Patch "x86/tlb: Drop the _GPL from the cpu_tlbstate export" has been added to the 4.14-stable tree

Patch "x86/tlb: Drop the _GPL from the cpu_tlbstate export" has been added to the 4.14-stable tree

[gregkh]

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 4.14-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-4.14 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>
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
@@ -870,7 +870,7 @@ __visible DEFINE_PER_CPU_SHARED_ALIGNED(
 	.next_asid = 1,
 	.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-4.14/x86-tlb-drop-the-_gpl-from-the-cpu_tlbstate-export.patch
queue-4.14/x86-alternatives-add-missing-n-at-end-of-alternative-inline-asm.patch
queue-4.14/x86-kaslr-fix-the-vaddr_end-mess.patch
queue-4.14/efi-capsule-loader-reinstate-virtual-capsule-mapping.patch
queue-4.14/x86-mm-set-modules_end-to-0xffffffffff000000.patch
queue-4.14/mm-sparse.c-wrong-allocation-for-mem_section.patch
queue-4.14/x86-events-intel-ds-use-the-proper-cache-flush-method-for-mapping-ds-buffers.patch
queue-4.14/x86-pti-rename-bug_cpu_insecure-to-bug_cpu_meltdown.patch
queue-4.14/x86-mm-map-cpu_entry_area-at-the-same-place-on-4-5-level.patch

Re: Patch "x86/tlb: Drop the _GPL from the cpu_tlbstate export" has been added to the 4.14-stable tree

[Thomas Backlund]

Den 06.01.2018 kl. 00:06, skrev 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 4.14-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-4.14 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.
>


This one is also needed in older stable branches, atleast down to 4.4 
where we (Mageia) got a note about broken fglrx build with 4.4.110.

--
Thomas

Re: Patch "x86/tlb: Drop the _GPL from the cpu_tlbstate export" has been added to the 4.14-stable tree

[Greg KH]

On Sun, Jan 07, 2018 at 03:58:26PM +0200, Thomas Backlund wrote:
> Den 06.01.2018 kl. 00:06, skrev 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 4.14-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-4.14 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.
> > 
> 
> 
> This one is also needed in older stable branches, atleast down to 4.4 where
> we (Mageia) got a note about broken fglrx build with 4.4.110.

Ugh, ok, thanks for the report, I'll backport this.  I didn't think it
was going to be needed given that some of the prerequsite patches were
not in 4.4 :(

greg k-h