From: Steven Rostedt <rostedt@goodmis.org>
To: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
Jeremy Fitzhardinge <jeremy@goop.org>,
x86@kernel.org, Andi Kleen <andi@firstfloor.org>,
Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
Arnd Bergmann <arnd@arndb.de>,
Peter Zijlstra <peterz@infradead.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Rusty Russell <rusty@rustcorp.com.au>,
"David S. Miller" <davem@davemloft.net>,
Chris Wright <chrisw@sous-sol.org>,
Sandeepa Prabhu <sandeepa.prabhu@linaro.org>,
fche@redhat.com, mingo@redhat.com, Rob Landley <rob@landley.net>,
"H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Alok Kataria <akataria@vmware.com>,
systemtap@sourceware.org
Subject: Re: [PATCH -tip v8 04/26] kprobes: Introduce NOKPROBE_SYMBOL() macro for blacklist
Date: Sat, 22 Mar 2014 00:49:00 -0000 [thread overview]
Message-ID: <20140321204917.636820fa@gandalf.local.home> (raw)
In-Reply-To: <20140305115911.22766.61140.stgit@ltc230.yrl.intra.hitachi.co.jp>
On Wed, 05 Mar 2014 20:59:11 +0900
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:
>
> diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt
> index 0cfb00f..7062631 100644
> --- a/Documentation/kprobes.txt
> +++ b/Documentation/kprobes.txt
> @@ -22,8 +22,9 @@ Appendix B: The kprobes sysctl interface
>
> Kprobes enables you to dynamically break into any kernel routine and
> collect debugging and performance information non-disruptively. You
> -can trap at almost any kernel code address, specifying a handler
> +can trap at almost any kernel code address(*), specifying a handler
> routine to be invoked when the breakpoint is hit.
> +(*: at some part of kernel code can not be trapped, see 1.5 Blacklist)
"*: some parts of the kernel code can not be trapped,"
>
> There are currently three types of probes: kprobes, jprobes, and
> kretprobes (also called return probes). A kprobe can be inserted
> @@ -273,6 +274,19 @@ using one of the following techniques:
> or
> - Execute 'sysctl -w debug.kprobes_optimization=n'
>
> +1.5 Blacklist
> +
> +Kprobes can probe almost of the kernel except itself. This means
s/almost/most/
> +that there are some functions where kprobes cannot probe. Probing
> +(trapping) such functions can cause recursive trap (e.g. double
cause a recursive trap
> +fault) or at least the nested probe handler never be called.
"or the nested probe handler may never be called."
> +Kprobes manages such functions as a blacklist.
> +If you want to add a function into the blacklist, you just need
> +to (1) include linux/kprobes.h and (2) use NOKPROBE_SYMBOL() macro
> +to specify a blacklisted function.
> +Kprobes checks given probe address with the blacklist and reject
"checks the given probe address against the black list and rejects"
> +registering if the given address is in the blacklist.
