1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
>> 2 /*
>> 3 * linux/arch/m68k/kernel/process.c
>> 4 *
>> 5 * Copyright (C) 1995 Hamish Macdonald
>> 6 *
>> 7 * 68060 fixes by Jesper Skov
>> 8 */
2 9
3 /* 10 /*
4 * This file handles the architecture independ !! 11 * This file handles the architecture-dependent parts of process handling..
5 */ 12 */
6 13
7 #include <linux/compat.h> <<
8 #include <linux/errno.h> 14 #include <linux/errno.h>
9 #include <linux/kernel.h> !! 15 #include <linux/module.h>
10 #include <linux/ptrace.h> <<
11 #include <linux/sched.h> 16 #include <linux/sched.h>
>> 17 #include <linux/sched/debug.h>
12 #include <linux/sched/task.h> 18 #include <linux/sched/task.h>
13 #include <linux/sched/task_stack.h> 19 #include <linux/sched/task_stack.h>
14 #include <linux/signal.h> !! 20 #include <linux/kernel.h>
>> 21 #include <linux/mm.h>
>> 22 #include <linux/slab.h>
>> 23 #include <linux/fs.h>
>> 24 #include <linux/smp.h>
>> 25 #include <linux/stddef.h>
>> 26 #include <linux/unistd.h>
>> 27 #include <linux/ptrace.h>
>> 28 #include <linux/user.h>
>> 29 #include <linux/reboot.h>
>> 30 #include <linux/init_task.h>
>> 31 #include <linux/mqueue.h>
>> 32 #include <linux/rcupdate.h>
>> 33 #include <linux/syscalls.h>
>> 34 #include <linux/uaccess.h>
>> 35
>> 36 #include <asm/traps.h>
>> 37 #include <asm/machdep.h>
>> 38 #include <asm/setup.h>
15 39
16 #include "kernel.h" <<
17 40
18 asmlinkage long sparc_fork(struct pt_regs *reg !! 41 asmlinkage void ret_from_fork(void);
>> 42 asmlinkage void ret_from_kernel_thread(void);
>> 43
>> 44 void arch_cpu_idle(void)
19 { 45 {
20 unsigned long orig_i1 = regs->u_regs[U !! 46 #if defined(MACH_ATARI_ONLY)
21 long ret; !! 47 /* block out HSYNC on the atari (falcon) */
22 struct kernel_clone_args args = { !! 48 __asm__("stop #0x2200" : : : "cc");
23 .exit_signal = SIGCHLD, !! 49 #else
24 /* Reuse the parent's stack fo !! 50 __asm__("stop #0x2000" : : : "cc");
25 .stack = regs->u_regs !! 51 #endif
26 }; !! 52 }
>> 53
>> 54 void machine_restart(char * __unused)
>> 55 {
>> 56 if (mach_reset)
>> 57 mach_reset();
>> 58 for (;;);
>> 59 }
27 60
28 ret = kernel_clone(&args); !! 61 void machine_halt(void)
>> 62 {
>> 63 if (mach_halt)
>> 64 mach_halt();
>> 65 for (;;);
>> 66 }
29 67
30 /* If we get an error and potentially !! 68 void machine_power_off(void)
31 * call, we're screwed because copy_th !! 69 {
32 * the parent's %o1. So detect that c !! 70 do_kernel_power_off();
33 * here. !! 71 for (;;);
34 */ !! 72 }
35 if ((unsigned long)ret >= -ERESTART_RE !! 73
36 regs->u_regs[UREG_I1] = orig_i !! 74 void (*pm_power_off)(void);
>> 75 EXPORT_SYMBOL(pm_power_off);
37 76
38 return ret; !! 77 void show_regs(struct pt_regs * regs)
>> 78 {
>> 79 pr_info("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
>> 80 regs->format, regs->vector, regs->pc, regs->sr,
>> 81 print_tainted());
>> 82 pr_info("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
>> 83 regs->orig_d0, regs->d0, regs->a2, regs->a1);
>> 84 pr_info("A0: %08lx D5: %08lx D4: %08lx\n", regs->a0, regs->d5,
>> 85 regs->d4);
>> 86 pr_info("D3: %08lx D2: %08lx D1: %08lx\n", regs->d3, regs->d2,
>> 87 regs->d1);
>> 88 if (!(regs->sr & PS_S))
>> 89 pr_info("USP: %08lx\n", rdusp());
39 } 90 }
40 91
41 asmlinkage long sparc_vfork(struct pt_regs *re !! 92 void flush_thread(void)
42 { 93 {
43 unsigned long orig_i1 = regs->u_regs[U !! 94 current->thread.fc = USER_DATA;
44 long ret; !! 95 #ifdef CONFIG_FPU
>> 96 if (!FPU_IS_EMU) {
>> 97 unsigned long zero = 0;
>> 98 asm volatile("frestore %0": :"m" (zero));
>> 99 }
>> 100 #endif
>> 101 }
45 102
>> 103 /*
>> 104 * Why not generic sys_clone, you ask? m68k passes all arguments on stack.
