4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Andy Lutomirski <[email protected]> commit 4b6bbe95b87966ba08999574db65c93c5e925a36 upstream. Map the ESPFIX pages into user space when PTI is enabled. Signed-off-by: Andy Lutomirski <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: David Laight <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Kees Cook <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/x86/mm/pti.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -288,6 +288,16 @@ static void __init pti_clone_user_shared } /* + * Clone the ESPFIX P4D into the user space visinble page table + */ +static void __init pti_setup_espfix64(void) +{ +#ifdef CONFIG_X86_ESPFIX64 + pti_clone_p4d(ESPFIX_BASE_ADDR); +#endif +} + +/* * Clone the populated PMDs of the entry and irqentry text and force it RO. */ static void __init pti_clone_entry_text(void) @@ -308,4 +318,5 @@ void __init pti_init(void) pti_clone_user_shared(); pti_clone_entry_text(); + pti_setup_espfix64(); }
