aboutsummaryrefslogtreecommitdiffstats
path: root/arch/unicore32/mm/fault.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/unicore32/mm/fault.c')
-rw-r--r--arch/unicore32/mm/fault.c481
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);
-}
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-04-26 22:11:10 +0000