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From: Lev Olshvang <levonshe@yandex.com>
To: kernelnewbies <kernelnewbies@kernelnewbies.org>,
	linux-il <linux-il@cs.huji.ac.il>
Subject: What will happen if 2 processes map same physical page
Date: Wed, 20 Mar 2019 16:42:39 +0300	[thread overview]
Message-ID: <6967041553089359@myt2-66bcb87429e6.qloud-c.yandex.net> (raw)

Hi all,

The question is it ipossiblle in Linux/MMU/TLB  that 2 processes map to the same physical address?
Will CPU or  TLB discover that second process tries to reach occupied physical page?

What if first process set page permission to read and second whats to write to this page ?
Perhaps during context switch all page access permissions of first process is flashed out from MMU ?


I confess I do not know what exactly happens in TLB and between Linux and hardware view of pages.

I am particularly intereste in ARMv7, perhaps its architecture have some solutions to these question.

Regards,
Lev



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             reply	other threads:[~2019-03-20 13:43 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-20 13:42 Lev Olshvang [this message]
2019-03-20 17:07 ` What will happen if 2 processes map same physical page Valdis Klētnieks
2019-03-21  9:56   ` Lev Olshvang
2019-03-21 10:45     ` Okash Khawaja
2019-03-22  9:15       ` Lev Olshvang
2019-03-22  9:59         ` Okash Khawaja
2019-03-22 23:19         ` Valdis Klētnieks

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