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authorAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>2006-06-26 00:25:27 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-26 09:58:22 -0700
commit4f9e87c0454059e80f3811f95ad9f40ed28c69a2 (patch)
treecc8290b8fc757b34e01a4e9c25bbe00496400084 /arch/powerpc
parentae9a5b85655d7133ab8e7c99b742ef20c8dbb7d2 (diff)
[PATCH] Notify page fault call chain for powerpc
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/powerpc')
-rw-r--r--arch/powerpc/mm/fault.c36
1 files changed, 35 insertions, 1 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index fdbba4206d5..a0a9e1e0061 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -40,6 +40,40 @@
#include <asm/kdebug.h>
#include <asm/siginfo.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
+
/*
* Check whether the instruction at regs->nip is a store using
* an update addressing form which will update r1.
@@ -142,7 +176,7 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
is_write = error_code & ESR_DST;
#endif /* CONFIG_4xx || CONFIG_BOOKE */
- if (notify_die(DIE_PAGE_FAULT, "page_fault", regs, error_code,
+ if (notify_page_fault(DIE_PAGE_FAULT, "page_fault", regs, error_code,
11, SIGSEGV) == NOTIFY_STOP)
return 0;