registering it, if
> +
> 2. Architectures Supported
>
> Kprobes, jprobes, and return probes are implemented on the following
> diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
> index 4582e8e..7730c1c 100644
> --- a/arch/x86/include/asm/asm.h
> +++ b/arch/x86/include/asm/asm.h
> @@ -57,6 +57,12 @@
> .long (from) - . ; \
> .long (to) - . + 0x7ffffff0 ; \
> .popsection
> +
> +# define _ASM_NOKPROBE(entry) \
> + .pushsection "_kprobe_blacklist","aw" ; \
> + _ASM_ALIGN ; \
> + _ASM_PTR (entry); \
> + .popsection
> #else
> # define _ASM_EXTABLE(from,to) \
> " .pushsection \"__ex_table\",\"a\"\n" \
> @@ -71,6 +77,7 @@
> " .long (" #from ") - .\n" \
> " .long (" #to ") - . + 0x7ffffff0\n" \
> " .popsection\n"
> +/* For C file, we already have NOKPROBE_SYMBOL macro */
> #endif
>
> #endif /* _ASM_X86_ASM_H */
> diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
> index 1b10af8..4c785fd 100644
> --- a/arch/x86/kernel/paravirt.c
> +++ b/arch/x86/kernel/paravirt.c
> @@ -23,6 +23,7 @@
> #include <linux/efi.h>
> #include <linux/bcd.h>
> #include <linux/highmem.h>
> +#include <linux/kprobes.h>
>
> #include <asm/bug.h>
> #include <asm/paravirt.h>
> @@ -389,6 +390,9 @@ __visible struct pv_cpu_ops pv_cpu_ops = {
> .end_context_switch = paravirt_nop,
> };
>
> +/* At this point, native_get_debugreg has real function entry */
"has a real"
-- Steve
> +NOKPROBE_SYMBOL(native_get_debugreg);
> +
> struct pv_apic_ops pv_apic_ops = {
> #ifdef CONFIG_X86_LOCAL_APIC
> .startup_ipi_hook = paravirt_nop,
> diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
> index bc2121f..81d07d5 100644
> --- a/include/asm-generic/vmlinux.lds.h
next prev parent reply other threads:[~2014-03-22 0:49 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-05 11:58 [PATCH -tip v8 00/26] kprobes: introduce NOKPROBE_SYMBOL, bugfixes and scalbility efforts Masami Hiramatsu
2014-03-05 11:59 ` [PATCH -tip v8 08/26] kprobes/x86: Call exception handlers directly from do_int3/do_debug Masami Hiramatsu
2014-03-22 1:05 ` Steven Rostedt
2014-03-24 8:47 ` Masami Hiramatsu
2014-03-24 18:58 ` Steven Rostedt
2014-03-05 11:59 ` [PATCH -tip v8 06/26] [BUGFIX] x86: Prohibit probing on native_set_debugreg/load_idt Masami Hiramatsu
2014-03-22 0:53 ` Steven Rostedt
2014-03-05 11:59 ` [PATCH -tip v8 09/26] x86: Call exception_enter after kprobes handled Masami Hiramatsu
2014-03-24 19:31 ` Steven Rostedt
2014-03-05 11:59 ` [PATCH -tip v8 02/26] kprobes/x86: Allow to handle reentered kprobe on singlestepping Masami Hiramatsu
2014-03-21 21:44 ` Steven Rostedt
2014-03-24 10:07 ` Masami Hiramatsu
2014-03-05 11:59 ` [PATCH -tip v8 03/26] kprobes: Prohibit probing on .entry.text code Masami Hiramatsu
2014-03-21 22:04 ` Steven Rostedt
2014-03-24 1:48 ` Masami Hiramatsu
2014-03-24 18:54 ` Steven Rostedt
2014-03-24 18:55 ` Steven Rostedt
2014-03-05 11:59 ` [PATCH -tip v8 05/26] [BUGFIX] kprobes/x86: Prohibit probing on debug_stack_* Masami Hiramatsu
2014-03-22 0:50 ` Steven Rostedt
2014-03-05 11:59 ` [PATCH -tip v8 01/26] [BUGFIX]kprobes/x86: Fix page-fault handling logic Masami Hiramatsu
2014-03-21 21:39 ` Steven Rostedt
2014-03-24 1:10 ` Masami Hiramatsu
