2 * arch/sh/kernel/ptrace_64.c
4 * Copyright (C) 2000, 2001 Paolo Alberelli
5 * Copyright (C) 2003 - 2007 Paul Mundt
7 * Started from SH3/4 version:
8 * SuperH version: Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
10 * Original x86 implementation:
11 * By Ross Biro 1/23/92
12 * edited by Linus Torvalds
14 * This file is subject to the terms and conditions of the GNU General Public
15 * License. See the file "COPYING" in the main directory of this archive
18 #include <linux/kernel.h>
19 #include <linux/rwsem.h>
20 #include <linux/sched.h>
22 #include <linux/smp.h>
23 #include <linux/smp_lock.h>
24 #include <linux/errno.h>
25 #include <linux/ptrace.h>
26 #include <linux/user.h>
27 #include <linux/signal.h>
28 #include <linux/syscalls.h>
29 #include <linux/audit.h>
30 #include <linux/seccomp.h>
32 #include <asm/uaccess.h>
33 #include <asm/pgtable.h>
34 #include <asm/system.h>
35 #include <asm/processor.h>
36 #include <asm/mmu_context.h>
39 /* This mask defines the bits of the SR which the user is not allowed to
40 change, which are everything except S, Q, M, PR, SZ, FR. */
41 #define SR_MASK (0xffff8cfd)
44 * does not yet catch signals sent when the child dies.
45 * in exit.c or in signal.c.
49 * This routine will get a word from the user area in the process kernel stack.
51 static inline int get_stack_long(struct task_struct *task, int offset)
55 stack = (unsigned char *)(task->thread.uregs);
57 return (*((int *)stack));
60 static inline unsigned long
61 get_fpu_long(struct task_struct *task, unsigned long addr)
65 regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1;
67 if (!tsk_used_math(task)) {
68 if (addr == offsetof(struct user_fpu_struct, fpscr)) {
71 tmp = 0xffffffffUL; /* matches initial value in fpu.c */
76 if (last_task_used_math == task) {
80 last_task_used_math = 0;
84 tmp = ((long *)&task->thread.fpu)[addr / sizeof(unsigned long)];
89 * This routine will put a word into the user area in the process kernel stack.
91 static inline int put_stack_long(struct task_struct *task, int offset,
96 stack = (unsigned char *)(task->thread.uregs);
98 *(unsigned long *) stack = data;
103 put_fpu_long(struct task_struct *task, unsigned long addr, unsigned long data)
105 struct pt_regs *regs;
107 regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1;
109 if (!tsk_used_math(task)) {
110 fpinit(&task->thread.fpu.hard);
111 set_stopped_child_used_math(task);
112 } else if (last_task_used_math == task) {
114 save_fpu(task, regs);
116 last_task_used_math = 0;
120 ((long *)&task->thread.fpu)[addr / sizeof(unsigned long)] = data;
124 void user_enable_single_step(struct task_struct *child)
126 struct pt_regs *regs = child->thread.uregs;
128 regs->sr |= SR_SSTEP; /* auto-resetting upon exception */
131 void user_disable_single_step(struct task_struct *child)
133 regs->sr &= ~SR_SSTEP;
136 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
141 /* read the word at location addr in the USER area. */
142 case PTRACE_PEEKUSR: {
146 if ((addr & 3) || addr < 0)
149 if (addr < sizeof(struct pt_regs))
150 tmp = get_stack_long(child, addr);
151 else if ((addr >= offsetof(struct user, fpu)) &&
152 (addr < offsetof(struct user, u_fpvalid))) {
153 tmp = get_fpu_long(child, addr - offsetof(struct user, fpu));
154 } else if (addr == offsetof(struct user, u_fpvalid)) {
155 tmp = !!tsk_used_math(child);
159 ret = put_user(tmp, (unsigned long *)data);
164 /* write the word at location addr in the USER area. We must
165 disallow any changes to certain SR bits or u_fpvalid, since
166 this could crash the kernel or result in a security
169 if ((addr & 3) || addr < 0)
172 if (addr < sizeof(struct pt_regs)) {
173 /* Ignore change of top 32 bits of SR */
174 if (addr == offsetof (struct pt_regs, sr)+4)
179 /* If lower 32 bits of SR, ignore non-user bits */
180 if (addr == offsetof (struct pt_regs, sr))
182 long cursr = get_stack_long(child, addr);
184 data |= (cursr & SR_MASK);
186 ret = put_stack_long(child, addr, data);
188 else if ((addr >= offsetof(struct user, fpu)) &&
189 (addr < offsetof(struct user, u_fpvalid))) {
190 ret = put_fpu_long(child, addr - offsetof(struct user, fpu), data);
195 ret = ptrace_request(child, request, addr, data);
201 asmlinkage int sh64_ptrace(long request, long pid, long addr, long data)
203 #define WPC_DBRMODE 0x0d104008
204 static int first_call = 1;
208 /* Set WPC.DBRMODE to 0. This makes all debug events get
209 * delivered through RESVEC, i.e. into the handlers in entry.S.
210 * (If the kernel was downloaded using a remote gdb, WPC.DBRMODE
211 * would normally be left set to 1, which makes debug events get
212 * delivered through DBRVEC, i.e. into the remote gdb's
213 * handlers. This prevents ptrace getting them, and confuses
214 * the remote gdb.) */
215 printk("DBRMODE set to 0 to permit native debugging\n");
216 poke_real_address_q(WPC_DBRMODE, 0);
221 return sys_ptrace(request, pid, addr, data);
224 asmlinkage void syscall_trace(struct pt_regs *regs, int entryexit)
226 struct task_struct *tsk = current;
228 secure_computing(regs->regs[9]);
230 if (unlikely(current->audit_context) && entryexit)
231 audit_syscall_exit(AUDITSC_RESULT(regs->regs[9]),
234 if (!test_thread_flag(TIF_SYSCALL_TRACE) &&
235 !test_thread_flag(TIF_SINGLESTEP))
237 if (!(tsk->ptrace & PT_PTRACED))
240 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) &&
241 !test_thread_flag(TIF_SINGLESTEP) ? 0x80 : 0));
244 * this isn't the same as continuing with a signal, but it will do
245 * for normal use. strace only continues with a signal if the
246 * stopping signal is not SIGTRAP. -brl
248 if (tsk->exit_code) {
249 send_sig(tsk->exit_code, tsk, 1);
254 if (unlikely(current->audit_context) && !entryexit)
255 audit_syscall_entry(AUDIT_ARCH_SH, regs->regs[1],
256 regs->regs[2], regs->regs[3],
257 regs->regs[4], regs->regs[5]);
260 /* Called with interrupts disabled */
261 asmlinkage void do_single_step(unsigned long long vec, struct pt_regs *regs)
263 /* This is called after a single step exception (DEBUGSS).
264 There is no need to change the PC, as it is a post-execution
265 exception, as entry.S does not do anything to the PC for DEBUGSS.
266 We need to clear the Single Step setting in SR to avoid
267 continually stepping. */
269 regs->sr &= ~SR_SSTEP;
270 force_sig(SIGTRAP, current);
273 /* Called with interrupts disabled */
274 asmlinkage void do_software_break_point(unsigned long long vec,
275 struct pt_regs *regs)
277 /* We need to forward step the PC, to counteract the backstep done
280 force_sig(SIGTRAP, current);
285 * Called by kernel/ptrace.c when detaching..
287 * Make sure single step bits etc are not set.
289 void ptrace_disable(struct task_struct *child)
291 user_disable_single_step(child);