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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | /* |
cbdc2292 | 3 | * This file handles the architecture dependent parts of process handling. |
1da177e4 | 4 | * |
a53c8fab | 5 | * Copyright IBM Corp. 1999, 2009 |
cbdc2292 HC |
6 | * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>, |
7 | * Hartmut Penner <hp@de.ibm.com>, | |
8 | * Denis Joseph Barrow, | |
1da177e4 LT |
9 | */ |
10 | ||
ca21872e | 11 | #include <linux/elf-randomize.h> |
1da177e4 LT |
12 | #include <linux/compiler.h> |
13 | #include <linux/cpu.h> | |
1da177e4 | 14 | #include <linux/sched.h> |
b17b0153 | 15 | #include <linux/sched/debug.h> |
29930025 | 16 | #include <linux/sched/task.h> |
68db0cf1 | 17 | #include <linux/sched/task_stack.h> |
1da177e4 LT |
18 | #include <linux/kernel.h> |
19 | #include <linux/mm.h> | |
638ad34a | 20 | #include <linux/elfcore.h> |
1da177e4 | 21 | #include <linux/smp.h> |
5a0e3ad6 | 22 | #include <linux/slab.h> |
1da177e4 | 23 | #include <linux/interrupt.h> |
5a62b192 | 24 | #include <linux/tick.h> |
9887a1fc | 25 | #include <linux/personality.h> |
26689452 | 26 | #include <linux/syscalls.h> |
3e86a8c6 | 27 | #include <linux/compat.h> |
860dba45 | 28 | #include <linux/kprobes.h> |
9887a1fc | 29 | #include <linux/random.h> |
3994a52b | 30 | #include <linux/export.h> |
0ac27779 | 31 | #include <linux/init_task.h> |
1da177e4 LT |
32 | #include <asm/io.h> |
33 | #include <asm/processor.h> | |
27f6b416 | 34 | #include <asm/vtimer.h> |
f6e38691 | 35 | #include <asm/exec.h> |
1da177e4 | 36 | #include <asm/irq.h> |
f5daba1d | 37 | #include <asm/nmi.h> |
da7f51c1 | 38 | #include <asm/smp.h> |
a0616cde | 39 | #include <asm/switch_to.h> |
e4b8b3f3 | 40 | #include <asm/runtime_instr.h> |
a806170e | 41 | #include "entry.h" |
1da177e4 | 42 | |
94c12cc7 | 43 | asmlinkage void ret_from_fork(void) asm ("ret_from_fork"); |
1da177e4 | 44 | |
7a5388de | 45 | extern void kernel_thread_starter(void); |
1da177e4 | 46 | |
1da177e4 LT |
47 | /* |
48 | * Free current thread data structures etc.. | |
49 | */ | |
e6464694 | 50 | void exit_thread(struct task_struct *tsk) |
1da177e4 | 51 | { |
916cda1a | 52 | if (tsk == current) { |
e6464694 | 53 | exit_thread_runtime_instr(); |
916cda1a MS |
54 | exit_thread_gs(); |
55 | } | |
1da177e4 LT |
56 | } |
57 | ||
58 | void flush_thread(void) | |
59 | { | |
1da177e4 LT |
60 | } |
61 | ||
62 | void release_thread(struct task_struct *dead_task) | |
63 | { | |
64 | } | |
65 | ||
6a039eab HB |
66 | void arch_release_task_struct(struct task_struct *tsk) |
67 | { | |
155e839a HB |
68 | } |
69 | ||
70 | int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) | |
71 | { | |
9977e886 HB |
72 | /* |
73 | * Save the floating-point or vector register state of the current | |
b5510d9b HB |
74 | * task and set the CIF_FPU flag to lazy restore the FPU register |
75 | * state when returning to user space. | |
9977e886 | 76 | */ |
d0164ee2 | 77 | save_fpu_regs(); |
b5510d9b | 78 | |
3f6813b9 MS |
79 | memcpy(dst, src, arch_task_struct_size); |
80 | dst->thread.fpu.regs = dst->thread.fpu.fprs; | |
155e839a | 81 | return 0; |
