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1 | /* | |
2 | * arch/sh/kernel/process.c | |
3 | * | |
4 | * This file handles the architecture-dependent parts of process handling.. | |
5 | * | |
6 | * Copyright (C) 1995 Linus Torvalds | |
7 | * | |
8 | * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima | |
9 | * Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC | |
10 | * Copyright (C) 2002 - 2008 Paul Mundt | |
11 | * | |
12 | * This file is subject to the terms and conditions of the GNU General Public | |
13 | * License. See the file "COPYING" in the main directory of this archive | |
14 | * for more details. | |
15 | */ | |
16 | #include <linux/module.h> | |
17 | #include <linux/mm.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/elfcore.h> | |
20 | #include <linux/kallsyms.h> | |
21 | #include <linux/fs.h> | |
22 | #include <linux/ftrace.h> | |
23 | #include <linux/hw_breakpoint.h> | |
24 | #include <asm/uaccess.h> | |
25 | #include <asm/mmu_context.h> | |
26 | #include <asm/system.h> | |
27 | #include <asm/fpu.h> | |
28 | #include <asm/syscalls.h> | |
29 | ||
30 | void show_regs(struct pt_regs * regs) | |
31 | { | |
32 | printk("\n"); | |
33 | printk("Pid : %d, Comm: \t\t%s\n", task_pid_nr(current), current->comm); | |
34 | printk("CPU : %d \t\t%s (%s %.*s)\n\n", | |
35 | smp_processor_id(), print_tainted(), init_utsname()->release, | |
36 | (int)strcspn(init_utsname()->version, " "), | |
37 | init_utsname()->version); | |
38 | ||
39 | print_symbol("PC is at %s\n", instruction_pointer(regs)); | |
40 | print_symbol("PR is at %s\n", regs->pr); | |
41 | ||
42 | printk("PC : %08lx SP : %08lx SR : %08lx ", | |
43 | regs->pc, regs->regs[15], regs->sr); | |
44 | #ifdef CONFIG_MMU | |
45 | printk("TEA : %08x\n", __raw_readl(MMU_TEA)); | |
46 | #else | |
47 | printk("\n"); | |
48 | #endif | |
49 | ||
50 | printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n", | |
51 | regs->regs[0],regs->regs[1], | |
52 | regs->regs[2],regs->regs[3]); | |
53 | printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n", | |
54 | regs->regs[4],regs->regs[5], | |
55 | regs->regs[6],regs->regs[7]); | |
56 | printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n", | |
57 | regs->regs[8],regs->regs[9], | |
58 | regs->regs[10],regs->regs[11]); | |
59 | printk("R12 : %08lx R13 : %08lx R14 : %08lx\n", | |
60 | regs->regs[12],regs->regs[13], | |
61 | regs->regs[14]); | |
62 | printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n", | |
63 | regs->mach, regs->macl, regs->gbr, regs->pr); | |
64 | ||
65 | show_trace(NULL, (unsigned long *)regs->regs[15], regs); | |
66 | show_code(regs); | |
67 | } | |
68 | ||
69 | /* | |
70 | * Create a kernel thread | |
71 | */ | |
72 | ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *)) | |
73 | { | |
74 | do_exit(fn(arg)); | |
75 | } | |
76 | ||
77 | /* Don't use this in BL=1(cli). Or else, CPU resets! */ | |
78 | int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) | |
79 | { | |
80 | struct pt_regs regs; | |
81 | int pid; | |
82 | ||
83 | memset(®s, 0, sizeof(regs)); | |
84 | regs.regs[4] = (unsigned long)arg; | |
85 | regs.regs[5] = (unsigned long)fn; | |
86 | ||
87 | regs.pc = (unsigned long)kernel_thread_helper; | |
88 | regs.sr = SR_MD; | |
89 | #if defined(CONFIG_SH_FPU) | |
90 | regs.sr |= SR_FD; | |
91 | #endif | |
92 | ||
93 | /* Ok, create the new process.. */ | |
94 | pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, | |
95 | ®s, 0, NULL, NULL); | |
96 | ||
97 | return pid; | |
98 | } | |
99 | EXPORT_SYMBOL(kernel_thread); | |
100 | ||
101 | void start_thread(struct pt_regs *regs, unsigned long new_pc, | |
102 | unsigned long new_sp) | |
103 | { | |
