X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fia64%2Fmm%2Ffault.c;h=5cb5ab612b6f399bebf61f3aba2be88d000655c1;hb=refs%2Fheads%2Fvserver;hp=ea0308f905bd07f325326d175b9fe168518f5e0f;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git

diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c
index ea0308f90..5cb5ab612 100644
--- a/arch/ia64/mm/fault.c
+++ b/arch/ia64/mm/fault.c
@@ -20,6 +20,40 @@
 
 extern void die (char *, struct pt_regs *, long);
 
+#ifdef CONFIG_KPROBES
+ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
+
+/* Hook to register for page fault notifications */
+int register_page_fault_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&notify_page_fault_chain, nb);
+}
+
+int unregister_page_fault_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_unregister(&notify_page_fault_chain, nb);
+}
+
+static inline int notify_page_fault(enum die_val val, const char *str,
+			struct pt_regs *regs, long err, int trap, int sig)
+{
+	struct die_args args = {
+		.regs = regs,
+		.str = str,
+		.err = err,
+		.trapnr = trap,
+		.signr = sig
+	};
+	return atomic_notifier_call_chain(&notify_page_fault_chain, val, &args);
+}
+#else
+static inline int notify_page_fault(enum die_val val, const char *str,
+			struct pt_regs *regs, long err, int trap, int sig)
+{
+	return NOTIFY_DONE;
+}
+#endif
+
 /*
  * Return TRUE if ADDRESS points at a page in the kernel's mapped segment
  * (inside region 5, on ia64) and that page is present.
@@ -61,6 +95,9 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
 	struct siginfo si;
 	unsigned long mask;
 
+	/* mmap_sem is performance critical.... */
+	prefetchw(&mm->mmap_sem);
+
 	/*
 	 * If we're in an interrupt or have no user context, we must not take the fault..
 	 */
@@ -82,7 +119,7 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
 	/*
 	 * This is to handle the kprobes on user space access instructions
 	 */
-	if (notify_die(DIE_PAGE_FAULT, "page fault", regs, code, TRAP_BRKPT,
+	if (notify_page_fault(DIE_PAGE_FAULT, "page fault", regs, code, TRAP_BRKPT,
 					SIGSEGV) == NOTIFY_STOP)
 		return;
 
@@ -110,9 +147,11 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
 #		error File is out of sync with <linux/mm.h>.  Please update.
 #	endif
 
+	if (((isr >> IA64_ISR_R_BIT) & 1UL) && (!(vma->vm_flags & (VM_READ | VM_WRITE))))
+		goto bad_area;
+
 	mask = (  (((isr >> IA64_ISR_X_BIT) & 1UL) << VM_EXEC_BIT)
-		| (((isr >> IA64_ISR_W_BIT) & 1UL) << VM_WRITE_BIT)
-		| (((isr >> IA64_ISR_R_BIT) & 1UL) << VM_READ_BIT));
+		| (((isr >> IA64_ISR_W_BIT) & 1UL) << VM_WRITE_BIT));
 
 	if ((vma->vm_flags & mask) != mask)
 		goto bad_area;
@@ -242,7 +281,7 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
 
   out_of_memory:
 	up_read(&mm->mmap_sem);
-	if (current->pid == 1) {
+	if (is_init(current)) {
 		yield();
 		down_read(&mm->mmap_sem);
 		goto survive;