2 * This file handles the architecture dependent parts of process handling.
4 * Copyright IBM Corp. 1999, 2009
5 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
6 * Hartmut Penner <hp@de.ibm.com>,
10 #include <linux/elf-randomize.h>
11 #include <linux/compiler.h>
12 #include <linux/cpu.h>
13 #include <linux/sched.h>
14 #include <linux/sched/debug.h>
15 #include <linux/sched/task.h>
16 #include <linux/sched/task_stack.h>
17 #include <linux/kernel.h>
19 #include <linux/elfcore.h>
20 #include <linux/smp.h>
21 #include <linux/slab.h>
22 #include <linux/interrupt.h>
23 #include <linux/tick.h>
24 #include <linux/personality.h>
25 #include <linux/syscalls.h>
26 #include <linux/compat.h>
27 #include <linux/kprobes.h>
28 #include <linux/random.h>
29 #include <linux/export.h>
30 #include <linux/init_task.h>
32 #include <asm/processor.h>
33 #include <asm/vtimer.h>
38 #include <asm/switch_to.h>
39 #include <asm/runtime_instr.h>
42 asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
44 extern void kernel_thread_starter(void);
46 void flush_thread(void)
50 void arch_release_task_struct(struct task_struct *tsk)
52 runtime_instr_release(tsk);
53 guarded_storage_release(tsk);
56 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
59 * Save the floating-point or vector register state of the current
60 * task and set the CIF_FPU flag to lazy restore the FPU register
61 * state when returning to user space.
65 memcpy(dst, src, arch_task_struct_size);
66 dst->thread.fpu.regs = dst->thread.fpu.fprs;
70 int copy_thread_tls(unsigned long clone_flags, unsigned long new_stackp,
71 unsigned long arg, struct task_struct *p, unsigned long tls)
75 struct stack_frame sf;
76 struct pt_regs childregs;
79 frame = container_of(task_pt_regs(p), struct fake_frame, childregs);
80 p->thread.ksp = (unsigned long) frame;
81 /* Save access registers to new thread structure. */
82 save_access_regs(&p->thread.acrs[0]);
83 /* start new process with ar4 pointing to the correct address space */
84 p->thread.mm_segment = get_fs();
85 /* Don't copy debug registers */
86 memset(&p->thread.per_user, 0, sizeof(p->thread.per_user));
87 memset(&p->thread.per_event, 0, sizeof(p->thread.per_event));
88 clear_tsk_thread_flag(p, TIF_SINGLE_STEP);
89 p->thread.per_flags = 0;
90 /* Initialize per thread user and system timer values */
91 p->thread.user_timer = 0;
92 p->thread.guest_timer = 0;
93 p->thread.system_timer = 0;
94 p->thread.hardirq_timer = 0;
95 p->thread.softirq_timer = 0;
97 frame->sf.back_chain = 0;
98 /* new return point is ret_from_fork */
99 frame->sf.gprs[8] = (unsigned long) ret_from_fork;
100 /* fake return stack for resume(), don't go back to schedule */
101 frame->sf.gprs[9] = (unsigned long) frame;
103 /* Store access registers to kernel stack of new process. */
104 if (unlikely(p->flags & PF_KTHREAD)) {
106 memset(&frame->childregs, 0, sizeof(struct pt_regs));
107 frame->childregs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_DAT |
108 PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
109 frame->childregs.psw.addr =
110 (unsigned long) kernel_thread_starter;
111 frame->childregs.gprs[9] = new_stackp; /* function */
112 frame->childregs.gprs[10] = arg;
113 frame->childregs.gprs[11] = (unsigned long) do_exit;
114 frame->childregs.orig_gpr2 = -1;
118 frame->childregs = *current_pt_regs();
119 frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */
120 frame->childregs.flags = 0;
122 frame->childregs.gprs[15] = new_stackp;
124 /* Don't copy runtime instrumentation info */
125 p->thread.ri_cb = NULL;
126 frame->childregs.psw.mask &= ~PSW_MASK_RI;
127 /* Don't copy guarded storage control block */
128 p->thread.gs_cb = NULL;
129 p->thread.gs_bc_cb = NULL;
131 /* Set a new TLS ? */
132 if (clone_flags & CLONE_SETTLS) {
133 if (is_compat_task()) {
134 p->thread.acrs[0] = (unsigned int)tls;
136 p->thread.acrs[0] = (unsigned int)(tls >> 32);
137 p->thread.acrs[1] = (unsigned int)tls;
143 asmlinkage void execve_tail(void)
145 current->thread.fpu.fpc = 0;
146 asm volatile("sfpc %0" : : "d" (0));
150 * fill in the FPU structure for a core dump.
152 int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
155 fpregs->fpc = current->thread.fpu.fpc;
158 convert_vx_to_fp((freg_t *)&fpregs->fprs,
159 current->thread.fpu.vxrs);
161 memcpy(&fpregs->fprs, current->thread.fpu.fprs,
162 sizeof(fpregs->fprs));
165 EXPORT_SYMBOL(dump_fpu);
167 unsigned long get_wchan(struct task_struct *p)
169 struct stack_frame *sf, *low, *high;
170 unsigned long return_address;
173 if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p))
175 low = task_stack_page(p);
176 high = (struct stack_frame *) task_pt_regs(p);
177 sf = (struct stack_frame *) p->thread.ksp;
178 if (sf <= low || sf > high)
180 for (count = 0; count < 16; count++) {
181 sf = (struct stack_frame *) sf->back_chain;
182 if (sf <= low || sf > high)
184 return_address = sf->gprs[8];
185 if (!in_sched_functions(return_address))
186 return return_address;
191 unsigned long arch_align_stack(unsigned long sp)
193 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
194 sp -= get_random_int() & ~PAGE_MASK;
198 static inline unsigned long brk_rnd(void)
200 return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
203 unsigned long arch_randomize_brk(struct mm_struct *mm)
207 ret = PAGE_ALIGN(mm->brk + brk_rnd());
208 return (ret > mm->brk) ? ret : mm->brk;
211 void set_fs_fixup(void)
213 struct pt_regs *regs = current_pt_regs();
219 WARN(1, "Unbalanced set_fs - int code: 0x%x\n", regs->int_code);
220 show_registers(regs);