104 | set_fs(USER_DS); | |
105 | ||
106 | regs->pr = 0; | |
107 | regs->sr = SR_FD; | |
108 | regs->pc = new_pc; | |
109 | regs->regs[15] = new_sp; | |
110 | ||
111 | free_thread_xstate(current); | |
112 | } | |
113 | EXPORT_SYMBOL(start_thread); | |
114 | ||
115 | /* | |
116 | * Free current thread data structures etc.. | |
117 | */ | |
118 | void exit_thread(void) | |
119 | { | |
120 | } | |
121 | ||
122 | void flush_thread(void) | |
123 | { | |
124 | struct task_struct *tsk = current; | |
125 | ||
126 | flush_ptrace_hw_breakpoint(tsk); | |
127 | ||
128 | #if defined(CONFIG_SH_FPU) | |
129 | /* Forget lazy FPU state */ | |
130 | clear_fpu(tsk, task_pt_regs(tsk)); | |
131 | clear_used_math(); | |
132 | #endif | |
133 | } | |
134 | ||
135 | void release_thread(struct task_struct *dead_task) | |
136 | { | |
137 | /* do nothing */ | |
138 | } | |
139 | ||
140 | /* Fill in the fpu structure for a core dump.. */ | |
141 | int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) | |
142 | { | |
143 | int fpvalid = 0; | |
144 | ||
145 | #if defined(CONFIG_SH_FPU) | |
146 | struct task_struct *tsk = current; | |
147 | ||
148 | fpvalid = !!tsk_used_math(tsk); | |
149 | if (fpvalid) | |
150 | fpvalid = !fpregs_get(tsk, NULL, 0, | |
151 | sizeof(struct user_fpu_struct), | |
152 | fpu, NULL); | |
153 | #endif | |
154 | ||
155 | return fpvalid; | |
156 | } | |
157 | EXPORT_SYMBOL(dump_fpu); | |
158 | ||
159 | /* | |
160 | * This gets called before we allocate a new thread and copy | |
161 | * the current task into it. | |
162 | */ | |
163 | void prepare_to_copy(struct task_struct *tsk) | |
164 | { | |
165 | unlazy_fpu(tsk, task_pt_regs(tsk)); | |
166 | } | |
167 | ||
168 | asmlinkage void ret_from_fork(void); | |
169 | ||
170 | int copy_thread(unsigned long clone_flags, unsigned long usp, | |
171 | unsigned long unused, | |
172 | struct task_struct *p, struct pt_regs *regs) | |
173 | { | |
174 | struct thread_info *ti = task_thread_info(p); | |
175 | struct pt_regs *childregs; | |
176 | ||
177 | #if defined(CONFIG_SH_DSP) | |
178 | struct task_struct *tsk = current; | |
179 | ||
180 | if (is_dsp_enabled(tsk)) { | |
181 | /* We can use the __save_dsp or just copy the struct: | |
182 | * __save_dsp(p); | |
183 | * p->thread.dsp_status.status |= SR_DSP | |
184 | */ | |
185 | p->thread.dsp_status = tsk->thread.dsp_status; | |
186 | } | |
187 | #endif | |
188 | ||
189 | childregs = task_pt_regs(p); | |
190 | *childregs = *regs; | |
191 | ||
192 | if (user_mode(regs)) { | |
193 | childregs->regs[15] = usp; | |
194 | ti->addr_limit = USER_DS; | |
195 | } else { | |
196 | childregs->regs[15] = (unsigned long)childregs; | |
197 | ti->addr_limit = KERNEL_DS; | |
198 | ti->status &= ~TS_USEDFPU; | |
199 | p->fpu_counter = 0; | |
200 | } | |
201 | ||
202 | if (clone_flags & CLONE_SETTLS) | |
203 | childregs->gbr = childregs->regs[0]; | |
204 | ||
205 | childregs->regs[0] = 0; /* Set return value for child */ | |
206 | ||
207 | p->thread.sp = (unsigned long) childregs; | |
208 | p->thread.pc = (unsigned long) ret_from_fork; | |
209 | ||
210 | memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps)); | |
211 | ||
212 | return 0; | |
213 | } | |
214 | ||
215 | /* | |
216 | * switch_to(x,y) should switch tasks from x to y. | |
217 | * | |
218 | */ | |
219 | __notrace_funcgraph struct task_struct * | |
220 | __switch_to(struct task_struct *prev, struct task_struct *next) | |
221 | { | |
222 | struct thread_struct *next_t = &next->thread; | |
223 | ||
224 | unlazy_fpu(prev, task_pt_regs(prev)); | |
225 | ||
226 | /* we're going to use this soon, after a few expensive things */ | |
227 | if (next->fpu_counter > 5) | |
228 | prefetch(next_t->xstate); | |
