2 * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
3 * these modifications are Copyright 2004-2009 Analog Devices Inc.
5 * Licensed under the GPL-2
8 #include <linux/kernel.h>
9 #include <linux/sched.h>
11 #include <linux/smp.h>
12 #include <linux/errno.h>
13 #include <linux/ptrace.h>
14 #include <linux/user.h>
15 #include <linux/signal.h>
16 #include <linux/uaccess.h>
19 #include <asm/pgtable.h>
20 #include <asm/system.h>
21 #include <asm/processor.h>
22 #include <asm/asm-offsets.h>
24 #include <asm/fixed_code.h>
25 #include <asm/cacheflush.h>
26 #include <asm/mem_map.h>
30 * does not yet catch signals sent when the child dies.
31 * in exit.c or in signal.c.
34 /* determines which bits in the SYSCFG reg the user has access to. */
35 /* 1 = access 0 = no access */
36 #define SYSCFG_MASK 0x0007 /* SYSCFG reg */
37 /* sets the trace bits. */
38 #define TRACE_BITS 0x0001
40 /* Find the stack offset for a register, relative to thread.esp0. */
41 #define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)
44 * Get the address of the live pt_regs for the specified task.
45 * These are saved onto the top kernel stack when the process
48 * Note: if a user thread is execve'd from kernel space, the
49 * kernel stack will not be empty on entry to the kernel, so
50 * ptracing these tasks will fail.
52 static inline struct pt_regs *get_user_regs(struct task_struct *task)
54 return (struct pt_regs *)
55 ((unsigned long)task_stack_page(task) +
56 (THREAD_SIZE - sizeof(struct pt_regs)));
60 * Get all user integer registers.
62 static inline int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
65 memcpy(®s, get_user_regs(tsk), sizeof(regs));
66 regs.usp = tsk->thread.usp;
67 return copy_to_user(uregs, ®s, sizeof(struct pt_regs)) ? -EFAULT : 0;
70 /* Mapping from PT_xxx to the stack offset at which the register is
71 * saved. Notice that usp has no stack-slot and needs to be treated
72 * specially (see get_reg/put_reg below).
76 * Get contents of register REGNO in task TASK.
78 static inline long get_reg(struct task_struct *task, int regno)
80 unsigned char *reg_ptr;
82 struct pt_regs *regs =
83 (struct pt_regs *)((unsigned long)task_stack_page(task) +
84 (THREAD_SIZE - sizeof(struct pt_regs)));
85 reg_ptr = (char *)regs;
89 return task->thread.usp;
92 return *(long *)(reg_ptr + regno);
94 /* slight mystery ... never seems to come here but kernel misbehaves without this code! */
96 printk(KERN_WARNING "Request to get for unknown register %d\n", regno);
101 * Write contents of register REGNO in task TASK.
104 put_reg(struct task_struct *task, int regno, unsigned long data)
108 struct pt_regs *regs =
109 (struct pt_regs *)((unsigned long)task_stack_page(task) +
110 (THREAD_SIZE - sizeof(struct pt_regs)));
111 reg_ptr = (char *)regs;
115 /*********************************************************************/
116 /* At this point the kernel is most likely in exception. */
117 /* The RETX register will be used to populate the pc of the process. */
118 /*********************************************************************/
123 break; /* regs->retx = data; break; */
126 task->thread.usp = data;
130 *(long *)(reg_ptr + regno) = data;
136 * check that an address falls within the bounds of the target process's memory mappings
138 static inline int is_user_addr_valid(struct task_struct *child,
139 unsigned long start, unsigned long len)
141 struct vm_area_struct *vma;
142 struct sram_list_struct *sraml;
145 if (start + len < start)
148 vma = find_vma(child->mm, start);
149 if (vma && start >= vma->vm_start && start + len <= vma->vm_end)
152 for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
153 if (start >= (unsigned long)sraml->addr
154 && start + len < (unsigned long)sraml->addr + sraml->length)
157 if (start >= FIXED_CODE_START && start + len < FIXED_CODE_END)
163 void ptrace_enable(struct task_struct *child)
166 tmp = get_reg(child, PT_SYSCFG) | (TRACE_BITS);
167 put_reg(child, PT_SYSCFG, tmp);
171 * Called by kernel/ptrace.c when detaching..
173 * Make sure the single step bit is not set.
