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: Hugh Dickins <hughd@google.com>
LKML-Reference: <alpine.LSU.2.00.1008242235120.2515@sister.anvils>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/arch/x86/kernel/trampoline.c b/arch/x86/kernel/trampoline.c
index a874495b3673..e2a595257390 100644
--- a/arch/x86/kernel/trampoline.c
+++ b/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,