From 28080329ede3e4110bb14306b4529a5b9a2ce163 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Mon, 14 May 2012 15:33:28 +0900 Subject: sh: Enable shared page fault handler for _32/_64. This moves the now generic _32 page fault handling code to a shared place and adapts the _64 implementation to make use of it. Signed-off-by: Paul Mundt --- arch/sh/mm/Makefile | 4 +- arch/sh/mm/fault.c | 508 ++++++++++++++++++++++++++++++++++++++++++ arch/sh/mm/fault_32.c | 564 ----------------------------------------------- arch/sh/mm/fault_64.c | 264 ---------------------- arch/sh/mm/tlbex_32.c | 78 +++++++ arch/sh/mm/tlbex_64.c | 264 ++++++++++++++++++++++ arch/sh/mm/tlbflush_64.c | 243 -------------------- 7 files changed, 852 insertions(+), 1073 deletions(-) create mode 100644 arch/sh/mm/fault.c delete mode 100644 arch/sh/mm/fault_32.c delete mode 100644 arch/sh/mm/fault_64.c create mode 100644 arch/sh/mm/tlbex_32.c create mode 100644 arch/sh/mm/tlbex_64.c (limited to 'arch/sh/mm') diff --git a/arch/sh/mm/Makefile b/arch/sh/mm/Makefile index 2228c8c..ba81910 100644 --- a/arch/sh/mm/Makefile +++ b/arch/sh/mm/Makefile @@ -15,8 +15,8 @@ cacheops-$(CONFIG_CPU_SHX3) += cache-shx3.o obj-y += $(cacheops-y) mmu-y := nommu.o extable_32.o -mmu-$(CONFIG_MMU) := extable_$(BITS).o fault_$(BITS).o gup.o \ - ioremap.o kmap.o pgtable.o tlbflush_$(BITS).o +mmu-$(CONFIG_MMU) := extable_$(BITS).o fault.o gup.o ioremap.o kmap.o \ + pgtable.o tlbex_$(BITS).o tlbflush_$(BITS).o obj-y += $(mmu-y) diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c new file mode 100644 index 0000000..16799f9 --- /dev/null +++ b/arch/sh/mm/fault.c @@ -0,0 +1,508 @@ +/* + * Page fault handler for SH with an MMU. + * + * Copyright (C) 1999 Niibe Yutaka + * Copyright (C) 2003 - 2012 Paul Mundt + * + * Based on linux/arch/i386/mm/fault.c: + * Copyright (C) 1995 Linus Torvalds + * + * 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. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static inline int notify_page_fault(struct pt_regs *regs, int trap) +{ + int ret = 0; + + if (kprobes_built_in() && !user_mode(regs)) { + preempt_disable(); + if (kprobe_running() && kprobe_fault_handler(regs, trap)) + ret = 1; + preempt_enable(); + } + + return ret; +} + +static void +force_sig_info_fault(int si_signo, int si_code, unsigned long address, + struct task_struct *tsk) +{ + siginfo_t info; + + info.si_signo = si_signo; + info.si_errno = 0; + info.si_code = si_code; + info.si_addr = (void __user *)address; + + force_sig_info(si_signo, &info, tsk); +} + +/* + * This is useful to dump out the page tables associated with + * 'addr' in mm 'mm'. + */ +static void show_pte(struct mm_struct *mm, unsigned long addr) +{ + pgd_t *pgd; + + if (mm) + pgd = mm->pgd; + else + pgd = get_TTB(); + + printk(KERN_ALERT "pgd = %p\n", pgd); + pgd += pgd_index(addr); + printk(KERN_ALERT "[%08lx] *pgd=%0*Lx", addr, + (u32)(sizeof(*pgd) * 2), (u64)pgd_val(*pgd)); + + do { + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + if (pgd_none(*pgd)) + break; + + if (pgd_bad(*pgd)) { + printk("(bad)"); + break; + } + + pud = pud_offset(pgd, addr); + if (PTRS_PER_PUD != 1) + printk(", *pud=%0*Lx", (u32)(sizeof(*pud) * 2), + (u64)pud_val(*pud)); + + if (pud_none(*pud)) + break; + + if (pud_bad(*pud)) { + printk("(bad)"); + break; + } + + pmd = pmd_offset(pud, addr); + if (PTRS_PER_PMD != 1) + printk(", *pmd=%0*Lx", (u32)(sizeof(*pmd) * 2), + (u64)pmd_val(*pmd)); + + if (pmd_none(*pmd)) + break; + + if (pmd_bad(*pmd)) { + printk("(bad)"); + break; + } + + /* We must not map this if we have highmem enabled */ + if (PageHighMem(pfn_to_page(pmd_val(*pmd) >> PAGE_SHIFT))) + break; + + pte = pte_offset_kernel(pmd, addr); + printk(", *pte=%0*Lx", (u32)(sizeof(*pte) * 2), + (u64)pte_val(*pte)); + } while (0); + + printk("\n"); +} + +static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address) +{ + unsigned index = pgd_index(address); + pgd_t *pgd_k; + pud_t *pud, *pud_k; + pmd_t *pmd, *pmd_k; + + pgd += index; + pgd_k = init_mm.pgd + index; + + if (!pgd_present(*pgd_k)) + return NULL; + + pud = pud_offset(pgd, address); + pud_k = pud_offset(pgd_k, address); + if (!pud_present(*pud_k)) + return NULL; + + if (!pud_present(*pud)) + set_pud(pud, *pud_k); + + pmd = pmd_offset(pud, address); + pmd_k = pmd_offset(pud_k, address); + if (!pmd_present(*pmd_k)) + return NULL; + + if (!pmd_present(*pmd)) + set_pmd(pmd, *pmd_k); + else { + /* + * The page tables are fully synchronised so there must + * be another reason for the fault. Return NULL here to + * signal that we have not taken care of the fault. + */ + BUG_ON(pmd_page(*pmd) != pmd_page(*pmd_k)); + return NULL; + } + + return pmd_k; +} + +/* + * Handle a fault on the vmalloc or module mapping area + */ +static noinline int vmalloc_fault(unsigned long address) +{ + pgd_t *pgd_k; + pmd_t *pmd_k; + pte_t *pte_k; + + /* Make sure we are in vmalloc/module area: */ + if (!is_vmalloc_addr((void *)address)) + return -1; + + /* + * Synchronize this task's top level page-table + * with the 'reference' page table. + * + * Do _not_ use "current" here. We might be inside + * an interrupt in the middle of a task switch.. + */ + pgd_k = get_TTB(); + pmd_k = vmalloc_sync_one(pgd_k, address); + if (!pmd_k) + return -1; + + pte_k = pte_offset_kernel(pmd_k, address); + if (!pte_present(*pte_k)) + return -1; + + return 0; +} + +static void +show_fault_oops(struct pt_regs *regs, unsigned long address) +{ + if (!oops_may_print()) + return; + + printk(KERN_ALERT "BUG: unable to handle kernel "); + if (address < PAGE_SIZE) + printk(KERN_CONT "NULL pointer dereference"); + else + printk(KERN_CONT "paging request"); + + printk(KERN_CONT " at %08lx\n", address); + printk(KERN_ALERT "PC:"); + printk_address(regs->pc, 1); + + show_pte(NULL, address); +} + +static noinline void +no_context(struct pt_regs *regs, unsigned long error_code, + unsigned long address) +{ + /* Are we prepared to handle this kernel fault? */ + if (fixup_exception(regs)) + return; + + if (handle_trapped_io(regs, address)) + return; + + /* + * Oops. The kernel tried to access some bad page. We'll have to + * terminate things with extreme prejudice. + */ + bust_spinlocks(1); + + show_fault_oops(regs, address); + + die("Oops", regs, error_code); + bust_spinlocks(0); + do_exit(SIGKILL); +} + +static void +__bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code, + unsigned long address, int si_code) +{ + struct task_struct *tsk = current; + + /* User mode accesses just cause a SIGSEGV */ + if (user_mode(regs)) { + /* + * It's possible to have interrupts off here: + */ + local_irq_enable(); + + force_sig_info_fault(SIGSEGV, si_code, address, tsk); + + return; + } + + no_context(regs, error_code, address); +} + +static noinline void +bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code, + unsigned long address) +{ + __bad_area_nosemaphore(regs, error_code, address, SEGV_MAPERR); +} + +static void +__bad_area(struct pt_regs *regs, unsigned long error_code, + unsigned long address, int si_code) +{ + struct mm_struct *mm = current->mm; + + /* + * Something tried to access memory that isn't in our memory map.. + * Fix it, but check if it's kernel or user first.. + */ + up_read(&mm->mmap_sem); + + __bad_area_nosemaphore(regs, error_code, address, si_code); +} + +static noinline void +bad_area(struct pt_regs *regs, unsigned long error_code, unsigned long address) +{ + __bad_area(regs, error_code, address, SEGV_MAPERR); +} + +static noinline void +bad_area_access_error(struct pt_regs *regs, unsigned long error_code, + unsigned long address) +{ + __bad_area(regs, error_code, address, SEGV_ACCERR); +} + +static void out_of_memory(void) +{ + /* + * We ran out of memory, call the OOM killer, and return the userspace + * (which will retry the fault, or kill us if we got oom-killed): + */ + up_read(¤t->mm->mmap_sem); + + pagefault_out_of_memory(); +} + +static void +do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address) +{ + struct task_struct *tsk = current; + struct mm_struct *mm = tsk->mm; + + up_read(&mm->mmap_sem); + + /* Kernel mode? Handle exceptions or die: */ + if (!user_mode(regs)) + no_context(regs, error_code, address); + + force_sig_info_fault(SIGBUS, BUS_ADRERR, address, tsk); +} + +static noinline int +mm_fault_error(struct pt_regs *regs, unsigned long error_code, + unsigned long address, unsigned int fault) +{ + /* + * Pagefault was interrupted by SIGKILL. We have no reason to + * continue pagefault. + */ + if (fatal_signal_pending(current)) { + if (!(fault & VM_FAULT_RETRY)) + up_read(¤t->mm->mmap_sem); + if (!user_mode(regs)) + no_context(regs, error_code, address); + return 1; + } + + if (!(fault & VM_FAULT_ERROR)) + return 0; + + if (fault & VM_FAULT_OOM) { + /* Kernel mode? Handle exceptions or die: */ + if (!user_mode(regs)) { + up_read(¤t->mm->mmap_sem); + no_context(regs, error_code, address); + return 1; + } + + out_of_memory(); + } else { + if (fault & VM_FAULT_SIGBUS) + do_sigbus(regs, error_code, address); + else + BUG(); + } + + return 1; +} + +static inline int access_error(int error_code, struct vm_area_struct *vma) +{ + if (error_code & FAULT_CODE_WRITE) { + /* write, present and write, not present: */ + if (unlikely(!(vma->vm_flags & VM_WRITE))) + return 1; + return 0; + } + + /* ITLB miss on NX page */ + if (unlikely((error_code & FAULT_CODE_ITLB) && + !(vma->vm_flags & VM_EXEC))) + return 1; + + /* read, not present: */ + if (unlikely(!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))) + return 1; + + return 0; +} + +static int fault_in_kernel_space(unsigned long address) +{ + return address >= TASK_SIZE; +} + +/* + * 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 __kprobes do_page_fault(struct pt_regs *regs, + unsigned long error_code, + unsigned long address) +{ + unsigned long vec; + struct task_struct *tsk; + struct mm_struct *mm; + struct vm_area_struct * vma; + int fault; + int write = error_code & FAULT_CODE_WRITE; + unsigned int flags = (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | + (write ? FAULT_FLAG_WRITE : 0)); + + tsk = current; + mm = tsk->mm; + vec = lookup_exception_vector(); + + /* + * 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(fault_in_kernel_space(address))) { + if (vmalloc_fault(address) >= 0) + return; + if (notify_page_fault(regs, vec)) + return; + + bad_area_nosemaphore(regs, error_code, address); + return; + } + + if (unlikely(notify_page_fault(regs, vec))) + return; + + /* Only enable interrupts if they were on before the fault */ + if ((regs->sr & SR_IMASK) != SR_IMASK) + local_irq_enable(); + + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); + + /* + * If we're in an interrupt, have no user context or are running + * in an atomic region then we must not take the fault: + */ + if (unlikely(in_atomic() || !mm)) { + bad_area_nosemaphore(regs, error_code, address); + return; + } + +retry: + down_read(&mm->mmap_sem); + + vma = find_vma(mm, address); + if (unlikely(!vma)) { + bad_area(regs, error_code, address); + return; + } + if (likely(vma->vm_start <= address)) + goto good_area; + if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) { + bad_area(regs, error_code, address); + return; + } + if (unlikely(expand_stack(vma, address))) { + bad_area(regs, error_code, address); + return; + } + + /* + * Ok, we have a good vm_area for this memory access, so + * we can handle it.. + */ +good_area: + if (unlikely(access_error(error_code, vma))) { + bad_area_access_error(regs, error_code, address); + return; + } + + set_thread_fault_code(error_code); + + /* + * 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_RETRY | VM_FAULT_ERROR))) + if (mm_fault_error(regs, error_code, address, fault)) + return; + + if (flags & FAULT_FLAG_ALLOW_RETRY) { + if (fault & VM_FAULT_MAJOR) { + tsk->maj_flt++; + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, + regs, address); + } else { + tsk->min_flt++; + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, + regs, address); + } + if (fault & VM_FAULT_RETRY) { + flags &= ~FAULT_FLAG_ALLOW_RETRY; + + /* + * 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); +} diff --git a/arch/sh/mm/fault_32.c b/arch/sh/mm/fault_32.c deleted file mode 100644 index 39e291c..0000000 --- a/arch/sh/mm/fault_32.c +++ /dev/null @@ -1,564 +0,0 @@ -/* - * Page fault handler for SH with an MMU. - * - * Copyright (C) 1999 Niibe Yutaka - * Copyright (C) 2003 - 2012 Paul Mundt - * - * Based on linux/arch/i386/mm/fault.c: - * Copyright (C) 1995 Linus Torvalds - * - * 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. - */ -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -static inline int notify_page_fault(struct pt_regs *regs, int trap) -{ - int ret = 0; - - if (kprobes_built_in() && !user_mode(regs)) { - preempt_disable(); - if (kprobe_running() && kprobe_fault_handler(regs, trap)) - ret = 1; - preempt_enable(); - } - - return ret; -} - -static void -force_sig_info_fault(int si_signo, int si_code, unsigned long address, - struct task_struct *tsk) -{ - siginfo_t info; - - info.si_signo = si_signo; - info.si_errno = 0; - info.si_code = si_code; - info.si_addr = (void __user *)address; - - force_sig_info(si_signo, &info, tsk); -} - -/* - * This is useful to dump out the page tables associated with - * 'addr' in mm 'mm'. - */ -static void show_pte(struct mm_struct *mm, unsigned long addr) -{ - pgd_t *pgd; - - if (mm) - pgd = mm->pgd; - else - pgd = get_TTB(); - - printk(KERN_ALERT "pgd = %p\n", pgd); - pgd += pgd_index(addr); - printk(KERN_ALERT "[%08lx] *pgd=%0*Lx", addr, - sizeof(*pgd) * 2, (u64)pgd_val(*pgd)); - - do { - pud_t *pud; - pmd_t *pmd; - pte_t *pte; - - if (pgd_none(*pgd)) - break; - - if (pgd_bad(*pgd)) { - printk("(bad)"); - break; - } - - pud = pud_offset(pgd, addr); - if (PTRS_PER_PUD != 1) - printk(", *pud=%0*Lx", sizeof(*pud) * 2, - (u64)pud_val(*pud)); - - if (pud_none(*pud)) - break; - - if (pud_bad(*pud)) { - printk("(bad)"); - break; - } - - pmd = pmd_offset(pud, addr); - if (PTRS_PER_PMD != 1) - printk(", *pmd=%0*Lx", sizeof(*pmd) * 2, - (u64)pmd_val(*pmd)); - - if (pmd_none(*pmd)) - break; - - if (pmd_bad(*pmd)) { - printk("(bad)"); - break; - } - - /* We must not map this if we have highmem enabled */ - if (PageHighMem(pfn_to_page(pmd_val(*pmd) >> PAGE_SHIFT))) - break; - - pte = pte_offset_kernel(pmd, addr); - printk(", *pte=%0*Lx", sizeof(*pte) * 2, (u64)pte_val(*pte)); - } while (0); - - printk("\n"); -} - -static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address) -{ - unsigned index = pgd_index(address); - pgd_t *pgd_k; - pud_t *pud, *pud_k; - pmd_t *pmd, *pmd_k; - - pgd += index; - pgd_k = init_mm.pgd + index; - - if (!pgd_present(*pgd_k)) - return NULL; - - pud = pud_offset(pgd, address); - pud_k = pud_offset(pgd_k, address); - if (!pud_present(*pud_k)) - return NULL; - - if (!pud_present(*pud)) - set_pud(pud, *pud_k); - - pmd = pmd_offset(pud, address); - pmd_k = pmd_offset(pud_k, address); - if (!pmd_present(*pmd_k)) - return NULL; - - if (!pmd_present(*pmd)) - set_pmd(pmd, *pmd_k); - else { - /* - * The page tables are fully synchronised so there must - * be another reason for the fault. Return NULL here to - * signal that we have not taken care of the fault. - */ - BUG_ON(pmd_page(*pmd) != pmd_page(*pmd_k)); - return NULL; - } - - return pmd_k; -} - -/* - * Handle a fault on the vmalloc or module mapping area - */ -static noinline int vmalloc_fault(unsigned long address) -{ - pgd_t *pgd_k; - pmd_t *pmd_k; - pte_t *pte_k; - - /* Make sure we are in vmalloc/module area: */ - if (!is_vmalloc_addr((void *)address)) - return -1; - - /* - * Synchronize this task's top level page-table - * with the 'reference' page table. - * - * Do _not_ use "current" here. We might be inside - * an interrupt in the middle of a task switch.. - */ - pgd_k = get_TTB(); - pmd_k = vmalloc_sync_one(pgd_k, address); - if (!pmd_k) - return -1; - - pte_k = pte_offset_kernel(pmd_k, address); - if (!pte_present(*pte_k)) - return -1; - - return 0; -} - -static void -show_fault_oops(struct pt_regs *regs, unsigned long address) -{ - if (!oops_may_print()) - return; - - printk(KERN_ALERT "BUG: unable to handle kernel "); - if (address < PAGE_SIZE) - printk(KERN_CONT "NULL pointer dereference"); - else - printk(KERN_CONT "paging request"); - - printk(KERN_CONT " at %08lx\n", address); - printk(KERN_ALERT "PC:"); - printk_address(regs->pc, 1); - - show_pte(NULL, address); -} - -static noinline void -no_context(struct pt_regs *regs, unsigned long error_code, - unsigned long address) -{ - /* Are we prepared to handle this kernel fault? */ - if (fixup_exception(regs)) - return; - - if (handle_trapped_io(regs, address)) - return; - - /* - * Oops. The kernel tried to access some bad page. We'll have to - * terminate things with extreme prejudice. - */ - bust_spinlocks(1); - - show_fault_oops(regs, address); - - die("Oops", regs, error_code); - bust_spinlocks(0); - do_exit(SIGKILL); -} - -static void -__bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code, - unsigned long address, int si_code) -{ - struct task_struct *tsk = current; - - /* User mode accesses just cause a SIGSEGV */ - if (user_mode(regs)) { - /* - * It's possible to have interrupts off