[PATCH 4.4 27/49] x86/mtrr: Fix PAT init handling when MTRR is disabled

From	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newsgroups	linux.kernel
Subject	[PATCH 4.4 27/49] x86/mtrr: Fix PAT init handling when MTRR is disabled
Date	2016-08-14 22:30 +0200
Message-ID	<s6acH-4ts-83@gated-at.bofh.it> (permalink)
References	<s6acF-4ts-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Toshi Kani <toshi.kani@hpe.com>

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@hpe.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: elliott@hpe.com
Cc: konrad.wilk@oracle.com
Cc: paul.gortmaker@windriver.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1458769323-24491-6-git-send-email-toshi.kani@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 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);

Thread

[PATCH 4.4 00/49] 4.4.18-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 33/49] mm: memcontrol: fix swap counter leak on swapout from offline cgroup Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 05/49] net: bgmac: Fix infinite loop in bgmac_dma_tx_add() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 26/49] x86/mtrr: Fix Xorg crashes in Qemu sessions Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 28/49] x86/xen, pat: Remove PAT table init code from Xen Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 01/49] tcp: make challenge acks less predictable Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 03/49] ipv4: reject RTNH_F_DEAD and RTNH_F_LINKDOWN from user space Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 12/49] PNP: Add Broadwell to Intel MCH size workaround Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 23/49] x86/mm/pat: Add support of non-default PAT MSR setting Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 24/49] x86/mm/pat: Add pat_disable() interface Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 10/49] scsi: ignore errors from scsi_dh_add_device() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 20/49] apparmor: fix ref count leak when profile sha1 hash is read Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 41/49] fs/dcache.c: avoid soft-lockup in dput() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 49/49] ext4: fix reference counting bug on block allocation error Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 07/49] qed: Fix setting/clearing bit in completion bitmap Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 38/49] fuse: fsync() did not return IO errors Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 46/49] ext4: dont call ext4_should_journal_data() on the journal inode Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 43/49] crypto: scatterwalk - Fix test in scatterwalk_done Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 19/49] Revert "s390/kdump: Clear subchannel ID to signal non-CCW/SCSI IPL" Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 45/49] ext4: fix deadlock during page writeback Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 22/49] devpts: clean up interface to pty drivers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 48/49] ext4: short-cut orphan cleanup on error Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 32/49] mm: memcontrol: fix cgroup creation failure after many small jobs Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 06/49] net/irda: fix NULL pointer dereference on memory allocation failure Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 27/49] x86/mtrr: Fix PAT init handling when MTRR is disabled Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 44/49] ext4: check for extents that wrap around Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 29/49] x86/pat: Document the PAT initialization sequence Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 36/49] block: fix use-after-free in seq file Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:30 +0200
  [PATCH 4.4 37/49] sysv, ipc: fix security-layer leaking Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:40 +0200
  [PATCH 4.4 09/49] ipath: Restrict use of the write() interface Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:40 +0200
  [PATCH 4.4 35/49] x86/syscalls/64: Add compat_sys_keyctl for 32-bit userspace Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:40 +0200
  [PATCH 4.4 21/49] random: strengthen input validation for RNDADDTOENTCNT Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:40 +0200
  [PATCH 4.4 04/49] bonding: set carrier off for devices created through netlink Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:40 +0200
  [PATCH 4.4 11/49] PNP: Add Haswell-ULT to Intel MCH size workaround Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-14 22:40 +0200
  Re: [PATCH 4.4 00/49] 4.4.18-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-15 10:00 +0200
  Re: [PATCH 4.4 00/49] 4.4.18-stable review Guenter Roeck <linux@roeck-us.net> - 2016-08-15 15:10 +0200
  Re: [PATCH 4.4 00/49] 4.4.18-stable review Shuah Khan <shuah.kh@samsung.com> - 2016-08-16 06:10 +0200

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