From: Dave Hansen <dave@sr71.net>
To: linux-kernel@vger.kernel.org
Cc: Dave Hansen <dave@sr71.net>, dave.hansen@linux.intel.com
Subject: [PATCH 2/9] x86, pkeys: add fault handling for PF_PK page fault bit
Date: Wed, 09 Mar 2016 14:00:11 -0800 [thread overview]
Message-ID: <20160309220011.D39177BC@viggo.jf.intel.com> (raw)
In-Reply-To: <20160309220008.D61AF421@viggo.jf.intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
PF_PK means that a memory access violated the protection key
access restrictions. It is unconditionally an access_error()
because the permissions set on the VMA don't matter (the PKRU
value overrides it), and we never "resolve" PK faults (like
how a COW can "resolve write fault).
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
---
b/arch/x86/mm/fault.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff -puN arch/x86/mm/fault.c~pkeys-105-add-pk-to-fault arch/x86/mm/fault.c
--- a/arch/x86/mm/fault.c~pkeys-105-add-pk-to-fault 2016-03-09 13:55:19.682431296 -0800
+++ b/arch/x86/mm/fault.c 2016-03-09 13:55:19.685431432 -0800
@@ -1121,6 +1121,15 @@ access_error(unsigned long error_code, s
{
/* This is only called for the current mm, so: */
bool foreign = false;
+
+ /*
+ * Read or write was blocked by protection keys. This is
+ * always an unconditional error and can never result in
+ * a follow-up action to resolve the fault, like a COW.
+ */
+ if (error_code & PF_PK)
+ return 1;
+
/*
* Make sure to check the VMA so that we do not perform
* faults just to hit a PF_PK as soon as we fill in a
_
next prev parent reply other threads:[~2016-03-09 22:03 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-09 22:00 [PATCH 0/9] System Calls for Memory Protection Keys Dave Hansen
2016-03-09 22:00 ` [PATCH 1/9] x86, pkeys: Documentation Dave Hansen
2016-03-09 22:00 ` Dave Hansen [this message]
2016-03-09 22:00 ` [PATCH 3/9] mm: implement new pkey_mprotect() system call Dave Hansen
2016-03-09 22:00 ` [PATCH 4/9] x86, pkeys: make mprotect_key() mask off additional vm_flags Dave Hansen
2016-03-09 22:00 ` [PATCH 5/9] x86: wire up mprotect_key() system call Dave Hansen
2016-03-09 22:00 ` [PATCH 6/9] x86, pkeys: allocation/free syscalls Dave Hansen
2016-03-09 22:00 ` [PATCH 7/9] x86, pkeys: add pkey set/get syscalls Dave Hansen
2016-03-09 22:00 ` [PATCH 8/9] pkeys: add details of system call use to Documentation/ Dave Hansen
2016-03-09 22:00 ` [PATCH 9/9] x86, pkeys: add self-tests Dave Hansen
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