2005-04-17 05:20:36 +07:00
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/*
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* arch/s390/mm/fault.c
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*
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* S390 version
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* Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
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* Author(s): Hartmut Penner (hp@de.ibm.com)
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* Ulrich Weigand (uweigand@de.ibm.com)
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*
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* Derived from "arch/i386/mm/fault.c"
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* Copyright (C) 1995 Linus Torvalds
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*/
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/ptrace.h>
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#include <linux/mman.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/smp_lock.h>
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#include <linux/init.h>
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#include <linux/console.h>
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#include <linux/module.h>
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#include <linux/hardirq.h>
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2006-09-20 20:58:39 +07:00
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#include <linux/kprobes.h>
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2007-04-27 21:01:44 +07:00
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#include <linux/uaccess.h>
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2005-04-17 05:20:36 +07:00
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#include <asm/system.h>
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#include <asm/pgtable.h>
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2006-09-20 20:58:39 +07:00
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#include <asm/kdebug.h>
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2006-12-04 21:40:40 +07:00
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#include <asm/s390_ext.h>
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2005-04-17 05:20:36 +07:00
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2006-01-06 15:19:28 +07:00
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#ifndef CONFIG_64BIT
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2005-04-17 05:20:36 +07:00
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#define __FAIL_ADDR_MASK 0x7ffff000
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#define __FIXUP_MASK 0x7fffffff
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#define __SUBCODE_MASK 0x0200
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#define __PF_RES_FIELD 0ULL
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2006-01-06 15:19:28 +07:00
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#else /* CONFIG_64BIT */
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2005-04-17 05:20:36 +07:00
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#define __FAIL_ADDR_MASK -4096L
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#define __FIXUP_MASK ~0L
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#define __SUBCODE_MASK 0x0600
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#define __PF_RES_FIELD 0x8000000000000000ULL
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2006-01-06 15:19:28 +07:00
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#endif /* CONFIG_64BIT */
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2005-04-17 05:20:36 +07:00
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#ifdef CONFIG_SYSCTL
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extern int sysctl_userprocess_debug;
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#endif
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extern void die(const char *,struct pt_regs *,long);
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2006-09-20 20:58:39 +07:00
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#ifdef CONFIG_KPROBES
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2007-02-06 03:16:47 +07:00
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static ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
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2006-09-20 20:58:39 +07:00
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int register_page_fault_notifier(struct notifier_block *nb)
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{
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return atomic_notifier_chain_register(¬ify_page_fault_chain, nb);
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}
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int unregister_page_fault_notifier(struct notifier_block *nb)
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{
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return atomic_notifier_chain_unregister(¬ify_page_fault_chain, nb);
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}
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2007-04-27 21:01:43 +07:00
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static int __kprobes __notify_page_fault(struct pt_regs *regs, long err)
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2006-09-20 20:58:39 +07:00
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{
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2007-04-27 21:01:43 +07:00
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struct die_args args = { .str = "page fault",
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.trapnr = 14,
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.signr = SIGSEGV };
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args.regs = regs;
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args.err = err;
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return atomic_notifier_call_chain(¬ify_page_fault_chain,
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DIE_PAGE_FAULT, &args);
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}
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static inline int notify_page_fault(struct pt_regs *regs, long err)
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{
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if (unlikely(kprobe_running()))
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return __notify_page_fault(regs, err);
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return NOTIFY_DONE;
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2006-09-20 20:58:39 +07:00
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}
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#else
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2007-04-27 21:01:43 +07:00
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static inline int notify_page_fault(struct pt_regs *regs, long err)
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2006-09-20 20:58:39 +07:00
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{
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return NOTIFY_DONE;
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}
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#endif
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2005-04-17 05:20:36 +07:00
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/*
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* Unlock any spinlocks which will prevent us from getting the
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2007-02-10 16:46:18 +07:00
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* message out.
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2005-04-17 05:20:36 +07:00
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*/
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void bust_spinlocks(int yes)
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{
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if (yes) {
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oops_in_progress = 1;
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} else {
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int loglevel_save = console_loglevel;
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console_unblank();
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oops_in_progress = 0;
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/*
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* OK, the message is on the console. Now we call printk()
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* without oops_in_progress set so that printk will give klogd
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* a poke. Hold onto your hats...
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*/
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console_loglevel = 15;
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printk(" ");
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console_loglevel = loglevel_save;
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}
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}
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/*
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2007-03-06 05:35:54 +07:00
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* Returns the address space associated with the fault.
