2 * Copyright (C) 2000-2003, Axis Communications AB.
5 #include <linux/kernel.h>
6 #include <linux/sched.h>
9 #include <linux/errno.h>
10 #include <linux/ptrace.h>
11 #include <linux/user.h>
12 #include <linux/signal.h>
13 #include <linux/security.h>
15 #include <asm/uaccess.h>
17 #include <asm/pgtable.h>
18 #include <asm/system.h>
19 #include <asm/processor.h>
20 #include <asm/arch/hwregs/supp_reg.h>
23 * Determines which bits in CCS the user has access to.
24 * 1 = access, 0 = no access.
26 #define CCS_MASK 0x00087c00 /* SXNZVC */
28 #define SBIT_USER (1 << (S_CCS_BITNR + CCS_SHIFT))
30 static int put_debugreg(long pid, unsigned int regno, long data);
31 static long get_debugreg(long pid, unsigned int regno);
32 static unsigned long get_pseudo_pc(struct task_struct *child);
33 void deconfigure_bp(long pid);
35 extern unsigned long cris_signal_return_page;
38 * Get contents of register REGNO in task TASK.
40 long get_reg(struct task_struct *task, unsigned int regno)
42 /* USP is a special case, it's not in the pt_regs struct but
43 * in the tasks thread struct
48 ret = ((unsigned long *)task_pt_regs(task))[regno];
49 else if (regno == PT_USP)
50 ret = task->thread.usp;
51 else if (regno == PT_PPC)
52 ret = get_pseudo_pc(task);
53 else if (regno <= PT_MAX)
54 ret = get_debugreg(task->pid, regno);
62 * Write contents of register REGNO in task TASK.
64 int put_reg(struct task_struct *task, unsigned int regno, unsigned long data)
67 ((unsigned long *)task_pt_regs(task))[regno] = data;
68 else if (regno == PT_USP)
69 task->thread.usp = data;
70 else if (regno == PT_PPC) {
71 /* Write pseudo-PC to ERP only if changed. */
72 if (data != get_pseudo_pc(task))
73 task_pt_regs(task)->erp = data;
74 } else if (regno <= PT_MAX)
75 return put_debugreg(task->pid, regno, data);
82 * Called by kernel/ptrace.c when detaching.
84 * Make sure the single step bit is not set.
87 ptrace_disable(struct task_struct *child)
91 /* Deconfigure SPC and S-bit. */
92 tmp = get_reg(child, PT_CCS) & ~SBIT_USER;
93 put_reg(child, PT_CCS, tmp);
94 put_reg(child, PT_SPC, 0);
96 /* Deconfigure any watchpoints associated with the child. */
97 deconfigure_bp(child->pid);
101 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
104 unsigned long __user *datap = (unsigned long __user *)data;
107 /* Read word at location address. */
108 case PTRACE_PEEKTEXT:
109 case PTRACE_PEEKDATA: {
115 /* The signal trampoline page is outside the normal user-addressable
116 * space but still accessible. This is hack to make it possible to
117 * access the signal handler code in GDB.
119 if ((addr & PAGE_MASK) == cris_signal_return_page) {
120 /* The trampoline page is globally mapped, no page table to traverse.*/
121 tmp = *(unsigned long*)addr;
123 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
125 if (copied != sizeof(tmp))
129 ret = put_user(tmp,datap);
133 /* Read the word at location address in the USER area. */
134 case PTRACE_PEEKUSR: {
138 if ((addr & 3) || addr < 0 || addr > PT_MAX << 2)
141 tmp = get_reg(child, addr >> 2);
142 ret = put_user(tmp, datap);
146 /* Write the word at location address. */
147 case PTRACE_POKETEXT:
148 case PTRACE_POKEDATA:
149 ret = generic_ptrace_pokedata(child, addr, data);
152 /* Write the word at location address in the USER area. */
155 if ((addr & 3) || addr < 0 || addr > PT_MAX << 2)
160 if (addr == PT_CCS) {
161 /* don't allow the tracing process to change stuff like
162 * interrupt enable, kernel/user bit, dma enables etc.
