2 * File: arch/blackfin/kernel/ptrace.c
3 * Based on: Taken from linux/kernel/ptrace.c
4 * Author: linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
10 * Copyright 2004-2006 Analog Devices Inc.
12 * Bugs: Enter bugs at http://blackfin.uclinux.org/
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, see the file COPYING, or write
26 * to the Free Software Foundation, Inc.,
27 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
30 #include <linux/kernel.h>
31 #include <linux/sched.h>
33 #include <linux/smp.h>
34 #include <linux/errno.h>
35 #include <linux/ptrace.h>
36 #include <linux/user.h>
37 #include <linux/signal.h>
38 #include <linux/uaccess.h>
41 #include <asm/pgtable.h>
42 #include <asm/system.h>
43 #include <asm/processor.h>
44 #include <asm/asm-offsets.h>
46 #include <asm/fixed_code.h>
47 #include <asm/cacheflush.h>
48 #include <asm/mem_map.h>
52 * does not yet catch signals sent when the child dies.
53 * in exit.c or in signal.c.
56 /* determines which bits in the SYSCFG reg the user has access to. */
57 /* 1 = access 0 = no access */
58 #define SYSCFG_MASK 0x0007 /* SYSCFG reg */
59 /* sets the trace bits. */
60 #define TRACE_BITS 0x0001
62 /* Find the stack offset for a register, relative to thread.esp0. */
63 #define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)
66 * Get the address of the live pt_regs for the specified task.
67 * These are saved onto the top kernel stack when the process
70 * Note: if a user thread is execve'd from kernel space, the
71 * kernel stack will not be empty on entry to the kernel, so
72 * ptracing these tasks will fail.
74 static inline struct pt_regs *get_user_regs(struct task_struct *task)
76 return (struct pt_regs *)
77 ((unsigned long)task_stack_page(task) +
78 (THREAD_SIZE - sizeof(struct pt_regs)));
82 * Get all user integer registers.
84 static inline int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
87 memcpy(®s, get_user_regs(tsk), sizeof(regs));
88 regs.usp = tsk->thread.usp;
89 return copy_to_user(uregs, ®s, sizeof(struct pt_regs)) ? -EFAULT : 0;
92 /* Mapping from PT_xxx to the stack offset at which the register is
93 * saved. Notice that usp has no stack-slot and needs to be treated
94 * specially (see get_reg/put_reg below).
98 * Get contents of register REGNO in task TASK.
100 static inline long get_reg(struct task_struct *task, int regno)
102 unsigned char *reg_ptr;
104 struct pt_regs *regs =
105 (struct pt_regs *)((unsigned long)task_stack_page(task) +
106 (THREAD_SIZE - sizeof(struct pt_regs)));
107 reg_ptr = (char *)regs;
111 return task->thread.usp;
114 return *(long *)(reg_ptr + regno);
116 /* slight mystery ... never seems to come here but kernel misbehaves without this code! */
118 printk(KERN_WARNING "Request to get for unknown register %d\n", regno);
123 * Write contents of register REGNO in task TASK.
126 put_reg(struct task_struct *task, int regno, unsigned long data)
130 struct pt_regs *regs =
131 (struct pt_regs *)((unsigned long)task_stack_page(task) +
132 (THREAD_SIZE - sizeof(struct pt_regs)));
133 reg_ptr = (char *)regs;
137 /*********************************************************************/
138 /* At this point the kernel is most likely in exception. */
139 /* The RETX register will be used to populate the pc of the process. */
140 /*********************************************************************/
145 break; /* regs->retx = data; break; */
148 task->thread.usp = data;
152 *(long *)(reg_ptr + regno) = data;
158 * check that an address falls within the bounds of the target process's memory mappings
160 static inline int is_user_addr_valid(struct task_struct *child,
161 unsigned long start, unsigned long len)
163 struct vm_area_struct *vma;
164 struct sram_list_struct *sraml;
167 if (start + len < start)
170 vma = find_vma(child->mm, start);
171 if (vma && start >= vma->vm_start && start + len <= vma->vm_end)
174 for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
175 if (start >= (unsigned long)sraml->addr
176 && start + len < (unsigned long)sraml->addr + sraml->length)
179 if (start >= FIXED_CODE_START && start + len < FIXED_CODE_END)
185 void ptrace_enable(struct task_struct *child)
188 tmp = get_reg(child, PT_SYSCFG) | (TRACE_BITS);
189 put_reg(child, PT_SYSCFG, tmp);
193 * Called by kernel/ptrace.c when detaching..