175 void ptrace_disable(struct task_struct *child)
178 /* make sure the single step bit is not set. */
179 tmp = get_reg(child, PT_SYSCFG) & ~TRACE_BITS;
180 put_reg(child, PT_SYSCFG, tmp);
183 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
186 unsigned long __user *datap = (unsigned long __user *)data;
187 void *paddr = (void *)addr;
190 /* when I and D space are separate, these will need to be fixed. */
191 case PTRACE_PEEKDATA:
192 pr_debug("ptrace: PEEKDATA\n");
194 case PTRACE_PEEKTEXT: /* read word at location addr. */
196 unsigned long tmp = 0;
197 int copied = 0, to_copy = sizeof(tmp);
200 pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + %i\n", addr, to_copy);
201 if (is_user_addr_valid(child, addr, to_copy) < 0)
203 pr_debug("ptrace: user address is valid\n");
205 switch (bfin_mem_access_type(addr, to_copy)) {
206 case BFIN_MEM_ACCESS_CORE:
207 case BFIN_MEM_ACCESS_CORE_ONLY:
208 copied = access_process_vm(child, addr, &tmp,
213 /* hrm, why didn't that work ... maybe no mapping */
214 if (addr >= FIXED_CODE_START &&
215 addr + to_copy <= FIXED_CODE_END) {
216 copy_from_user_page(0, 0, 0, &tmp, paddr, to_copy);
218 } else if (addr >= BOOT_ROM_START) {
219 memcpy(&tmp, paddr, to_copy);
224 case BFIN_MEM_ACCESS_DMA:
225 if (safe_dma_memcpy(&tmp, paddr, to_copy))
228 case BFIN_MEM_ACCESS_ITEST:
229 if (isram_memcpy(&tmp, paddr, to_copy))
237 pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp);
238 if (copied == to_copy)
239 ret = put_user(tmp, datap);
243 /* read the word at location addr in the USER area. */
249 if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
250 printk(KERN_WARNING "ptrace error : PEEKUSR : temporarily returning "
251 "0 - %x sizeof(pt_regs) is %lx\n",
252 (int)addr, sizeof(struct pt_regs));
255 if (addr == sizeof(struct pt_regs)) {
257 tmp = child->mm->start_code + TEXT_OFFSET;
258 } else if (addr == (sizeof(struct pt_regs) + 4)) {
259 /* PT_TEXT_END_ADDR */
260 tmp = child->mm->end_code;
261 } else if (addr == (sizeof(struct pt_regs) + 8)) {
263 tmp = child->mm->start_data;
264 #ifdef CONFIG_BINFMT_ELF_FDPIC
265 } else if (addr == (sizeof(struct pt_regs) + 12)) {
266 goto case_PTRACE_GETFDPIC_EXEC;
267 } else if (addr == (sizeof(struct pt_regs) + 16)) {
268 goto case_PTRACE_GETFDPIC_INTERP;
271 tmp = get_reg(child, addr);
273 ret = put_user(tmp, datap);
277 #ifdef CONFIG_BINFMT_ELF_FDPIC
278 case PTRACE_GETFDPIC: {
279 unsigned long tmp = 0;
282 case_PTRACE_GETFDPIC_EXEC:
283 case PTRACE_GETFDPIC_EXEC:
284 tmp = child->mm->context.exec_fdpic_loadmap;
286 case_PTRACE_GETFDPIC_INTERP:
287 case PTRACE_GETFDPIC_INTERP:
288 tmp = child->mm->context.interp_fdpic_loadmap;
294 ret = put_user(tmp, datap);
299 /* when I and D space are separate, this will have to be fixed. */
300 case PTRACE_POKEDATA:
301 pr_debug("ptrace: PTRACE_PEEKDATA\n");
303 case PTRACE_POKETEXT: /* write the word at location addr. */
305 int copied = 0, to_copy = sizeof(data);
308 pr_debug("ptrace: POKETEXT at addr 0x%08lx + %i bytes %lx\n",
309 addr, to_copy, data);
310 if (is_user_addr_valid(child, addr, to_copy) < 0)
312 pr_debug("ptrace: user address is valid\n");
314 switch (bfin_mem_access_type(addr, to_copy)) {
315 case BFIN_MEM_ACCESS_CORE:
316 case BFIN_MEM_ACCESS_CORE_ONLY:
317 copied = access_process_vm(child, addr, &data,
322 /* hrm, why didn't that work ... maybe no mapping */
323 if (addr >= FIXED_CODE_START &&
324 addr + to_copy <= FIXED_CODE_END) {
325 copy_to_user_page(0, 0, 0, paddr, &data, to_copy);
327 } else if (addr >= BOOT_ROM_START) {
328 memcpy(paddr, &data, to_copy);
333 case BFIN_MEM_ACCESS_DMA:
334 if (safe_dma_memcpy(paddr, &data, to_copy))
337 case BFIN_MEM_ACCESS_ITEST:
338 if (isram_memcpy(paddr, &data, to_copy))
346 pr_debug("ptrace: copied size %d\n", copied);
347 if (copied == to_copy)
352 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
354 if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
355 printk(KERN_WARNING "ptrace error : POKEUSR: temporarily returning 0\n");
359 if (addr >= (sizeof(struct pt_regs))) {
363 if (addr == PT_SYSCFG) {
365 data |= get_reg(child, PT_SYSCFG);
367 ret = put_reg(child, addr, data);
370 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
371 case PTRACE_CONT: /* restart after signal. */
372 pr_debug("ptrace: syscall/cont\n");
375 if (!valid_signal(data))
377 if (request == PTRACE_SYSCALL)
378 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
380 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
381 child->exit_code = data;
382 ptrace_disable(child);
383 pr_debug("ptrace: before wake_up_process\n");
384 wake_up_process(child);
389 * make the child exit. Best I can do is send it a sigkill.
390 * perhaps it should be put in the status that it wants to
395 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
397 child->exit_code = SIGKILL;
398 ptrace_disable(child);
399 wake_up_process(child);
402 case PTRACE_SINGLESTEP: /* set the trap flag. */
403 pr_debug("ptrace: single step\n");
405 if (!valid_signal(data))
407 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
408 ptrace_enable(child);
409 child->exit_code = data;
410 wake_up_process(child);
415 /* Get all gp regs from the child. */
416 ret = ptrace_getregs(child, datap);
420 printk(KERN_WARNING "ptrace: SETREGS: **** NOT IMPLEMENTED ***\n");
421 /* Set all gp regs in the child. */
426 ret = ptrace_request(child, request, addr, data);
433 asmlinkage void syscall_trace(void)
435 if (!test_thread_flag(TIF_SYSCALL_TRACE))
438 if (!(current->ptrace & PT_PTRACED))
441 /* the 0x80 provides a way for the tracing parent to distinguish
442 * between a syscall stop and SIGTRAP delivery
444 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
448 * this isn't the same as continuing with a signal, but it will do
449 * for normal use. strace only continues with a signal if the
450 * stopping signal is not SIGTRAP. -brl
452 if (current->exit_code) {
453 send_sig(current->exit_code, current, 1);
454 current->exit_code = 0;