here: - */ - local_irq_enable(); - - force_sig_info_fault(SIGSEGV, si_code, address, tsk); - - return; - } - - no_context(regs, error_code, address); -} - -static noinline void -bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code, - unsigned long address) -{ - __bad_area_nosemaphore(regs, error_code, address, SEGV_MAPERR); -} - -static void -__bad_area(struct pt_regs *regs, unsigned long error_code, - unsigned long address, int si_code) -{ - struct mm_struct *mm = current->mm; - - /* - * Something tried to access memory that isn't in our memory map.. - * Fix it, but check if it's kernel or user first.. - */ - up_read(&mm->mmap_sem); - - __bad_area_nosemaphore(regs, error_code, address, si_code); -} - -static noinline void -bad_area(struct pt_regs *regs, unsigned long error_code, unsigned long address) -{ - __bad_area(regs, error_code, address, SEGV_MAPERR); -} - -static noinline void -bad_area_access_error(struct pt_regs *regs, unsigned long error_code, - unsigned long address) -{ - __bad_area(regs, error_code, address, SEGV_ACCERR); -} - -static void out_of_memory(void) -{ - /* - * We ran out of memory, call the OOM killer, and return the userspace - * (which will retry the fault, or kill us if we got oom-killed): - */ - up_read(¤t->mm->mmap_sem); - - pagefault_out_of_memory(); -} - -static void -do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address) -{ - struct task_struct *tsk = current; - struct mm_struct *mm = tsk->mm; - - up_read(&mm->mmap_sem); - - /* Kernel mode? Handle exceptions or die: */ - if (!user_mode(regs)) - no_context(regs, error_code, address); - - force_sig_info_fault(SIGBUS, BUS_ADRERR, address, tsk); -} - -static noinline int -mm_fault_error(struct pt_regs *regs, unsigned long error_code, - unsigned long address, unsigned int fault) -{ - /* - * Pagefault was interrupted by SIGKILL. We have no reason to - * continue pagefault. - */ - if (fatal_signal_pending(current)) { - if (!(fault & VM_FAULT_RETRY)) - up_read(¤t->mm->mmap_sem); - if (!user_mode(regs)) - no_context(regs, error_code, address); - return 1; - } - - if (!(fault & VM_FAULT_ERROR)) - return 0; - - if (fault & VM_FAULT_OOM) { - /* Kernel mode? Handle exceptions or die: */ - if (!user_mode(regs)) { - up_read(¤t->mm->mmap_sem); - no_context(regs, error_code, address); - return 1; - } - - out_of_memory(); - } else { - if (fault & VM_FAULT_SIGBUS) - do_sigbus(regs, error_code, address); - else - BUG(); - } - - return 1; -} - -static inline int access_error(int write, struct vm_area_struct *vma) -{ - if (write) { - /* write, present and write, not present: */ - if (unlikely(!(vma->vm_flags & VM_WRITE))) - return 1; - return 0; - } - - /* read, not present: */ - if (unlikely(!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))) - return 1; - - return 0; -} - -static int fault_in_kernel_space(unsigned long address) -{ - return address >= TASK_SIZE; -} - -/* - * 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 __kprobes do_page_fault(struct pt_regs *regs, - unsigned long error_code, - unsigned long address) -{ - unsigned long vec; - struct task_struct *tsk; - struct mm_struct *mm; - struct vm_area_struct * vma; - int fault; - int write = error_code & FAULT_CODE_WRITE; - unsigned int flags = (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (write ? FAULT_FLAG_WRITE : 0)); - - tsk = current; - mm = tsk->mm; - vec = lookup_exception_vector(); - - /* - * 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(fault_in_kernel_space(address))) { - if (vmalloc_fault(address) >= 0) - return; - if (notify_page_fault(regs, vec)) - return; - - bad_area_nosemaphore(regs, error_code, address); - return; - } - - if (unlikely(notify_page_fault(regs, vec))) - return; - - /* Only enable interrupts if they were on before the fault */ - if ((regs->sr & SR_IMASK) != SR_IMASK) - local_irq_enable(); - - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); - - /* - * If we're in an interrupt, have no user context or are running - * in an atomic region then we must not take the fault: - */ - if (unlikely(in_atomic() || !mm)) { - bad_area_nosemaphore(regs, error_code, address); - return; - } - -retry: - down_read(&mm->mmap_sem); - - vma = find_vma(mm, address); - if (unlikely(!vma)) { - bad_area(regs, error_code, address); - return; - } - if (likely(vma->vm_start <= address)) - goto good_area; - if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) { - bad_area(regs, error_code, address); - return; - } - if (unlikely(expand_stack(vma, address))) { - bad_area(regs, error_code, address); - return; - } - - /* - * Ok, we have a good vm_area for this memory access, so - * we can handle it.. - */ -good_area: - if (unlikely(access_error(error_code, vma))) { - bad_area_access_error(regs, error_code, address); - return; - } - - set_thread_fault_code(error_code); - - /* - * 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_RETRY | VM_FAULT_ERROR))) - if (mm_fault_error(regs, error_code, address, fault)) - return; - - if (flags & FAULT_FLAG_ALLOW_RETRY) { - if (fault & VM_FAULT_MAJOR) { - tsk->maj_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, - regs, address); - } else { - tsk->min_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, - regs, address); - } - if (fault & VM_FAULT_RETRY) { - flags &= ~FAULT_FLAG_ALLOW_RETRY; - - /* - * 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); -} - -/* - * Called with interrupts disabled. - */ -asmlinkage int __kprobes -handle_tlbmiss(struct pt_regs *regs, unsigned long error_code, - unsigned long address) -{ - pgd_t *pgd; - pud_t *pud; - pmd_t *pmd; - pte_t *pte; - pte_t entry; - - /* - * We don't take page faults for P1, P2, and parts of P4, these - * are always mapped, whether it be due to legacy