x86, mm: Fix CONFIG_VMSPLIT_1G and 2G_OPT trampoline

rc2 kernel crashes when booting second cpu on this CONFIG_VMSPLIT_2G_OPT
laptop: whereas cloning from kernel to low mappings pgd range does need
to limit by both KERNEL_PGD_PTRS and KERNEL_PGD_BOUNDARY, cloning kernel
pgd range itself must not be limited by the smaller KERNEL_PGD_BOUNDARY.
Signed-off-by: NHugh Dickins <hughd@google.com>
LKML-Reference: <alpine.LSU.2.00.1008242235120.2515@sister.anvils>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

arch/x86/kernel/trampoline.c

@@ -45,8 +45,7 @@ void __init setup_trampoline_page_table(void)
 	/* Copy kernel address range */
 	clone_pgd_range(trampoline_pg_dir + KERNEL_PGD_BOUNDARY,
 			swapper_pg_dir + KERNEL_PGD_BOUNDARY,
-			min_t(unsigned long, KERNEL_PGD_PTRS,
-			      KERNEL_PGD_BOUNDARY));
+			KERNEL_PGD_PTRS);
 
 	/* Initialize low mappings */
 	clone_pgd_range(trampoline_pg_dir,