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From:   Kent Overstreet <kent.overstreet@linux.dev>
To:     Mike Rapoport <rppt@kernel.org>
Cc:     Matthew Wilcox <willy@infradead.org>,
        Kees Cook <keescook@chromium.org>,
        Johannes Thumshirn <Johannes.Thumshirn@wdc.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
        "linux-bcachefs@vger.kernel.org" <linux-bcachefs@vger.kernel.org>,
        Kent Overstreet <kent.overstreet@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Uladzislau Rezki <urezki@gmail.com>,
        "hch@infradead.org" <hch@infradead.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-hardening@vger.kernel.org" <linux-hardening@vger.kernel.org>,
        song@kernel.org
Subject: Re: [PATCH 07/32] mm: Bring back vmalloc_exec
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On Wed, May 17, 2023 at 06:44:12PM +0300, Mike Rapoport wrote:
> On Wed, May 17, 2023 at 10:18:11AM -0400, Kent Overstreet wrote:
> > On Wed, May 17, 2023 at 05:04:27PM +0300, Mike Rapoport wrote:
> > 
> > And I'm really curious why text_poke() is needed at all. Seems like we
> > could just use kmap_local() to create a temporary writeable mapping,
> 
> On 64 bit kmap_local_page() is aliased to page_address() and does not map
> anything. text_poke() is needed to actually create a temporary writable
> mapping without touching page tables in vmalloc and/or direct map.

Duh - thanks!