process_32.c 5.1 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * arch/sh/kernel/process.c
  4. *
  5. * This file handles the architecture-dependent parts of process handling..
  6. *
  7. * Copyright (C) 1995 Linus Torvalds
  8. *
  9. * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
  10. * Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
  11. * Copyright (C) 2002 - 2008 Paul Mundt
  12. */
  13. #include <linux/module.h>
  14. #include <linux/mm.h>
  15. #include <linux/sched/debug.h>
  16. #include <linux/sched/task.h>
  17. #include <linux/sched/task_stack.h>
  18. #include <linux/slab.h>
  19. #include <linux/elfcore.h>
  20. #include <linux/fs.h>
  21. #include <linux/ftrace.h>
  22. #include <linux/hw_breakpoint.h>
  23. #include <linux/prefetch.h>
  24. #include <linux/stackprotector.h>
  25. #include <linux/uaccess.h>
  26. #include <asm/mmu_context.h>
  27. #include <asm/fpu.h>
  28. #include <asm/syscalls.h>
  29. #include <asm/switch_to.h>
  30. void show_regs(struct pt_regs * regs)
  31. {
  32. pr_info("\n");
  33. show_regs_print_info(KERN_DEFAULT);
  34. pr_info("PC is at %pS\n", (void *)instruction_pointer(regs));
  35. pr_info("PR is at %pS\n", (void *)regs->pr);
  36. pr_info("PC : %08lx SP : %08lx SR : %08lx ", regs->pc,
  37. regs->regs[15], regs->sr);
  38. #ifdef CONFIG_MMU
  39. pr_cont("TEA : %08x\n", __raw_readl(MMU_TEA));
  40. #else
  41. pr_cont("\n");
  42. #endif
  43. pr_info("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
  44. regs->regs[0], regs->regs[1], regs->regs[2], regs->regs[3]);
  45. pr_info("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
  46. regs->regs[4], regs->regs[5], regs->regs[6], regs->regs[7]);
  47. pr_info("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
  48. regs->regs[8], regs->regs[9], regs->regs[10], regs->regs[11]);
  49. pr_info("R12 : %08lx R13 : %08lx R14 : %08lx\n",
  50. regs->regs[12], regs->regs[13], regs->regs[14]);
  51. pr_info("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
  52. regs->mach, regs->macl, regs->gbr, regs->pr);
  53. show_trace(NULL, (unsigned long *)regs->regs[15], regs, KERN_DEFAULT);
  54. show_code(regs);
  55. }
  56. void start_thread(struct pt_regs *regs, unsigned long new_pc,
  57. unsigned long new_sp)
  58. {
  59. regs->pr = 0;
  60. regs->sr = SR_FD;
  61. regs->pc = new_pc;
  62. regs->regs[15] = new_sp;
  63. free_thread_xstate(current);
  64. }
  65. EXPORT_SYMBOL(start_thread);
  66. void flush_thread(void)
  67. {
  68. struct task_struct *tsk = current;
  69. flush_ptrace_hw_breakpoint(tsk);
  70. #if defined(CONFIG_SH_FPU)
  71. /* Forget lazy FPU state */
  72. clear_fpu(tsk, task_pt_regs(tsk));
  73. clear_used_math();
  74. #endif
  75. }
  76. void release_thread(struct task_struct *dead_task)
  77. {
  78. /* do nothing */
  79. }
  80. asmlinkage void ret_from_fork(void);
  81. asmlinkage void ret_from_kernel_thread(void);
  82. int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
  83. struct task_struct *p, unsigned long tls)
  84. {
  85. struct thread_info *ti = task_thread_info(p);
  86. struct pt_regs *childregs;
  87. #if defined(CONFIG_SH_DSP)
  88. struct task_struct *tsk = current;
  89. if (is_dsp_enabled(tsk)) {
  90. /* We can use the __save_dsp or just copy the struct:
  91. * __save_dsp(p);
  92. * p->thread.dsp_status.status |= SR_DSP
  93. */
  94. p->thread.dsp_status = tsk->thread.dsp_status;
  95. }
  96. #endif
  97. memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
  98. childregs = task_pt_regs(p);
  99. p->thread.sp = (unsigned long) childregs;
  100. if (unlikely(p->flags & PF_KTHREAD)) {
  101. memset(childregs, 0, sizeof(struct pt_regs));
  102. p->thread.pc = (unsigned long) ret_from_kernel_thread;
  103. childregs->regs[4] = arg;
  104. childregs->regs[5] = usp;
  105. childregs->sr = SR_MD;
  106. #if defined(CONFIG_SH_FPU)
  107. childregs->sr |= SR_FD;
  108. #endif
  109. ti->addr_limit = KERNEL_DS;
  110. ti->status &= ~TS_USEDFPU;
  111. p->thread.fpu_counter = 0;
  112. return 0;
  113. }
  114. *childregs = *current_pt_regs();
  115. if (usp)
  116. childregs->regs[15] = usp;
  117. ti->addr_limit = USER_DS;
  118. if (clone_flags & CLONE_SETTLS)
  119. childregs->gbr = tls;
  120. childregs->regs[0] = 0; /* Set return value for child */
  121. p->thread.pc = (unsigned long) ret_from_fork;
  122. return 0;
  123. }
  124. /*
  125. * switch_to(x,y) should switch tasks from x to y.
  126. *
  127. */
  128. __notrace_funcgraph struct task_struct *
  129. __switch_to(struct task_struct *prev, struct task_struct *next)
  130. {
  131. struct thread_struct *next_t = &next->thread;
  132. #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
  133. __stack_chk_guard = next->stack_canary;
  134. #endif
  135. unlazy_fpu(prev, task_pt_regs(prev));
  136. /* we're going to use this soon, after a few expensive things */
  137. if (next->thread.fpu_counter > 5)
  138. prefetch(next_t->xstate);
  139. #ifdef CONFIG_MMU
  140. /*
  141. * Restore the kernel mode register
  142. * k7 (r7_bank1)
  143. */
  144. asm volatile("ldc %0, r7_bank"
  145. : /* no output */
  146. : "r" (task_thread_info(next)));
  147. #endif
  148. /*
  149. * If the task has used fpu the last 5 timeslices, just do a full
  150. * restore of the math state immediately to avoid the trap; the
  151. * chances of needing FPU soon are obviously high now
  152. */
  153. if (next->thread.fpu_counter > 5)
  154. __fpu_state_restore();
  155. return prev;
  156. }
  157. unsigned long get_wchan(struct task_struct *p)
  158. {
  159. unsigned long pc;
  160. if (!p || p == current || p->state == TASK_RUNNING)
  161. return 0;
  162. /*
  163. * The same comment as on the Alpha applies here, too ...
  164. */
  165. pc = thread_saved_pc(p);
  166. #ifdef CONFIG_FRAME_POINTER
  167. if (in_sched_functions(pc)) {
  168. unsigned long schedule_frame = (unsigned long)p->thread.sp;
  169. return ((unsigned long *)schedule_frame)[21];
  170. }
  171. #endif
  172. return pc;
  173. }