6a039eab | 82 | } |
6a039eab | 83 | |
f50c0e63 HC |
84 | int copy_thread_tls(unsigned long clone_flags, unsigned long new_stackp, |
85 | unsigned long arg, struct task_struct *p, unsigned long tls) | |
1da177e4 | 86 | { |
cbdc2292 HC |
87 | struct fake_frame |
88 | { | |
89 | struct stack_frame sf; | |
90 | struct pt_regs childregs; | |
91 | } *frame; | |
92 | ||
93 | frame = container_of(task_pt_regs(p), struct fake_frame, childregs); | |
94 | p->thread.ksp = (unsigned long) frame; | |
f9a7e025 AV |
95 | /* Save access registers to new thread structure. */ |
96 | save_access_regs(&p->thread.acrs[0]); | |
97 | /* start new process with ar4 pointing to the correct address space */ | |
98 | p->thread.mm_segment = get_fs(); | |
99 | /* Don't copy debug registers */ | |
100 | memset(&p->thread.per_user, 0, sizeof(p->thread.per_user)); | |
101 | memset(&p->thread.per_event, 0, sizeof(p->thread.per_event)); | |
102 | clear_tsk_thread_flag(p, TIF_SINGLE_STEP); | |
f9a7e025 | 103 | /* Initialize per thread user and system timer values */ |
90c53e65 | 104 | p->thread.user_timer = 0; |
3c915bdc | 105 | p->thread.guest_timer = 0; |
90c53e65 | 106 | p->thread.system_timer = 0; |
3c915bdc MS |
107 | p->thread.hardirq_timer = 0; |
108 | p->thread.softirq_timer = 0; | |
1da177e4 | 109 | |
f9a7e025 | 110 | frame->sf.back_chain = 0; |
cbdc2292 HC |
111 | /* new return point is ret_from_fork */ |
112 | frame->sf.gprs[8] = (unsigned long) ret_from_fork; | |
cbdc2292 HC |
113 | /* fake return stack for resume(), don't go back to schedule */ |
114 | frame->sf.gprs[9] = (unsigned long) frame; | |
1da177e4 | 115 | |
f9a7e025 | 116 | /* Store access registers to kernel stack of new process. */ |
87f1ca8f | 117 | if (unlikely(p->flags & PF_KTHREAD)) { |
f9a7e025 AV |
118 | /* kernel thread */ |
119 | memset(&frame->childregs, 0, sizeof(struct pt_regs)); | |
e258d719 | 120 | frame->childregs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_DAT | |
f9a7e025 | 121 | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK; |
fecc868a | 122 | frame->childregs.psw.addr = |
f9a7e025 AV |
123 | (unsigned long) kernel_thread_starter; |
124 | frame->childregs.gprs[9] = new_stackp; /* function */ | |
125 | frame->childregs.gprs[10] = arg; | |
126 | frame->childregs.gprs[11] = (unsigned long) do_exit; | |
127 | frame->childregs.orig_gpr2 = -1; | |
128 | ||
129 | return 0; | |
130 | } | |
87f1ca8f | 131 | frame->childregs = *current_pt_regs(); |
f9a7e025 | 132 | frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */ |
d3a73acb | 133 | frame->childregs.flags = 0; |
87f1ca8f AV |
134 | if (new_stackp) |
135 | frame->childregs.gprs[15] = new_stackp; | |
1da177e4 | 136 | |
e4b8b3f3 JG |
137 | /* Don't copy runtime instrumentation info */ |
138 | p->thread.ri_cb = NULL; | |
e4b8b3f3 | 139 | frame->childregs.psw.mask &= ~PSW_MASK_RI; |
916cda1a MS |
140 | /* Don't copy guarded storage control block */ |
141 | p->thread.gs_cb = NULL; | |
142 | p->thread.gs_bc_cb = NULL; | |
e4b8b3f3 | 143 | |
1da177e4 LT |
144 | /* Set a new TLS ? */ |
145 | if (clone_flags & CLONE_SETTLS) { | |
7757591a | 146 | if (is_compat_task()) { |
