x86/mm: remove vmalloc faulting

Remove fault handling on vmalloc areas, as the vmalloc code now takes
care of synchronizing changes to all page-tables in the system.

Signed-off-by: Joerg Roedel <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Acked-by: Andy Lutomirski <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "H . Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 0 insertions, 37 deletions

diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 66f96f21a7b6..f3fe261e5936 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -161,34 +161,6 @@ void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 	local_irq_restore(flags);
 }
 
-static void sync_current_stack_to_mm(struct mm_struct *mm)
-{
-	unsigned long sp = current_stack_pointer;
-	pgd_t *pgd = pgd_offset(mm, sp);
-
-	if (pgtable_l5_enabled()) {
-		if (unlikely(pgd_none(*pgd))) {
-			pgd_t *pgd_ref = pgd_offset_k(sp);
-
-			set_pgd(pgd, *pgd_ref);
-		}
-	} else {
-		/*
-		 * "pgd" is faked.  The top level entries are "p4d"s, so sync
-		 * the p4d.  This compiles to approximately the same code as
-		 * the 5-level case.
-		 */
-		p4d_t *p4d = p4d_offset(pgd, sp);
-
-		if (unlikely(p4d_none(*p4d))) {
-			pgd_t *pgd_ref = pgd_offset_k(sp);
-			p4d_t *p4d_ref = p4d_offset(pgd_ref, sp);
-
-			set_p4d(p4d, *p4d_ref);
-		}
-	}
-}
-
 static inline unsigned long mm_mangle_tif_spec_ib(struct task_struct *next)
 {
 	unsigned long next_tif = task_thread_info(next)->flags;
@@ -377,15 +349,6 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
 		 */
 		cond_ibpb(tsk);
 
-		if (IS_ENABLED(CONFIG_VMAP_STACK)) {
-			/*
-			 * If our current stack is in vmalloc space and isn't
-			 * mapped in the new pgd, we'll double-fault.  Forcibly
-			 * map it.
-			 */
-			sync_current_stack_to_mm(next);
-		}
-
 		/*
 		 * Stop remote flushes for the previous mm.
 		 * Skip kernel threads; we never send init_mm TLB flushing IPIs,