Commit d98f8f05 authored by Anil S Keshavamurthy's avatar Anil S Keshavamurthy Committed by Linus Torvalds
Browse files

[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: default avatarAnil S Keshavamurthy <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 4f9e87c0
......@@ -31,6 +31,40 @@
#include <asm/kdebug.h>
#include <asm/mmu_context.h>
/* 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);
static inline int notify_page_fault(enum die_val val, const char *str,
struct pt_regs *regs, long err, int trap, int sig)
* 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)
......@@ -17,6 +17,8 @@ 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 *);
extern struct atomic_notifier_head sparc64die_chain;
extern void bad_trap(struct pt_regs *, long);
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment