exit_code = data;
		/* give it a chance to run. */
		wake_up_process(child);
		ret = 0;
		break;
	}

	default:
		ret = ptrace_request(child, request, addr, data);
		break;
	}
	return ret;
}

254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276
asmlinkage int sh64_ptrace(long request, long pid, long addr, long data)
{
#define WPC_DBRMODE 0x0d104008
	static int first_call = 1;

	lock_kernel();
	if (first_call) {
		/* Set WPC.DBRMODE to 0.  This makes all debug events get
		 * delivered through RESVEC, i.e. into the handlers in entry.S.
		 * (If the kernel was downloaded using a remote gdb, WPC.DBRMODE
		 * would normally be left set to 1, which makes debug events get
		 * delivered through DBRVEC, i.e. into the remote gdb's
		 * handlers.  This prevents ptrace getting them, and confuses
		 * the remote gdb.) */
		printk("DBRMODE set to 0 to permit native debugging\n");
		poke_real_address_q(WPC_DBRMODE, 0);
		first_call = 0;
	}
	unlock_kernel();

	return sys_ptrace(request, pid, addr, data);
}

P
Paul Mundt 已提交
277
asmlinkage void syscall_trace(struct pt_regs *regs, int entryexit)
L
Linus Torvalds 已提交
278 279 280
{
	struct task_struct *tsk = current;

P
Paul Mundt 已提交
281 282
	secure_computing(regs->regs[9]);

P
Paul Mundt 已提交
283 284 285 286 287 288 289
	if (unlikely(current->audit_context) && entryexit)
		audit_syscall_exit(AUDITSC_RESULT(regs->regs[9]),
				   regs->regs[9]);

	if (!test_thread_flag(TIF_SYSCALL_TRACE) &&
	    !test_thread_flag(TIF_SINGLESTEP))
		goto out;
L
Linus Torvalds 已提交
290
	if (!(tsk->ptrace & PT_PTRACED))
P
Paul Mundt 已提交
291 292 293 294
		goto out;

	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) &&
				!test_thread_flag(TIF_SINGLESTEP) ? 0x80 : 0));
L
Linus Torvalds 已提交
295 296 297 298 299 300 301 302 303 304

	/*
	 * this isn't the same as continuing with a signal, but it will do
	 * for normal use.  strace only continues with a signal if the
	 * stopping signal is not SIGTRAP.  -brl
	 */
	if (tsk->exit_code) {
		send_sig(tsk->exit_code, tsk, 1);
		tsk->exit_code = 0;
	}
P
Paul Mundt 已提交
305 306 307 308 309 310

out:
	if (unlikely(current->audit_context) && !entryexit)
		audit_syscall_entry(AUDIT_ARCH_SH, regs->regs[1],
				    regs->regs[2], regs->regs[3],
				    regs->regs[4], regs->regs[5]);
L
Linus Torvalds 已提交
311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345
}

/* Called with interrupts disabled */
asmlinkage void do_single_step(unsigned long long vec, struct pt_regs *regs)
{
	/* This is called after a single step exception (DEBUGSS).
	   There is no need to change the PC, as it is a post-execution
	   exception, as entry.S does not do anything to the PC for DEBUGSS.
	   We need to clear the Single Step setting in SR to avoid
	   continually stepping. */
	local_irq_enable();
	regs->sr &= ~SR_SSTEP;
	force_sig(SIGTRAP, current);
}

/* Called with interrupts disabled */
asmlinkage void do_software_break_point(unsigned long long vec,
					struct pt_regs *regs)
{
	/* We need to forward step the PC, to counteract the backstep done
	   in signal.c. */
	local_irq_enable();
	force_sig(SIGTRAP, current);
	regs->pc += 4;
}

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure single step bits etc are not set.
 */
void ptrace_disable(struct task_struct *child)
{
        /* nothing to do.. */
}