From 64f53a0492b4bc11868307990bb8f7c1e0764f89 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge <jeremy@goop.org> Date: Sun, 27 Jul 2008 08:42:32 -0700 Subject: x86: fix initialization of 'l' bit in ldt descriptors Make sure that fill_ldt() initializes the 'l' bit in the descriptor. It always sets it to 0, ignoring 'lm' in user_desc, preserving original x86_64 behaviour. Previously it was leaving 'l' uninitialized. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Glauber de Oliveira Costa <gcosta@redhat.com> --- include/asm-x86/desc.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/asm-x86') diff --git a/include/asm-x86/desc.h b/include/asm-x86/desc.h index 24a524f5e1a2..06f786f4b4fb 100644 --- a/include/asm-x86/desc.h +++ b/include/asm-x86/desc.h @@ -24,6 +24,11 @@ static inline void fill_ldt(struct desc_struct *desc, desc->d = info->seg_32bit; desc->g = info->limit_in_pages; desc->base2 = (info->base_addr & 0xff000000) >> 24; + /* + * Don't allow setting of the lm bit. It is useless anyway + * because 64bit system calls require __USER_CS: + */ + desc->l = 0; } extern struct desc_ptr idt_descr; -- cgit v1.2.3