165 data |= get_reg(child, PT_CCS) & ~CCS_MASK;
167 if (put_reg(child, addr, data))
176 if (!valid_signal(data))
179 /* Continue means no single-step. */
180 put_reg(child, PT_SPC, 0);
182 if (!get_debugreg(child->pid, PT_BP_CTRL)) {
184 /* If no h/w bp configured, disable S bit. */
185 tmp = get_reg(child, PT_CCS) & ~SBIT_USER;
186 put_reg(child, PT_CCS, tmp);
189 if (request == PTRACE_SYSCALL) {
190 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
193 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
196 child->exit_code = data;
198 /* TODO: make sure any pending breakpoint is killed */
199 wake_up_process(child);
204 /* Make the child exit by sending it a sigkill. */
208 if (child->exit_state == EXIT_ZOMBIE)
211 child->exit_code = SIGKILL;
213 /* Deconfigure single-step and h/w bp. */
214 ptrace_disable(child);
216 /* TODO: make sure any pending breakpoint is killed */
217 wake_up_process(child);
220 /* Set the trap flag. */
221 case PTRACE_SINGLESTEP: {
225 /* Set up SPC if not set already (in which case we have
226 no other choice but to trust it). */
227 if (!get_reg(child, PT_SPC)) {
228 /* In case we're stopped in a delay slot. */
229 tmp = get_reg(child, PT_ERP) & ~1;
230 put_reg(child, PT_SPC, tmp);
232 tmp = get_reg(child, PT_CCS) | SBIT_USER;
233 put_reg(child, PT_CCS, tmp);
235 if (!valid_signal(data))
238 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
240 /* TODO: set some clever breakpoint mechanism... */
242 child->exit_code = data;
243 wake_up_process(child);
248 /* Get all GP registers from the child. */
249 case PTRACE_GETREGS: {
253 for (i = 0; i <= PT_MAX; i++) {
254 tmp = get_reg(child, i);
256 if (put_user(tmp, datap)) {
268 /* Set all GP registers in the child. */
269 case PTRACE_SETREGS: {
273 for (i = 0; i <= PT_MAX; i++) {
274 if (get_user(tmp, datap)) {
281 tmp |= get_reg(child, PT_CCS) & ~CCS_MASK;
284 put_reg(child, i, tmp);
293 ret = ptrace_request(child, request, addr, data);
300 void do_syscall_trace(void)
302 if (!test_thread_flag(TIF_SYSCALL_TRACE))
305 if (!(current->ptrace & PT_PTRACED))
308 /* the 0x80 provides a way for the tracing parent to distinguish
309 between a syscall stop and SIGTRAP delivery */
310 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
314 * This isn't the same as continuing with a signal, but it will do for
317 if (current->exit_code) {
318 send_sig(current->exit_code, current, 1);
319 current->exit_code = 0;
323 /* Returns the size of an instruction that has a delay slot. */
325 static int insn_size(struct task_struct *child, unsigned long pc)
327 unsigned long opcode;
331 /* Read the opcode at pc (do what PTRACE_PEEKTEXT would do). */
332 copied = access_process_vm(child, pc, &opcode, sizeof(opcode), 0);
333 if (copied != sizeof(opcode))
336 switch ((opcode & 0x0f00) >> 8) {
347 /* Could be 4 or 6; check more bits. */
348 if ((opcode & 0xff) == 0xff)
354 panic("ERROR: Couldn't find size of opcode 0x%lx at 0x%lx\n",
361 static unsigned long get_pseudo_pc(struct task_struct *child)
363 /* Default value for PC is ERP. */
364 unsigned long pc = get_reg(child, PT_ERP);
367 unsigned long spc = get_reg(child, PT_SPC);
368 /* Delay slot bit set. Report as stopped on proper
371 /* Rely on SPC if set. FIXME: We might want to check
372 that EXS indicates we stopped due to a single-step
376 /* Calculate the PC from the size of the instruction
377 that the delay slot we're in belongs to. */
378 pc += insn_size(child, pc & ~1) - 1;
384 static long bp_owner = 0;
386 /* Reachable from exit_thread in signal.c, so not static. */
387 void deconfigure_bp(long pid)
391 /* Only deconfigure if the pid is the owner. */
395 for (bp = 0; bp < 6; bp++) {
397 /* Deconfigure start and end address (also gets rid of ownership). */
398 put_debugreg(pid, PT_BP + 3 + (bp * 2), 0);
399 put_debugreg(pid, PT_BP + 4 + (bp * 2), 0);
401 /* Deconfigure relevant bits in control register. */
402 tmp = get_debugreg(pid, PT_BP_CTRL) & ~(3 << (2 + (bp * 4)));
403 put_debugreg(pid, PT_BP_CTRL, tmp);
409 static int put_debugreg(long pid, unsigned int regno, long data)
412 register int old_srs;
414 #ifdef CONFIG_ETRAX_KGDB
415 /* Ignore write, but pretend it was ok if value is 0
416 (we don't want POKEUSR/SETREGS failing unnessecarily). */
417 return (data == 0) ? ret : -1;
420 /* Simple owner management. */
423 else if (bp_owner != pid) {
424 /* Ignore write, but pretend it was ok if value is 0
425 (we don't want POKEUSR/SETREGS failing unnessecarily). */
426 return (data == 0) ? ret : -1;
429 /* Remember old SRS. */
430 SPEC_REG_RD(SPEC_REG_SRS, old_srs);
431 /* Switch to BP bank. */
432 SUPP_BANK_SEL(BANK_BP);
434 switch (regno - PT_BP) {
436 SUPP_REG_WR(0, data); break;
443 SUPP_REG_WR(3, data); break;
445 SUPP_REG_WR(4, data); break;
447 SUPP_REG_WR(5, data); break;
449 SUPP_REG_WR(6, data); break;
451 SUPP_REG_WR(7, data); break;
453 SUPP_REG_WR(8, data); break;
455 SUPP_REG_WR(9, data); break;
457 SUPP_REG_WR(10, data); break;
459 SUPP_REG_WR(11, data); break;
461 SUPP_REG_WR(12, data); break;
463 SUPP_REG_WR(13, data); break;
465 SUPP_REG_WR(14, data); break;
472 SPEC_REG_WR(SPEC_REG_SRS, old_srs);
481 static long get_debugreg(long pid, unsigned int regno)
483 register int old_srs;
486 if (pid != bp_owner) {
490 /* Remember old SRS. */
491 SPEC_REG_RD(SPEC_REG_SRS, old_srs);
492 /* Switch to BP bank. */
493 SUPP_BANK_SEL(BANK_BP);
495 switch (regno - PT_BP) {
497 SUPP_REG_RD(0, data); break;
500 /* error return value? */
504 SUPP_REG_RD(3, data); break;
506 SUPP_REG_RD(4, data); break;
508 SUPP_REG_RD(5, data); break;
510 SUPP_REG_RD(6, data); break;
512 SUPP_REG_RD(7, data); break;
514 SUPP_REG_RD(8, data); break;
516 SUPP_REG_RD(9, data); break;
518 SUPP_REG_RD(10, data); break;
520 SUPP_REG_RD(11, data); break;
522 SUPP_REG_RD(12, data); break;
524 SUPP_REG_RD(13, data); break;
526 SUPP_REG_RD(14, data); break;
528 /* error return value? */
533 SPEC_REG_WR(SPEC_REG_SRS, old_srs);