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* Returns 0 for kernel space, 1 for user space and
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* 2 for code execution in user space with noexec=on.
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2005-04-17 05:20:36 +07:00
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*/
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2007-03-06 05:35:54 +07:00
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static inline int check_space(struct task_struct *tsk)
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2005-04-17 05:20:36 +07:00
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{
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/*
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2007-03-06 05:35:54 +07:00
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* The lowest two bits of S390_lowcore.trans_exc_code
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* indicate which paging table was used.
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2005-04-17 05:20:36 +07:00
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*/
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2007-03-06 05:35:54 +07:00
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int desc = S390_lowcore.trans_exc_code & 3;
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if (desc == 3) /* Home Segment Table Descriptor */
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return switch_amode == 0;
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if (desc == 2) /* Secondary Segment Table Descriptor */
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return tsk->thread.mm_segment.ar4;
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#ifdef CONFIG_S390_SWITCH_AMODE
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if (unlikely(desc == 1)) { /* STD determined via access register */
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/* %a0 always indicates primary space. */
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if (S390_lowcore.exc_access_id != 0) {
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save_access_regs(tsk->thread.acrs);
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/*
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* An alet of 0 indicates primary space.
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* An alet of 1 indicates secondary space.
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* Any other alet values generate an
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* alen-translation exception.
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*/
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if (tsk->thread.acrs[S390_lowcore.exc_access_id])
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return tsk->thread.mm_segment.ar4;
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}
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}
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#endif
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/* Primary Segment Table Descriptor */
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return switch_amode << s390_noexec;
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2005-04-17 05:20:36 +07:00
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}
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/*
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* Send SIGSEGV to task. This is an external routine
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* to keep the stack usage of do_page_fault small.
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*/
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static void do_sigsegv(struct pt_regs *regs, unsigned long error_code,
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int si_code, unsigned long address)
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{
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struct siginfo si;
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#if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
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#if defined(CONFIG_SYSCTL)
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if (sysctl_userprocess_debug)
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#endif
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{
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printk("User process fault: interruption code 0x%lX\n",
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error_code);
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printk("failing address: %lX\n", address);
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show_regs(regs);
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}
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#endif
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si.si_signo = SIGSEGV;
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si.si_code = si_code;
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2006-07-12 21:41:55 +07:00
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si.si_addr = (void __user *) address;
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2005-04-17 05:20:36 +07:00
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force_sig_info(SIGSEGV, &si, current);
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}
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2007-04-27 21:01:43 +07:00
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static void do_no_context(struct pt_regs *regs, unsigned long error_code,
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unsigned long address)
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{
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const struct exception_table_entry *fixup;
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/* Are we prepared to handle this kernel fault? */
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fixup = search_exception_tables(regs->psw.addr & __FIXUP_MASK);
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if (fixup) {
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regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
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return;
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}
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/*
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* Oops. The kernel tried to access some bad page. We'll have to
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* terminate things with extreme prejudice.
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*/
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if (check_space(current) == 0)
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printk(KERN_ALERT "Unable to handle kernel pointer dereference"
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" at virtual kernel address %p\n", (void *)address);
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else
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printk(KERN_ALERT "Unable to handle kernel paging request"
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" at virtual user address %p\n", (void *)address);
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die("Oops", regs, error_code);
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do_exit(SIGKILL);
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}
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static void do_low_address(struct pt_regs *regs, unsigned long error_code)
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{
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/* Low-address protection hit in kernel mode means
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NULL pointer write access in kernel mode. */
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if (regs->psw.mask & PSW_MASK_PSTATE) {
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/* Low-address protection hit in user mode 'cannot happen'. */
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die ("Low-address protection", regs, error_code);
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do_exit(SIGKILL);
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}
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do_no_context(regs, error_code, 0);
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}
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/*
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* We ran out of memory, or some other thing happened to us that made
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* us unable to handle the page fault gracefully.
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*/
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static int do_out_of_memory(struct pt_regs *regs, unsigned long error_code,
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unsigned long address)
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{
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struct task_struct *tsk = current;
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struct mm_struct *mm = tsk->mm;
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up_read(&mm->mmap_sem);
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if (is_init(tsk)) {
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yield();
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down_read(&mm->mmap_sem);
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return 1;
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}
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printk("VM: killing process %s\n", tsk->comm);
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if (regs->psw.mask & PSW_MASK_PSTATE)
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do_exit(SIGKILL);
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do_no_context(regs, error_code, address);
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return 0;
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}
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static void do_sigbus(struct pt_regs *regs, unsigned long error_code,
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unsigned long address)
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{
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struct task_struct *tsk = current;
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struct mm_struct *mm = tsk->mm;
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up_read(&mm->mmap_sem);
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/*
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* Send a sigbus, regardless of whether we were in kernel
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* or user mode.
