256 lines
6.9 KiB
C
256 lines
6.9 KiB
C
/*
|
|
* 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 <linux/init_task.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");
|
|
|
|
/* FPU save area for the init task */
|
|
__vector128 init_task_fpu_regs[__NUM_VXRS] __init_task_data;
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
/* Free either the floating-point or the vector register save area */
|
|
kfree(tsk->thread.fpu.regs);
|
|
}
|
|
|
|
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
|
|
{
|
|
size_t fpu_regs_size;
|
|
|
|
*dst = *src;
|
|
|
|
/*
|
|
* If the vector extension is available, it is enabled for all tasks,
|
|
* and, thus, the FPU register save area must be allocated accordingly.
|
|
*/
|
|
fpu_regs_size = MACHINE_HAS_VX ? sizeof(__vector128) * __NUM_VXRS
|
|
: sizeof(freg_t) * __NUM_FPRS;
|
|
dst->thread.fpu.regs = kzalloc(fpu_regs_size, GFP_KERNEL|__GFP_REPEAT);
|
|
if (!dst->thread.fpu.regs)
|
|
return -ENOMEM;
|
|
|
|
/*
|
|
* Save the floating-point or vector register state of the current
|
|
* task and set the CIF_FPU flag to lazy restore the FPU register
|
|
* state when returning to user space.
|
|
*/
|
|
save_fpu_regs();
|
|
dst->thread.fpu.fpc = current->thread.fpu.fpc;
|
|
memcpy(dst->thread.fpu.regs, current->thread.fpu.regs, fpu_regs_size);
|
|
|
|
return 0;
|
|
}
|
|
|
|
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;
|
|
frame->childregs.psw.mask &= ~PSW_MASK_RI;
|
|
|
|
/* 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.fpu.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_fpu_regs();
|
|
fpregs->fpc = current->thread.fpu.fpc;
|
|
fpregs->pad = 0;
|
|
if (MACHINE_HAS_VX)
|
|
convert_vx_to_fp((freg_t *)&fpregs->fprs,
|
|
current->thread.fpu.vxrs);
|
|
else
|
|
memcpy(&fpregs->fprs, current->thread.fpu.fprs,
|
|
sizeof(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)
|
|
{
|
|
return (get_random_int() & BRK_RND_MASK) << 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;
|
|
}
|