This is a note to let you know that I've just added the patch titled
x86/mtrr: Fix PAT init handling when MTRR is disabled
to the 4.6-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-mtrr-fix-pat-init-handling-when-mtrr-is-disabled.patch
and it can be found in the queue-4.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ad025a73f0e9344ac73ffe1b74c184033e08e7d5 Mon Sep 17 00:00:00 2001
From: Toshi Kani <toshi.kani@xxxxxxx>
Date: Wed, 23 Mar 2016 15:42:01 -0600
Subject: x86/mtrr: Fix PAT init handling when MTRR is disabled
From: Toshi Kani <toshi.kani@xxxxxxx>
commit ad025a73f0e9344ac73ffe1b74c184033e08e7d5 upstream.
get_mtrr_state() calls pat_init() on BSP even if MTRR is disabled.
This results in calling pat_init() on BSP only since APs do not call
pat_init() when MTRR is disabled. This inconsistency between BSP
and APs leads to undefined behavior.
Make BSP's calling condition to pat_init() consistent with AP's,
mtrr_ap_init() and mtrr_aps_init().
Signed-off-by: Toshi Kani <toshi.kani@xxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Luis R. Rodriguez <mcgrof@xxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Toshi Kani <toshi.kani@xxxxxx>
Cc: elliott@xxxxxxx
Cc: konrad.wilk@xxxxxxxxxx
Cc: paul.gortmaker@xxxxxxxxxxxxx
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1458769323-24491-6-git-send-email-toshi.kani@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/mtrr/generic.c | 24 ++++++++++++++----------
arch/x86/kernel/cpu/mtrr/main.c | 3 +++
arch/x86/kernel/cpu/mtrr/mtrr.h | 1 +
3 files changed, 18 insertions(+), 10 deletions(-)
--- a/arch/x86/kernel/cpu/mtrr/generic.c
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -444,11 +444,24 @@ static void __init print_mtrr_state(void
pr_debug("TOM2: %016llx aka %lldM\n", mtrr_tom2, mtrr_tom2>>20);
}
+/* PAT setup for BP. We need to go through sync steps here */
+void __init mtrr_bp_pat_init(void)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ prepare_set();
+
+ pat_init();
+
+ post_set();
+ local_irq_restore(flags);
+}
+
/* Grab all of the MTRR state for this CPU into *state */
bool __init get_mtrr_state(void)
{
struct mtrr_var_range *vrs;
- unsigned long flags;
unsigned lo, dummy;
unsigned int i;
@@ -481,15 +494,6 @@ bool __init get_mtrr_state(void)
mtrr_state_set = 1;
- /* PAT setup for BP. We need to go through sync steps here */
- local_irq_save(flags);
- prepare_set();
-
- pat_init();
-
- post_set();
- local_irq_restore(flags);
-
return !!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED);
}
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -752,6 +752,9 @@ void __init mtrr_bp_init(void)
/* BIOS may override */
__mtrr_enabled = get_mtrr_state();
+ if (mtrr_enabled())
+ mtrr_bp_pat_init();
+
if (mtrr_cleanup(phys_addr)) {
changed_by_mtrr_cleanup = 1;
mtrr_if->set_all();
--- a/arch/x86/kernel/cpu/mtrr/mtrr.h
+++ b/arch/x86/kernel/cpu/mtrr/mtrr.h
@@ -52,6 +52,7 @@ void set_mtrr_prepare_save(struct set_mt
void fill_mtrr_var_range(unsigned int index,
u32 base_lo, u32 base_hi, u32 mask_lo, u32 mask_hi);
bool get_mtrr_state(void);
+void mtrr_bp_pat_init(void);
extern void set_mtrr_ops(const struct mtrr_ops *ops);
Patches currently in stable-queue which might be from toshi.kani@xxxxxxx are
queue-4.6/x86-mm-pat-replace-cpu_has_pat-with-boot_cpu_has.patch
queue-4.6/x86-mtrr-fix-xorg-crashes-in-qemu-sessions.patch
queue-4.6/libnvdimm-pfn-dax-fix-initialization-vs-autodetect-for-mode-alignment.patch
queue-4.6/x86-mm-pat-add-support-of-non-default-pat-msr-setting.patch
queue-4.6/x86-xen-pat-remove-pat-table-init-code-from-xen.patch
queue-4.6/x86-mtrr-fix-pat-init-handling-when-mtrr-is-disabled.patch
queue-4.6/x86-mm-pat-add-pat_disable-interface.patch
queue-4.6/x86-mm-pat-fix-bug_on-in-mmap_mem-on-qemu-i386.patch
queue-4.6/x86-pat-document-the-pat-initialization-sequence.patch
--
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