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