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*/
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tsk->thread.prot_addr = address;
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tsk->thread.trap_no = error_code;
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force_sig(SIGBUS, tsk);
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/* Kernel mode? Handle exceptions or die */
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if (!(regs->psw.mask & PSW_MASK_PSTATE))
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do_no_context(regs, error_code, address);
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}
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2007-02-06 03:18:17 +07:00
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#ifdef CONFIG_S390_EXEC_PROTECT
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extern long sys_sigreturn(struct pt_regs *regs);
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extern long sys_rt_sigreturn(struct pt_regs *regs);
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extern long sys32_sigreturn(struct pt_regs *regs);
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extern long sys32_rt_sigreturn(struct pt_regs *regs);
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2007-04-27 21:01:44 +07:00
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static int signal_return(struct mm_struct *mm, struct pt_regs *regs,
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unsigned long address, unsigned long error_code)
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2007-02-06 03:18:17 +07:00
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{
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2007-04-27 21:01:44 +07:00
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u16 instruction;
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int rc, compat;
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pagefault_disable();
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rc = __get_user(instruction, (u16 __user *) regs->psw.addr);
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pagefault_enable();
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if (rc)
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return -EFAULT;
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2007-02-06 03:18:17 +07:00
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up_read(&mm->mmap_sem);
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clear_tsk_thread_flag(current, TIF_SINGLE_STEP);
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#ifdef CONFIG_COMPAT
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2007-04-27 21:01:44 +07:00
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compat = test_tsk_thread_flag(current, TIF_31BIT);
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if (compat && instruction == 0x0a77)
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sys32_sigreturn(regs);
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else if (compat && instruction == 0x0aad)
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sys32_rt_sigreturn(regs);
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2007-02-06 03:18:17 +07:00
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else
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2007-04-27 21:01:44 +07:00
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#endif
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if (instruction == 0x0a77)
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2007-02-06 03:18:17 +07:00
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sys_sigreturn(regs);
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2007-04-27 21:01:44 +07:00
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else if (instruction == 0x0aad)
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sys_rt_sigreturn(regs);
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2007-02-06 03:18:17 +07:00
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else {
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current->thread.prot_addr = address;
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current->thread.trap_no = error_code;
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do_sigsegv(regs, error_code, SEGV_MAPERR, address);
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}
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return 0;
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}
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#endif /* CONFIG_S390_EXEC_PROTECT */
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2005-04-17 05:20:36 +07:00
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/*
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* This routine handles page faults. It determines the address,
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* and the problem, and then passes it off to one of the appropriate
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* routines.
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*
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* error_code:
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* 04 Protection -> Write-Protection (suprression)
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* 10 Segment translation -> Not present (nullification)
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* 11 Page translation -> Not present (nullification)
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* 3b Region third trans. -> Not present (nullification)
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*/
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2007-03-06 05:35:54 +07:00
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static inline void
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2007-04-27 21:01:43 +07:00
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do_exception(struct pt_regs *regs, unsigned long error_code, int write)
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2005-04-17 05:20:36 +07:00
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{
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2007-04-27 21:01:43 +07:00
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struct task_struct *tsk;
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struct mm_struct *mm;
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struct vm_area_struct *vma;
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unsigned long address;
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2007-03-06 05:35:54 +07:00
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int space;
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2007-04-27 21:01:43 +07:00
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int si_code;
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2005-04-17 05:20:36 +07:00
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2007-04-27 21:01:43 +07:00
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if (notify_page_fault(regs, error_code) == NOTIFY_STOP)
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2006-09-20 20:58:39 +07:00
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return;
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2007-04-27 21:01:43 +07:00
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tsk = current;
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mm = tsk->mm;
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2005-04-17 05:20:36 +07:00
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2007-04-27 21:01:43 +07:00
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/* get the failing address and the affected space */
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address = S390_lowcore.trans_exc_code & __FAIL_ADDR_MASK;
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2007-03-06 05:35:54 +07:00
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space = check_space(tsk);
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2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Verify that the fault happened in user space, that
|
|
|
|
* we are not in an interrupt and that there is a
|
|
|
|
* user context.
