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authorAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>2006-06-26 03:25:27 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-26 12:58:22 -0400
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 fdbba4206d59..a0a9e1e0061e 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -40,6 +40,40 @@
40#include <asm/kdebug.h> 40#include <asm/kdebug.h>
41#include <asm/siginfo.h> 41#include <asm/siginfo.h>
42 42
43#ifdef CONFIG_KPROBES
44ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
45
46/* Hook to register for page fault notifications */
47int register_page_fault_notifier(struct notifier_block *nb)
48{
49 return atomic_notifier_chain_register(&notify_page_fault_chain, nb);
50}
51
52int unregister_page_fault_notifier(struct notifier_block *nb)
53{
54 return atomic_notifier_chain_unregister(&notify_page_fault_chain, nb);
55}
56
57static inline int notify_page_fault(enum die_val val, const char *str,
58 struct pt_regs *regs, long err, int trap, int sig)
59{
60 struct die_args args = {
61 .regs = regs,
62 .str = str,
63 .err = err,
64 .trapnr = trap,
65 .signr = sig
66 };
67 return atomic_notifier_call_chain(&notify_page_fault_chain, val, &args);
68}
69#else
70static inline int notify_page_fault(enum die_val val, const char *str,
71 struct pt_regs *regs, long err, int trap, int sig)
72{
73 return NOTIFY_DONE;
74}
75#endif
76
43/* 77/*
44 * Check whether the instruction at regs->nip is a store using 78 * Check whether the instruction at regs->nip is a store using
45 * an update addressing form which will update r1. 79 * an update addressing form which will update r1.
@@ -142,7 +176,7 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
142 is_write = error_code & ESR_DST; 176 is_write = error_code & ESR_DST;
143#endif /* CONFIG_4xx || CONFIG_BOOKE */ 177#endif /* CONFIG_4xx || CONFIG_BOOKE */
144 178
145 if (notify_die(DIE_PAGE_FAULT, "page_fault", regs, error_code, 179 if (notify_page_fault(DIE_PAGE_FAULT, "page_fault", regs, error_code,
146 11, SIGSEGV) == NOTIFY_STOP) 180 11, SIGSEGV) == NOTIFY_STOP)
147 return 0; 181 return 0;
148 182