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authorAnil S Keshavamurthy2006-06-26 00:25:27 -0700
committerLinus Torvalds2006-06-26 09:58:22 -0700
commitd98f8f05188b45168db43df8ddc9feeb0b1cd512 (patch)
tree505edc88aa4e8ec3593d7a218c470e7cb9640fb7 /arch/sparc64
parent4f9e87c0454059e80f3811f95ad9f40ed28c69a2 (diff)
[PATCH] Notify page fault call chain for sparc64
Overloading of page fault notification with the notify_die() has performance issues(since the only interested components for page fault is kprobes and/or kdb) and hence this patch introduces the new notifier call chain exclusively for page fault notifications their by avoiding notifying unnecessary components in the do_page_fault() code path. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/sparc64')
-rw-r--r--arch/sparc64/mm/fault.c36
1 files changed, 35 insertions, 1 deletions
diff --git a/arch/sparc64/mm/fault.c b/arch/sparc64/mm/fault.c
index 6e002aacb961..1605967cce91 100644
--- a/arch/sparc64/mm/fault.c
+++ b/arch/sparc64/mm/fault.c
@@ -31,6 +31,40 @@
#include <asm/kdebug.h>
#include <asm/mmu_context.h>
+#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
+
/*
* To debug kernel to catch accesses to certain virtual/physical addresses.
* Mode = 0 selects physical watchpoints, mode = 1 selects virtual watchpoints.
@@ -263,7 +297,7 @@ asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
fault_code = get_thread_fault_code();
- if (notify_die(DIE_PAGE_FAULT, "page_fault", regs,
+ if (notify_page_fault(DIE_PAGE_FAULT, "page_fault", regs,
fault_code, 0, SIGSEGV) == NOTIFY_STOP)
return;