diff options
Diffstat (limited to 'arch/unicore32/mm/fault.c')
-rw-r--r-- | arch/unicore32/mm/fault.c | 481 |
1 files changed, 0 insertions, 481 deletions
diff --git a/arch/unicore32/mm/fault.c b/arch/unicore32/mm/fault.c deleted file mode 100644 index 7654bddde133..000000000000 --- a/arch/unicore32/mm/fault.c +++ /dev/null @@ -1,481 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * linux/arch/unicore32/mm/fault.c - * - * Code specific to PKUnity SoC and UniCore ISA - * - * Copyright (C) 2001-2010 GUAN Xue-tao - */ -#include <linux/extable.h> -#include <linux/signal.h> -#include <linux/mm.h> -#include <linux/hardirq.h> -#include <linux/init.h> -#include <linux/kprobes.h> -#include <linux/uaccess.h> -#include <linux/page-flags.h> -#include <linux/sched/signal.h> -#include <linux/io.h> - -#include <asm/tlbflush.h> - -/* - * Fault status register encodings. We steal bit 31 for our own purposes. - */ -#define FSR_LNX_PF (1 << 31) - -static inline int fsr_fs(unsigned int fsr) -{ - /* xyabcde will be abcde+xy */ - return (fsr & 31) + ((fsr & (3 << 5)) >> 5); -} - -/* - * This is useful to dump out the page tables associated with - * 'addr' in mm 'mm'. - */ -void show_pte(struct mm_struct *mm, unsigned long addr) -{ - pgd_t *pgd; - - if (!mm) - mm = &init_mm; - - printk(KERN_ALERT "pgd = %p\n", mm->pgd); - pgd = pgd_offset(mm, addr); - printk(KERN_ALERT "[%08lx] *pgd=%08lx", addr, pgd_val(*pgd)); - - do { - pmd_t *pmd; - pte_t *pte; - - if (pgd_none(*pgd)) - break; - - if (pgd_bad(*pgd)) { - printk("(bad)"); - break; - } - - pmd = pmd_offset((pud_t *) pgd, addr); - if (PTRS_PER_PMD != 1) - printk(", *pmd=%08lx", 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_map(pmd, addr); - printk(", *pte=%08lx", pte_val(*pte)); - pte_unmap(pte); - } while (0); - - printk("\n"); -} - -/* - * Oops. The kernel tried to access some page that wasn't present. - */ -static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr, - unsigned int fsr, struct pt_regs *regs) -{ - /* - * Are we prepared to handle this kernel fault? - */ - if (fixup_exception(regs)) - return; - - /* - * No handler, we'll have to terminate things with extreme prejudice. - */ - bust_spinlocks(1); - printk(KERN_ALERT - "Unable to handle kernel %s at virtual address %08lx\n", - (addr < PAGE_SIZE) ? "NULL pointer dereference" : - "paging request", addr); - - show_pte(mm, addr); - die("Oops", regs, fsr); - bust_spinlocks(0); - do_exit(SIGKILL); -} - -/* - * Something tried to access memory that isn't in our memory map.. - * User mode accesses just cause a SIGSEGV - */ -static void __do_user_fault(unsigned long addr, unsigned int fsr, - unsigned int sig, int code, struct pt_regs *regs) -{ - struct task_struct *tsk = current; - - tsk->thread.address = addr; - tsk->thread.error_code = fsr; - tsk->thread.trap_no = 14; - force_sig_fault(sig, code, (void __user *)addr); -} - -void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs) -{ - struct task_struct *tsk = current; - struct mm_struct *mm = tsk->active_mm; - - /* - * If we are in kernel mode at this point, we - * have no context to handle this fault with. - */ - if (user_mode(regs)) - __do_user_fault(addr, fsr, SIGSEGV, SEGV_MAPERR, regs); - else - __do_kernel_fault(mm, addr, fsr, regs); -} - -#define VM_FAULT_BADMAP 0x010000 -#define VM_FAULT_BADACCESS 0x020000 - -/* - * Check that the permissions on the VMA allow for the fault which occurred. - * If we encountered a write fault, we must have write permission, otherwise - * we allow any permission. - */ -static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma) -{ - unsigned int mask = VM_ACCESS_FLAGS; - - if (!