>> 105 * And we need all registers saved, which means a bunch of stuff pushed
>> 106 * on top of pt_regs, which means that sys_clone() arguments would be
>> 107 * buried. We could, of course, copy them, but it's too costly for no
>> 108 * good reason - generic clone() would have to copy them *again* for
>> 109 * kernel_clone() anyway. So in this case it's actually better to pass pt_regs *
>> 110 * and extract arguments for kernel_clone() from there. Eventually we might
>> 111 * go for calling kernel_clone() directly from the wrapper, but only after we
>> 112 * are finished with kernel_clone() prototype conversion.
>> 113 */
>> 114 asmlinkage int m68k_clone(struct pt_regs *regs)
>> 115 {
>> 116 /* regs will be equal to current_pt_regs() */
46 struct kernel_clone_args args = { 117 struct kernel_clone_args args = {
47 .flags = CLONE_VFORK !! 118 .flags = (u32)(regs->d1) & ~CSIGNAL,
48 .exit_signal = SIGCHLD, !! 119 .pidfd = (int __user *)regs->d3,
49 /* Reuse the parent's stack fo !! 120 .child_tid = (int __user *)regs->d4,
50 .stack = regs->u_regs !! 121 .parent_tid = (int __user *)regs->d3,
>> 122 .exit_signal = regs->d1 & CSIGNAL,
>> 123 .stack = regs->d2,
>> 124 .tls = regs->d5,
51 }; 125 };
52 126
53 ret = kernel_clone(&args); !! 127 return kernel_clone(&args);
>> 128 }
>> 129
>> 130 /*
>> 131 * Because extra registers are saved on the stack after the sys_clone3()
>> 132 * arguments, this C wrapper extracts them from pt_regs * and then calls the
>> 133 * generic sys_clone3() implementation.
>> 134 */
>> 135 asmlinkage int m68k_clone3(struct pt_regs *regs)
>> 136 {
>> 137 return sys_clone3((struct clone_args __user *)regs->d1, regs->d2);
>> 138 }
54 139
55 /* If we get an error and potentially !! 140 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
56 * call, we're screwed because copy_th !! 141 {
57 * the parent's %o1. So detect that c !! 142 unsigned long clone_flags = args->flags;
58 * here. !! 143 unsigned long usp = args->stack;
>> 144 unsigned long tls = args->tls;
>> 145 struct fork_frame {
>> 146 struct switch_stack sw;
>> 147 struct pt_regs regs;
>> 148 } *frame;
>> 149
>> 150 frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1;
>> 151
>> 152 p->thread.ksp = (unsigned long)frame;
>> 153 p->thread.esp0 = (unsigned long)&frame->regs;
>> 154
>> 155 /*
>> 156 * Must save the current SFC/DFC value, NOT the value when
>> 157 * the parent was last descheduled - RGH 10-08-96
59 */ 158 */
60 if ((unsigned long)ret >= -ERESTART_RE !! 159 p->thread.fc = USER_DATA;
61 regs->u_regs[UREG_I1] = orig_i !! 160
>> 161 if (unlikely(args->fn)) {
>> 162 /* kernel thread */
>> 163 memset(frame, 0, sizeof(struct fork_frame));
>> 164 frame->regs.sr = PS_S;
>> 165 frame->sw.a3 = (unsigned long)args->fn;
>> 166 frame->sw.d7 = (unsigned long)args->fn_arg;
>> 167 frame->sw.retpc = (unsigned long)ret_from_kernel_thread;
>> 168 p->thread.usp = 0;
>> 169 return 0;
>> 170 }
>> 171 memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs),
>> 172 sizeof(struct fork_frame));
>> 173 frame->regs.d0 = 0;
>> 174 frame->sw.retpc = (unsigned long)ret_from_fork;
>> 175 p->thread.usp = usp ?: rdusp();
>> 176
>> 177 if (clone_flags & CLONE_SETTLS)
>> 178 task_thread_info(p)->tp_value = tls;
>> 179
>> 180 #ifdef CONFIG_FPU
>> 181 if (!FPU_IS_EMU) {
>> 182 /* Copy the current fpu state */
>> 183 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
>> 184
>> 185 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
>> 186 if (CPU_IS_COLDFIRE) {
>> 187 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
>> 188 "fmovel %/fpiar,%1\n\t"
>> 189 "fmovel %/fpcr,%2\n\t"
>> 190 "fmovel %/fpsr,%3"
>> 191 :
>> 192 : "m" (p->thread.fp[0]),
>> 193 "m" (p->thread.fpcntl[0]),
