diff options
Diffstat (limited to 'arch/m68k/mm/fault.c')
| -rw-r--r-- | arch/m68k/mm/fault.c | 88 |
1 files changed, 47 insertions, 41 deletions
diff --git a/arch/m68k/mm/fault.c b/arch/m68k/mm/fault.c index a96394a0333..2bd7487440c 100644 --- a/arch/m68k/mm/fault.c +++ b/arch/m68k/mm/fault.c @@ -13,12 +13,10 @@ #include <asm/setup.h> #include <asm/traps.h> -#include <asm/system.h> #include <asm/uaccess.h> #include <asm/pgalloc.h> extern void die_if_kernel(char *, struct pt_regs *, long); -extern const int frame_extra_sizes[]; /* in m68k/kernel/signal.c */ int send_fault_sig(struct pt_regs *regs) { @@ -27,29 +25,15 @@ int send_fault_sig(struct pt_regs *regs) siginfo.si_signo = current->thread.signo; siginfo.si_code = current->thread.code; siginfo.si_addr = (void *)current->thread.faddr; -#ifdef DEBUG - printk("send_fault_sig: %p,%d,%d\n", siginfo.si_addr, siginfo.si_signo, siginfo.si_code); -#endif + pr_debug("send_fault_sig: %p,%d,%d\n", siginfo.si_addr, + siginfo.si_signo, siginfo.si_code); if (user_mode(regs)) { force_sig_info(siginfo.si_signo, &siginfo, current); } else { - const struct exception_table_entry *fixup; - - /* Are we prepared to handle this kernel fault? */ - if ((fixup = search_exception_tables(regs->pc))) { - struct pt_regs *tregs; - /* Create a new four word stack frame, discarding the old - one. */ - regs->stkadj = frame_extra_sizes[regs->format]; - tregs = (struct pt_regs *)((ulong)regs + regs->stkadj); - tregs->vector = regs->vector; - tregs->format = 0; - tregs->pc = fixup->fixup; - tregs->sr = regs->sr; + if (handle_kernel_fault(regs)) return -1; - } //if (siginfo.si_signo == SIGBUS) // force_sig_info(siginfo.si_signo, @@ -60,10 +44,10 @@ int send_fault_sig(struct pt_regs *regs) * terminate things with extreme prejudice. */ if ((unsigned long)siginfo.si_addr < PAGE_SIZE) - printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference"); + pr_alert("Unable to handle kernel NULL pointer dereference"); else - printk(KERN_ALERT "Unable to handle kernel access"); - printk(" at virtual address %p\n", siginfo.si_addr); + pr_alert("Unable to handle kernel access"); + pr_cont(" at virtual address %p\n", siginfo.si_addr); die_if_kernel("Oops", regs, 0 /*error_code*/); do_exit(SIGKILL); } @@ -87,13 +71,11 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, { struct mm_struct *mm = current->mm; struct vm_area_struct * vma; - int write, fault; + int fault; + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; -#ifdef DEBUG - printk ("do page fault:\nregs->sr=%#x, regs->pc=%#lx, address=%#lx, %ld, %p\n", - regs->sr, regs->pc, address, error_code, - current->mm->pgd); -#endif + pr_debug("do page fault:\nregs->sr=%#x, regs->pc=%#lx, address=%#lx, %ld, %p\n", + regs->sr, regs->pc, address, error_code, mm ? mm->pgd : NULL); /* * If we're in an interrupt or have no user @@ -102,6 +84,9 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, if (in_atomic() || !mm) goto no_context; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; +retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); @@ -129,17 +114,14 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, * we can handle it.. */ good_area: -#ifdef DEBUG - printk("do_page_fault: good_area\n"); -#endif - write = 0; + pr_debug("do_page_fault: good_area\n"); switch (error_code & 3) { default: /* 3: write, present */ /* fall through */ case 2: /* write, not present */ if (!(vma->vm_flags & VM_WRITE)) goto acc_err; - write++; + flags |= FAULT_FLAG_WRITE; break; case 1: /* read, present */ goto acc_err; @@ -154,10 +136,12 @@ good_area: * the fault. */ - fault = handle_mm_fault(mm, vma, address, write ? FAULT_FLAG_WRITE : 0); -#ifdef DEBUG - printk("handle_mm_fault returns %d\n",fault); -#endif + fault = handle_mm_fault(mm, vma, address, flags); + pr_debug("handle_mm_fault returns %d\n", fault); + + if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) + return 0; + if (unlikely(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_OOM) goto out_of_memory; @@ -165,10 +149,32 @@ good_area: goto bus_err; BUG(); } - if (fault & VM_FAULT_MAJOR) - current->maj_flt++; - else - current->min_flt++; + + /* + * 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 0; |