| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Tue, 30 Apr 2024 21:25:32 +0200 From: David Hildenbrand <david@...hat.com> To: Guillaume Morin <guillaume@...infr.org> Cc: oleg@...hat.com, linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org, muchun.song@...ux.dev Subject: Re: [RFC][PATCH] uprobe: support for private hugetlb mappings On 26.04.24 21:55, Guillaume Morin wrote: > On 26 Apr 9:19, David Hildenbrand wrote: >> A couple of points: >> >> a) Don't use page_mapcount(). Either folio_mapcount(), but likely you want >> to check PageAnonExclusive. >> >> b) If you're not following the can_follow_write_pte/_pmd model, you are >> doing something wrong :) >> >> c) The code was heavily changed in mm/mm-unstable. It was merged with t >> the common code. >> >> Likely, in mm/mm-unstable, the existing can_follow_write_pte and >> can_follow_write_pmd checks will already cover what you want in most cases. >> >> We'd need a can_follow_write_pud() to cover follow_huge_pud() and >> (unfortunately) something to handle follow_hugepd() as well similarly. >> >> Copy-pasting what we do in can_follow_write_pte() and adjusting for >> different PTE types is the right thing to do. Maybe now it's time to factor >> out the common checks into a separate helper. > > I tried to get the hugepd stuff right but this was the first I heard > about it :-) Afaict follow_huge_pmd and friends were already DTRT I'll have to have a closer look at some details (the hugepd writability check looks a bit odd), but it's mostly what I would have expected! -- Cheers, David / dhildenb
Powered by blists - more mailing lists