Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7dda0387 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by H. Peter Anvin
Browse files

x86_32, mm: Remove user bit from identity map PDE 



The only reason that the user bit was set was to support userspace
access to the compat vDSO in the fixmap.  The compat vDSO is gone,
so the user bit can be removed.

Signed-off-by: default avatarAndy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/e240a977f3c7cbd525a091fd6521499ec4b8e94f.1394751608.git.luto@amacapital.net


Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent b0b49f26

arch/x86/include/asm/pgtable_types.h

+1 −6
Original line number Diff line number Diff line
@@ -214,13 +214,8 @@ 
#ifdef CONFIG_X86_64

#define __PAGE_KERNEL_IDENT_LARGE_EXEC	__PAGE_KERNEL_LARGE_EXEC

#else

/*

 * For PDE_IDENT_ATTR include USER bit. As the PDE and PTE protection

 * bits are combined, this will alow user to access the high address mapped

 * VDSO in the presence of CONFIG_COMPAT_VDSO

 */

#define PTE_IDENT_ATTR	 0x003		/* PRESENT+RW */

#define PDE_IDENT_ATTR	 0x067		/* PRESENT+RW+USER+DIRTY+ACCESSED */

#define PDE_IDENT_ATTR	 0x063		/* PRESENT+RW+DIRTY+ACCESSED */

#define PGD_IDENT_ATTR	 0x001		/* PRESENT (no other attributes) */

#endif