From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Luis Chamberlain <mcgrof@kernel.org>
Cc: Jessica Yu <jeyu@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
"kgdb-bugreport@lists.sourceforge.net"
<kgdb-bugreport@lists.sourceforge.net>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
Subject: Re: [PATCH 0/7] Allocate module text and data separately
Date: Wed, 26 Jan 2022 05:54:55 +0000 [thread overview]
Message-ID: <68e18364-b904-4ac2-2bf3-504a0b147ecf@csgroup.eu> (raw)
In-Reply-To: <YfBjBRFEbljfbrvx@bombadil.infradead.org>
Le 25/01/2022 à 21:52, Luis Chamberlain a écrit :
> On Mon, Jan 24, 2022 at 09:22:11AM +0000, Christophe Leroy wrote:
>> This series allow architectures to request having modules data in
>> vmalloc area instead of module area.
>>
>> This is required on powerpc book3s/32 in order to set data non
>> executable, because it is not possible to set executability on page
>> basis, this is done per 256 Mbytes segments. The module area has exec
>> right, vmalloc area has noexec.
>>
>> This can also be useful on other powerpc/32 in order to maximize the
>> chance of code being close enough to kernel core to avoid branch
>> trampolines.
>
> Am I understanding that this entire effort is for 32-bit powerpc?
> If so, why such an interest in 32-bit these days?
>
32 bit powerpc processors are still manufactured and are widely used in
embedded products like internet boxes, small routers, etc ...
One of the reason is that there power consumption hence their heat
dissipation is way lower than 64 bits variants.
I found the effort quite small compared to the benefit it provides.
Christophe
prev parent reply other threads:[~2022-01-26 5:55 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-24 9:22 [PATCH 0/7] Allocate module text and data separately Christophe Leroy
2022-01-24 9:22 ` [PATCH 1/7] modules: Refactor within_module_core() and within_module_init() Christophe Leroy
2022-01-24 12:32 ` Christoph Hellwig
2022-01-24 13:01 ` Christophe Leroy
2022-01-27 11:32 ` Christophe Leroy
2022-01-26 21:36 ` Mike Rapoport
2022-01-27 11:33 ` Christophe Leroy
2022-01-24 9:22 ` [PATCH 2/7] modules: Add within_module_text() macro Christophe Leroy
2022-01-24 9:22 ` [PATCH 3/7] modules: Always have struct mod_tree_root Christophe Leroy
2022-01-24 9:22 ` [PATCH 4/7] modules: Prepare for handling several RB trees Christophe Leroy
2022-01-24 9:22 ` [PATCH 5/7] modules: Introduce data_layout Christophe Leroy
2022-01-24 9:22 ` [PATCH 6/7] modules: Add CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC Christophe Leroy
2022-01-24 21:43 ` Doug Anderson
2022-01-25 5:43 ` Christophe Leroy
2022-01-25 21:10 ` Luis Chamberlain
2022-01-26 6:38 ` Christophe Leroy
2022-02-02 23:34 ` Luis Chamberlain
2022-01-27 16:05 ` Miroslav Benes
2022-01-27 18:04 ` Christophe Leroy
2022-01-24 9:22 ` [PATCH 7/7] powerpc: Select ARCH_WANTS_MODULES_DATA_IN_VMALLOC on book3s/32 and 8xx Christophe Leroy
2022-01-24 12:27 ` kernel test robot
2022-01-25 20:52 ` [PATCH 0/7] Allocate module text and data separately Luis Chamberlain
2022-01-26 5:54 ` Christophe Leroy [this message]
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