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| author | Ananth N Mavinakayanahalli <ananth@in.ibm.com> | 2005-11-07 10:00:14 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-07 16:53:46 +0100 |
| commit | d217d5450f11d8c907c0458d175b0dc999b4d06d (patch) | |
| tree | ebd68eb9e0b632049d22240a3589887ca27077a5 /arch/sparc64/kernel/kprobes.c | |
| parent | [PATCH] Kprobes: Use RCU for (un)register synchronization - arch changes (diff) | |
| download | linux-d217d5450f11d8c907c0458d175b0dc999b4d06d.tar.xz linux-d217d5450f11d8c907c0458d175b0dc999b4d06d.zip | |
[PATCH] Kprobes: preempt_disable/enable() simplification
Reorganize the preempt_disable/enable calls to eliminate the extra preempt
depth. Changes based on Paul McKenney's review suggestions for the kprobes
RCU changeset.
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/kernel/kprobes.c')
| -rw-r--r-- | arch/sparc64/kernel/kprobes.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/arch/sparc64/kernel/kprobes.c b/arch/sparc64/kernel/kprobes.c index 58a815e90373..96bd09b098f4 100644 --- a/arch/sparc64/kernel/kprobes.c +++ b/arch/sparc64/kernel/kprobes.c @@ -113,7 +113,14 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) struct kprobe *p; void *addr = (void *) regs->tpc; int ret = 0; - struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + struct kprobe_ctlblk *kcb; + + /* + * We don't want to be preempted for the entire + * duration of kprobe processing + */ + preempt_disable(); + kcb = get_kprobe_ctlblk(); if (kprobe_running()) { p = get_kprobe(addr); @@ -159,11 +166,6 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) goto no_kprobe; } - /* - * This preempt_disable() matches the preempt_enable_no_resched() - * in post_kprobes_handler() - */ - preempt_disable(); set_current_kprobe(p, regs, kcb); kcb->kprobe_status = KPROBE_HIT_ACTIVE; if (p->pre_handler && p->pre_handler(p, regs)) @@ -175,6 +177,7 @@ ss_probe: return 1; no_kprobe: + preempt_enable_no_resched(); return ret; } @@ -321,7 +324,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, struct die_args *args = (struct die_args *)data; int ret = NOTIFY_DONE; - rcu_read_lock(); switch (val) { case DIE_DEBUG: if (kprobe_handler(args->regs)) @@ -333,14 +335,16 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, break; case DIE_GPF: 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; } - rcu_read_unlock(); return ret; } @@ -426,6 +430,7 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) &(kcb->jprobe_saved_stack), sizeof(kcb->jprobe_saved_stack)); + preempt_enable_no_resched(); return 1; } return 0; |