X-Git-Url: http://git.rot13.org/?p=bcm963xx.git;a=blobdiff_plain;f=kernel%2Flinux%2Farch%2Fmips%2Fmm%2Ffault.c;h=40f825f17188c913a43a61d62ca852fa06711f0b;hp=820c3af0868a5846a15ee890e7d09b5079e47195;hb=57a096f051259ceaefd5977f30d269884e1dd248;hpb=a69849c98808437716b821267cd97529c56f45b0 diff --git a/kernel/linux/arch/mips/mm/fault.c b/kernel/linux/arch/mips/mm/fault.c index 820c3af0..40f825f1 100755 --- a/kernel/linux/arch/mips/mm/fault.c +++ b/kernel/linux/arch/mips/mm/fault.c @@ -1,237 +1,237 @@ -/* - * This file is subject to the terms and conditions of the GNU General Public - * License. See the file "COPYING" in the main directory of this archive - * for more details. - * - * Copyright (C) 1995 - 2000 by Ralf Baechle - */ -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include /* For unblank_screen() */ -#include - -#include -#include -#include -#include -#include -#include - -/* - * This routine handles page faults. It determines the address, - * and the problem, and then passes it off to one of the appropriate - * routines. - */ -asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write, - unsigned long address) -{ - struct vm_area_struct * vma = NULL; - struct task_struct *tsk = current; - struct mm_struct *mm = tsk->mm; - const int field = sizeof(unsigned long) * 2; - siginfo_t info; - -#if 0 - printk("Cpu%d[%s:%d:%0*lx:%ld:%0*lx]\n", smp_processor_id(), - current->comm, current->pid, field, address, write, - field, regs->cp0_epc); -#endif - - info.si_code = SEGV_MAPERR; - - /* - * We fault-in kernel-space virtual memory on-demand. The - * 'reference' page table is init_mm.pgd. - * - * NOTE! We MUST NOT take any locks for this case. We may - * be in an interrupt or a critical region, and should - * only copy the information from the master page table, - * nothing more. - */ - if (unlikely(address >= VMALLOC_START)) - goto vmalloc_fault; - - /* - * If we're in an interrupt or have no user - * context, we must not take the fault.. - */ - if (in_atomic() || !mm) - goto bad_area_nosemaphore; - - down_read(&mm->mmap_sem); - vma = find_vma(mm, address); - if (!vma) - goto bad_area; - 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; -/* - * Ok, we have a good vm_area for this memory access, so - * we can handle it.. - */ -good_area: - info.si_code = SEGV_ACCERR; - - if (write) { - if (!(vma->vm_flags & VM_WRITE)) - goto bad_area; - } else { - if (!(vma->vm_flags & (VM_READ | VM_EXEC))) - 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. - */ - switch (handle_mm_fault(mm, vma, address, write)) { - case VM_FAULT_MINOR: - tsk->min_flt++; - break; - case VM_FAULT_MAJOR: - tsk->maj_flt++; - break; - case VM_FAULT_SIGBUS: - goto do_sigbus; - case VM_FAULT_OOM: - goto out_of_memory; - default: - BUG(); - } - - up_read(&mm->mmap_sem); - 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: - up_read(&mm->mmap_sem); - -bad_area_nosemaphore: - /* User mode accesses just cause a SIGSEGV */ - if (user_mode(regs)) { - tsk->thread.cp0_badvaddr = address; - tsk->thread.error_code = write; -#if 0 - printk("do_page_fault() #2: sending SIGSEGV to %s for " - "invalid %s\n%0*lx (epc == %0*lx, ra == %0*lx)\n", - tsk->comm, - write ? "write access to" : "read access from", - field, address, - field, (unsigned long) regs->cp0_epc, - field, (unsigned long) regs->regs[31]); -#endif - info.si_signo = SIGSEGV; - info.si_errno = 0; - /* info.si_code has been set above */ - info.si_addr = (void *) address; - force_sig_info(SIGSEGV, &info, tsk); - return; - } - -no_context: - /* Are we prepared to handle this kernel fault? */ - if (fixup_exception(regs)) { - current->thread.cp0_baduaddr = address; - return; - } - - /* - * Oops. The kernel tried to access some bad page. We'll have to - * terminate things with extreme prejudice. - */ - - bust_spinlocks(1); - - printk(KERN_ALERT "CPU %d Unable to handle kernel paging request at " - "virtual address %0*lx, epc == %0*lx, ra == %0*lx\n", - smp_processor_id(), field, address, field, regs->cp0_epc, - field, regs->regs[31]); - die("Oops", regs); - -/* - * We ran out of memory, or some other thing happened to us that made - * us unable to handle the page fault gracefully. - */ -out_of_memory: - up_read(&mm->mmap_sem); - if (tsk->pid == 1) { - yield(); - down_read(&mm->mmap_sem); - goto survive; - } - printk("VM: killing process %s\n", tsk->comm); - if (user_mode(regs)) - do_exit(SIGKILL); - goto no_context; - -do_sigbus: - up_read(&mm->mmap_sem); - - /* Kernel mode? Handle exceptions or die */ - if (!user_mode(regs)) - goto no_context; - - /* - * Send a sigbus, regardless of whether we were in kernel - * or user mode. - */ - tsk->thread.cp0_badvaddr = address; - info.si_signo = SIGBUS; - info.si_errno = 0; - info.si_code = BUS_ADRERR; - info.si_addr = (void *) address; - force_sig_info(SIGBUS, &info, tsk); - - return; - -vmalloc_fault: - { - /* - * Synchronize this task's top level page-table - * with the 'reference' page table. - * - * Do _not_ use "tsk" here. We might be inside - * an interrupt in the middle of a task switch.. - */ - int offset = __pgd_offset(address); - pgd_t *pgd, *pgd_k; - pmd_t *pmd, *pmd_k; - pte_t *pte_k; - - pgd = (pgd_t *) pgd_current[smp_processor_id()] + offset; - pgd_k = init_mm.pgd + offset; - - if (!pgd_present(*pgd_k)) - goto no_context; - set_pgd(pgd, *pgd_k); - - pmd = pmd_offset(pgd, address); - pmd_k = pmd_offset(pgd_k, address); - if (!pmd_present(*pmd_k)) - goto no_context; - set_pmd(pmd, *pmd_k); - - pte_k = pte_offset_kernel(pmd_k, address); - if (!pte_present(*pte_k)) - goto no_context; - return; - } -} +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1995 - 2000 by Ralf Baechle + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include /* For unblank_screen() */ +#include + +#include +#include +#include +#include +#include +#include + +/* + * This routine handles page faults. It determines the address, + * and the problem, and then passes it off to one of the appropriate + * routines. + */ +asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write, + unsigned long address) +{ + struct vm_area_struct * vma = NULL; + struct task_struct *tsk = current; + struct mm_struct *mm = tsk->mm; + const int field = sizeof(unsigned long) * 2; + siginfo_t info; + +#if 0 + printk("Cpu%d[%s:%d:%0*lx:%ld:%0*lx]\n", smp_processor_id(), + current->comm, current->pid, field, address, write, + field, regs->cp0_epc); +#endif + + info.si_code = SEGV_MAPERR; + + /* + * We fault-in kernel-space virtual memory on-demand. The + * 'reference' page table is init_mm.pgd. + * + * NOTE! We MUST NOT take any locks for this case. We may + * be in an interrupt or a critical region, and should + * only copy the information from the master page table, + * nothing more. + */ + if (unlikely(address >= VMALLOC_START)) + goto vmalloc_fault; + + /* + * If we're in an interrupt or have no user + * context, we must not take the fault.. + */ + if (in_atomic() || !mm) + goto bad_area_nosemaphore; + + down_read(&mm->mmap_sem); + vma = find_vma(mm, address); + if (!vma) + goto bad_area; + 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; +/* + * Ok, we have a good vm_area for this memory access, so + * we can handle it.. + */ +good_area: + info.si_code = SEGV_ACCERR; + + if (write) { + if (!