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From: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
To: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>,
	Andi Kleen <andi@firstfloor.org>,
	Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
	Sandeepa Prabhu <sandeepa.prabhu@linaro.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	x86@kernel.org, Steven Rostedt <rostedt@goodmis.org>,
	fche@redhat.com, mingo@redhat.com, Rob Landley <rob@landley.net>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	"David S. Miller" <davem@davemloft.net>,
	systemtap@sourceware.org
Subject: [PATCH -tip v9 20/26] kprobes: Support blacklist functions in module
Date: Thu, 17 Apr 2014 17:18:56 +0900
Message-ID: <20140417081856.26341.53535.stgit@ltc230.yrl.intra.hitachi.co.jp> (raw)
In-Reply-To: <20140417081636.26341.87858.stgit@ltc230.yrl.intra.hitachi.co.jp>

To blacklist the functions in a module (e.g. user-defined
kprobe handler and the functions invoked from it), expand
blacklist support for modules.
With this change, users can use NOKPROBE_SYMBOL() macro in
their own modules.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Rob Landley <rob@landley.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
---
 Documentation/kprobes.txt |    8 ++++++
 include/linux/module.h    |    5 ++++
 kernel/kprobes.c          |   63 ++++++++++++++++++++++++++++++++++++++-------
 kernel/module.c           |    6 ++++
 4 files changed, 72 insertions(+), 10 deletions(-)

diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt
index 4bbeca8..2845956 100644
--- a/Documentation/kprobes.txt
+++ b/Documentation/kprobes.txt
@@ -512,6 +512,14 @@ int enable_jprobe(struct jprobe *jp);
 Enables *probe which has been disabled by disable_*probe(). You must specify
 the probe which has been registered.
 
+4.9 NOKPROBE_SYMBOL()
+
+#include <linux/kprobes.h>
+NOKPROBE_SYMBOL(FUNCTION);
+
+Protects given FUNCTION from other kprobes. This is useful for handler
+functions and functions called from the handlers.
+
 5. Kprobes Features and Limitations
 
 Kprobes allows multiple probes at the same address.  Currently,
diff --git a/include/linux/module.h b/include/linux/module.h
index f520a76..2fdb673 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -16,6 +16,7 @@
 #include <linux/kobject.h>
 #include <linux/moduleparam.h>
 #include <linux/jump_label.h>
+#include <linux/kprobes.h>
 #include <linux/export.h>
 
 #include <linux/percpu.h>
@@ -357,6 +358,10 @@ struct module {
 	unsigned int num_ftrace_callsites;
 	unsigned long *ftrace_callsites;
 #endif
+#ifdef CONFIG_KPROBES
+	unsigned int num_kprobe_blacklist;
+	unsigned long  *kprobe_blacklist;
+#endif
 
 #ifdef CONFIG_MODULE_UNLOAD
 	/* What modules depend on me? */
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 3214289..8319048 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -88,6 +88,7 @@ static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash)
 
 /* Blacklist -- list of struct kprobe_blacklist_entry */
 static LIST_HEAD(kprobe_blacklist);
+static DEFINE_MUTEX(kprobe_blacklist_mutex);
 
 #ifdef __ARCH_WANT_KPROBES_INSN_SLOT
 /*
@@ -1331,22 +1332,27 @@ bool __weak arch_within_kprobe_blacklist(unsigned long addr)
 	       addr < (unsigned long)__kprobes_text_end;
 }
 
-static bool within_kprobe_blacklist(unsigned long addr)
+static struct kprobe_blacklist_entry *find_blacklist_entry(unsigned long addr)
 {
 	struct kprobe_blacklist_entry *ent;
 
+	list_for_each_entry(ent, &kprobe_blacklist, list) {
+		if (addr >= ent->start_addr && addr < ent->end_addr)
+			return ent;
+	}
+
+	return NULL;
+}
+
+static bool within_kprobe_blacklist(unsigned long addr)
+{
 	if (arch_within_kprobe_blacklist(addr))
 		return true;
 	/*
 	 * If there exists a kprobe_blacklist, verify and
 	 * fail any probe registration in the prohibited area
 	 */
-	list_for_each_entry(ent, &kprobe_blacklist, list) {
-		if (addr >= ent->start_addr && addr < ent->end_addr)
-			return true;
-	}
-
-	return false;
+	return !!find_blacklist_entry(addr);
 }
 
