From: James Bottomley Date: Thu, 14 Apr 2011 23:25:21 +0000 (-0500) Subject: [PARISC] only make executable areas executable X-Git-Tag: v3.0-rc1~365^2^2~1 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d7dd2ff11b7fcd425aca5a875983c862d19a67ae;p=pandora-kernel.git [PARISC] only make executable areas executable Currently parisc has the whole kernel marked as RWX, meaning any kernel page at all is eligible to be executed. This can cause a theoretical problem on systems with combined I/D TLB because the act of referencing a page causes a TLB insertion with an executable bit. This TLB entry may be used by the CPU as the basis for speculating the page into the I-Cache. If this speculated page is subsequently used for a user process, there is the possibility we will get a stale I-cache line picked up as the binary executes. As a point of good practise, only mark actual kernel text pages as executable. The same has to be done for init_text pages, but they're converted to data pages (and the I-Cache flushed) when the init memory is released. Signed-off-by: James Bottomley --- Reading git-diff-tree failed