From 36721656776f177280ccb50477a02e86e6444292 Mon Sep 17 00:00:00 2001 From: "mao, bibo" Date: Mon, 26 Jun 2006 00:25:22 -0700 Subject: [PATCH] [PATCH] Kprobe: multi kprobe posthandler for booster If there are multi kprobes on the same probepoint, there will be one extra aggr_kprobe on the head of kprobe list. The aggr_kprobe has aggr_post_handler/aggr_break_handler whether the other kprobe post_hander/break_handler is NULL or not. This patch modifies this, only when there is one or more kprobe in the list whose post_handler is not NULL, post_handler of aggr_kprobe will be set as aggr_post_handler. [soshima@redhat.com: !CONFIG_PREEMPT fix] Signed-off-by: bibo, mao Cc: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: "Keshavamurthy, Anil S" Cc: Prasanna S Panchamukhi Cc: Jim Keniston Cc: Yumiko Sugita Cc: Hideo Aoki Signed-off-by: Satoshi Oshima Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/kprobes.c | 16 +++++----------- kernel/kprobes.c | 32 ++++++++++++++++++++++++-------- 2 files changed, 29 insertions(+), 19 deletions(-) diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c index 37f86234bdd7..727e419ad78a 100644 --- a/arch/i386/kernel/kprobes.c +++ b/arch/i386/kernel/kprobes.c @@ -259,7 +259,9 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) struct kprobe_ctlblk *kcb; #ifdef CONFIG_PREEMPT unsigned pre_preempt_count = preempt_count(); -#endif /* CONFIG_PREEMPT */ +#else + unsigned pre_preempt_count = 1; +#endif addr = (kprobe_opcode_t *)(regs->eip - sizeof(kprobe_opcode_t)); @@ -336,22 +338,14 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) /* handler has already set things up, so skip ss setup */ return 1; - if (p->ainsn.boostable == 1 && -#ifdef CONFIG_PREEMPT - !(pre_preempt_count) && /* - * This enables booster when the direct - * execution path aren't preempted. - */ -#endif /* CONFIG_PREEMPT */ - !p->post_handler && !p->break_handler ) { +ss_probe: + if (pre_preempt_count && p->ainsn.boostable == 1 && !p->post_handler){ /* Boost up -- we can execute copied instructions directly */ reset_current_kprobe(); regs->eip = (unsigned long)p->ainsn.insn; preempt_enable_no_resched(); return 1; } - -ss_probe: prepare_singlestep(p, regs); kcb->kprobe_status = KPROBE_HIT_SS; return 1; diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 1fbf466a29aa..f095178e48c3 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -368,16 +368,15 @@ static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p) */ static int __kprobes add_new_kprobe(struct kprobe *old_p, struct kprobe *p) { - struct kprobe *kp; - if (p->break_handler) { - list_for_each_entry_rcu(kp, &old_p->list, list) { - if (kp->break_handler) - return -EEXIST; - } + if (old_p->break_handler) + return -EEXIST; list_add_tail_rcu(&p->list, &old_p->list); + old_p->break_handler = aggr_break_handler; } else list_add_rcu(&p->list, &old_p->list); + if (p->post_handler && !old_p->post_handler) + old_p->post_handler = aggr_post_handler; return 0; } @@ -390,9 +389,11 @@ static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p) copy_kprobe(p, ap); ap->addr = p->addr; ap->pre_handler = aggr_pre_handler; - ap->post_handler = aggr_post_handler; ap->fault_handler = aggr_fault_handler; - ap->break_handler = aggr_break_handler; + if (p->post_handler) + ap->post_handler = aggr_post_handler; + if (p->break_handler) + ap->break_handler = aggr_break_handler; INIT_LIST_HEAD(&ap->list); list_add_rcu(&p->list, &ap->list); @@ -536,6 +537,21 @@ valid_p: kfree(old_p); } arch_remove_kprobe(p); + } else { + mutex_lock(&kprobe_mutex); + if (p->break_handler) + old_p->break_handler = NULL; + if (p->post_handler){ + list_for_each_entry_rcu(list_p, &old_p->list, list){ + if (list_p->post_handler){ + cleanup_p = 2; + break; + } + } + if (cleanup_p == 0) + old_p->post_handler = NULL; + } + mutex_unlock(&kprobe_mutex); } } -- 2.20.1