Commit-ID: 16dce603adc9de4237b7bf2ff5c5290f34373e7b Gitweb: https://git.kernel.org/tip/16dce603adc9de4237b7bf2ff5c5290f34373e7b Author: Dave Hansen <[email protected]> AuthorDate: Fri, 20 Apr 2018 15:20:19 -0700 Committer: Thomas Gleixner <[email protected]> CommitDate: Tue, 24 Apr 2018 09:50:53 +0200
x86/pti: Fix boot problems from Global-bit setting Part of the global bit _setting_ patches also includes clearing the Global bit when it should not be enabled. That is done with set_memory_nonglobal(), which uses change_page_attr_clear() in pageattr.c under the covers. The TLB flushing code inside pageattr.c has has checks like BUG_ON(irqs_disabled()), looking for interrupt disabling that might cause deadlocks. But, these also trip in early boot on certain preempt configurations. Just copy the existing BUG_ON() sequence from cpa_flush_range() to the other two sites and check for early boot. Fixes: 39114b7a7 (x86/pti: Never implicitly clear _PAGE_GLOBAL for kernel image) Reported-by: Mariusz Ceier <[email protected]> Reported-by: Aaro Koskinen <[email protected]> Signed-off-by: Dave Hansen <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: Aaro Koskinen <[email protected]> Acked-by: Ingo Molnar <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Nadav Amit <[email protected]> Cc: Kees Cook <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: David Woodhouse <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: [email protected] Cc: Linus Torvalds <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Dan Williams <[email protected]> Cc: Arjan van de Ven <[email protected]> Link: https://lkml.kernel.org/r/[email protected] --- arch/x86/mm/pageattr.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 0f3d50f4c48c..4fadfd2b7017 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -172,7 +172,7 @@ static void __cpa_flush_all(void *arg) static void cpa_flush_all(unsigned long cache) { - BUG_ON(irqs_disabled()); + BUG_ON(irqs_disabled() && !early_boot_irqs_disabled); on_each_cpu(__cpa_flush_all, (void *) cache, 1); } @@ -236,7 +236,7 @@ static void cpa_flush_array(unsigned long *start, int numpages, int cache, unsigned long do_wbinvd = cache && numpages >= 1024; /* 4M threshold */ #endif - BUG_ON(irqs_disabled()); + BUG_ON(irqs_disabled() && !early_boot_irqs_disabled); on_each_cpu(__cpa_flush_all, (void *) do_wbinvd, 1);