behaviour in - * 29-bit mode, or due to PMB configuration in 32-bit mode. - */ - if (address >= P3SEG && address < P3_ADDR_MAX) { - pgd = pgd_offset_k(address); - } else { - if (unlikely(address >= TASK_SIZE || !current->mm)) - return 1; - - pgd = pgd_offset(current->mm, address); - } - - pud = pud_offset(pgd, address); - if (pud_none_or_clear_bad(pud)) - return 1; - pmd = pmd_offset(pud, address); - if (pmd_none_or_clear_bad(pmd)) - return 1; - pte = pte_offset_kernel(pmd, address); - entry = *pte; - if (unlikely(pte_none(entry) || pte_not_present(entry))) - return 1; - if (unlikely(error_code && !pte_write(entry))) - return 1; - - if (error_code) - entry = pte_mkdirty(entry); - entry = pte_mkyoung(entry); - - set_pte(pte, entry); - -#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SMP) - /* - * SH-4 does not set MMUCR.RC to the corresponding TLB entry in - * the case of an initial page write exception, so we need to - * flush it in order to avoid potential TLB entry duplication. - */ - if (error_code == FAULT_CODE_INITIAL) - local_flush_tlb_one(get_asid(), address & PAGE_MASK); -#endif - - set_thread_fault_code(error_code); - update_mmu_cache(NULL, address, pte); - - return 0; -} diff --git a/arch/sh/mm/fault_64.c b/arch/sh/mm/fault_64.c deleted file mode 100644 index 33a9219..0000000 --- a/arch/sh/mm/fault_64.c +++ /dev/null @@ -1,264 +0,0 @@ -/* - * The SH64 TLB miss. - * - * Original code from fault.c - * Copyright (C) 2000, 2001 Paolo Alberelli - * - * Fast PTE->TLB refill path - * Copyright (C) 2003 Richard.Curnow@superh.com - * - * IMPORTANT NOTES : - * The do_fast_page_fault function is called from a context in entry.S - * where very few registers have been saved. In particular, the code in - * this file must be compiled not to use ANY caller-save registers that - * are not part of the restricted save set. Also, it means that code in - * this file must not make calls to functions elsewhere in the kernel, or - * else the excepting context will see corruption in its caller-save - * registers. Plus, the entry.S save area is non-reentrant, so this code - * has to run with SR.BL==1, i.e. no interrupts taken inside it and panic - * on any exception. - * - * 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. - */ -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -/* Callable from fault.c, so not static */ -inline void __do_tlb_refill(unsigned long address, - unsigned long long is_text_not_data, pte_t *pte) -{ - unsigned long long ptel; - unsigned long long pteh=0; - struct tlb_info *tlbp; - unsigned long long next; - - /* Get PTEL first */ - ptel = pte_val(*pte); - - /* - * Set PTEH register - */ - pteh = neff_sign_extend(address & MMU_VPN_MASK); - - /* Set the ASID. */ - pteh |= get_asid() << PTEH_ASID_SHIFT; - pteh |= PTEH_VALID; - - /* Set PTEL register, set_pte has performed the sign extension */ - ptel &= _PAGE_FLAGS_HARDWARE_MASK; /* drop software flags */ - - tlbp = is_text_not_data ? &(cpu_data->itlb) : &(cpu_data->dtlb); - next = tlbp->next; - __flush_tlb_slot(next); - asm volatile ("putcfg %0,1,%2\n\n\t" - "putcfg %0,0,%1\n" - : : "r" (next), "r" (pteh), "r" (ptel) ); - - next += TLB_STEP; - if (next > tlbp->last) next = tlbp->first; - tlbp->next = next; - -} - -static int handle_vmalloc_fault(struct mm_struct *mm, - unsigned long protection_flags, - unsigned long long textaccess, - unsigned long address) -{ - pgd_t *dir; - pud_t *pud; - pmd_t *pmd; - static pte_t *pte; - pte_t entry; - - dir = pgd_offset_k(address); - - pud = pud_offset(dir, address); - if (pud_none_or_clear_bad(pud)) - return 0; - - pmd = pmd_offset(pud, address); - if (pmd_none_or_clear_bad(pmd)) - return 0; - - pte = pte_offset_kernel(pmd, address); - entry = *pte; - - if (pte_none(entry) || !pte_present(entry)) - return 0; - if ((pte_val(entry) & protection_flags) != protection_flags) - return 0; - - __do_tlb_refill(address, textaccess, pte); - - return 1; -} - -static int handle_tlbmiss(struct mm_struct *mm, - unsigned long long protection_flags, - unsigned long long textaccess, - unsigned long address) -{ - pgd_t *dir; - pud_t *pud; - pmd_t *pmd; - pte_t *pte; - pte_t entry; - - /* NB. The PGD currently only contains a single entry - there is no - page table tree stored for the top half of the address space since - virtual pages in that region should never be mapped in user mode. - (In kernel mode, the only things in that region are the 512Mb super - page (locked in), and vmalloc (modules) + I/O device pages (handled - by handle_vmalloc_fault), so no PGD for the upper half is required - by kernel mode either). - - See how mm->pgd is allocated and initialised in pgd_alloc to see why - the next test is necessary. - RPC */ - if (address >= (unsigned long) TASK_SIZE) - /* upper half - never has page table entries. */ - return 0; - - dir = pgd_offset(mm, address); - if (pgd_none(*dir) || !pgd_present(*dir)) - return 0; - if (!pgd_present(*dir)) - return 0; - - pud = pud_offset(dir, address); - if (pud_none(*pud) || !pud_present(*pud)) - return 0; - - pmd = pmd_offset(pud, address); - if (pmd_none(*pmd) || !pmd_present(*pmd)) - return 0; - - pte = pte_offset_kernel(pmd, address); - entry = *pte; - - if (pte_none(entry) || !pte_present(entry)) - return 0; - - /* - * If the page doesn't have sufficient protection bits set to - * service the kind of fault being handled, there's not much - * point doing the TLB refill. Punt the fault to the general - * handler. - */ - if ((pte_val(entry) & protection_flags) != protection_flags) - return 0; - - __do_tlb_refill(address, textaccess, pte); - - return 1; -} - -/* - * Put all this information into one structure so that everything is just - * arithmetic relative to a single base address. This reduces