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