/* * copy_user_page * @to: kernel logical address * @from: kernel logical address * @address: U0 address to be mapped * @page: page (virt_to_page(to)) */ void copy_user_page(void *to, void *from, unsigned long address, struct page *page) { extern void __copy_page_wb(void *to, void *from); if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0) __copy_page_wb(to, from); else { pgprot_t pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_CACHABLE | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_HW_SHARED | _PAGE_FLAGS_HARD); unsigned long phys_addr = virt_to_phys(to); unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS); pgd_t *pgd = pgd_offset_k(p3_addr); pud_t *pud = pud_offset(pgd, p3_addr); pmd_t *pmd = pmd_offset(pud, p3_addr); pte_t *pte = pte_offset_kernel(pmd, p3_addr); pte_t entry; unsigned long flags; entry = pfn_pte(phys_addr >> PAGE_SHIFT, pgprot); inc_preempt_count(); BUG_ON(atomic_inc_return(&concurreny_check[(address & CACHE_ALIAS)>>12]) != 1); set_pte(pte, entry); local_irq_save(flags); flush_tlb_one(get_asid(), p3_addr); local_irq_restore(flags); update_mmu_cache(NULL, p3_addr, entry); __copy_user_page((void *)p3_addr, from, to); pte_clear(&init_mm, p3_addr, pte); atomic_dec(&concurreny_check[(address & CACHE_ALIAS)>>12]); dec_preempt_count(); } }
void *__kmap(struct page *page) { void *addr; might_sleep(); if (!PageHighMem(page)) return page_address(page); addr = kmap_high(page); flush_tlb_one((unsigned long)addr); return addr; }
void *__kmap(struct page *page) { void *addr; might_sleep(); if (page < highmem_start_page) return page_address(page); addr = kmap_high(page); flush_tlb_one((unsigned long)addr); return addr; }
/* * This is the same as kmap_atomic() but can map memory that doesn't * have a struct page associated with it. */ void *kmap_atomic_pfn(unsigned long pfn, enum km_type type) { enum fixed_addresses idx; unsigned long vaddr; pagefault_disable(); idx = type + KM_TYPE_NR*smp_processor_id(); vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); set_pte(kmap_pte-idx, pfn_pte(pfn, kmap_prot)); flush_tlb_one(vaddr); return (void*) vaddr; }
void *kmap(struct page *page) { void *addr; if (in_interrupt()) BUG(); if (page < highmem_start_page) return page_address(page); addr = kmap_high(page); flush_tlb_one((unsigned long)addr); return addr; }
/* * This is the same as kmap_atomic() but can map memory that doesn't * have a struct page associated with it. */ void *kmap_atomic_pfn(unsigned long pfn, enum km_type unused) { unsigned long vaddr; int idx, type; pagefault_disable(); type = kmap_atomic_idx_push(); idx = type + KM_TYPE_NR*smp_processor_id(); vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL)); flush_tlb_one(vaddr); return (void*) vaddr; }
static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot) { pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t *pte; pgd = pgd_offset_k(addr); if (pgd_none(*pgd)) { pgd_ERROR(*pgd); return; } pud = pud_alloc(NULL, pgd, addr); if (unlikely(!pud)) { pud_ERROR(*pud); return; } pmd = pmd_alloc(NULL, pud, addr); if (unlikely(!pmd)) { pmd_ERROR(*pmd); return; } pte = pte_offset_kernel(pmd, addr); if (!pte_none(*pte)) { pte_ERROR(*pte); return; } set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot)); if (cached_to_uncached) flush_tlb_one(get_asid(), addr); }
/* * 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 cause, unsigned long address) { struct vm_area_struct *vma = NULL; struct task_struct *tsk = current; struct mm_struct *mm = tsk->mm; int code = SEGV_MAPERR; int fault; unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; cause >>= 2; /* Restart the instruction */ regs->ea -= 4; /* * 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 && address <= VMALLOC_END)) { if (user_mode(regs)) goto bad_area_nosemaphore; else goto vmalloc_fault; } if (unlikely(address >= TASK_SIZE)) goto bad_area_nosemaphore; /* * If we're in an interrupt or have no user * context, we must not take the fault.. */ if (faulthandler_disabled() || !mm) goto bad_area_nosemaphore; if (user_mode(regs)) flags |= FAULT_FLAG_USER; if (!down_read_trylock(&mm->mmap_sem)) { if (!user_mode(regs) && !search_exception_tables(regs->ea)) goto bad_area_nosemaphore; retry: 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: code = SEGV_ACCERR; switch (cause) { case EXC_SUPERV_INSN_ACCESS: goto bad_area; case EXC_SUPERV_DATA_ACCESS: goto bad_area; case EXC_X_PROTECTION_FAULT: if (!(vma->vm_flags & VM_EXEC)) goto bad_area; break; case EXC_R_PROTECTION_FAULT: if (!(vma->vm_flags & VM_READ)) goto bad_area; break; case EXC_W_PROTECTION_FAULT: if (!