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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 | /* * This file handles the architecture dependent parts of process handling. * * Copyright IBM Corp. 1999, 2009 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>, * Hartmut Penner <hp@de.ibm.com>, * Denis Joseph Barrow, */ #include <linux/compiler.h> #include <linux/cpu.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/elfcore.h> #include <linux/smp.h> #include <linux/slab.h> #include <linux/interrupt.h> #include <linux/tick.h> #include <linux/personality.h> #include <linux/syscalls.h> #include <linux/compat.h> #include <linux/kprobes.h> #include <linux/random.h> #include <linux/module.h> #include <asm/io.h> #include <asm/processor.h> #include <asm/vtimer.h> #include <asm/exec.h> #include <asm/irq.h> #include <asm/nmi.h> #include <asm/smp.h> #include <asm/switch_to.h> #include <asm/runtime_instr.h> #include "entry.h" asmlinkage void ret_from_fork(void) asm ("ret_from_fork"); /* * Return saved PC of a blocked thread. used in kernel/sched. * resume in entry.S does not create a new stack frame, it * just stores the registers %r6-%r15 to the frame given by * schedule. We want to return the address of the caller of * schedule, so we have to walk the backchain one time to * find the frame schedule() store its return address. */ unsigned long thread_saved_pc(struct task_struct *tsk) { struct stack_frame *sf, *low, *high; if (!tsk || !task_stack_page(tsk)) return 0; low = task_stack_page(tsk); high = (struct stack_frame *) task_pt_regs(tsk); sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN); if (sf <= low || sf > high) return 0; sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN); if (sf <= low || sf > high) return 0; return sf->gprs[8]; } extern void kernel_thread_starter(void); /* * Free current thread data structures etc.. */ void exit_thread(void) { exit_thread_runtime_instr(); } void flush_thread(void) { } void release_thread(struct task_struct *dead_task) { } void arch_release_task_struct(struct task_struct *tsk) { if (tsk->thread.vxrs) kfree(tsk->thread.vxrs); } int copy_thread(unsigned long clone_flags, unsigned long new_stackp, unsigned long arg, struct task_struct *p) { struct thread_info *ti; struct fake_frame { struct stack_frame sf; struct pt_regs childregs; } *frame; frame = container_of(task_pt_regs(p), struct fake_frame, childregs); p->thread.ksp = (unsigned long) frame; /* Save access registers to new thread structure. */ save_access_regs(&p->thread.acrs[0]); /* start new process with ar4 pointing to the correct address space */ p->thread.mm_segment = get_fs(); /* Don't copy debug registers */ memset(&p->thread.per_user, 0, sizeof(p->thread.per_user)); memset(&p->thread.per_event, 0, sizeof(p->thread.per_event)); clear_tsk_thread_flag(p, TIF_SINGLE_STEP); /* Initialize per thread user and system timer values */ ti = task_thread_info(p); ti->user_timer = 0; ti->system_timer = 0; frame->sf.back_chain = 0; /* new return point is ret_from_fork */ frame->sf.gprs[8] = (unsigned long) ret_from_fork; /* fake return stack for resume(), don't go back to schedule */ frame->sf.gprs[9] = (unsigned long) frame; /* Store access registers to kernel stack of new process. */ if (unlikely(p->flags & PF_KTHREAD)) { /* kernel thread */ memset(&frame->childregs, 0, sizeof(struct pt_regs)); frame->childregs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK; frame->childregs.psw.addr = PSW_ADDR_AMODE | (unsigned long) kernel_thread_starter; frame->childregs.gprs[9] = new_stackp; /* function */ frame->childregs.gprs[10] = arg; frame->childregs.gprs[11] = (unsigned long) do_exit; frame->childregs.orig_gpr2 = -1; return 0; } frame->childregs = *current_pt_regs(); frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */ frame->childregs.flags = 0; if (new_stackp) frame->childregs.gprs[15] = new_stackp; /* Don't copy runtime instrumentation info */ p->thread.ri_cb = NULL; p->thread.ri_signum = 0; frame->childregs.psw.mask &= ~PSW_MASK_RI; /* Save the fpu registers to new thread structure. */ save_fp_ctl(&p->thread.fp_regs.fpc); save_fp_regs(p->thread.fp_regs.fprs); p->thread.fp_regs.pad = 0; p->thread.vxrs = NULL; /* Set a new TLS ? */ if (clone_flags & CLONE_SETTLS) { unsigned long tls = frame->childregs.gprs[6]; if (is_compat_task()) { p->thread.acrs[0] = (unsigned int)tls; } else { p->thread.acrs[0] = (unsigned int)(tls >> 32); p->thread.acrs[1] = (unsigned int)tls; } } return 0; } asmlinkage void execve_tail(void) { current->thread.fp_regs.fpc = 0; asm volatile("sfpc %0" : : "d" (0)); } /* * fill in the FPU structure for a core dump. */ int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs) { save_fp_ctl(&fpregs->fpc); save_fp_regs(fpregs->fprs); return 1; } EXPORT_SYMBOL(dump_fpu); unsigned long get_wchan(struct task_struct *p) { struct stack_frame *sf, *low, *high; unsigned long return_address; int count; if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p)) return 0; low = task_stack_page(p); high = (struct stack_frame *) task_pt_regs(p); sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN); if (sf <= low || sf > high) return 0; for (count = 0; count < 16; count++) { sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN); if (sf <= low || sf > high) return 0; return_address = sf->gprs[8] & PSW_ADDR_INSN; if (!in_sched_functions(return_address)) return return_address; } return 0; } unsigned long arch_align_stack(unsigned long sp) { if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) sp -= get_random_int() & ~PAGE_MASK; return sp & ~0xf; } static inline unsigned long brk_rnd(void) { /* 8MB for 32bit, 1GB for 64bit */ if (is_32bit_task()) return (get_random_int() & 0x7ffUL) << PAGE_SHIFT; else return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT; } unsigned long arch_randomize_brk(struct mm_struct *mm) { unsigned long ret; ret = PAGE_ALIGN(mm->brk + brk_rnd()); return (ret > mm->brk) ? ret : mm->brk; } |