 /*
@@ -1432,6 +1438,7 @@ static int check_kprobe_address_safe(struct kprobe *p,
 #endif
 	}
 
+	mutex_lock(&kprobe_blacklist_mutex);
 	jump_label_lock();
 	preempt_disable();
 
@@ -1469,6 +1476,7 @@ static int check_kprobe_address_safe(struct kprobe *p,
 out:
 	preempt_enable();
 	jump_label_unlock();
+	mutex_unlock(&kprobe_blacklist_mutex);
 
 	return ret;
 }
@@ -2032,13 +2040,13 @@ NOKPROBE_SYMBOL(dump_kprobe);
  * since a kprobe need not necessarily be at the beginning
  * of a function.
  */
-static int __init populate_kprobe_blacklist(unsigned long *start,
-					     unsigned long *end)
+static int populate_kprobe_blacklist(unsigned long *start, unsigned long *end)
 {
 	unsigned long *iter;
 	struct kprobe_blacklist_entry *ent;
 	unsigned long offset = 0, size = 0;
 
+	mutex_lock(&kprobe_blacklist_mutex);
 	for (iter = start; iter < end; iter++) {
 		if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) {
 			pr_err("Failed to find blacklist %p\n", (void *)*iter);
@@ -2053,9 +2061,28 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
 		INIT_LIST_HEAD(&ent->list);
 		list_add_tail(&ent->list, &kprobe_blacklist);
 	}
+	mutex_unlock(&kprobe_blacklist_mutex);
+
 	return 0;
 }
 
+/* Shrink the blacklist */
+static void shrink_kprobe_blacklist(unsigned long *start, unsigned long *end)
+{
+	struct kprobe_blacklist_entry *ent;
+	unsigned long *iter;
+
+	mutex_lock(&kprobe_blacklist_mutex);
+	for (iter = start; iter < end; iter++) {
+		ent = find_blacklist_entry(*iter);
+		if (!ent)
+			continue;
+		list_del(&ent->list);
+		kfree(ent);
+	}
+	mutex_unlock(&kprobe_blacklist_mutex);
+}
+
 /* Module notifier call back, checking kprobes on the module */
 static int kprobes_module_callback(struct notifier_block *nb,
 				   unsigned long val, void *data)
@@ -2066,6 +2093,16 @@ static int kprobes_module_callback(struct notifier_block *nb,
 	unsigned int i;
 	int checkcore = (val == MODULE_STATE_GOING);
 
+	/* Add/remove module blacklist */
+	if (val == MODULE_STATE_COMING)
+		populate_kprobe_blacklist(mod->kprobe_blacklist,
+					  mod->kprobe_blacklist +
+					  mod->num_kprobe_blacklist);
+	else if (val == MODULE_STATE_GOING)
+		shrink_kprobe_blacklist(mod->kprobe_blacklist,
+					mod->kprobe_blacklist +
+					mod->num_kprobe_blacklist);
+
 	if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE)
 		return NOTIFY_DONE;
 
@@ -2252,6 +2289,7 @@ static const struct file_operations debugfs_kprobes_operations = {
 /* kprobes/blacklist -- shows which functions can not be probed */
 static void *kprobe_blacklist_seq_start(struct seq_file *m, loff_t *pos)
 {
+	mutex_lock(&kprobe_blacklist_mutex);
 	return seq_list_start(&kprobe_blacklist, *pos);
 }
 
@@ -2260,6 +2298,11 @@ static void *kprobe_blacklist_seq_next(struct seq_file *m, void *v, loff_t *pos)
 	return seq_list_next(v, &kprobe_blacklist, pos);
 }
 
