Patch "x86/tlb: Drop the _GPL from the cpu_tlbstate export" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    x86/tlb: Drop the _GPL from the cpu_tlbstate export

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-tlb-drop-the-_gpl-from-the-cpu_tlbstate-export.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@vger.kernel.org> know about it.


>From 1e5476815fd7f98b888e01a0f9522b63085f96c9 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 4 Jan 2018 22:19:04 +0100
Subject: x86/tlb: Drop the _GPL from the cpu_tlbstate export

From: Thomas Gleixner <tglx@linutronix.de>

commit 1e5476815fd7f98b888e01a0f9522b63085f96c9 upstream.

The recent changes for PTI touch cpu_tlbstate from various tlb_flush
inlines. cpu_tlbstate is exported as GPL symbol, so this causes a
regression when building out of tree drivers for certain graphics cards.

Aside of that the export was wrong since it was introduced as it should
have been EXPORT_PER_CPU_SYMBOL_GPL().

Use the correct PER_CPU export and drop the _GPL to restore the previous
state which allows users to utilize the cards they payed for.

As always I'm really thrilled to make this kind of change to support the
#friends (or however the hot hashtag of today is spelled) from that closet
sauce graphics corp.

Fixes: 1e02ce4cccdc ("x86: Store a per-cpu shadow copy of CR4")
Fixes: 6fd166aae78c ("x86/mm: Use/Fix PCID to optimize user/kernel switches")
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Backlund <tmb@mageia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/mm/init.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -757,7 +757,7 @@ DEFINE_PER_CPU_SHARED_ALIGNED(struct tlb
 	.state = 0,
 	.cr4 = ~0UL,	/* fail hard if we screw up cr4 shadow initialization */
 };
-EXPORT_SYMBOL_GPL(cpu_tlbstate);
+EXPORT_PER_CPU_SYMBOL(cpu_tlbstate);
 
 void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache)
 {


Patches currently in stable-queue which might be from tglx@linutronix.de are

queue-4.4/x86-tlb-drop-the-_gpl-from-the-cpu_tlbstate-export.patch
queue-4.4/x86-kasan-write-protect-kasan-zero-shadow.patch
queue-4.4/x86-microcode-amd-add-support-for-fam17h-microcode-loading.patch