|
|
|
|
*/
|
2007-03-06 05:35:54 +07:00
|
|
|
if (unlikely(space == 0 || in_atomic() || !mm))
|
|
|
|
goto no_context;
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
/*
|
|
|
|
* When we get here, the fault happened in the current
|
|
|
|
* task's user address space, so we can switch on the
|
|
|
|
* interrupts again and then search the VMAs
|
|
|
|
*/
|
|
|
|
local_irq_enable();
|
|
|
|
|
2007-04-27 21:01:43 +07:00
|
|
|
down_read(&mm->mmap_sem);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
2007-03-06 05:35:54 +07:00
|
|
|
si_code = SEGV_MAPERR;
|
|
|
|
vma = find_vma(mm, address);
|
|
|
|
if (!vma)
|
|
|
|
goto bad_area;
|
2007-02-06 03:18:17 +07:00
|
|
|
|
|
|
|
#ifdef CONFIG_S390_EXEC_PROTECT
|
2007-03-06 05:35:54 +07:00
|
|
|
if (unlikely((space == 2) && !(vma->vm_flags & VM_EXEC)))
|
2007-02-06 03:18:17 +07:00
|
|
|
if (!signal_return(mm, regs, address, error_code))
|
|
|
|
/*
|
|
|
|
* signal_return() has done an up_read(&mm->mmap_sem)
|
|
|
|
* if it returns 0.
|
|
|
|
*/
|
|
|
|
return;
|
|
|
|
#endif
|
|
|
|
|
2007-04-27 21:01:43 +07:00
|
|
|
if (vma->vm_start <= address)
|
|
|
|
goto good_area;
|
|
|
|
if (!(vma->vm_flags & VM_GROWSDOWN))
|
|
|
|
goto bad_area;
|
|
|
|
if (expand_stack(vma, address))
|
|
|
|
goto bad_area;
|
2005-04-17 05:20:36 +07:00
|
|
|
/*
|
|
|
|
* Ok, we have a good vm_area for this memory access, so
|
|
|
|
* we can handle it..
|
|
|
|
*/
|
|
|
|
good_area:
|
|
|
|
si_code = SEGV_ACCERR;
|
2007-04-27 21:01:43 +07:00
|
|
|
if (!write) {
|
2005-04-17 05:20:36 +07:00
|
|
|
/* page not present, check vm flags */
|
|
|
|
if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
|
|
|
|
goto bad_area;
|
|
|
|
} else {
|
|
|
|
if (!(vma->vm_flags & VM_WRITE))
|
|
|
|
goto bad_area;
|
|
|
|
}
|
|
|
|
|
|
|
|
survive:
|
|
|
|
/*
|
|
|
|
* If for any reason at all we couldn't handle the fault,
|
|
|
|
* make sure we exit gracefully rather than endlessly redo
|
|
|
|
* the fault.
|
|
|
|
*/
|
2007-04-27 21:01:43 +07:00
|
|
|
switch (handle_mm_fault(mm, vma, address, write)) {
|
2005-04-17 05:20:36 +07:00
|
|
|
case VM_FAULT_MINOR:
|
|
|
|
tsk->min_flt++;
|
|
|
|
break;
|
|
|
|
case VM_FAULT_MAJOR:
|
|
|
|
tsk->maj_flt++;
|
|
|
|
break;
|
|
|
|
case VM_FAULT_SIGBUS:
|
2007-04-27 21:01:43 +07:00
|
|
|
do_sigbus(regs, error_code, address);
|
|
|
|
return;
|
2005-04-17 05:20:36 +07:00
|
|
|
case VM_FAULT_OOM:
|
2007-04-27 21:01:43 +07:00
|
|
|
if (do_out_of_memory(regs, error_code, address))
|
|
|
|
goto survive;
|
|
|
|
return;
|
2005-04-17 05:20:36 +07:00
|
|
|
default:
|
|
|
|
BUG();
|
|
|
|
}
|
|
|
|
|
|
|
|
up_read(&mm->mmap_sem);
|
|
|
|
/*
|
|
|
|
* The instruction that caused the program check will
|
|
|
|
* be repeated. Don't signal single step via SIGTRAP.
|
|
|
|
*/
|
2007-03-06 05:35:54 +07:00
|
|
|
clear_tsk_thread_flag(tsk, TIF_SINGLE_STEP);
|
2005-04-17 05:20:36 +07:00
|
|
|
return;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Something tried to access memory that isn't in our memory map..
|
|
|
|
* Fix it, but check if it's kernel or user first..
