1 // SPDX-License-Identifier: GPL-2.0 !! 1 /*
>> 2 * linux/arch/m68k/kernel/process.c
>> 3 *
>> 4 * Copyright (C) 1995 Hamish Macdonald
>> 5 *
>> 6 * 68060 fixes by Jesper Skov
>> 7 */
2 8
3 /* 9 /*
4 * This file handles the architecture independ !! 10 * This file handles the architecture-dependent parts of process handling..
5 */ 11 */
6 12
7 #include <linux/compat.h> <<
8 #include <linux/errno.h> 13 #include <linux/errno.h>
>> 14 #include <linux/module.h>
>> 15 #include <linux/sched.h>
9 #include <linux/kernel.h> 16 #include <linux/kernel.h>
>> 17 #include <linux/mm.h>
>> 18 #include <linux/slab.h>
>> 19 #include <linux/fs.h>
>> 20 #include <linux/smp.h>
>> 21 #include <linux/stddef.h>
>> 22 #include <linux/unistd.h>
10 #include <linux/ptrace.h> 23 #include <linux/ptrace.h>
11 #include <linux/sched.h> !! 24 #include <linux/user.h>
12 #include <linux/sched/task.h> !! 25 #include <linux/reboot.h>
13 #include <linux/sched/task_stack.h> !! 26 #include <linux/init_task.h>
14 #include <linux/signal.h> !! 27 #include <linux/mqueue.h>
15 !! 28 #include <linux/rcupdate.h>
16 #include "kernel.h" !! 29
17 !! 30 #include <linux/uaccess.h>
18 asmlinkage long sparc_fork(struct pt_regs *reg !! 31 #include <asm/traps.h>
19 { !! 32 #include <asm/machdep.h>
20 unsigned long orig_i1 = regs->u_regs[U !! 33 #include <asm/setup.h>
21 long ret; !! 34 #include <asm/pgtable.h>
22 struct kernel_clone_args args = { !! 35
23 .exit_signal = SIGCHLD, !! 36
24 /* Reuse the parent's stack fo !! 37 asmlinkage void ret_from_fork(void);
25 .stack = regs->u_regs !! 38 asmlinkage void ret_from_kernel_thread(void);
26 }; !! 39
27 !! 40
28 ret = kernel_clone(&args); !! 41 /*
29 !! 42 * Return saved PC from a blocked thread
30 /* If we get an error and potentially !! 43 */
31 * call, we're screwed because copy_th !! 44 unsigned long thread_saved_pc(struct task_struct *tsk)
32 * the parent's %o1. So detect that c !! 45 {
33 * here. !! 46 struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
34 */ !! 47 /* Check whether the thread is blocked in resume() */
35 if ((unsigned long)ret >= -ERESTART_RE !! 48 if (in_sched_functions(sw->retpc))
36 regs->u_regs[UREG_I1] = orig_i !! 49 return ((unsigned long *)sw->a6)[1];
>> 50 else
>> 51 return sw->retpc;
>> 52 }
37 53
38 return ret; !! 54 void arch_cpu_idle(void)
>> 55 {
>> 56 #if defined(MACH_ATARI_ONLY)
>> 57 /* block out HSYNC on the atari (falcon) */
>> 58 __asm__("stop #0x2200" : : : "cc");
>> 59 #else
>> 60 __asm__("stop #0x2000" : : : "cc");
>> 61 #endif
39 } 62 }
40 63
41 asmlinkage long sparc_vfork(struct pt_regs *re !! 64 void machine_restart(char * __unused)
42 { 65 {
43 unsigned long orig_i1 = regs->u_regs[U !! 66 if (mach_reset)
44 long ret; !! 67 mach_reset();
>> 68 for (;;);
>> 69 }
45 70
46 struct kernel_clone_args args = { !! 71 void machine_halt(void)
47 .flags = CLONE_VFORK !! 72 {
48 .exit_signal = SIGCHLD, !! 73 if (mach_halt)
49 /* Reuse the parent's stack fo !! 74 mach_halt();
50 .stack = regs->u_regs !! 75 for (;;);
51 }; !! 76 }
52 77
53 ret = kernel_clone(&args); !! 78 void machine_power_off(void)
>> 79 {
>> 80 if (mach_power_off)
>> 81 mach_power_off();
>> 82 for (;;);
>> 83 }
54 84
55 /* If we get an error and potentially !! 85 void (*pm_power_off)(void) = machine_power_off;
56 * call, we're screwed because copy_th !! 86 EXPORT_SYMBOL(pm_power_off);
57 * the parent's %o1. So detect that c <<
58 * here. <<
59 */ <<
60 if ((unsigned long)ret >= -ERESTART_RE <<
61 regs->u_regs[UREG_I1] = orig_i <<
62 87
63 return ret; !! 88 void show_regs(struct pt_regs * regs)
>> 89 {
>> 90 printk("\n");