229 | ||
230 | #ifdef CONFIG_MMU | |
231 | /* | |
232 | * Restore the kernel mode register | |
233 | * k7 (r7_bank1) | |
234 | */ | |
235 | asm volatile("ldc %0, r7_bank" | |
236 | : /* no output */ | |
237 | : "r" (task_thread_info(next))); | |
238 | #endif | |
239 | ||
240 | /* | |
241 | * If the task has used fpu the last 5 timeslices, just do a full | |
242 | * restore of the math state immediately to avoid the trap; the | |
243 | * chances of needing FPU soon are obviously high now | |
244 | */ | |
245 | if (next->fpu_counter > 5) | |
246 | __fpu_state_restore(); | |
247 | ||
248 | return prev; | |
249 | } | |
250 | ||
251 | asmlinkage int sys_fork(unsigned long r4, unsigned long r5, | |
252 | unsigned long r6, unsigned long r7, | |
253 | struct pt_regs __regs) | |
254 | { | |
255 | #ifdef CONFIG_MMU | |
256 | struct pt_regs *regs = RELOC_HIDE(&__regs, 0); | |
257 | return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL); | |
258 | #else | |
259 | /* fork almost works, enough to trick you into looking elsewhere :-( */ | |
260 | return -EINVAL; | |
261 | #endif | |
262 | } | |
263 | ||
264 | asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, | |
265 | unsigned long parent_tidptr, | |
266 | unsigned long child_tidptr, | |
267 | struct pt_regs __regs) | |
268 | { | |
269 | struct pt_regs *regs = RELOC_HIDE(&__regs, 0); | |
270 | if (!newsp) | |
271 | newsp = regs->regs[15]; | |
272 | return do_fork(clone_flags, newsp, regs, 0, | |
273 | (int __user *)parent_tidptr, | |
274 | (int __user *)child_tidptr); | |
275 | } | |
276 | ||
277 | /* | |
278 | * This is trivial, and on the face of it looks like it | |
279 | * could equally well be done in user mode. | |
280 | * | |
281 | * Not so, for quite unobvious reasons - register pressure. | |
282 | * In user mode vfork() cannot have a stack frame, and if | |
283 | * done by calling the "clone()" system call directly, you | |
284 | * do not have enough call-clobbered registers to hold all | |
285 | * the information you need. | |
286 | */ | |
287 | asmlinkage int sys_vfork(unsigned long r4, unsigned long r5, | |
288 | unsigned long r6, unsigned long r7, | |
289 | struct pt_regs __regs) | |
290 | { | |
291 | struct pt_regs *regs = RELOC_HIDE(&__regs, 0); | |
292 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs, | |
293 | 0, NULL, NULL); | |
294 | } | |
295 | ||
296 | /* | |
297 | * sys_execve() executes a new program. | |
298 | */ | |
299 | asmlinkage int sys_execve(const char __user *ufilename, | |
300 | const char __user *const __user *uargv, | |
301 | const char __user *const __user *uenvp, | |
302 | unsigned long r7, struct pt_regs __regs) | |
303 | { | |
304 | struct pt_regs *regs = RELOC_HIDE(&__regs, 0); | |
305 | int error; | |
306 | char *filename; | |
307 | ||
308 | filename = getname(ufilename); | |
309 | error = PTR_ERR(filename); | |
310 | if (IS_ERR(filename)) | |
311 | goto out; | |
312 | ||
313 | error = do_execve(filename, uargv, uenvp, regs); | |
314 | putname(filename); | |
315 | out: | |
316 | return error; | |
317 | } | |
318 | ||
319 | unsigned long get_wchan(struct task_struct *p) | |
320 | { | |
321 | unsigned long pc; | |
322 | ||
323 | if (!p || p == current || p->state == TASK_RUNNING) | |
324 | return 0; | |
325 | ||
326 | /* | |
327 | * The same comment as on the Alpha applies here, too ... | |
328 | */ | |
329 | pc = thread_saved_pc(p); | |
330 | ||
331 | #ifdef CONFIG_FRAME_POINTER | |
332 | if (in_sched_functions(pc)) { | |
333 | unsigned long schedule_frame = (unsigned long)p->thread.sp; | |
334 | return ((unsigned long *)schedule_frame)[21]; | |
335 | } | |
336 | #endif | |
337 | ||
338 | return pc; | |
339 | } |