2014-03-05 11:59 ` [PATCH -tip v8 04/26] kprobes: Introduce NOKPROBE_SYMBOL() macro for blacklist Masami Hiramatsu
2014-03-22 0:49 ` Steven Rostedt [this message]
2014-03-26 7:04 ` Masami Hiramatsu
2014-03-05 11:59 ` [PATCH -tip v8 07/26] [BUGFIX] x86: Prohibit probing on thunk functions and restore Masami Hiramatsu
2014-03-22 1:00 ` Steven Rostedt
2014-03-24 3:04 ` Masami Hiramatsu
2014-03-24 18:56 ` Steven Rostedt
2014-03-05 12:00 ` [PATCH -tip v8 18/26] sched: Use NOKPROBE_SYMBOL macro in sched Masami Hiramatsu
2014-03-24 20:14 ` Steven Rostedt
2014-03-05 12:00 ` [PATCH -tip v8 15/26] kprobes: Use NOKPROBE_SYMBOL macro instead of __kprobes Masami Hiramatsu
2014-03-24 19:46 ` Steven Rostedt
2014-03-05 12:00 ` [PATCH -tip v8 11/26] kprobes: Allow probe on some kprobe functions Masami Hiramatsu
2014-03-24 19:37 ` Steven Rostedt
2014-03-25 9:23 ` Masami Hiramatsu
2014-03-05 12:00 ` [PATCH -tip v8 16/26] ftrace/kprobes: Use NOKPROBE_SYMBOL macro in ftrace Masami Hiramatsu
2014-03-24 20:10 ` Steven Rostedt
2014-03-25 10:31 ` Masami Hiramatsu
2014-03-05 12:00 ` [PATCH -tip v8 14/26] x86: Use NOKPROBE_SYMBOL() instead of __kprobes annotation Masami Hiramatsu
2014-03-24 19:45 ` Steven Rostedt
2014-03-25 10:33 ` Masami Hiramatsu
2014-03-05 12:00 ` [PATCH -tip v8 13/26] x86: Allow kprobes on text_poke/hw_breakpoint Masami Hiramatsu
2014-03-24 19:40 ` Steven Rostedt
2014-03-05 12:00 ` [PATCH -tip v8 17/26] notifier: Use NOKPROBE_SYMBOL macro in notifier Masami Hiramatsu
2014-03-24 20:12 ` Steven Rostedt
2014-03-25 10:24 ` Masami Hiramatsu
2014-03-25 10:58 ` Steven Rostedt
2014-03-05 12:00 ` [PATCH -tip v8 10/26] kprobes/x86: Allow probe on some kprobe preparation functions Masami Hiramatsu
2014-03-24 19:36 ` Steven Rostedt
2014-03-25 9:20 ` Masami Hiramatsu
2014-03-27 5:50 ` Masami Hiramatsu
2014-03-05 12:00 ` [PATCH -tip v8 12/26] ftrace/*probes: Allow probing on some functions Masami Hiramatsu
2014-03-24 19:38 ` Steven Rostedt
2014-03-25 9:30 ` Masami Hiramatsu
2014-03-05 12:01 ` [PATCH -tip v8 22/26] kprobes/x86: Use kprobe_blacklist for .kprobes.text and .entry.text Masami Hiramatsu
2014-03-05 12:01 ` [PATCH -tip v8 23/26] kprobes/x86: Remove unneeded preempt_disable/enable in interrupt handlers Masami Hiramatsu
2014-03-05 12:01 ` [PATCH -tip v8 20/26] kprobes: Support blacklist functions in module Masami Hiramatsu
2014-03-05 12:01 ` [PATCH -tip v8 25/26] kprobes: Introduce kprobe cache to reduce cache misshits Masami Hiramatsu
2014-03-05 12:01 ` [PATCH -tip v8 24/26] kprobes: Enlarge hash table to 512 entries Masami Hiramatsu
2014-03-05 12:01 ` [PATCH -tip v8 26/26] ftrace: Introduce FTRACE_OPS_FL_SELF_FILTER for ftrace-kprobe Masami Hiramatsu
2014-03-05 12:01 ` [PATCH -tip v8 19/26] kprobes: Show blacklist entries via debugfs Masami Hiramatsu
2014-03-24 20:19 ` Steven Rostedt
2014-03-25 10:30 ` Masami Hiramatsu
2014-03-05 12:01 ` [PATCH -tip v8 21/26] kprobes: Use NOKPROBE_SYMBOL() in sample modules Masami Hiramatsu
2014-03-14 13:11 ` [PATCH -tip v8 00/26] kprobes: introduce NOKPROBE_SYMBOL, bugfixes and scalbility efforts Masami Hiramatsu
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