|
|
|
|
*/
|
|
|
|
bad_area:
|
2007-04-27 21:01:43 +07:00
|
|
|
up_read(&mm->mmap_sem);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
2007-04-27 21:01:43 +07:00
|
|
|
/* User mode accesses just cause a SIGSEGV */
|
|
|
|
if (regs->psw.mask & PSW_MASK_PSTATE) {
|
|
|
|
tsk->thread.prot_addr = address;
|
|
|
|
tsk->thread.trap_no = error_code;
|
2005-04-17 05:20:36 +07:00
|
|
|
do_sigsegv(regs, error_code, si_code, address);
|
2007-04-27 21:01:43 +07:00
|
|
|
return;
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
no_context:
|
2007-04-27 21:01:43 +07:00
|
|
|
do_no_context(regs, error_code, address);
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
2007-03-06 05:35:54 +07:00
|
|
|
void __kprobes do_protection_exception(struct pt_regs *regs,
|
|
|
|
unsigned long error_code)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
2007-04-27 21:01:43 +07:00
|
|
|
/* Protection exception is supressing, decrement psw address. */
|
2005-04-17 05:20:36 +07:00
|
|
|
regs->psw.addr -= (error_code >> 16);
|
2007-04-27 21:01:43 +07:00
|
|
|
/*
|
|
|
|
* Check for low-address protection. This needs to be treated
|
|
|
|
* as a special case because the translation exception code
|
|
|
|
* field is not guaranteed to contain valid data in this case.
|
|
|
|
*/
|
|
|
|
if (unlikely(!(S390_lowcore.trans_exc_code & 4))) {
|
|
|
|
do_low_address(regs, error_code);
|
|
|
|
return;
|
|
|
|
}
|
2005-04-17 05:20:36 +07:00
|
|
|
do_exception(regs, 4, 1);
|
|
|
|
}
|
|
|
|
|
2007-03-06 05:35:54 +07:00
|
|
|
void __kprobes do_dat_exception(struct pt_regs *regs, unsigned long error_code)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
|
|
|
do_exception(regs, error_code & 0xff, 0);
|
|
|
|
}
|
|
|
|
|
|
|
|
#ifdef CONFIG_PFAULT
|
|
|
|
/*
|
|
|
|
* 'pfault' pseudo page faults routines.
|
|
|
|
*/
|
2006-12-04 21:40:40 +07:00
|
|
|
static ext_int_info_t ext_int_pfault;
|
2005-04-17 05:20:36 +07:00
|
|
|
static int pfault_disable = 0;
|
|
|
|
|
|
|
|
static int __init nopfault(char *str)
|
|
|
|
{
|
|
|
|
pfault_disable = 1;
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
__setup("nopfault", nopfault);
|
|
|
|
|
|
|
|
typedef struct {
|
|
|
|
__u16 refdiagc;
|
|
|
|
__u16 reffcode;
|
|
|
|
__u16 refdwlen;
|
|
|
|
__u16 refversn;
|
|
|
|
__u64 refgaddr;
|
|
|
|
__u64 refselmk;
|
|
|
|
__u64 refcmpmk;
|
|
|
|
__u64 reserved;
|
|
|
|
} __attribute__ ((packed)) pfault_refbk_t;
|
|
|
|
|
|
|
|
int pfault_init(void)
|
|
|
|
{
|
|
|
|
pfault_refbk_t refbk =
|
|
|
|
{ 0x258, 0, 5, 2, __LC_CURRENT, 1ULL << 48, 1ULL << 48,
|
|
|
|
__PF_RES_FIELD };
|
|
|
|
int rc;
|
|
|
|
|
2006-12-04 21:40:40 +07:00
|
|
|
if (!MACHINE_IS_VM || pfault_disable)
|
2005-04-17 05:20:36 +07:00
|
|
|
return -1;
|
2006-09-28 21:56:43 +07:00
|
|
|
asm volatile(
|
|
|
|
" diag %1,%0,0x258\n"
|
|
|
|
"0: j 2f\n"
|
|
|
|
"1: la %0,8\n"
|
2005-04-17 05:20:36 +07:00
|
|
|
"2:\n"
|
2006-09-28 21:56:43 +07:00
|
|
|
EX_TABLE(0b,1b)
|
|
|
|
: "=d" (rc) : "a" (&refbk), "m" (refbk) : "cc");
|
2005-04-17 05:20:36 +07:00
|
|
|
__ctl_set_bit(0, 9);
|
|
|
|
return rc;
|
|
|
|
}
|
|
|
|
|
|
|
|
void pfault_fini(void)
|
|
|
|
{
|
|
|
|
pfault_refbk_t refbk =
|
|
|
|
{ 0x258, 1, 5, 2, 0ULL, 0ULL, 0ULL, 0ULL };
|
|
|
|
|
2006-12-04 21:40:40 +07:00
|
|
|
if (!MACHINE_IS_VM || pfault_disable)
|
2005-04-17 05:20:36 +07:00
|
|
|
return;
|
|
|
|
__ctl_clear_bit(0,9);
|
2006-09-28 21:56:43 +07:00
|
|
|
asm volatile(
|
|
|
|
" diag %0,0,0x258\n"
|
2005-04-17 05:20:36 +07:00
|
|
|
"0:\n"
|
2006-09-28 21:56:43 +07:00
|
|
|
EX_TABLE(0b,0b)
|
|
|
|
: : "a" (&refbk), "m" (refbk) : "cc");
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
2007-02-06 03:16:47 +07:00
|
|
|
static void pfault_interrupt(__u16 error_code)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
|
|
|
struct task_struct *tsk;
|
|
|
|
__u16 subcode;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Get the external interruption subcode & pfault
|
|
|
|
* initial/completion signal bit. VM stores this
|
|
|
|
* in the 'cpu address' field associated with the
|
|
|
|
* external interrupt.