195 * Make sure the single step bit is not set.
197 void ptrace_disable(struct task_struct *child)
200 /* make sure the single step bit is not set. */
201 tmp = get_reg(child, PT_SYSCFG) & ~TRACE_BITS;
202 put_reg(child, PT_SYSCFG, tmp);
205 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
208 unsigned long __user *datap = (unsigned long __user *)data;
209 void *paddr = (void *)addr;
212 /* when I and D space are separate, these will need to be fixed. */
213 case PTRACE_PEEKDATA:
214 pr_debug("ptrace: PEEKDATA\n");
216 case PTRACE_PEEKTEXT: /* read word at location addr. */
218 unsigned long tmp = 0;
219 int copied = 0, to_copy = sizeof(tmp);
222 pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + %i\n", addr, to_copy);
223 if (is_user_addr_valid(child, addr, to_copy) < 0)
225 pr_debug("ptrace: user address is valid\n");
227 switch (bfin_mem_access_type(addr, to_copy)) {
228 case BFIN_MEM_ACCESS_CORE:
229 case BFIN_MEM_ACCESS_CORE_ONLY:
230 copied = access_process_vm(child, addr, &tmp,
235 /* hrm, why didn't that work ... maybe no mapping */
236 if (addr >= FIXED_CODE_START &&
237 addr + to_copy <= FIXED_CODE_END) {
238 copy_from_user_page(0, 0, 0, &tmp, paddr, to_copy);
240 } else if (addr >= BOOT_ROM_START) {
241 memcpy(&tmp, paddr, to_copy);
246 case BFIN_MEM_ACCESS_DMA:
247 if (safe_dma_memcpy(&tmp, paddr, to_copy))
250 case BFIN_MEM_ACCESS_ITEST:
251 if (isram_memcpy(&tmp, paddr, to_copy))
259 pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp);
260 if (copied == to_copy)
261 ret = put_user(tmp, datap);
265 /* read the word at location addr in the USER area. */
271 if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
272 printk(KERN_WARNING "ptrace error : PEEKUSR : temporarily returning "
273 "0 - %x sizeof(pt_regs) is %lx\n",
274 (int)addr, sizeof(struct pt_regs));
277 if (addr == sizeof(struct pt_regs)) {
279 tmp = child->mm->start_code + TEXT_OFFSET;
280 } else if (addr == (sizeof(struct pt_regs) + 4)) {
281 /* PT_TEXT_END_ADDR */
282 tmp = child->mm->end_code;
283 } else if (addr == (sizeof(struct pt_regs) + 8)) {
285 tmp = child->mm->start_data;
286 #ifdef CONFIG_BINFMT_ELF_FDPIC
287 } else if (addr == (sizeof(struct pt_regs) + 12)) {
288 goto case_PTRACE_GETFDPIC_EXEC;
289 } else if (addr == (sizeof(struct pt_regs) + 16)) {
290 goto case_PTRACE_GETFDPIC_INTERP;
293 tmp = get_reg(child, addr);
295 ret = put_user(tmp, datap);
299 #ifdef CONFIG_BINFMT_ELF_FDPIC
300 case PTRACE_GETFDPIC: {
301 unsigned long tmp = 0;
304 case_PTRACE_GETFDPIC_EXEC:
305 case PTRACE_GETFDPIC_EXEC:
306 tmp = child->mm->context.exec_fdpic_loadmap;
308 case_PTRACE_GETFDPIC_INTERP:
309 case PTRACE_GETFDPIC_INTERP:
310 tmp = child->mm->context.interp_fdpic_loadmap;
316 ret = put_user(tmp, datap);
321 /* when I and D space are separate, this will have to be fixed. */
322 case PTRACE_POKEDATA:
323 pr_debug("ptrace: PTRACE_PEEKDATA\n");
325 case PTRACE_POKETEXT: /* write the word at location addr. */
327 int copied = 0, to_copy = sizeof(data);
