From: Masami Hiramatsu <mhiramat@kernel.org>
To: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@kernel.org>
Cc: x86@kernel.org, Masami Hiramatsu <mhiramat@kernel.org>,
Yang Bo <yangbo@deepin.com>, Ingo Molnar <mingo@redhat.com>,
"H . Peter Anvin" <hpa@zytor.com>,
linux-kernel@vger.kernel.org,
Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Steven Rostedt <rostedt@goodmis.org>,
Laura Abbott <labbott@redhat.com>, Josef Bacik <jbacik@fb.com>,
Alexei Starovoitov <ast@kernel.org>
Subject: [RFC PATCH -tip 4/9] kprobes: Ignore break_handler
Date: Fri, 9 Mar 2018 21:37:17 +0900 [thread overview]
Message-ID: <152059903731.4214.9268892607457902327.stgit@devbox> (raw)
In-Reply-To: <152059891712.4214.9539716544254881611.stgit@devbox>
Ignore break_handler related code because it was only
used by jprobe and jprobe is removed.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
Documentation/kprobes.txt | 2 +-
kernel/kprobes.c | 39 +++++----------------------------------
2 files changed, 6 insertions(+), 35 deletions(-)
diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt
index 22208bf2386d..94df43224c6c 100644
--- a/Documentation/kprobes.txt
+++ b/Documentation/kprobes.txt
@@ -262,7 +262,7 @@ is optimized, that modification is ignored. Thus, if you want to
tweak the kernel's execution path, you need to suppress optimization,
using one of the following techniques:
-- Specify an empty function for the kprobe's post_handler or break_handler.
+- Specify an empty function for the kprobe's post_handler.
or
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 6d5a7c29cf99..889986ee3d06 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -627,8 +627,8 @@ static void optimize_kprobe(struct kprobe *p)
(kprobe_disabled(p) || kprobes_all_disarmed))
return;
- /* Both of break_handler and post_handler are not supported. */
- if (p->break_handler || p->post_handler)
+ /* kprobes with post_handler can not be optimized */
+ if (p->post_handler)
return;
op = container_of(p, struct optimized_kprobe, kp);
@@ -1116,20 +1116,6 @@ static int aggr_fault_handler(struct kprobe *p, struct pt_regs *regs,
}
NOKPROBE_SYMBOL(aggr_fault_handler);
-static int aggr_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe *cur = __this_cpu_read(kprobe_instance);
- int ret = 0;
-
- if (cur && cur->break_handler) {
- if (cur->break_handler(cur, regs))
- ret = 1;
- }
- reset_kprobe_instance();
- return ret;
-}
-NOKPROBE_SYMBOL(aggr_break_handler);
-
/* Walks the list and increments nmissed count for multiprobe case */
void kprobes_inc_nmissed_count(struct kprobe *p)
{
@@ -1270,24 +1256,15 @@ static void cleanup_rp_inst(struct kretprobe *rp)
}
NOKPROBE_SYMBOL(cleanup_rp_inst);
-/*
-* Add the new probe to ap->list. Fail if this is the
-* second break_handler at the address
-*/
+/* Add the new probe to ap->list */
static int add_new_kprobe(struct kprobe *ap, struct kprobe *p)
{
BUG_ON(kprobe_gone(ap) || kprobe_gone(p));
- if (p->break_handler || p->post_handler)
+ if (p->post_handler)
unoptimize_kprobe(ap, true); /* Fall back to normal kprobe */
- if (p->break_handler) {
- if (ap->break_handler)
- return -EEXIST;
- list_add_tail_rcu(&p->list, &ap->list);
- ap->break_handler = aggr_break_handler;
- } else
- list_add_rcu(&p->list, &ap->list);
+ list_add_rcu(&p->list, &ap->list);
if (p->post_handler && !ap->post_handler)
ap->post_handler = aggr_post_handler;
@@ -1310,8 +1287,6 @@ static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p)
/* We don't care the kprobe which has gone. */
if (p->post_handler && !kprobe_gone(p))
ap->post_handler = aggr_post_handler;
- if (p->break_handler && !kprobe_gone(p))
- ap->break_handler = aggr_break_handler;
INIT_LIST_HEAD(&ap->list);
INIT_HLIST_NODE(&ap->hlist);
@@ -1706,8 +1681,6 @@ static int __unregister_kprobe_top(struct kprobe *p)
goto disarmed;
else {
/* If disabling probe has special handlers, update aggrprobe */
- if (p->break_handler && !kprobe_gone(p))
- ap->break_handler = NULL;
if (p->post_handler && !kprobe_gone(p)) {
list_for_each_entry_rcu(list_p, &ap->list, list) {
if ((list_p != p) && (list_p->post_handler))
@@ -1911,7 +1884,6 @@ int register_kretprobe(struct kretprobe *rp)
rp->kp.pre_handler = pre_handler_kretprobe;
rp->kp.post_handler = NULL;
rp->kp.fault_handler = NULL;
- rp->kp.break_handler = NULL;
/* Pre-allocate memory for max kretprobe instances */
if (rp->maxactive <= 0) {
@@ -2034,7 +2006,6 @@ static void kill_kprobe(struct kprobe *p)
list_for_each_entry_rcu(kp, &p->list, list)
kp->flags |= KPROBE_FLAG_GONE;
p->post_handler = NULL;
- p->break_handler = NULL;
kill_optimized_kprobe(p);
}
/*
next prev parent reply other threads:[~2018-03-09 12:37 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-09 12:35 [RFC PATCH -tip 0/9] kprobes: Cleanup jprobe implementation Masami Hiramatsu
2018-03-09 12:35 ` [RFC PATCH -tip 1/9] kprobes: Remove jprobe API implementation Masami Hiramatsu
2018-03-09 12:36 ` [RFC PATCH -tip 2/9] x86: kprobes: Remove jprobe implementation Masami Hiramatsu
2018-03-09 12:36 ` [RFC PATCH -tip 3/9] kprobes: Remove jprobe data structure and interfaces Masami Hiramatsu
2018-03-09 12:37 ` Masami Hiramatsu [this message]
2018-03-09 12:37 ` [RFC PATCH -tip 5/9] x86: kprobes: Ignore break_handler Masami Hiramatsu
2018-03-09 12:38 ` [RFC PATCH -tip 6/9] kprobes: Remove break_handler from struct kprobe Masami Hiramatsu
2018-03-09 12:38 ` [RFC PATCH -tip 7/9] x86: kprobes: Do not disable preempt on int3 path Masami Hiramatsu
2018-03-09 12:39 ` [RFC PATCH -tip 8/9] error-injection: Fix to not enabling preemption in pre_handler Masami Hiramatsu
2018-03-10 8:22 ` Ingo Molnar
2018-03-11 15:05 ` Masami Hiramatsu
2018-03-09 12:39 ` [RFC PATCH -tip 9/9] tracing: kprobes: Fix to not enabling preemption Masami Hiramatsu
2018-03-09 23:54 ` [RFC PATCH -tip 0/9] kprobes: Cleanup jprobe implementation Steven Rostedt
2018-03-10 13:55 ` Masami Hiramatsu
2018-03-10 8:24 ` Ingo Molnar
2018-03-11 15:13 ` Masami Hiramatsu
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