This is a note to let you know that I've just added the patch titled
x86/kaiser: Move feature detection up
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-kaiser-move-feature-detection-up.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Jan 3 18:58:12 CET 2018
From: Borislav Petkov <bp@xxxxxxx>
Date: Mon, 25 Dec 2017 13:57:16 +0100
Subject: x86/kaiser: Move feature detection up
From: Borislav Petkov <bp@xxxxxxx>
... before the first use of kaiser_enabled as otherwise funky
things happen:
about to get started...
(XEN) d0v0 Unhandled page fault fault/trap [#14, ec=0000]
(XEN) Pagetable walk from ffff88022a449090:
(XEN) L4[0x110] = 0000000229e0e067 0000000000001e0e
(XEN) L3[0x008] = 0000000000000000 ffffffffffffffff
(XEN) domain_crash_sync called from entry.S: fault at ffff82d08033fd08
entry.o#create_bounce_frame+0x135/0x14d
(XEN) Domain 0 (vcpu#0) crashed on cpu#0:
(XEN) ----[ Xen-4.9.1_02-3.21 x86_64 debug=n Not tainted ]----
(XEN) CPU: 0
(XEN) RIP: e033:[<ffffffff81007460>]
(XEN) RFLAGS: 0000000000000286 EM: 1 CONTEXT: pv guest (d0v0)
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/kaiser.h | 2 ++
arch/x86/kernel/setup.c | 7 +++++++
arch/x86/mm/kaiser.c | 2 --
3 files changed, 9 insertions(+), 2 deletions(-)
--- a/arch/x86/include/asm/kaiser.h
+++ b/arch/x86/include/asm/kaiser.h
@@ -96,8 +96,10 @@ DECLARE_PER_CPU(unsigned long, x86_cr3_p
extern char __per_cpu_user_mapped_start[], __per_cpu_user_mapped_end[];
extern int kaiser_enabled;
+extern void __init kaiser_check_boottime_disable(void);
#else
#define kaiser_enabled 0
+static inline void __init kaiser_check_boottime_disable(void) {}
#endif /* CONFIG_KAISER */
/*
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -112,6 +112,7 @@
#include <asm/alternative.h>
#include <asm/prom.h>
#include <asm/microcode.h>
+#include <asm/kaiser.h>
/*
* max_low_pfn_mapped: highest direct mapped pfn under 4GB
@@ -1016,6 +1017,12 @@ void __init setup_arch(char **cmdline_p)
*/
init_hypervisor_platform();
+ /*
+ * This needs to happen right after XENPV is set on xen and
+ * kaiser_enabled is checked below in cleanup_highmap().
+ */
+ kaiser_check_boottime_disable();
+
x86_init.resources.probe_roms();
/* after parse_early_param, so could debug it */
--- a/arch/x86/mm/kaiser.c
+++ b/arch/x86/mm/kaiser.c
@@ -311,8 +311,6 @@ void __init kaiser_init(void)
{
int cpu;
- kaiser_check_boottime_disable();
-
if (!kaiser_enabled)
return;
Patches currently in stable-queue which might be from bp@xxxxxxx are
queue-4.4/x86-paravirt-dont-patch-flush_tlb_single.patch
queue-4.4/x86-kaiser-reenable-paravirt.patch
queue-4.4/x86-kaiser-rename-and-simplify-x86_feature_kaiser-handling.patch
queue-4.4/x86-kaiser-check-boottime-cmdline-params.patch
queue-4.4/x86-kaiser-move-feature-detection-up.patch