linux-kernel - [PATCH 0/8] [v2] x86/mm: page fault handling cleanups

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20180928160219.3402F0AA@viggo.jf.intel.com>
Date:   Fri, 28 Sep 2018 09:02:19 -0700
From:   Dave Hansen <dave.hansen@...ux.intel.com>
To:     linux-kernel@...r.kernel.org
Cc:     Dave Hansen <dave.hansen@...ux.intel.com>,
        sean.j.christopherson@...el.com, peterz@...radead.org,
        tglx@...utronix.de, luto@...nel.org, jannh@...gle.com,
        x86@...nel.org
Subject: [PATCH 0/8] [v2] x86/mm: page fault handling cleanups

Changes from v1:
 * Take "space_" out of do_kern/user_addr_fault()
 * Make "bad fault" comment in do_kern_addr_fault() less scary
 * Add clarifying comment for the conditions under which 
   do_kern_addr_fault() is called.
 * Remove mention of hw_error_code in search_exception_tables()
   comment.
 * Clarify that the exception tables spell out individual
   instructions, not larger sections of code.
 * Use PAGE_MASK in is_vsyscall_vaddr()
 * Add some additional reasoning behind the code move when
   moving the vsyscall handling to user address space handler
 * Remove hard-coded ~0xfff and replace with PAGE_MASK

---

I went trying to clean up the spurious protection key checks.
But, I got distracted by some other warts in the code.  I hope this
makes things more comprehendable with some improved structure,
commenting and naming.

We come out the other side of it with a new warning in for pkey
faults in the kernel portion of the address space, and removal
of some dead pkeys code, but no other functional changes.

There is a potential impact from moving the vsyscall emulation.
But, this does pass the x86 selftests without any fuss.

Cc: Sean Christopherson <sean.j.christopherson@...el.com>
Cc: "Peter Zijlstra (Intel)" <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Jann Horn <jannh@...gle.com>
Cc: x86@...nel.org