(fsr ^ 0x12)) /* write? */ - mask = VM_WRITE; - if (fsr & FSR_LNX_PF) - mask = VM_EXEC; - - return vma->vm_flags & mask ? false : true; -} - -static vm_fault_t __do_pf(struct mm_struct *mm, unsigned long addr, - unsigned int fsr, unsigned int flags, struct task_struct *tsk) -{ - struct vm_area_struct *vma; - vm_fault_t fault; - - vma = find_vma(mm, addr); - fault = VM_FAULT_BADMAP; - if (unlikely(!vma)) - goto out; - if (unlikely(vma->vm_start > addr)) - goto check_stack; - - /* - * Ok, we have a good vm_area for this - * memory access, so we can handle it. - */ -good_area: - if (access_error(fsr, vma)) { - fault = VM_FAULT_BADACCESS; - goto out; - } - - /* - * 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(vma, addr & PAGE_MASK, flags); - return fault; - -check_stack: - if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) - goto good_area; -out: - return fault; -} - -static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs) -{ - struct task_struct *tsk; - struct mm_struct *mm; - int sig, code; - vm_fault_t fault; - unsigned int flags = FAULT_FLAG_DEFAULT; - - tsk = current; - mm = tsk->mm; - - /* - * If we're in an interrupt or have no user - * context, we must not take the fault.. - */ - if (faulthandler_disabled() || !mm) - goto no_context; - - if (user_mode(regs)) - flags |= FAULT_FLAG_USER; - if (!(fsr ^ 0x12)) - flags |= FAULT_FLAG_WRITE; - - /* - * As per x86, we may deadlock here. However, since the kernel only - * validly references user space from well defined areas of the code, - * we can bug out early if this is from code which shouldn't. - */ - if (!mmap_read_trylock(mm)) { - if (!user_mode(regs) - && !search_exception_tables(regs->UCreg_pc)) - goto no_context; -retry: - mmap_read_lock(mm); - } else { - /* - * The above down_read_trylock() might have succeeded in - * which case, we'll have missed the might_sleep() from - * down_read() - */ - might_sleep(); -#ifdef CONFIG_DEBUG_VM - if (!user_mode(regs) && - !search_exception_tables(regs->UCreg_pc)) - goto no_context; -#endif - } - - fault = __do_pf(mm, addr, fsr, flags, tsk); - - /* If we need to retry but a fatal signal is pending, handle the - * signal first. We do not need to release the mmap_lock because - * it would already be released in __lock_page_or_retry in - * mm/filemap.c. */ - if (fault_signal_pending(fault, regs)) - return 0; - - if (!(fault & VM_FAULT_ERROR) && (flags & FAULT_FLAG_ALLOW_RETRY)) { - if (fault & VM_FAULT_MAJOR) - tsk->maj_flt++; - else - tsk->min_flt++; - if (fault & VM_FAULT_RETRY) { - flags |= FAULT_FLAG_TRIED; - goto retry; - } - } - - mmap_read_unlock(mm); - - /* - * Handle the "normal" case first - VM_FAULT_MAJOR - */ - if (likely(!(fault & - (VM_FAULT_ERROR | VM_FAULT_BADMAP | VM_FAULT_BADACCESS)))) - return 0; - - /* - * If we are in kernel mode at this point, we - * have no context to handle this fault with. - */ - if (!user_mode(regs)) - goto no_context; - - if (fault & VM_FAULT_OOM) { - /* - * We ran out of memory, call the OOM killer, and return to - * userspace (which will retry the fault, or kill us if we - * got oom-killed) - */ - pagefault_out_of_memory(); - return 0; - } - - if (fault & VM_FAULT_SIGBUS) { - /* - * We had some memory, but were unable to - * successfully fix up this page fault. - */ - sig = SIGBUS; - code = BUS_ADRERR; - } else { - /* - * Something tried to access memory that - * isn't in our memory map.. - */ - sig = SIGSEGV; - code = fault == VM_FAULT_BADACCESS ? SEGV_ACCERR : SEGV_MAPERR; - } - - __do_user_fault(addr, fsr, sig, code, regs); - return 0; - -no_context: - __do_kernel_fault(mm, addr, fsr, regs); - return 0; -} - -/* - * First Level Translation Fault Handler - * - * We enter here because the first level page table doesn't contain - * a valid entry for the address. - * - * If the address is in kernel space (>= TASK_SIZE), then we are - * probably faulting in the vmalloc() area. - * - * If the init_task's first level page tables contains the relevant - * entry, we copy the it to this task. If not, we send the process - * a signal, fixup the exception, or oops the kernel. - * - * 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. - */ -static int do_ifault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) -{ - unsigned int