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Message-ID: <1494987032.30802.6.camel@gmail.com>
Subject: Re: [RFC 0/2] Consolidate patch_instruction
From: Balbir Singh <bsingharora@gmail.com>
To: LEROY Christophe <christophe.leroy@c-s.fr>
Cc: naveen.n.rao@linux.vnet.ibm.com, mpe@ellerman.id.au,
 linuxppc-dev@lists.ozlabs.org
Date: Wed, 17 May 2017 12:10:32 +1000
In-Reply-To: <20170516222015.Horde.fwWhnIwI59SuB64Du97wdg2@messagerie.c-s.fr>
References: <20170516222015.Horde.fwWhnIwI59SuB64Du97wdg2@messagerie.c-s.fr>
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On Tue, 2017-05-16 at 22:20 +0200, LEROY Christophe wrote:
> Balbir Singh <bsingharora@gmail.com> a écrit :
> 
> > patch_instruction is enhanced in this RFC to support
> > patching via a different virtual address (text_poke_area).
> > The mapping of text_poke_area->addr is RW and not RWX.
> > This way the mapping allows write for patching and then we tear
> > down the mapping. The downside is that we introduce a spinlock
> > which serializes our patching to one patch at a time.
> 
> Very nice patch, would fit great with my patch for impmementing  
> CONFIG_DEBUG_RODATA (https://patchwork.ozlabs.org/patch/754289 ).
> Would avoid having to set the text area back to RW for patching
> 

Awesome! It seems like you have some of the work for CONFIG_STRICT_KERNEL_RWX
any reason why this is under CONFIG_DEBUG_RODATA? But I think there is
reuse capability across the future patches and the current set.

Cheers,
Balbir  Singh.