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s=k20201202; t=1684338266; bh=CWH2pztIOxMe+ekz7FPDOiiqxPpYYmkV6Bjtj8FaKhc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=S8yqKPipt+vunH2g5aUufq37y/MGQZ4ijZGLIT3VzuwM9BzjnhxDZz471LRMl4jXD 8ZpG4eUF8dr8JxX99DI1OaxcFhorHnv4oWxGM8C8TNz9Fdj9vKgsX/TwvEN1MroAoJ sNc5C9I5qJDT5Mzh5bqUw499jLFaYAM67otU1Bl62J8WQfsEImW4sZ0PYuVoQVN+1Z fgRDJMMz1IYy7a9GV87WnXxyv7DjvDLCrZF7P7iLTGM6yCCrNObF2i1vrxco+JfEXT B2rZ417mW+tSWt7xZKCkfHnT8h7lmnqNksSLOUczAdTmQY5MAX60pTJGirG3bNKM2r WDdi6PFoLVdRw== Date: Wed, 17 May 2023 18:44:12 +0300 From: Mike Rapoport To: Kent Overstreet Cc: Matthew Wilcox , Kees Cook , Johannes Thumshirn , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-bcachefs@vger.kernel.org" , Kent Overstreet , Andrew Morton , Uladzislau Rezki , "hch@infradead.org" , "linux-mm@kvack.org" , "linux-hardening@vger.kernel.org" , song@kernel.org Subject: Re: [PATCH 07/32] mm: Bring back vmalloc_exec Message-ID: <20230517154412.GC4967@kernel.org> References: <20230509165657.1735798-8-kent.overstreet@linux.dev> <3508afc0-6f03-a971-e716-999a7373951f@wdc.com> <202305111525.67001E5C4@keescook> <202305161401.F1E3ACFAC@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 2146318000A X-Rspam-User: X-Rspamd-Server: rspam06 X-Stat-Signature: z6dy4ggxatx5736ub87o5giy9bz39c9h X-HE-Tag: 1684338267-614729 X-HE-Meta: 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 CUzR55GN 70p+hvVGfnKcg3JCnCgpQJe+hcGm9vhMyn1YXLXhD4kb3XIlsQjPNayFYBqblEA2dkBtrHM3KldXvPv5KFliBgraQTvwmQRXGdHQ7AM97k0VFb/aY3Lp4/iEbpq3tI9iYjI4L7I1/3PjuN7DCDyLEKyvn7UrgmmoAWPV8BldHTFPulP0tDcH7ttym6OeP9EInEYymvaNKTgtawv81hBbiC0i6rSYCaipq/HJA/XC18wwO4+bkY5yHwzTNAEvY+Hge1GLQniB96aoAvJ3qS9rbdk9e8AiYh2Mw4jyBO5EG6Zz6ME6/AaYA4Bal2TfD/IvrfhWleL52toHC9ABey+Nzu8TqmGtLcJTA/yf0tvJF99ii8+IZMuHu1bYZjtMqeHJm0kacMfvASGvuFyJvPrc3mp2HIOit1IlkbgURDPmaQtM4LKMSnCQkHo4efWR1KdI5Aq7vGusupMfEM0I= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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. -- Sincerely yours, Mike.