[PATCH 1/1] fill vdso with syscall32_setup_pages if TIF_IA32 on x86_64

["Serge E. Hallyn" <serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>]

arch_setup_additional_pages() on x86_64 fills in a 64-bit
vdso page.

With this patch, restart of 32-bit tasks (both self- and external
checkpoints) on x86-64 succeeds.

Signed-off-by: Serge E. Hallyn <serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
---
 mm/mmap.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 1759a7f..e3d4178 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2324,6 +2324,10 @@ int special_mapping_restore(struct ckpt_ctx *ctx,
 	 * Even that, is very basic - call arch_setup_additional_pages
 	 * requiring the same mapping (start address) as before.
 	 */
+#ifdef CONFIG_X86_64 && CONFIG_COMPAT
+	if (test_thread_flag(TIF_IA32))
+		return syscall32_setup_pages(NULL, h->vm_start, 0);
+#endif
 	return arch_setup_additional_pages(NULL, h->vm_start, 0);
 }
 #else /* !CONFIG_CHECKPOINT */
-- 
1.6.0.6