the number - * of movi/shori pairs needed just to load addresses of static data. - */ -struct expevt_lookup { - unsigned short protection_flags[8]; - unsigned char is_text_access[8]; - unsigned char is_write_access[8]; -}; - -#define PRU (1<<9) -#define PRW (1<<8) -#define PRX (1<<7) -#define PRR (1<<6) - -#define DIRTY (_PAGE_DIRTY | _PAGE_ACCESSED) -#define YOUNG (_PAGE_ACCESSED) - -/* Sized as 8 rather than 4 to allow checking the PTE's PRU bit against whether - the fault happened in user mode or privileged mode. */ -static struct expevt_lookup expevt_lookup_table = { - .protection_flags = {PRX, PRX, 0, 0, PRR, PRR, PRW, PRW}, - .is_text_access = {1, 1, 0, 0, 0, 0, 0, 0} -}; - -/* - This routine handles page faults that can be serviced just by refilling a - TLB entry from an existing page table entry. (This case represents a very - large majority of page faults.) Return 1 if the fault was successfully - handled. Return 0 if the fault could not be handled. (This leads into the - general fault handling in fault.c which deals with mapping file-backed - pages, stack growth, segmentation faults, swapping etc etc) - */ -asmlinkage int do_fast_page_fault(unsigned long long ssr_md, - unsigned long long expevt, - unsigned long address) -{ - struct task_struct *tsk; - struct mm_struct *mm; - unsigned long long textaccess; - unsigned long long protection_flags; - unsigned long long index; - unsigned long long expevt4; - - /* The next few lines implement a way of hashing EXPEVT into a - * small array index which can be used to lookup parameters - * specific to the type of TLBMISS being handled. - * - * Note: - * ITLBMISS has EXPEVT==0xa40 - * RTLBMISS has EXPEVT==0x040 - * WTLBMISS has EXPEVT==0x060 - */ - expevt4 = (expevt >> 4); - /* TODO : xor ssr_md into this expression too. Then we can check - * that PRU is set when it needs to be. */ - index = expevt4 ^ (expevt4 >> 5); - index &= 7; - protection_flags = expevt_lookup_table.protection_flags[index]; - textaccess = expevt_lookup_table.is_text_access[index]; - - /* SIM - * Note this is now called with interrupts still disabled - * This is to cope with being called for a missing IO port - * address with interrupts disabled. This should be fixed as - * soon as we have a better 'fast path' miss handler. - * - * Plus take care how you try and debug this stuff. - * For example, writing debug data to a port which you - * have just faulted on is not going to work. - */ - - tsk = current; - mm = tsk->mm; - - if ((address >= VMALLOC_START && address < VMALLOC_END)) { - if (ssr_md) - /* - * Process-contexts can never have this address - * range mapped - */ - if (handle_vmalloc_fault(mm, protection_flags, - textaccess, address)) - return 1; - } else if (!in_interrupt() && mm) { - if (handle_tlbmiss(mm, protection_flags, textaccess, address)) - return 1; - } - - return 0; -} diff --git a/arch/sh/mm/tlbex_32.c b/arch/sh/mm/tlbex_32.c new file mode 100644 index 0000000..382262d --- /dev/null +++ b/arch/sh/mm/tlbex_32.c @@ -0,0 +1,78 @@ +/* + * TLB miss handler for SH with an MMU. + * + * Copyright (C) 1999 Niibe Yutaka + * Copyright (C) 2003 - 2012 Paul Mundt + * + * 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. + */ +#include +#include +#include +#include +#include +#include + +/* + * Called with interrupts disabled. + */ +asmlinkage int __kprobes +handle_tlbmiss(struct pt_regs *regs, unsigned long error_code, + unsigned long address) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + pte_t entry; + + /* + * We don't take page faults for P1, P2, and parts of P4, these + * are always mapped, whether it be due to legacy behaviour in + * 29-bit mode, or due to PMB configuration in 32-bit mode. + */ + if (address >= P3SEG && address < P3_ADDR_MAX) { + pgd = pgd_offset_k(address); + } else { + if (unlikely(address >= TASK_SIZE || !current->mm)) + return 1; + + pgd = pgd_offset(current->mm, address); + } + + pud = pud_offset(pgd, address); + if (pud_none_or_clear_bad(pud)) + return 1; + pmd = pmd_offset(pud, address); + if (pmd_none_or_clear_bad(pmd)) + return 1; + pte = pte_offset_kernel(pmd, address); + entry = *pte; + if (unlikely(pte_none(entry) || pte_not_present(entry))) + return 1; + if (unlikely(error_code && !pte_write(entry))) + return 1; + + if (error_code) + entry = pte_mkdirty(entry); + entry = pte_mkyoung(entry); + + set_pte(pte, entry); + +#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SMP) + /* + * SH-4 does not set MMUCR.RC to the corresponding TLB entry in + * the case of an initial page write exception, so we need to + * flush it in order to avoid potential TLB entry duplication. + */ + if (error_code == FAULT_CODE_INITIAL) + local_flush_tlb_one(get_asid(), address & PAGE_MASK); +#endif + + set_thread_fault_code(error_code); + update_mmu_cache(NULL, address, pte); + + return 0; +} diff --git a/arch/sh/mm/tlbex_64.c b/arch/sh/mm/tlbex_64.c new file mode 100644 index 0000000..d15b994 --- /dev/null +++ b/arch/sh/mm/tlbex_64.c @@ -0,0 +1,264 @@ +/* + * The SH64 TLB miss. + * + * Original code from fault.c + * Copyright (C) 2000, 2001 Paolo Alberelli + * + * Fast PTE->TLB refill path + * Copyright (C) 2003 Richard.Curnow@superh.com + * + * IMPORTANT NOTES : + * The do_fast_page_fault function is called from a context in entry.S + * where very few registers have been saved. In particular, the code in + * this file must be compiled not to use ANY caller-save registers that + * are not part of the restricted save set. Also, it means that code in + * this file must not make calls to functions elsewhere in the kernel, or + * else the excepting context will see corruption in its caller-save + * registers. Plus, the entry.S save area is non-reentrant, so this code + * has to run with SR.BL==1, i.e. no interrupts taken inside it and panic + * on any exception. + * + * 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. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* Callable from fault.c, so not static */ +inline void __do_tlb_refill(unsigned long address, + unsigned long long is_text_not_data, pte_t *pte) +{ + unsigned long long ptel; + unsigned long long pteh=0; + struct tlb_info *tlbp; + unsigned long long next; + + /* Get PTEL first */ + ptel = pte_val(*pte); + + /* + * Set PTEH register + */ + pteh = neff_sign_extend(address & MMU_VPN_MASK); + + /* Set the ASID. */ + pteh |= get_asid() << PTEH_ASID_SHIFT; + pteh |= PTEH_VALID; + + /* Set PTEL register, set_pte has performed the sign extension */ + ptel &= _PAGE_FLAGS_HARDWARE_MASK; /* drop software flags */ + + tlbp = is_text_not_data ? &(cpu_data->itlb) : &(cpu_data->dtlb); + next = tlbp->next; + __flush_tlb_slot(next); + asm volatile ("putcfg %0,1,%2\n\n\t" + "putcfg %0,0,%1\n" + : : "r" (next), "r" (pteh), "r" (ptel) ); + + next += TLB_STEP; + if (next > tlbp->last) next = tlbp->first; + tlbp->next = next; + +} + +static int handle_vmalloc_fault(struct mm_struct *mm, + unsigned long protection_flags, + unsigned long long textaccess, + unsigned long address) +{ + pgd_t *dir; + pud_t *pud; + pmd_t *pmd; + static pte_t *pte; + pte_t entry; + + dir = pgd_offset_k(address); + + pud = pud_offset(dir, address); + if (pud_none_or_clear_bad(pud)) + return 0; + + pmd = pmd_offset(pud, address); + if (pmd_none_or_clear_bad(pmd)) + return 0; + + pte = pte_offset_kernel(pmd, address); + entry = *pte; + + if (pte_none(entry) || !pte_present(entry)) + return 0; + if ((pte_val(entry) & protection_flags) != protection_flags) + return 0; + + __do_tlb_refill(address, textaccess, pte); + + return 1; +} + +static int handle_tlbmiss(struct mm_struct *mm, + unsigned long long protection_flags, + unsigned long long textaccess, + unsigned long address) +{ + pgd_t *dir; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + pte_t entry; + + /* NB. The PGD currently only contains a single entry - there is no + page table tree stored for the top half of the address space since + virtual pages in that region should never be mapped in user mode. + (In kernel mode, the only things in that region are the 512Mb super + page (locked in), and vmalloc (modules) + I/O device pages (handled + by handle_vmalloc_fault), so no PGD for the upper half is required + by kernel mode either). + + See how mm->pgd is allocated and initialised in pgd_alloc to see why + the next test is necessary. - RPC */ + if (address >= (unsigned long) TASK_SIZE) + /* upper half - never has page table entries. */ + return 0; + + dir = pgd_offset(mm, address); + if (pgd_none(*dir) || !pgd_present(*dir)) + return 0; + if (!pgd_present(*dir)) + return 0; + + pud = pud_offset(dir, address); + if (pud_none(*pud) || !pud_present(*pud)) + return 0; + + pmd = pmd_offset(pud, address); + if (pmd_none(*pmd) || !pmd_present(*pmd)) + return 0; + + pte = pte_offset_kernel(pmd, address); + entry = *pte; + + if (pte_none(entry) || !pte_present(entry)) + return 0; + + /* + * If the page doesn't have sufficient protection bits set to + * service the kind of fault being handled, there's not much + * point doing the TLB refill. Punt the fault to the general + * handler. + */ + if ((pte_val(entry) & protection_flags) != protection_flags) + return 0; + + __do_tlb_refill(address, textaccess, pte); + + return 1; +} + +/* + * Put all this information into one structure so that everything is just + * arithmetic relative to a single base address. This reduces the number + * of movi/shori pairs needed just to load addresses of static data. + */ +struct expevt_lookup { + unsigned short protection_flags[8]; + unsigned char is_text_access[8]; + unsigned char is_write_access[8]; +}; + +#define PRU (1<<9) +#define PRW (1<<8) +#define PRX (1<<7) +#define PRR (1<<6) + +#define DIRTY (_PAGE_DIRTY | _PAGE_ACCESSED) +#define YOUNG (_PAGE_ACCESSED) + +/* Sized as 8 rather than 4 to allow checking the PTE's PRU bit against whether + the fault happened in user mode or privileged mode. */ +static struct expevt_lookup expevt_lookup_table = { + .protection_flags = {PRX, PRX, 0, 0, PRR, PRR, PRW, PRW}, + .is_text_access = {1, 1, 0, 0, 0, 0, 0, 0} +}; + +/* + This routine handles page faults that can be serviced just by refilling a + TLB entry from an existing page table entry. (This case represents a very + large majority of page faults.) Return 1 if the fault was successfully + handled. Return 0 if the fault could not be handled. (This leads into the + general fault handling in fault.c which deals with mapping file-backed + pages, stack growth, segmentation faults, swapping etc etc) + */ +asmlinkage int do_fast_page_fault(unsigned long long ssr_md, + unsigned long long expevt, + unsigned long address) +{ + struct task_struct *tsk; + struct mm_struct *mm; + unsigned long long textaccess; + unsigned long long protection_flags; + unsigned long long index; + unsigned long long expevt4; + + /* The next few lines implement a way of hashing EXPEVT into a + * small array index which can be used to lookup parameters + * specific to the type of TLBMISS being handled. + * + * Note: + * ITLBMISS has EXPEVT==0xa40 + * RTLBMISS has EXPEVT==0x040 + * WTLBMISS has EXPEVT==0x060 + */ + expevt4 = (expevt >> 4); + /* TODO : xor ssr_md into this expression too. Then we can check + * that PRU is set when it needs to be. */ + index = expevt4 ^ (expevt4 >> 5); + index &= 7; + protection_flags = expevt_lookup_table.protection_flags[index]; + textaccess = expevt_lookup_table.is_text_access[index]; + + /* SIM + * Note this is now called with interrupts still disabled + * This