|
|
|
|
*/
|
|
|
|
subcode = S390_lowcore.cpu_addr;
|
|
|
|
if ((subcode & 0xff00) != __SUBCODE_MASK)
|
|
|
|
return;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Get the token (= address of the task structure of the affected task).
|
|
|
|
*/
|
|
|
|
tsk = *(struct task_struct **) __LC_PFAULT_INTPARM;
|
|
|
|
|
|
|
|
if (subcode & 0x0080) {
|
|
|
|
/* signal bit is set -> a page has been swapped in by VM */
|
|
|
|
if (xchg(&tsk->thread.pfault_wait, -1) != 0) {
|
|
|
|
/* Initial interrupt was faster than the completion
|
|
|
|
* interrupt. pfault_wait is valid. Set pfault_wait
|
|
|
|
* back to zero and wake up the process. This can
|
|
|
|
* safely be done because the task is still sleeping
|
2005-09-04 05:58:02 +07:00
|
|
|
* and can't produce new pfaults. */
|
2005-04-17 05:20:36 +07:00
|
|
|
tsk->thread.pfault_wait = 0;
|
|
|
|
wake_up_process(tsk);
|
2005-09-04 05:58:02 +07:00
|
|
|
put_task_struct(tsk);
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
} else {
|
|
|
|
/* signal bit not set -> a real page is missing. */
|
2005-09-04 05:58:02 +07:00
|
|
|
get_task_struct(tsk);
|
2005-04-17 05:20:36 +07:00
|
|
|
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
|
|
|
|
if (xchg(&tsk->thread.pfault_wait, 1) != 0) {
|
|
|
|
/* Completion interrupt was faster than the initial
|
|
|
|
* interrupt (swapped in a -1 for pfault_wait). Set
|
|
|
|
* pfault_wait back to zero and exit. This can be
|
|
|
|
* done safely because tsk is running in kernel
|
|
|
|
* mode and can't produce new pfaults. */
|
|
|
|
tsk->thread.pfault_wait = 0;
|
|
|
|
set_task_state(tsk, TASK_RUNNING);
|
2005-09-04 05:58:02 +07:00
|
|
|
put_task_struct(tsk);
|
2005-04-17 05:20:36 +07:00
|
|
|
} else
|
|
|
|
set_tsk_need_resched(tsk);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2006-12-04 21:40:40 +07:00
|
|
|
void __init pfault_irq_init(void)
|
|
|
|
{
|
|
|
|
if (!MACHINE_IS_VM)
|
|
|
|
return;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Try to get pfault pseudo page faults going.
|
|
|
|
*/
|
|
|
|
if (register_early_external_interrupt(0x2603, pfault_interrupt,
|
|
|
|
&ext_int_pfault) != 0)
|
|
|
|
panic("Couldn't request external interrupt 0x2603");
|
|
|
|
|
|
|
|
if (pfault_init() == 0)
|
|
|
|
return;
|
|
|
|
|
|
|
|
/* Tough luck, no pfault. */
|
|
|
|
pfault_disable = 1;
|
|
|
|
unregister_early_external_interrupt(0x2603, pfault_interrupt,
|
|
|
|
&ext_int_pfault);
|
|
|
|
}
|
|
|
|
#endif
|