>> 91 printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
>> 92 regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
>> 93 printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
>> 94 regs->orig_d0, regs->d0, regs->a2, regs->a1);
>> 95 printk("A0: %08lx D5: %08lx D4: %08lx\n",
>> 96 regs->a0, regs->d5, regs->d4);
>> 97 printk("D3: %08lx D2: %08lx D1: %08lx\n",
>> 98 regs->d3, regs->d2, regs->d1);
>> 99 if (!(regs->sr & PS_S))
>> 100 printk("USP: %08lx\n", rdusp());
64 } 101 }
65 102
66 asmlinkage long sparc_clone(struct pt_regs *re !! 103 void flush_thread(void)
67 { 104 {
68 unsigned long orig_i1 = regs->u_regs[U !! 105 current->thread.fs = __USER_DS;
69 unsigned int flags = lower_32_bits(reg !! 106 #ifdef CONFIG_FPU
70 long ret; !! 107 if (!FPU_IS_EMU) {
71 !! 108 unsigned long zero = 0;
72 struct kernel_clone_args args = { !! 109 asm volatile("frestore %0": :"m" (zero));
73 .flags = (flags & ~CS <<
74 .exit_signal = (flags & CSI <<
75 .tls = regs->u_regs <<
76 }; <<
77 <<
78 #ifdef CONFIG_COMPAT <<
79 if (test_thread_flag(TIF_32BIT)) { <<
80 args.pidfd = compat_ptr(r <<
81 args.child_tid = compat_ptr(r <<
82 args.parent_tid = compat_ptr(r <<
83 } else <<
84 #endif <<
85 { <<
86 args.pidfd = (int __user <<
87 args.child_tid = (int __user <<
88 args.parent_tid = (int __user <<
89 } 110 }
>> 111 #endif
>> 112 }
>> 113
>> 114 /*
>> 115 * Why not generic sys_clone, you ask? m68k passes all arguments on stack.
>> 116 * And we need all registers saved, which means a bunch of stuff pushed
>> 117 * on top of pt_regs, which means that sys_clone() arguments would be
>> 118 * buried. We could, of course, copy them, but it's too costly for no
>> 119 * good reason - generic clone() would have to copy them *again* for
>> 120 * do_fork() anyway. So in this case it's actually better to pass pt_regs *
>> 121 * and extract arguments for do_fork() from there. Eventually we might
>> 122 * go for calling do_fork() directly from the wrapper, but only after we
>> 123 * are finished with do_fork() prototype conversion.
>> 124 */
>> 125 asmlinkage int m68k_clone(struct pt_regs *regs)
>> 126 {
>> 127 /* regs will be equal to current_pt_regs() */
>> 128 return do_fork(regs->d1, regs->d2, 0,
>> 129 (int __user *)regs->d3, (int __user *)regs->d4);
>> 130 }
90 131
91 /* Did userspace give setup a separate !! 132 int copy_thread(unsigned long clone_flags, unsigned long usp,
92 * reusing the parent's? !! 133 unsigned long arg, struct task_struct *p)
>> 134 {
>> 135 struct fork_frame {
>> 136 struct switch_stack sw;
>> 137 struct pt_regs regs;
>> 138 } *frame;
>> 139
>> 140 frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1;
>> 141
>> 142 p->thread.ksp = (unsigned long)frame;
>> 143 p->thread.esp0 = (unsigned long)&frame->regs;
>> 144
>> 145 /*
>> 146 * Must save the current SFC/DFC value, NOT the value when
>> 147 * the parent was last descheduled - RGH 10-08-96
93 */ 148 */
94 if (regs->u_regs[UREG_I1]) !! 149 p->thread.fs = get_fs().seg;
95 args.stack = regs->u_regs[UREG <<
96 else <<
97 args.stack = regs->u_regs[UREG <<
98 150
99 ret = kernel_clone(&args); !! 151 if (unlikely(p->flags & PF_KTHREAD)) {
>> 152 /* kernel thread */
>> 153 memset(frame, 0, sizeof(struct fork_frame));
>> 154 frame->regs.sr = PS_S;
>> 155 frame->sw.a3 = usp; /* function */
>> 156 frame->sw.d7 = arg;
>> 157 frame->sw.retpc = (unsigned long)ret_from_kernel_thread;
>> 158 p->thread.usp = 0;
>> 159 return 0;
>> 160 }
>> 161 memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs),
>> 162 sizeof(struct fork_frame));
>> 163 frame->regs.d0 = 0;
>> 164 frame->sw.retpc = (unsigned long)ret_from_fork;