(vma->vm_flags & VM_WRITE)) goto bad_area; flags = FAULT_FLAG_WRITE; break; } /* * If for any reason at all we couldn't handle the fault, * make sure we exit gracefully rather than endlessly redo * the fault. */ fault = handle_mm_fault(mm, vma, address, flags); if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) return; if (unlikely(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_OOM) goto out_of_memory; else if (fault & VM_FAULT_SIGSEGV) goto bad_area; else if (fault & VM_FAULT_SIGBUS) goto do_sigbus; BUG(); } /* * Major/minor page fault accounting is only done on the * initial attempt. If we go through a retry, it is extremely * likely that the page will be found in page cache at that point. */ if (flags & FAULT_FLAG_ALLOW_RETRY) { if (fault & VM_FAULT_MAJOR) current->maj_flt++; else current->min_flt++; if (fault & VM_FAULT_RETRY) { /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk * of starvation. */ flags &= ~FAULT_FLAG_ALLOW_RETRY; flags |= FAULT_FLAG_TRIED; /* * No need to up_read(&mm->mmap_sem) as we would * have already released it in __lock_page_or_retry * in mm/filemap.c. */ goto retry; } } 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)) { if (unhandled_signal(current, SIGSEGV) && printk_ratelimit()) { pr_info("%s: unhandled page fault (%d) at 0x%08lx, " "cause %ld\n", current->comm, SIGSEGV, address, cause); show_regs(regs); } _exception(SIGSEGV, regs, code, address); return; } no_context: /* Are we prepared to handle this kernel fault? */ if (fixup_exception(regs)) return; /* * Oops. The kernel tried to access some bad page. We'll have to * terminate things with extreme prejudice. */ bust_spinlocks(1); pr_alert("Unable to handle kernel %s at virtual address %08lx", address < PAGE_SIZE ? "NULL pointer dereference" : "paging request", address); pr_alert("ea = %08lx, ra = %08lx, cause = %ld\n", regs->ea, regs->ra, cause); panic("Oops"); return; /* * 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 (!user_mode(regs)) goto no_context; pagefault_out_of_memory(); return; do_sigbus: up_read(&mm->mmap_sem); /* Kernel mode? Handle exceptions or die */ if (!user_mode(regs)) goto no_context; _exception(SIGBUS, regs, BUS_ADRERR, address); 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_index(address); pgd_t *pgd, *pgd_k; pud_t *pud, *pud_k; pmd_t *pmd, *pmd_k; pte_t *pte_k; pgd = pgd_current + offset; pgd_k = init_mm.pgd + offset; if (!pgd_present(*pgd_k)) goto no_context; set_pgd(pgd, *pgd_k); pud = pud_offset(pgd, address); pud_k = pud_offset(pgd_k, address); if (!pud_present(*pud_k)) goto no_context; pmd = pmd_offset(pud, address); pmd_k = pmd_offset(pud_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; flush_tlb_one(address); return; } }
/* * 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 cause, unsigned long address) { struct vm_area_struct *vma = NULL; struct task_struct *tsk = current; struct mm_struct *mm = tsk->mm; int code = SEGV_MAPERR; int fault; unsigned int flags = 0; cause >>= 2; /* Restart the instruction */ regs->ea -= 4; /* * 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 && address <= VMALLOC_END)) { if (user_mode(regs)) goto bad_area_nosemaphore; else goto vmalloc_fault; } if (unlikely(address >= TASK_SIZE)) goto bad_area_nosemaphore; /* * 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: code = SEGV_ACCERR; switch (cause) { case EXC_SUPERV_INSN_ACCESS: goto bad_area; case EXC_SUPERV_DATA_ACCESS: goto bad_area; case EXC_X_PROTECTION_FAULT: if (!(vma->vm_flags & VM_EXEC)) goto bad_area; break; case EXC_R_PROTECTION_FAULT: if (!(vma->vm_flags & VM_READ)) goto bad_area; break; case EXC_W_PROTECTION_FAULT: flags = FAULT_FLAG_WRITE; if (!(vma->vm_flags & VM_WRITE)) goto bad_area; break; } survive: /* * If for any reason at all we couldn't handle the fault, * make sure we exit gracefully rather than endlessly redo * the fault. */ fault = handle_mm_fault(mm, vma, address, flags); if (unlikely(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_OOM) goto out_of_memory; else if (fault & VM_FAULT_SIGBUS) goto do_sigbus; BUG(); } if (fault & VM_FAULT_MAJOR) tsk->maj_flt++; else tsk->min_flt++; 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)) { _exception(SIGSEGV, regs, code, address); return; } no_context: /* Are we prepared to handle this kernel fault? */ if (fixup_exception(regs)) return; /* * Oops. The kernel tried to access some bad page. We'll have to * terminate things with extreme prejudice. */ bust_spinlocks(1); pr_alert("Unable to handle kernel %s at virtual address %08lx", address < PAGE_SIZE ? "NULL pointer dereference" : "paging request", address); pr_alert("ea = %08lx, ra = %08lx, cause = %ld\n", regs->ea, regs->ra, cause); panic("Oops"); return; /* * 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 (is_global_init(tsk)) { yield(); down_read(&mm->mmap_sem); goto survive; } pr_info("VM: killing process %s\n", tsk->comm); if (user_mode(regs)) do_group_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; _exception(SIGBUS, regs, BUS_ADRERR, address); 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_index(address); pgd_t *pgd, *pgd_k; pud_t *pud, *pud_k; pmd_t *pmd, *pmd_k; pte_t *pte_k; #if 1 /* FIXME: Is this entirely correct ? */ pgd = pgd_current + offset; #else pgd = ¤t->mm->pgd[offset]; #endif pgd_k = init_mm.pgd + offset; if (!pgd_present(*pgd_k)) goto no_context; set_pgd(pgd, *pgd_k); pud = pud_offset(pgd, address); pud_k = pud_offset(pgd_k, address); if (!pud_present(*pud_k)) goto no_context; pmd = pmd_offset(pud, address); pmd_k = pmd_offset(pud_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; flush_tlb_one(address); return; } }