The patch titled
powerpc: minor fault path optimization
has been added to the -mm tree. Its filename is
powerpc-minor-fault-path-optimization.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: powerpc: minor fault path optimization
From: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Call the kprobes pagefault handler directly instead of going through
the complex notifier chain.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/kprobes.c | 10 --------
arch/powerpc/mm/fault.c | 40 +++++++++++---------------------
include/asm-powerpc/kdebug.h | 17 +++++++++++--
include/asm-powerpc/kprobes.h | 1
4 files changed, 30 insertions(+), 38 deletions(-)
diff -puN arch/powerpc/kernel/kprobes.c~powerpc-minor-fault-path-optimization arch/powerpc/kernel/kprobes.c
--- a/arch/powerpc/kernel/kprobes.c~powerpc-minor-fault-path-optimization
+++ a/arch/powerpc/kernel/kprobes.c
@@ -410,7 +410,7 @@ out:
return 1;
}
-static int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
@@ -495,14 +495,6 @@ int __kprobes kprobe_exceptions_notify(s
if (post_kprobe_handler(args->regs))
ret = NOTIFY_STOP;
break;
- case DIE_PAGE_FAULT:
- /* kprobe_running() needs smp_processor_id() */
- preempt_disable();
- if (kprobe_running() &&
- kprobe_fault_handler(args->regs, args->trapnr))
- ret = NOTIFY_STOP;
- preempt_enable();
- break;
default:
break;
}
diff -puN arch/powerpc/mm/fault.c~powerpc-minor-fault-path-optimization arch/powerpc/mm/fault.c
--- a/arch/powerpc/mm/fault.c~powerpc-minor-fault-path-optimization
+++ a/arch/powerpc/mm/fault.c
@@ -39,37 +39,26 @@
#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)
+#ifdef CONFIG_KPROBES
+static inline int notify_page_fault(struct pt_regs *regs)
{
- return atomic_notifier_chain_register(¬ify_page_fault_chain, nb);
-}
+ int ret = 0;
-int unregister_page_fault_notifier(struct notifier_block *nb)
-{
- return atomic_notifier_chain_unregister(¬ify_page_fault_chain, nb);
-}
+ /* kprobe_running() needs smp_processor_id() */
+ if (!user_mode(regs)) {
+ preempt_disable();
+ if (kprobe_running() && kprobe_fault_handler(regs, 11))
+ ret = 1;
+ preempt_enable();
+ }
-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(¬ify_page_fault_chain, val, &args);
+ return ret;
}
#else
-static inline int notify_page_fault(enum die_val val, const char *str,
- struct pt_regs *regs, long err, int trap, int sig)
+static inline int notify_page_fault(struct pt_regs *regs)
{
- return NOTIFY_DONE;
+ return 0;
}
#endif
@@ -175,8 +164,7 @@ int __kprobes do_page_fault(struct pt_re
is_write = error_code & ESR_DST;
#endif /* CONFIG_4xx || CONFIG_BOOKE */
- if (notify_page_fault(DIE_PAGE_FAULT, "page_fault", regs, error_code,
- 11, SIGSEGV) == NOTIFY_STOP)
+ if (notify_page_fault(regs))
return 0;
if (trap == 0x300) {
diff -puN include/asm-powerpc/kdebug.h~powerpc-minor-fault-path-optimization include/asm-powerpc/kdebug.h
--- a/include/asm-powerpc/kdebug.h~powerpc-minor-fault-path-optimization
+++ a/include/asm-powerpc/kdebug.h
@@ -18,8 +18,20 @@ struct die_args {
extern int register_die_notifier(struct notifier_block *);
extern int unregister_die_notifier(struct notifier_block *);
-extern int register_page_fault_notifier(struct notifier_block *);
-extern int unregister_page_fault_notifier(struct notifier_block *);
+
+/*
+ * These are only here because kprobes.c wants them to implement a
+ * blatant layering violation. Will hopefully go away soon once all
+ * architectures are updated.
+ */
+static inline int register_page_fault_notifier(struct notifier_block *nb)
+{
+ return 0;
+}
+static inline int unregister_page_fault_notifier(struct notifier_block *nb)
+{
+ return 0;
+}
extern struct atomic_notifier_head powerpc_die_chain;
/* Grossly misnamed. */
@@ -29,7 +41,6 @@ enum die_val {
DIE_DABR_MATCH,
DIE_BPT,
DIE_SSTEP,
- DIE_PAGE_FAULT,
};
static inline int notify_die(enum die_val val,char *str,struct pt_regs *regs,long err,int trap, int sig)
diff -puN include/asm-powerpc/kprobes.h~powerpc-minor-fault-path-optimization include/asm-powerpc/kprobes.h
--- a/include/asm-powerpc/kprobes.h~powerpc-minor-fault-path-optimization
+++ a/include/asm-powerpc/kprobes.h
@@ -110,5 +110,6 @@ struct kprobe_ctlblk {
extern int kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data);
+extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_KPROBES_H */
_
Patches currently in -mm which might be from hch@xxxxxxxxxxxxx are
origin.patch
powerpc-minor-fault-path-optimization.patch
dvb_en_50221-convert-to-kthread-api.patch
git-nfs-server-cluster-locking-api.patch
remove-pci_dac_dma_-apis.patch
vfs-delay-the-dentry-name-generation-on-sockets-and.patch
consolidate-generic_writepages-and-mpage_writepages.patch
udf-use-sector_t-and-loff_t-for-file-offsets.patch
udf-introduce-struct-extent_position.patch
udf-use-get_bh.patch
udf-add-assertions.patch
udf-support-files-larger-than-1g.patch
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