+static void kprobe_blacklist_seq_stop(struct seq_file *m, void *v)
+{
+	mutex_unlock(&kprobe_blacklist_mutex);
+}
+
 static int kprobe_blacklist_seq_show(struct seq_file *m, void *v)
 {
 	struct kprobe_blacklist_entry *ent =
@@ -2273,7 +2316,7 @@ static int kprobe_blacklist_seq_show(struct seq_file *m, void *v)
 static const struct seq_operations kprobe_blacklist_seq_ops = {
 	.start = kprobe_blacklist_seq_start,
 	.next  = kprobe_blacklist_seq_next,
-	.stop  = kprobe_seq_stop,	/* Reuse void function */
+	.stop  = kprobe_blacklist_seq_stop,
 	.show  = kprobe_blacklist_seq_show,
 };
 
diff --git a/kernel/module.c b/kernel/module.c
index 1186940..895c635 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -58,6 +58,7 @@
 #include <linux/percpu.h>
 #include <linux/kmemleak.h>
 #include <linux/jump_label.h>
+#include <linux/kprobes.h>
 #include <linux/pfn.h>
 #include <linux/bsearch.h>
 #include <linux/fips.h>
@@ -2772,6 +2773,11 @@ static int find_module_sections(struct module *mod, struct load_info *info)
 					     sizeof(*mod->ftrace_callsites),
 					     &mod->num_ftrace_callsites);
 #endif
+#ifdef CONFIG_KPROBES
+	mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
+					     sizeof(*mod->kprobe_blacklist),
+					     &mod->num_kprobe_blacklist);
+#endif
 
 	mod->extable = section_objs(info, "__ex_table",
 				    sizeof(*mod->extable), &mod->num_exentries);



