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@@ -300,3 +300,86 @@ retry:
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*/
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might_sleep();
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#ifdef CONFIG_DEBUG_VM
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+ if (!user_mode(regs) &&
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+ !search_exception_tables(regs->ARM_pc))
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+ goto no_context;
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+#endif
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+ }
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+
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+ fault = __do_page_fault(mm, addr, fsr, flags, tsk);
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+
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+ /* If we need to retry but a fatal signal is pending, handle the
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+ * signal first. We do not need to release the mmap_sem because
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+ * it would already be released in __lock_page_or_retry in
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+ * mm/filemap.c. */
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+ if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
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+ return 0;
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+
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+ /*
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+ * Major/minor page fault accounting is only done on the
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+ * initial attempt. If we go through a retry, it is extremely
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+ * likely that the page will be found in page cache at that point.
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+ */
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+
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+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
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+ if (!(fault & VM_FAULT_ERROR) && flags & FAULT_FLAG_ALLOW_RETRY) {
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+ if (fault & VM_FAULT_MAJOR) {
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+ tsk->maj_flt++;
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+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1,
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+ regs, addr);
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+ } else {
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+ tsk->min_flt++;
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+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1,
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+ regs, addr);
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+ }
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+ if (fault & VM_FAULT_RETRY) {
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+ /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk
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+ * of starvation. */
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+ flags &= ~FAULT_FLAG_ALLOW_RETRY;
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+ flags |= FAULT_FLAG_TRIED;
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+ goto retry;
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+ }
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+ }
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+
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+ up_read(&mm->mmap_sem);
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+
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+ /*
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+ * Handle the "normal" case first - VM_FAULT_MAJOR / VM_FAULT_MINOR
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+ */
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+ if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | VM_FAULT_BADACCESS))))
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+ return 0;
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+
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+ if (fault & VM_FAULT_OOM) {
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+ /*
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+ * We ran out of memory, call the OOM killer, and return to
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+ * userspace (which will retry the fault, or kill us if we
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+ * got oom-killed)
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+ */
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+ pagefault_out_of_memory();
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+ return 0;
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+ }
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+
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+ /*
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+ * If we are in kernel mode at this point, we
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+ * have no context to handle this fault with.
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+ */
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+ if (!user_mode(regs))
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+ goto no_context;
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+
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+ if (fault & VM_FAULT_SIGBUS) {
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+ /*
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+ * We had some memory, but were unable to
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+ * successfully fix up this page fault.
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+ */
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+ sig = SIGBUS;
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+ code = BUS_ADRERR;
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+ } else {
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+ /*
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+ * Something tried to access memory that
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+ * isn't in our memory map..
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+ */
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+ sig = SIGSEGV;
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+ code = fault == VM_FAULT_BADACCESS ?
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+ SEGV_ACCERR : SEGV_MAPERR;
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+ }
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+
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