Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
This commit is contained in:
Linus Torvalds
251
arch/um/kernel/trap_kern.c
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251
arch/um/kernel/trap_kern.c
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/*
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* Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
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* Licensed under the GPL
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*/
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#include "linux/kernel.h"
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#include "asm/errno.h"
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#include "linux/sched.h"
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#include "linux/mm.h"
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#include "linux/spinlock.h"
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#include "linux/config.h"
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#include "linux/init.h"
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#include "linux/ptrace.h"
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#include "asm/semaphore.h"
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#include "asm/pgtable.h"
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#include "asm/pgalloc.h"
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#include "asm/tlbflush.h"
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#include "asm/a.out.h"
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#include "asm/current.h"
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#include "asm/irq.h"
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#include "user_util.h"
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#include "kern_util.h"
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#include "kern.h"
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#include "chan_kern.h"
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#include "mconsole_kern.h"
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#include "2_5compat.h"
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#include "mem.h"
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#include "mem_kern.h"
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int handle_page_fault(unsigned long address, unsigned long ip,
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int is_write, int is_user, int *code_out)
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{
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte;
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unsigned long page;
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int err = -EFAULT;
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*code_out = SEGV_MAPERR;
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down_read(&mm->mmap_sem);
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vma = find_vma(mm, address);
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if(!vma)
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goto out;
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else if(vma->vm_start <= address)
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goto good_area;
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else if(!(vma->vm_flags & VM_GROWSDOWN))
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goto out;
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else if(!ARCH_IS_STACKGROW(address))
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goto out;
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else if(expand_stack(vma, address))
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goto out;
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good_area:
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*code_out = SEGV_ACCERR;
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if(is_write && !(vma->vm_flags & VM_WRITE))
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goto out;
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page = address & PAGE_MASK;
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pgd = pgd_offset(mm, page);
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pud = pud_offset(pgd, page);
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pmd = pmd_offset(pud, page);
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do {
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survive:
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switch (handle_mm_fault(mm, vma, address, is_write)){
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case VM_FAULT_MINOR:
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current->min_flt++;
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break;
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case VM_FAULT_MAJOR:
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current->maj_flt++;
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break;
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case VM_FAULT_SIGBUS:
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err = -EACCES;
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goto out;
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case VM_FAULT_OOM:
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err = -ENOMEM;
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goto out_of_memory;
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default:
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BUG();
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}
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pgd = pgd_offset(mm, page);
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pud = pud_offset(pgd, page);
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pmd = pmd_offset(pud, page);
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pte = pte_offset_kernel(pmd, page);
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} while(!pte_present(*pte));
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err = 0;
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*pte = pte_mkyoung(*pte);
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if(pte_write(*pte)) *pte = pte_mkdirty(*pte);
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flush_tlb_page(vma, page);
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out:
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up_read(&mm->mmap_sem);
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return(err);
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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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out_of_memory:
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if (current->pid == 1) {
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up_read(&mm->mmap_sem);
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yield();
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down_read(&mm->mmap_sem);
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goto survive;
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}
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goto out;
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}
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LIST_HEAD(physmem_remappers);
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void register_remapper(struct remapper *info)
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{
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list_add(&info->list, &physmem_remappers);
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}
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static int check_remapped_addr(unsigned long address, int is_write)
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{
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struct remapper *remapper;
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struct list_head *ele;
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__u64 offset;
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int fd;
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fd = phys_mapping(__pa(address), &offset);
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if(fd == -1)
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return(0);
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list_for_each(ele, &physmem_remappers){
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remapper = list_entry(ele, struct remapper, list);
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if((*remapper->proc)(fd, address, is_write, offset))
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return(1);
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}
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return(0);
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}
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unsigned long segv(unsigned long address, unsigned long ip, int is_write,
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int is_user, void *sc)
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{
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struct siginfo si;
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void *catcher;
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int err;
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if(!is_user && (address >= start_vm) && (address < end_vm)){
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flush_tlb_kernel_vm();
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return(0);
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}
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else if(check_remapped_addr(address & PAGE_MASK, is_write))
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return(0);
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else if(current->mm == NULL)
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panic("Segfault with no mm");
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err = handle_page_fault(address, ip, is_write, is_user, &si.si_code);
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catcher = current->thread.fault_catcher;
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if(!err)
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return(0);
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else if(catcher != NULL){
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current->thread.fault_addr = (void *) address;
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do_longjmp(catcher, 1);
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}
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else if(current->thread.fault_addr != NULL)
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panic("fault_addr set but no fault catcher");
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else if(arch_fixup(ip, sc))
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return(0);
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if(!is_user)
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panic("Kernel mode fault at addr 0x%lx, ip 0x%lx",
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address, ip);
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if(err == -EACCES){
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si.si_signo = SIGBUS;
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si.si_errno = 0;
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si.si_code = BUS_ADRERR;
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si.si_addr = (void *)address;
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force_sig_info(SIGBUS, &si, current);
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}
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else if(err == -ENOMEM){
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printk("VM: killing process %s\n", current->comm);
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do_exit(SIGKILL);
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}
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else {
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si.si_signo = SIGSEGV;
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si.si_addr = (void *) address;
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current->thread.cr2 = address;
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current->thread.err = is_write;
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force_sig_info(SIGSEGV, &si, current);
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}
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return(0);
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}
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void bad_segv(unsigned long address, unsigned long ip, int is_write)
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{
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struct siginfo si;
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si.si_signo = SIGSEGV;
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si.si_code = SEGV_ACCERR;
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si.si_addr = (void *) address;
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current->thread.cr2 = address;
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current->thread.err = is_write;
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force_sig_info(SIGSEGV, &si, current);
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}
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void relay_signal(int sig, union uml_pt_regs *regs)
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{
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if(arch_handle_signal(sig, regs)) return;
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if(!UPT_IS_USER(regs))
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panic("Kernel mode signal %d", sig);
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force_sig(sig, current);
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}
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void bus_handler(int sig, union uml_pt_regs *regs)
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{
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if(current->thread.fault_catcher != NULL)
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do_longjmp(current->thread.fault_catcher, 1);
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else relay_signal(sig, regs);
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}
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void winch(int sig, union uml_pt_regs *regs)
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{
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do_IRQ(WINCH_IRQ, regs);
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}
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void trap_init(void)
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{
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}
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DEFINE_SPINLOCK(trap_lock);
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static int trap_index = 0;
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int next_trap_index(int limit)
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{
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int ret;
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spin_lock(&trap_lock);
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ret = trap_index;
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if(++trap_index == limit)
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trap_index = 0;
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spin_unlock(&trap_lock);
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return(ret);
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}
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/*
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* Overrides for Emacs so that we follow Linus's tabbing style.
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* Emacs will notice this stuff at the end of the file and automatically
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* adjust the settings for this buffer only. This must remain at the end
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* of the file.
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* ---------------------------------------------------------------------------
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* Local variables:
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* c-file-style: "linux"
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* End:
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*/
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