(vma->vm_flags & VM_WRITE)) + goto bad_area; + } else { + if (!(vma->vm_flags & (VM_READ | VM_EXEC))) + 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. + */ + switch (handle_mm_fault(mm, vma, address, write)) { + case VM_FAULT_MINOR: + tsk->min_flt++; + break; + case VM_FAULT_MAJOR: + tsk->maj_flt++; + break; + case VM_FAULT_SIGBUS: + goto do_sigbus; + case VM_FAULT_OOM: + goto out_of_memory; + default: + BUG(); + } + + up_read(&mm->mmap_sem); + 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: + up_read(&mm->mmap_sem); + +bad_area_nosemaphore: + /* User mode accesses just cause a SIGSEGV */ + if (user_mode(regs)) { + tsk->thread.cp0_badvaddr = address; + tsk->thread.error_code = write; +#if 1 + printk("do_page_fault() #2: sending SIGSEGV to %s for " + "invalid %s\n%0*lx (epc == %0*lx, ra == %0*lx)\n", + tsk->comm, + write ? "write access to" : "read access from", + field, address, + field, (unsigned long) regs->cp0_epc, + field, (unsigned long) regs->regs[31]); +#endif + info.si_signo = SIGSEGV; + info.si_errno = 0; + /* info.si_code has been set above */ + info.si_addr = (void *) address; + force_sig_info(SIGSEGV, &info, tsk); + return; + } + +no_context: + /* Are we prepared to handle this kernel fault? */ + if (fixup_exception(regs)) { + current->thread.cp0_baduaddr = address; + return; + } + + /* + * Oops. The kernel tried to access some bad page. We'll have to + * terminate things with extreme prejudice. + */ + + bust_spinlocks(1); + + printk(KERN_ALERT "CPU %d Unable to handle kernel paging request at " + "virtual address %0*lx, epc == %0*lx, ra == %0*lx\n", + smp_processor_id(), field, address, field, regs->cp0_epc, + field, regs->regs[31]); + die("Oops", regs); + +/* + * We ran out of memory, or some other thing happened to us that made + * us unable to handle the page fault gracefully. + */ +out_of_memory: + up_read(&mm->mmap_sem); + if (tsk->pid == 1) { + yield(); + down_read(&mm->mmap_sem); + goto survive; + } + printk("VM: killing process %s\n", tsk->comm); + if (user_mode(regs)) + do_exit(SIGKILL); + goto no_context; + +do_sigbus: + up_read(&mm->mmap_sem); + + /* Kernel mode? Handle exceptions or die */ + if (!user_mode(regs)) + goto no_context; + + /* + * Send a sigbus, regardless of whether we were in kernel + * or user mode. + */ + tsk->thread.cp0_badvaddr = address; + info.si_signo = SIGBUS; + info.si_errno = 0; + info.si_code = BUS_ADRERR; + info.si_addr = (void *) address; + force_sig_info(SIGBUS, &info, tsk); + + return; + +vmalloc_fault: + { + /* + * Synchronize this task's top level page-table + * with the 'reference' page table. + * + * Do _not_ use "tsk" here. We might be inside + * an interrupt in the middle of a task switch.. + */ + int offset = __pgd_offset(address); + pgd_t *pgd, *pgd_k; + pmd_t *pmd, *pmd_k; + pte_t *pte_k; + + pgd = (pgd_t *) pgd_current[smp_processor_id()] + offset; + pgd_k = init_mm.pgd + offset; + + if (!pgd_present(*pgd_k)) + goto no_context; + set_pgd(pgd, *pgd_k); + + pmd = pmd_offset(pgd, address); + pmd_k = pmd_offset(pgd_k, address); + if (!pmd_present(*pmd_k)) + goto no_context; + set_pmd(pmd, *pmd_k); + + pte_k = pte_offset_kernel(pmd_k, address); + if (!pte_present(*pte_k)) + goto no_context; + return; + } +}