Re: [PATCH -tip v4 0/6] kprobes: introduce NOKPROBE_SYMBOL() and fixes crash bugs

[Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>]

(2013/12/04 11:54), Sandeepa Prabhu wrote:
> On 4 December 2013 06:58, Masami Hiramatsu
> <masami.hiramatsu.pt@hitachi.com> wrote:
>> Hi,
>> Here is the version 4 of NOKPORBE_SYMBOL series.
>>
>> In this version, I removed the cleanup patches and
>> add bugfixes I've found, since those bugs will be
>> critical.
>> Rest of the cleanup and visible blacklists will be
>> proposed later in another series.
>>
>> Oh, just one new thing, I added a new RFC patch which
>> removes the dependency of notify_die() from kprobes
>> miss-hit/recovery path. Since the notify_die() involves
>> locking and lockdep code which invokes a lot of heavy
>> printk functions etc. This helped me to minimize the
>> blacklist and provides more stability for kprobes.
>> Actually, most of int3 handlers are already called
>> from do_int3 directly, I think this change is acceptable
>> too.
>>
>> Here is the updates about NOKPROBE_SYMBOL().
>>  - Now _ASM_NOKPROBE() macro is introduced for assembly
>>    symbols on x86.
>>  - Rename kprobe_blackpoint to kprobe_blacklist_entry
>>    and simplify it. Also NOKPROBE_SYMBOL() macro just
>>    saves the address of non-probe-able symbols.
>>
>> ---
>>
>> Masami Hiramatsu (6):
> 
>>       kprobes: Prohibit probing on .entry.text code
>>       kprobes: Introduce NOKPROBE_SYMBOL() macro for blacklist
> Hi Masami,
> Is it good idea to split  "arch/x86" code from generic kernel changes?
> Then we just need to take above two patches for verifying it on arm64
> or other platforms.

Yeah, it can be.
However I think you can apply it without any problem on arm64 tree too,
since it "just adds" an asm macro in arch/x86/include/asm/asm.h.
It should not have any effect for other arch. Could you try it? :)

Thank you,


-- 
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com