is to cope with being called for a missing IO port + * address with interrupts disabled. This should be fixed as + * soon as we have a better 'fast path' miss handler. + * + * Plus take care how you try and debug this stuff. + * For example, writing debug data to a port which you + * have just faulted on is not going to work. + */ + + tsk = current; + mm = tsk->mm; + + if (is_vmalloc_addr((void *)address)) { + if (ssr_md) + /* + * Process-contexts can never have this address + * range mapped + */ + if (handle_vmalloc_fault(mm, protection_flags, + textaccess, address)) + return 1; + } else if (!in_interrupt() && mm) { + if (handle_tlbmiss(mm, protection_flags, textaccess, address)) + return 1; + } + + return 0; +} diff --git a/arch/sh/mm/tlbflush_64.c b/arch/sh/mm/tlbflush_64.c index 99c5833..908167b 100644 --- a/arch/sh/mm/tlbflush_64.c +++ b/arch/sh/mm/tlbflush_64.c @@ -28,249 +28,6 @@ #include #include -static pte_t *lookup_pte(struct mm_struct *mm, unsigned long address) -{ - pgd_t *dir; - pud_t *pud; - pmd_t *pmd; - pte_t *pte; - pte_t entry; - - dir = pgd_offset(mm, address); - if (pgd_none(*dir)) - return NULL; - - pud = pud_offset(dir, address); - if (pud_none(*pud)) - return NULL; - - pmd = pmd_offset(pud, address); - if (pmd_none(*pmd)) - return NULL; - - pte = pte_offset_kernel(pmd, address); - entry = *pte; - if (pte_none(entry) || !pte_present(entry)) - return NULL; - - return pte; -} - -/* - * 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 error_code, - unsigned long address) -{ - struct task_struct *tsk; - struct mm_struct *mm; - struct vm_area_struct * vma; - const struct exception_table_entry *fixup; - int write = error_code & FAULT_CODE_WRITE; - int textaccess = error_code & FAULT_CODE_ITLB; - unsigned int flags = (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (write ? FAULT_FLAG_WRITE : 0)); - pte_t *pte; - int fault; - - /* SIM - * Note this is now called with interrupts still disabled - * This is to cope with being called for a missing IO port - * address with interrupts disabled. This should be fixed as - * soon as we have a better 'fast path' miss handler. - * - * Plus take care how you try and debug this stuff. - * For example, writing debug data to a port which you - * have just faulted on is not going to work. - */ - - tsk = current; - mm = tsk->mm; - - /* Not an IO address, so reenable interrupts */ - local_irq_enable(); - - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); - - /* - * If we're in an interrupt or have no user - * context, we must not take the fault.. - */ - if (in_atomic() || !mm) - goto no_context; - -retry: - /* TLB misses upon some cache flushes get done under cli() */ - 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: - if (textaccess) { - if (!(vma->vm_flags & VM_EXEC)) - goto bad_area; - } else { - if (write) { - if (!(vma->vm_flags & VM_WRITE)) - goto bad_area; - } else { - if (!(vma->vm_flags & VM_READ)) - goto bad_area; - } - } - - /* - * 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_SIGBUS) - goto do_sigbus; - BUG(); - } - - if (flags & FAULT_FLAG_ALLOW_RETRY) { - if (fault & VM_FAULT_MAJOR) { - tsk->maj_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, - regs, address); - } else { - tsk->min_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, - regs, address); - } - - if (fault & VM_FAULT_RETRY) { - flags &= ~FAULT_FLAG_ALLOW_RETRY; - - /* - * 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; - } - } - - /* If we get here, the page fault has been handled. Do the TLB refill - now from the newly-setup PTE, to avoid having to fault again right - away on the same instruction. */ - pte = lookup_pte (mm, address); - if (!pte) { - /* From empirical evidence, we can get here, due to - !pte_present(pte). (e.g. if a swap-in occurs, and the page - is swapped back out again before the process that wanted it - gets rescheduled?) */ - goto no_pte; - } - - __do_tlb_refill(address, textaccess, pte); - -no_pte: - - 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); - - if (user_mode(regs)) { - static int count=0; - siginfo_t info; - if (count < 4) { - /* This is really to help debug faults when starting - * usermode, so only need a few */ - count++; - printk("user mode bad_area address=%08lx pid=%d (%s) pc=%08lx\n", - address, task_pid_nr(current), current->comm, - (unsigned long) regs->pc); - } - if (is_global_init(tsk)) { - panic("INIT had user mode bad_area\n"); - } - tsk->thread.address = address; - info.si_signo = SIGSEGV; - info.si_errno = 0; - info.si_addr = (void *) address; - force_sig_info(SIGSEGV, &info, tsk); - return; - } - -no_context: - /* Are we prepared to handle this kernel fault? */ - fixup = search_exception_tables(regs->pc); - if (fixup) { - regs->pc = fixup->fixup; - return; - } - -/* - * Oops. The kernel tried to access some bad page. We'll have to - * terminate things with extreme prejudice. - * - */ - if (address < PAGE_SIZE) - printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference"); - else - printk(KERN_ALERT "Unable to handle kernel paging request"); - printk(" at virtual address %08lx\n", address); - printk(KERN_ALERT "pc = %08Lx%08Lx\n", regs->pc >> 32, regs->pc & 0xffffffff); - die("Oops", regs, error_code); - do_exit(SIGKILL); - -/* - * 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: - printk("fault:Do sigbus\n"); - up_read(&mm->mmap_sem); - - /* - * Send a sigbus, regardless of whether we were in kernel - * or user mode. - */ - tsk->thread.address = address; - force_sig(SIGBUS, tsk); - - /* Kernel mode? Handle exceptions or die */ - if (!user_mode(regs)) - goto no_context; -} - void local_flush_tlb_one(unsigned long asid, unsigned long page) { unsigned long long match, pteh=0, lpage; -- cgit v1.1