linux-kernel - Re: [RFT PATCH -next ] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <536C8C90.2050601@hitachi.com>
Date:	Fri, 09 May 2014 17:06:40 +0900
From:	Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>
To:	ananth@...ibm.com
Cc:	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Paul Mackerras <paulus@...ba.org>,
	Tony Luck <tony.luck@...il.com>,
	Jeremy Fitzhardinge <jeremy@...p.org>,
	linux-ia64@...r.kernel.org, sparse@...isli.org,
	"H. Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	linux-tip-commits@...r.kernel.org, anil.s.keshavamurthy@...el.com,
	Ingo Molnar <mingo@...nel.org>,
	Fenghua Yu <fenghua.yu@...el.com>,
	Arnd Bergmann <arnd@...db.de>,
	Rusty Russell <rusty@...tcorp.com.au>,
	Chris Wright <chrisw@...s-sol.org>,
	yrl.pp-manager.tt@...achi.com, akataria@...are.com,
	Tony Luck <tony.luck@...el.com>,
	Kevin Hao <haokexin@...il.com>, linuxppc-dev@...ts.ozlabs.org,
	rdunlap@...radead.org,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	dl9pf@....de, Andrew Morton <akpm@...ux-foundation.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	"David S. Miller" <davem@...emloft.net>
Subject: Re: [RFT PATCH -next ] [BUGFIX] kprobes: Fix "Failed to find blacklist"
 error on ia64 and ppc64

(2014/05/08 15:16), Ananth N Mavinakayanahalli wrote:
> On Thu, May 08, 2014 at 02:40:00PM +0900, Masami Hiramatsu wrote:
>> (2014/05/08 13:47), Ananth N Mavinakayanahalli wrote:
>>> On Wed, May 07, 2014 at 08:55:51PM +0900, Masami Hiramatsu wrote:
>>>
>>> ...
>>>
>>>> +#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF == 1)
>>>> +/*
>>>> + * On PPC64 ABIv1 the function pointer actually points to the
>>>> + * function's descriptor. The first entry in the descriptor is the
>>>> + * address of the function text.
>>>> + */
>>>> +#define constant_function_entry(fn)	(((func_descr_t *)(fn))->entry)
>>>> +#else
>>>> +#define constant_function_entry(fn)	((unsigned long)(fn))
>>>> +#endif
>>>> +
>>>>  #endif /* __ASSEMBLY__ */
>>>
>>> Hi Masami,
>>>
>>> You could just use ppc_function_entry() instead.
>>
>> No, I think ppc_function_entry() has two problems (on the latest -next kernel)
>>
>> At first, that is an inlined functions which is not applied in build time.
>> Since the NOKPROBE_SYMBOL() is used outside of any functions as like as
>> EXPORT_SYMBOL(), we can only use preprocessed macros.
>> Next, on PPC64 ABI*v2*, ppc_function_entry() returns local function entry,
>> which seems global function entry + 2 insns. I'm not sure about implementation
>> of the kallsyms on PPC64 ABIv2, but I guess we need global function entry
>> for kallsyms.
> 
> ABIv2 does away with function descriptors and Anton fixed up that
> routine to handle the change (the +2 is an artefact of that).

Hmm, do you mean that the address +2 is the actual entry point?
I'd like to know which address is same as the address shown in /proc/kallsyms.

>> BTW, could you test this patch on the latest -next tree on PPC64 if possible?
> 
> I'll test it, but it may take a bit.

Thanks for your help!

> 
> Ananth
> 
> 


-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@...achi.com


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/