87f1ca8f | 147 | p->thread.acrs[0] = (unsigned int)tls; |
1da177e4 | 148 | } else { |
87f1ca8f AV |
149 | p->thread.acrs[0] = (unsigned int)(tls >> 32); |
150 | p->thread.acrs[1] = (unsigned int)tls; | |
1da177e4 LT |
151 | } |
152 | } | |
cbdc2292 | 153 | return 0; |
1da177e4 LT |
154 | } |
155 | ||
03ff9a23 MS |
156 | asmlinkage void execve_tail(void) |
157 | { | |
904818e2 | 158 | current->thread.fpu.fpc = 0; |
e47994dd | 159 | asm volatile("sfpc %0" : : "d" (0)); |
1da177e4 LT |
160 | } |
161 | ||
1da177e4 LT |
162 | /* |
163 | * fill in the FPU structure for a core dump. | |
164 | */ | |
165 | int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs) | |
166 | { | |
d0164ee2 | 167 | save_fpu_regs(); |
9977e886 HB |
168 | fpregs->fpc = current->thread.fpu.fpc; |
169 | fpregs->pad = 0; | |
b5510d9b | 170 | if (MACHINE_HAS_VX) |
9977e886 HB |
171 | convert_vx_to_fp((freg_t *)&fpregs->fprs, |
172 | current->thread.fpu.vxrs); | |
173 | else | |
174 | memcpy(&fpregs->fprs, current->thread.fpu.fprs, | |
175 | sizeof(fpregs->fprs)); | |
1da177e4 LT |
176 | return 1; |
177 | } | |
1485c5c8 | 178 | EXPORT_SYMBOL(dump_fpu); |
1da177e4 | 179 | |
1da177e4 LT |
180 | unsigned long get_wchan(struct task_struct *p) |
181 | { | |
182 | struct stack_frame *sf, *low, *high; | |
183 | unsigned long return_address; | |
184 | int count; | |
185 | ||
30af7120 | 186 | if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p)) |
1da177e4 | 187 | return 0; |
30af7120 AV |
188 | low = task_stack_page(p); |
189 | high = (struct stack_frame *) task_pt_regs(p); | |
9cb1ccec | 190 | sf = (struct stack_frame *) p->thread.ksp; |
1da177e4 LT |
191 | if (sf <= low || sf > high) |
192 | return 0; | |
193 | for (count = 0; count < 16; count++) { | |
9cb1ccec | 194 | sf = (struct stack_frame *) sf->back_chain; |
1da177e4 LT |
195 | if (sf <= low || sf > high) |
196 | return 0; | |
9cb1ccec | 197 | return_address = sf->gprs[8]; |
1da177e4 LT |
198 | if (!in_sched_functions(return_address)) |
199 | return return_address; | |
200 | } | |
201 | return 0; | |
202 | } | |
9887a1fc HC |
203 | |
204 | unsigned long arch_align_stack(unsigned long sp) | |
205 | { | |
206 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) | |
207 | sp -= get_random_int() & ~PAGE_MASK; | |
208 | return sp & ~0xf; | |
209 | } | |
33519182 HC |
210 | |
211 | static inline unsigned long brk_rnd(void) | |
212 | { | |
c7e8b2c2 | 213 | return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT; |
33519182 HC |
214 | } |
215 | ||
216 | unsigned long arch_randomize_brk(struct mm_struct *mm) | |
217 | { | |
9efe4f29 | 218 | unsigned long ret; |
33519182 | 219 | |
9efe4f29 MS |
220 | ret = PAGE_ALIGN(mm->brk + brk_rnd()); |
221 | return (ret > mm->brk) ? ret : mm->brk; | |
33519182 | 222 | } |
b5a882fc HC |
223 | |
224 | void set_fs_fixup(void) | |
225 | { | |
226 | struct pt_regs *regs = current_pt_regs(); | |
227 | static bool warned; | |
228 | ||
229 | set_fs(USER_DS); | |
230 | if (warned) | |
231 | return; | |
232 | WARN(1, "Unbalanced set_fs - int code: 0x%x\n", regs->int_code); | |
233 | show_registers(regs); | |
234 | warned = true; | |
235 | } |