X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fi386%2Fmm%2Ffault.c;h=7f0fcf219a26e4cec52d2e5bbd729601c356d261;hb=9464c7cf61b9433057924c36e6e02f303a00e768;hp=f7279468323a62cef22984f3e81707eaa6a93b4b;hpb=41689045f6a3cbe0550e1d34e9cc20d2e8c432ba;p=linux-2.6.git

diff --git a/arch/i386/mm/fault.c b/arch/i386/mm/fault.c
index f72794683..7f0fcf219 100644
--- a/arch/i386/mm/fault.c
+++ b/arch/i386/mm/fault.c
@@ -30,40 +30,6 @@
 
 extern void die(const char *,struct pt_regs *,long);
 
-#ifdef CONFIG_KPROBES
-ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
-int register_page_fault_notifier(struct notifier_block *nb)
-{
-	vmalloc_sync_all();
-	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
-
-
 /*
  * Unlock any spinlocks which will prevent us from getting the
  * message out 
@@ -111,15 +77,12 @@ static inline unsigned long get_segment_eip(struct pt_regs *regs,
 	unsigned seg = regs->xcs & 0xffff;
 	u32 seg_ar, seg_limit, base, *desc;
 
-	/* Unlikely, but must come before segment checks. */
-	if (unlikely(regs->eflags & VM_MASK)) {
-		base = seg << 4;
-		*eip_limit = base + 0xffff;
-		return base + (eip & 0xffff);
-	}
-
 	/* The standard kernel/user address space limit. */
 	*eip_limit = (seg & 3) ? USER_DS.seg : KERNEL_DS.seg;
+
+	/* Unlikely, but must come before segment checks. */
+	if (unlikely((regs->eflags & VM_MASK) != 0))
+		return eip + (seg << 4);
 	
 	/* By far the most common cases. */
 	if (likely(seg == __USER_CS || seg == __KERNEL_CS))
@@ -358,7 +321,7 @@ fastcall void __kprobes do_page_fault(struct pt_regs *regs,
 	if (unlikely(address >= TASK_SIZE)) {
 		if (!(error_code & 0x0000000d) && vmalloc_fault(address) >= 0)
 			return;
-		if (notify_page_fault(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
+		if (notify_die(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
 						SIGSEGV) == NOTIFY_STOP)
 			return;
 		/*
@@ -368,7 +331,7 @@ fastcall void __kprobes do_page_fault(struct pt_regs *regs,
 		goto bad_area_nosemaphore;
 	}
 
-	if (notify_page_fault(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
+	if (notify_die(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
 					SIGSEGV) == NOTIFY_STOP)
 		return;
 
@@ -389,7 +352,7 @@ fastcall void __kprobes do_page_fault(struct pt_regs *regs,
 	/* When running in the kernel we expect faults to occur only to
 	 * addresses in user space.  All other faults represent errors in the
 	 * kernel and should generate an OOPS.  Unfortunatly, in the case of an
-	 * erroneous fault occurring in a code path which already holds mmap_sem
+	 * erroneous fault occuring in a code path which already holds mmap_sem
 	 * we will deadlock attempting to validate the fault against the
 	 * address space.  Luckily the kernel only validly references user
 	 * space from well defined areas of code, which are listed in the
@@ -417,12 +380,12 @@ fastcall void __kprobes do_page_fault(struct pt_regs *regs,
 		goto bad_area;
 	if (error_code & 4) {
 		/*
-		 * Accessing the stack below %esp is always a bug.
-		 * The large cushion allows instructions like enter
-		 * and pusha to work.  ("enter $65535,$31" pushes
-		 * 32 pointers and then decrements %esp by 65535.)
+		 * accessing the stack below %esp is always a bug.
+		 * The "+ 32" is there due to some instructions (like
+		 * pusha) doing post-decrement on the stack and that
+		 * doesn't show up until later..
 		 */
-		if (address + 65536 + 32 * sizeof(unsigned long) < regs->esp)
+		if (address + 32 < regs->esp)
 			goto bad_area;
 	}
 	if (expand_stack(vma, address))