index; - pgd_t *pgd, *pgd_k; - pmd_t *pmd, *pmd_k; - - if (addr < TASK_SIZE) - return do_pf(addr, fsr, regs); - - if (user_mode(regs)) - goto bad_area; - - index = pgd_index(addr); - - pgd = cpu_get_pgd() + index; - pgd_k = init_mm.pgd + index; - - if (pgd_none(*pgd_k)) - goto bad_area; - - pmd_k = pmd_offset((pud_t *) pgd_k, addr); - pmd = pmd_offset((pud_t *) pgd, addr); - - if (pmd_none(*pmd_k)) - goto bad_area; - - set_pmd(pmd, *pmd_k); - flush_pmd_entry(pmd); - return 0; - -bad_area: - do_bad_area(addr, fsr, regs); - return 0; -} - -/* - * This abort handler always returns "fault". - */ -static int do_bad(unsigned long addr, unsigned int fsr, struct pt_regs *regs) -{ - return 1; -} - -static int do_good(unsigned long addr, unsigned int fsr, struct pt_regs *regs) -{ - unsigned int res1, res2; - - printk("dabt exception but no error!\n"); - - __asm__ __volatile__( - "mff %0,f0\n" - "mff %1,f1\n" - : "=r"(res1), "=r"(res2) - : - : "memory"); - - printk(KERN_EMERG "r0 :%08x r1 :%08x\n", res1, res2); - panic("shut up\n"); - return 0; -} - -static struct fsr_info { - int (*fn) (unsigned long addr, unsigned int fsr, struct pt_regs *regs); - int sig; - int code; - const char *name; -} fsr_info[] = { - /* - * The following are the standard Unicore-I and UniCore-II aborts. - */ - { do_good, SIGBUS, 0, "no error" }, - { do_bad, SIGBUS, BUS_ADRALN, "alignment exception" }, - { do_bad, SIGBUS, BUS_OBJERR, "external exception" }, - { do_bad, SIGBUS, 0, "burst operation" }, - { do_bad, SIGBUS, 0, "unknown 00100" }, - { do_ifault, SIGSEGV, SEGV_MAPERR, "2nd level pt non-exist"}, - { do_bad, SIGBUS, 0, "2nd lvl large pt non-exist" }, - { do_bad, SIGBUS, 0, "invalid pte" }, - { do_pf, SIGSEGV, SEGV_MAPERR, "page miss" }, - { do_bad, SIGBUS, 0, "middle page miss" }, - { do_bad, SIGBUS, 0, "large page miss" }, - { do_pf, SIGSEGV, SEGV_MAPERR, "super page (section) miss" }, - { do_bad, SIGBUS, 0, "unknown 01100" }, - { do_bad, SIGBUS, 0, "unknown 01101" }, - { do_bad, SIGBUS, 0, "unknown 01110" }, - { do_bad, SIGBUS, 0, "unknown 01111" }, - { do_bad, SIGBUS, 0, "addr: up 3G or IO" }, - { do_pf, SIGSEGV, SEGV_ACCERR, "read unreadable addr" }, - { do_pf, SIGSEGV, SEGV_ACCERR, "write unwriteable addr"}, - { do_pf, SIGSEGV, SEGV_ACCERR, "exec unexecutable addr"}, - { do_bad, SIGBUS, 0, "unknown 10100" }, - { do_bad, SIGBUS, 0, "unknown 10101" }, - { do_bad, SIGBUS, 0, "unknown 10110" }, - { do_bad, SIGBUS, 0, "unknown 10111" }, - { do_bad, SIGBUS, 0, "unknown 11000" }, - { do_bad, SIGBUS, 0, "unknown 11001" }, - { do_bad, SIGBUS, 0, "unknown 11010" }, - { do_bad, SIGBUS, 0, "unknown 11011" }, - { do_bad, SIGBUS, 0, "unknown 11100" }, - { do_bad, SIGBUS, 0, "unknown 11101" }, - { do_bad, SIGBUS, 0, "unknown 11110" }, - { do_bad, SIGBUS, 0, "unknown 11111" } -}; - -void __init hook_fault_code(int nr, - int (*fn) (unsigned long, unsigned int, struct pt_regs *), - int sig, int code, const char *name) -{ - if (nr < 0 || nr >= ARRAY_SIZE(fsr_info)) - BUG(); - - fsr_info[nr].fn = fn; - fsr_info[nr].sig = sig; - fsr_info[nr].code = code; - fsr_info[nr].name = name; -} - -/* - * Dispatch a data abort to the relevant handler. - */ -asmlinkage void do_DataAbort(unsigned long addr, unsigned int fsr, - struct pt_regs *regs) -{ - const struct fsr_info *inf = fsr_info + fsr_fs(fsr); - - if (!inf->fn(addr, fsr & ~FSR_LNX_PF, regs)) - return; - - printk(KERN_ALERT "Unhandled fault: %s (0x%03x) at 0x%08lx\n", - inf->name, fsr, addr); - - uc32_notify_die("", regs, inf->sig, inf->code, (void __user *)addr, - fsr, 0); -} - -asmlinkage void do_PrefetchAbort(unsigned long addr, - unsigned int ifsr, struct pt_regs *regs) -{ - const struct fsr_info *inf = fsr_info + fsr_fs(ifsr); - - if (!inf->fn(addr, ifsr | FSR_LNX_PF, regs)) - return; - - printk(KERN_ALERT "Unhandled prefetch abort: %s (0x%03x) at 0x%08lx\n", - inf->name, ifsr, addr); - - uc32_notify_die("", regs, inf->sig, inf->code, (void __user *)addr, - ifsr, 0); -} |