  parent reply index

Thread overview: 103+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-17  8:16 [PATCH -tip v9 00/26] kprobes: introduce NOKPROBE_SYMBOL, bugfixes and scalbility efforts Masami Hiramatsu
2014-04-17  8:16 ` [PATCH -tip v9 01/26] [BUGFIX]kprobes/x86: Fix page-fault handling logic Masami Hiramatsu
2014-04-17  9:58   ` [tip:perf/urgent] kprobes/x86: " tip-bot for Masami Hiramatsu
2014-04-17  8:16 ` [PATCH -tip v9 02/26] kprobes/x86: Allow to handle reentered kprobe on singlestepping Masami Hiramatsu
2014-04-24 10:57   ` [tip:perf/kprobes] kprobes/x86: Allow to handle reentered kprobe on single-stepping tip-bot for Masami Hiramatsu
2014-04-17  8:16 ` [PATCH -tip v9 03/26] kprobes: Prohibit probing on .entry.text code Masami Hiramatsu
2014-04-24 10:57   ` [tip:perf/kprobes] " tip-bot for Masami Hiramatsu
2014-04-17  8:17 ` [PATCH -tip v9 04/26] kprobes: Introduce NOKPROBE_SYMBOL() macro for blacklist Masami Hiramatsu
2014-04-24 10:58   ` [tip:perf/kprobes] kprobes: Introduce NOKPROBE_SYMBOL() macro to maintain kprobes blacklist tip-bot for Masami Hiramatsu
2014-05-01  5:26     ` kprobes broken in linux-next (was Re: [tip:perf/kprobes] kprobes: Introduce NOKPROBE_SYMBOL() macro to maintain kprobes blacklist) Vineet Gupta
2014-05-02  1:13       ` Masami Hiramatsu
2014-05-07  4:56         ` Vineet Gupta
2014-05-07 19:18       ` [tip:perf/kprobes] kprobes: Ensure blacklist data is aligned tip-bot for Vineet Gupta
2014-05-05 20:48     ` [tip:perf/kprobes] kprobes: Introduce NOKPROBE_SYMBOL() macro to maintain kprobes blacklist Tony Luck
2014-05-06  9:25       ` Masami Hiramatsu
2014-05-06 10:03       ` Masami Hiramatsu
2014-05-07 11:19         ` Masami Hiramatsu
2014-05-07 11:55           ` [RFT PATCH -next ] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64 Masami Hiramatsu
2014-05-07 11:59             ` Masami Hiramatsu
2014-05-14  8:19               ` Masami Hiramatsu
2014-05-08  4:47             ` Ananth N Mavinakayanahalli
2014-05-08  5:40               ` Masami Hiramatsu
2014-05-08  6:16                 ` Ananth N Mavinakayanahalli
2014-05-09  8:06                   ` Masami Hiramatsu
2014-05-26 11:25             ` Suzuki K. Poulose
2014-05-26 11:48               ` Masami Hiramatsu
2014-05-27  6:31               ` [RFT PATCH -next v2] " Masami Hiramatsu
2014-05-29 19:13                 ` Suzuki K. Poulose
2014-05-30  2:47                   ` Masami Hiramatsu
2014-05-30  3:18                     ` [RFT PATCH -next v3] " Masami Hiramatsu
2014-06-06  6:38                       ` Masami Hiramatsu
2014-06-17 23:03                         ` Tony Luck
2014-06-18  7:56                         ` Michael Ellerman
2014-06-18  8:46                           ` Masami Hiramatsu
2014-06-19  1:30                             ` Michael Ellerman
2014-06-19  4:52                               ` Masami Hiramatsu
2014-06-19  6:40                                 ` Suzuki K. Poulose
2014-06-19  7:26                                   ` Masami Hiramatsu
2014-06-19  9:45                                     ` Suzuki K. Poulose
2014-06-19 11:01                                       ` Masami Hiramatsu
2014-06-19 11:20                                         ` Masami Hiramatsu
2014-06-20  0:37                                           ` Michael Ellerman
2014-06-20  2:13                                             ` Masami Hiramatsu
2014-04-17  8:17 ` [PATCH -tip v9 05/26] [BUGFIX] kprobes/x86: Prohibit probing on debug_stack_* Masami Hiramatsu
2014-04-24 10:58   ` [tip:perf/kprobes] kprobes, x86: Prohibit probing on debug_stack_*() tip-bot for Masami Hiramatsu
2014-04-17  8:17 ` [PATCH -tip v9 06/26] [BUGFIX] x86: Prohibit probing on native_set_debugreg/load_idt Masami Hiramatsu
2014-04-24 10:58   ` [tip:perf/kprobes] kprobes, x86: Prohibit probing on native_set_debugreg()/load_idt() tip-bot for Masami Hiramatsu
2014-04-17  8:17 ` [PATCH -tip v9 07/26] [BUGFIX] x86: Prohibit probing on thunk functions and restore Masami Hiramatsu
2014-04-24 10:58   ` [tip:perf/kprobes] kprobes, " tip-bot for Masami Hiramatsu
2014-04-17  8:17 ` [PATCH -tip v9 08/26] kprobes/x86: Call exception handlers directly from do_int3/do_debug Masami Hiramatsu