>> 194 "m" (p->thread.fpcntl[1]),
>> 195 "m" (p->thread.fpcntl[2])
>> 196 : "memory");
>> 197 } else {
>> 198 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
>> 199 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
>> 200 :
>> 201 : "m" (p->thread.fp[0]),
>> 202 "m" (p->thread.fpcntl[0])
>> 203 : "memory");
>> 204 }
>> 205 }
62 206
63 return ret; !! 207 /* Restore the state in case the fpu was busy */
>> 208 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
>> 209 }
>> 210 #endif /* CONFIG_FPU */
>> 211
>> 212 return 0;
64 } 213 }
65 214
66 asmlinkage long sparc_clone(struct pt_regs *re !! 215 /* Fill in the fpu structure for a core dump. */
>> 216 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
67 { 217 {
68 unsigned long orig_i1 = regs->u_regs[U !! 218 if (FPU_IS_EMU) {
69 unsigned int flags = lower_32_bits(reg !! 219 int i;
70 long ret; <<
71 220
72 struct kernel_clone_args args = { !! 221 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
73 .flags = (flags & ~CS !! 222 memcpy(fpu->fpregs, current->thread.fp, 96);
74 .exit_signal = (flags & CSI !! 223 /* Convert internal fpu reg representation
75 .tls = regs->u_regs !! 224 * into long double format
76 }; !! 225 */
>> 226 for (i = 0; i < 24; i += 3)
>> 227 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
>> 228 ((fpu->fpregs[i] & 0x0000ffff) << 16);
>> 229 return 1;
>> 230 }
77 231
78 #ifdef CONFIG_COMPAT !! 232 if (IS_ENABLED(CONFIG_FPU)) {
79 if (test_thread_flag(TIF_32BIT)) { !! 233 char fpustate[216];
80 args.pidfd = compat_ptr(r !! 234
81 args.child_tid = compat_ptr(r !! 235 /* First dump the fpu context to avoid protocol violation. */
82 args.parent_tid = compat_ptr(r !! 236 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
83 } else !! 237 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
84 #endif !! 238 return 0;
85 { !! 239
86 args.pidfd = (int __user !! 240 if (CPU_IS_COLDFIRE) {
87 args.child_tid = (int __user !! 241 asm volatile ("fmovel %/fpiar,%0\n\t"
88 args.parent_tid = (int __user !! 242 "fmovel %/fpcr,%1\n\t"
>> 243 "fmovel %/fpsr,%2\n\t"
>> 244 "fmovemd %/fp0-%/fp7,%3"
>> 245 :
>> 246 : "m" (fpu->fpcntl[0]),
>> 247 "m" (fpu->fpcntl[1]),
>> 248 "m" (fpu->fpcntl[2]),
>> 249 "m" (fpu->fpregs[0])
>> 250 : "memory");
>> 251 } else {
>> 252 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
>> 253 :
>> 254 : "m" (fpu->fpcntl[0])
>> 255 : "memory");
>> 256 asm volatile ("fmovemx %/fp0-%/fp7,%0"
>> 257 :
>> 258 : "m" (fpu->fpregs[0])
>> 259 : "memory");
>> 260 }
89 } 261 }
90 262
91 /* Did userspace give setup a separate !! 263 return 1;
92 * reusing the parent's? !! 264 }
93 */ !! 265 EXPORT_SYMBOL(dump_fpu);
94 if (regs->u_regs[UREG_I1]) <<
95 args.stack = regs->u_regs[UREG <<
96 else <<
97 args.stack = regs->u_regs[UREG <<
98 <<
99 ret = kernel_clone(&args); <<
100 <<
101 /* If we get an error and potentially <<
102 * call, we're screwed because copy_th <<
103 * the parent's %o1. So detect that c <<
104 * here. <<
105 */ <<
106 if ((unsigned long)ret >= -ERESTART_RE <<
107 regs->u_regs[UREG_I1] = orig_i <<
108 266
109 return ret; !! 267 unsigned long __get_wchan(struct task_struct *p)
>> 268 {
>> 269 unsigned long fp, pc;
>> 270 unsigned long stack_page;
>> 271 int count = 0;
>> 272
>> 273 stack_page = (unsigned long)task_stack_page(p);
>> 274 fp = ((struct switch_stack *)p->thread.ksp)->a6;
>> 275 do {
>> 276 if (fp < stack_page+sizeof(struct thread_info) ||
>> 277 fp >= 8184+stack_page)
>> 278 return 0;
>> 279 pc = ((unsigned long *)fp)[1];
>> 280 if (!in_sched_functions(pc))
>> 281 return pc;
>> 282 fp = *(unsigned long *) fp;
>> 283 } while (count++ < 16);
>> 284 return 0;
110 } 285 }
111 286
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