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

Commit 9a0be5af authored by Ben Hutchings's avatar Ben Hutchings Committed by Greg Kroah-Hartman
Browse files

vsyscall: Fix permissions for emulate mode with KAISER/PTI 



The backport of KAISER to 4.4 turned vsyscall emulate mode into native
mode.  Add a vsyscall_pgprot variable to hold the correct page
protections, like Borislav and Hugh did for 3.2 and 3.18.

Cc: Borislav Petkov <bp@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: default avatarBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 1be7d46e

arch/x86/entry/vsyscall/vsyscall_64.c

+4 −3
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ static enum { EMULATE, NATIVE, NONE } vsyscall_mode = 
#else

	EMULATE;

#endif

unsigned long vsyscall_pgprot = __PAGE_KERNEL_VSYSCALL;



static int __init vsyscall_setup(char *str)

{
@@ -336,11 +337,11 @@ void __init map_vsyscall(void) 
	extern char __vsyscall_page;

	unsigned long physaddr_vsyscall = __pa_symbol(&__vsyscall_page);



	if (vsyscall_mode != NATIVE)

		vsyscall_pgprot = __PAGE_KERNEL_VVAR;

	if (vsyscall_mode != NONE)

		__set_fixmap(VSYSCALL_PAGE, physaddr_vsyscall,

			     vsyscall_mode == NATIVE

			     ? PAGE_KERNEL_VSYSCALL

			     : PAGE_KERNEL_VVAR);

			     __pgprot(vsyscall_pgprot));



	BUILD_BUG_ON((unsigned long)__fix_to_virt(VSYSCALL_PAGE) !=

		     (unsigned long)VSYSCALL_ADDR);

arch/x86/include/asm/vsyscall.h

+1 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ extern void map_vsyscall(void); 
 */

extern bool emulate_vsyscall(struct pt_regs *regs, unsigned long address);

extern bool vsyscall_enabled(void);

extern unsigned long vsyscall_pgprot;

#else

static inline void map_vsyscall(void) {}

static inline bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)

arch/x86/mm/kaiser.c

+1 −1
Original line number Diff line number Diff line
@@ -344,7 +344,7 @@ void __init kaiser_init(void) 
	if (vsyscall_enabled())

		kaiser_add_user_map_early((void *)VSYSCALL_ADDR,

					  PAGE_SIZE,

					   __PAGE_KERNEL_VSYSCALL);

					  vsyscall_pgprot);



	for_each_possible_cpu(cpu) {

		void *percpu_vaddr = __per_cpu_user_mapped_start +