2014-04-24 10:59   ` [tip:perf/kprobes] " tip-bot for Masami Hiramatsu
2014-04-24 11:26     ` Jiri Kosina
2014-04-17  8:17 ` [PATCH -tip v9 09/26] x86: Call exception_enter after kprobes handled Masami Hiramatsu
2014-04-24 10:59   ` [tip:perf/kprobes] kprobes, " tip-bot for Masami Hiramatsu
2014-06-13 17:14     ` Frederic Weisbecker
2014-06-14  5:44       ` Masami Hiramatsu
2014-06-14  6:47         ` [PATCH -tip ] [Bugfix] x86/kprobes: Fix build errors and blacklist context_track_user Masami Hiramatsu
2014-06-14  8:58           ` [tip:perf/urgent] " tip-bot for Masami Hiramatsu
2014-06-16 15:52           ` [PATCH -tip ] [Bugfix] " Frederic Weisbecker
2014-04-17  8:17 ` [PATCH -tip v9 10/26] kprobes/x86: Allow probe on some kprobe preparation functions Masami Hiramatsu
2014-04-24 10:59   ` [tip:perf/kprobes] " tip-bot for Masami Hiramatsu
2014-04-17  8:17 ` [PATCH -tip v9 11/26] kprobes: Allow probe on some kprobe functions Masami Hiramatsu
2014-04-24 10:59   ` [tip:perf/kprobes] " tip-bot for Masami Hiramatsu
2014-04-17  8:18 ` [PATCH -tip v9 12/26] ftrace/*probes: Allow probing on some functions Masami Hiramatsu
2014-04-24 10:59   ` [tip:perf/kprobes] kprobes, ftrace: " tip-bot for Masami Hiramatsu
2014-04-17  8:18 ` [PATCH -tip v9 13/26] x86: Allow kprobes on text_poke/hw_breakpoint Masami Hiramatsu
2014-04-24 11:00   ` [tip:perf/kprobes] kprobes, x86: Allow kprobes on text_poke/ hw_breakpoint tip-bot for Masami Hiramatsu
2014-04-24 11:26     ` Jiri Kosina
2014-04-17  8:18 ` [PATCH -tip v9 14/26] x86: Use NOKPROBE_SYMBOL() instead of __kprobes annotation Masami Hiramatsu
2014-04-24 11:00   ` [tip:perf/kprobes] kprobes, " tip-bot for Masami Hiramatsu
2014-04-17  8:18 ` [PATCH -tip v9 15/26] kprobes: Use NOKPROBE_SYMBOL macro instead of __kprobes Masami Hiramatsu
2014-04-24 11:00   ` [tip:perf/kprobes] " tip-bot for Masami Hiramatsu
2014-04-17  8:18 ` [PATCH -tip v9 16/26] ftrace/kprobes: Use NOKPROBE_SYMBOL macro in ftrace Masami Hiramatsu
2014-04-24 11:00   ` [tip:perf/kprobes] kprobes, ftrace: " tip-bot for Masami Hiramatsu
2014-04-17  8:18 ` [PATCH -tip v9 17/26] notifier: Use NOKPROBE_SYMBOL macro in notifier Masami Hiramatsu
2014-04-17 14:40   ` Josh Triplett
2014-04-24 11:00   ` [tip:perf/kprobes] kprobes, " tip-bot for Masami Hiramatsu
2014-04-17  8:18 ` [PATCH -tip v9 18/26] sched: Use NOKPROBE_SYMBOL macro in sched Masami Hiramatsu
2014-04-24 11:01   ` [tip:perf/kprobes] kprobes, " tip-bot for Masami Hiramatsu
2014-04-17  8:18 ` [PATCH -tip v9 19/26] kprobes: Show blacklist entries via debugfs Masami Hiramatsu
2014-04-24 11:01   ` [tip:perf/kprobes] " tip-bot for Masami Hiramatsu
2014-04-17  8:18 ` Masami Hiramatsu [this message]
2014-04-24  8:56   ` [PATCH -tip v9 20/26] kprobes: Support blacklist functions in module Ingo Molnar
2014-04-24 11:24     ` Masami Hiramatsu
2014-04-25  8:19       ` Ingo Molnar
2014-04-25 10:12         ` Masami Hiramatsu
2014-04-25 10:55           ` Masami Hiramatsu
2014-04-17  8:19 ` [PATCH -tip v9 21/26] kprobes: Use NOKPROBE_SYMBOL() in sample modules Masami Hiramatsu
2014-04-17  8:19 ` [PATCH -tip v9 22/26] kprobes/x86: Use kprobe_blacklist for .kprobes.text and .entry.text Masami Hiramatsu
2014-04-24  8:58   ` Ingo Molnar
2014-04-24 11:22     ` Masami Hiramatsu
2014-04-17  8:19 ` [PATCH -tip v9 23/26] kprobes/x86: Remove unneeded preempt_disable/enable in interrupt handlers Masami Hiramatsu
2014-04-17  8:19 ` [PATCH -tip v9 24/26] kprobes: Enlarge hash table to 512 entries Masami Hiramatsu
2014-04-17  8:19 ` [PATCH -tip v9 25/26] kprobes: Introduce kprobe cache to reduce cache misshits Masami Hiramatsu
2014-04-24  9:01   ` Ingo Molnar
2014-04-24 11:38     ` Masami Hiramatsu
2014-04-25  8:20       ` Ingo Molnar
2014-04-25  9:43         ` Masami Hiramatsu
2014-04-26  7:12           ` Ingo Molnar
2014-04-27 12:49             ` Masami Hiramatsu
2014-04-17  8:19 ` [PATCH -tip v9 26/26] ftrace: Introduce FTRACE_OPS_FL_SELF_FILTER for ftrace-kprobe Masami Hiramatsu
2014-04-17  8:37 ` [PATCH -tip v9 00/26] kprobes: introduce NOKPROBE_SYMBOL, bugfixes and scalbility efforts Ingo Molnar
2014-04-17  8:53   ` Masami Hiramatsu

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