>> 165 p->thread.usp = usp ?: rdusp();
>> 166
>> 167 if (clone_flags & CLONE_SETTLS)
>> 168 task_thread_info(p)->tp_value = frame->regs.d5;
>> 169
>> 170 #ifdef CONFIG_FPU
>> 171 if (!FPU_IS_EMU) {
>> 172 /* Copy the current fpu state */
>> 173 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
>> 174
>> 175 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
>> 176 if (CPU_IS_COLDFIRE) {
>> 177 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
>> 178 "fmovel %/fpiar,%1\n\t"
>> 179 "fmovel %/fpcr,%2\n\t"
>> 180 "fmovel %/fpsr,%3"
>> 181 :
>> 182 : "m" (p->thread.fp[0]),
>> 183 "m" (p->thread.fpcntl[0]),
>> 184 "m" (p->thread.fpcntl[1]),
>> 185 "m" (p->thread.fpcntl[2])
>> 186 : "memory");
>> 187 } else {
>> 188 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
>> 189 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
>> 190 :
>> 191 : "m" (p->thread.fp[0]),
>> 192 "m" (p->thread.fpcntl[0])
>> 193 : "memory");
>> 194 }
>> 195 }
100 196
101 /* If we get an error and potentially !! 197 /* Restore the state in case the fpu was busy */
102 * call, we're screwed because copy_th !! 198 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
103 * the parent's %o1. So detect that c !! 199 }
104 * here. !! 200 #endif /* CONFIG_FPU */
105 */ <<
106 if ((unsigned long)ret >= -ERESTART_RE <<
107 regs->u_regs[UREG_I1] = orig_i <<
108 201
109 return ret; !! 202 return 0;
>> 203 }
>> 204
>> 205 /* Fill in the fpu structure for a core dump. */
>> 206 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
>> 207 {
>> 208 if (FPU_IS_EMU) {
>> 209 int i;
>> 210
>> 211 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
>> 212 memcpy(fpu->fpregs, current->thread.fp, 96);
>> 213 /* Convert internal fpu reg representation
>> 214 * into long double format
>> 215 */
>> 216 for (i = 0; i < 24; i += 3)
>> 217 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
>> 218 ((fpu->fpregs[i] & 0x0000ffff) << 16);
>> 219 return 1;
>> 220 }
>> 221
>> 222 if (IS_ENABLED(CONFIG_FPU)) {
>> 223 char fpustate[216];
>> 224
>> 225 /* First dump the fpu context to avoid protocol violation. */
>> 226 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
>> 227 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
>> 228 return 0;
>> 229
>> 230 if (CPU_IS_COLDFIRE) {
>> 231 asm volatile ("fmovel %/fpiar,%0\n\t"
>> 232 "fmovel %/fpcr,%1\n\t"
>> 233 "fmovel %/fpsr,%2\n\t"
>> 234 "fmovemd %/fp0-%/fp7,%3"
>> 235 :
>> 236 : "m" (fpu->fpcntl[0]),
>> 237 "m" (fpu->fpcntl[1]),
>> 238 "m" (fpu->fpcntl[2]),
>> 239 "m" (fpu->fpregs[0])
>> 240 : "memory");
>> 241 } else {
>> 242 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
>> 243 :
>> 244 : "m" (fpu->fpcntl[0])
>> 245 : "memory");
>> 246 asm volatile ("fmovemx %/fp0-%/fp7,%0"
>> 247 :
>> 248 : "m" (fpu->fpregs[0])
>> 249 : "memory");
>> 250 }
>> 251 }
>> 252
>> 253 return 1;
>> 254 }
>> 255 EXPORT_SYMBOL(dump_fpu);
>> 256
>> 257 unsigned long get_wchan(struct task_struct *p)
>> 258 {
>> 259 unsigned long fp, pc;
>> 260 unsigned long stack_page;
>> 261 int count = 0;
>> 262 if (!p || p == current || p->state == TASK_RUNNING)
>> 263 return 0;
>> 264
>> 265 stack_page = (unsigned long)task_stack_page(p);
>> 266 fp = ((struct switch_stack *)p->thread.ksp)->a6;
>> 267 do {
>> 268 if (fp < stack_page+sizeof(struct thread_info) ||
>> 269 fp >= 8184+stack_page)
>> 270 return 0;
>> 271 pc = ((unsigned long *)fp)[1];
>> 272 if (!in_sched_functions(pc))
>> 273 return pc;
>> 274 fp = *(unsigned long *) fp;
>> 275 } while (count++ < 16);
>> 276 return 0;
110 } 277 }
111 278
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