330 pr_debug("ptrace: POKETEXT at addr 0x%08lx + %i bytes %lx\n",
331 addr, to_copy, data);
332 if (is_user_addr_valid(child, addr, to_copy) < 0)
334 pr_debug("ptrace: user address is valid\n");
336 switch (bfin_mem_access_type(addr, to_copy)) {
337 case BFIN_MEM_ACCESS_CORE:
338 case BFIN_MEM_ACCESS_CORE_ONLY:
339 copied = access_process_vm(child, addr, &data,
344 /* hrm, why didn't that work ... maybe no mapping */
345 if (addr >= FIXED_CODE_START &&
346 addr + to_copy <= FIXED_CODE_END) {
347 copy_to_user_page(0, 0, 0, paddr, &data, to_copy);
349 } else if (addr >= BOOT_ROM_START) {
350 memcpy(paddr, &data, to_copy);
355 case BFIN_MEM_ACCESS_DMA:
356 if (safe_dma_memcpy(paddr, &data, to_copy))
359 case BFIN_MEM_ACCESS_ITEST:
360 if (isram_memcpy(paddr, &data, to_copy))
368 pr_debug("ptrace: copied size %d\n", copied);
369 if (copied == to_copy)
374 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
376 if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
377 printk(KERN_WARNING "ptrace error : POKEUSR: temporarily returning 0\n");
381 if (addr >= (sizeof(struct pt_regs))) {
385 if (addr == PT_SYSCFG) {
387 data |= get_reg(child, PT_SYSCFG);
389 ret = put_reg(child, addr, data);
392 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
393 case PTRACE_CONT: /* restart after signal. */
394 pr_debug("ptrace: syscall/cont\n");
397 if (!valid_signal(data))
399 if (request == PTRACE_SYSCALL)
400 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
402 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
403 child->exit_code = data;
404 ptrace_disable(child);
405 pr_debug("ptrace: before wake_up_process\n");
406 wake_up_process(child);
411 * make the child exit. Best I can do is send it a sigkill.
412 * perhaps it should be put in the status that it wants to
417 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
419 child->exit_code = SIGKILL;
420 ptrace_disable(child);
421 wake_up_process(child);
424 case PTRACE_SINGLESTEP: /* set the trap flag. */
425 pr_debug("ptrace: single step\n");
427 if (!valid_signal(data))
429 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
430 ptrace_enable(child);
431 child->exit_code = data;
432 wake_up_process(child);
437 /* Get all gp regs from the child. */
438 ret = ptrace_getregs(child, datap);
442 printk(KERN_WARNING "ptrace: SETREGS: **** NOT IMPLEMENTED ***\n");
443 /* Set all gp regs in the child. */
448 ret = ptrace_request(child, request, addr, data);
455 asmlinkage void syscall_trace(void)
457 if (!test_thread_flag(TIF_SYSCALL_TRACE))
460 if (!(current->ptrace & PT_PTRACED))
463 /* the 0x80 provides a way for the tracing parent to distinguish
464 * between a syscall stop and SIGTRAP delivery
466 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
470 * this isn't the same as continuing with a signal, but it will do
471 * for normal use. strace only continues with a signal if the
472 * stopping signal is not SIGTRAP. -brl
474 if (current->exit_code) {
475 send_sig(current->exit_code, current, 1);
476 current->exit_code = 0;