4.4-stable review patch. If anyone has any objections, please let me know.
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From: Ben Hutchings ben.hutchings@codethink.co.uk
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: Ben Hutchings ben.hutchings@codethink.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/entry/vsyscall/vsyscall_64.c | 7 ++++--- arch/x86/include/asm/vsyscall.h | 1 + arch/x86/mm/kaiser.c | 2 +- 3 files changed, 6 insertions(+), 4 deletions(-)
--- a/arch/x86/entry/vsyscall/vsyscall_64.c +++ b/arch/x86/entry/vsyscall/vsyscall_64.c @@ -46,6 +46,7 @@ static enum { EMULATE, NATIVE, NONE } vs #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); --- a/arch/x86/include/asm/vsyscall.h +++ b/arch/x86/include/asm/vsyscall.h @@ -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) --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -345,7 +345,7 @@ 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 +