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authorAnanth N Mavinakayanahalli <ananth@in.ibm.com>2005-11-07 01:00:14 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2005-11-07 07:53:46 -0800
commit991a51d83a3d9bebfafdd1e692cf310899d60791 (patch)
tree4cc6eaa2a868838e59c7737da9868f2358f2bb19 /arch/sparc64
parent3516a46042508a495fac13c2e73530d936ebe015 (diff)
[PATCH] Kprobes: Use RCU for (un)register synchronization - arch changes
Changes to the arch kprobes infrastructure to take advantage of the locking changes introduced by usage of RCU for synchronization. All handlers are now run without any locks held, so they have to be re-entrant or provide their own synchronization. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> 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/kernel/kprobes.c14
1 files changed, 2 insertions, 12 deletions
diff --git a/arch/sparc64/kernel/kprobes.c b/arch/sparc64/kernel/kprobes.c
index b95984154dba..58a815e90373 100644
--- a/arch/sparc64/kernel/kprobes.c
+++ b/arch/sparc64/kernel/kprobes.c
@@ -116,15 +116,11 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
if (kprobe_running()) {
- /* We *are* holding lock here, so this is safe.
- * Disarm the probe we just hit, and ignore it.
- */
p = get_kprobe(addr);
if (p) {
if (kcb->kprobe_status == KPROBE_HIT_SS) {
regs->tstate = ((regs->tstate & ~TSTATE_PIL) |
kcb->kprobe_orig_tstate_pil);
- unlock_kprobes();
goto no_kprobe;
}
/* We have reentered the kprobe_handler(), since
@@ -144,14 +140,11 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
if (p->break_handler && p->break_handler(p, regs))
goto ss_probe;
}
- /* If it's not ours, can't be delete race, (we hold lock). */
goto no_kprobe;
}
- lock_kprobes();
p = get_kprobe(addr);
if (!p) {
- unlock_kprobes();
if (*(u32 *)addr != BREAKPOINT_INSTRUCTION) {
/*
* The breakpoint instruction was removed right
@@ -296,14 +289,12 @@ static inline int post_kprobe_handler(struct pt_regs *regs)
goto out;
}
reset_current_kprobe();
- unlock_kprobes();
out:
preempt_enable_no_resched();
return 1;
}
-/* Interrupts disabled, kprobe_lock held. */
static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
struct kprobe *cur = kprobe_running();
@@ -316,7 +307,6 @@ static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
resume_execution(cur, regs, kcb);
reset_current_kprobe();
- unlock_kprobes();
preempt_enable_no_resched();
}
return 0;
@@ -331,7 +321,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
struct die_args *args = (struct die_args *)data;
int ret = NOTIFY_DONE;
- preempt_disable();
+ rcu_read_lock();
switch (val) {
case DIE_DEBUG:
if (kprobe_handler(args->regs))
@@ -350,7 +340,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
default:
break;
}
- preempt_enable();
+ rcu_read_unlock();
return ret;
}