From 2435b4a96e04e9be7dbb5f7d2b1741db78e0e127 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski <luto@kernel.org> Date: Fri, 15 Dec 2017 22:08:18 +0100 Subject: [PATCH] x86/mm/pti: Map ESPFIX into user space Map the ESPFIX pages into user space when PTI is enabled. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/mm/pti.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index 0e78797650a7e..b1c38ef9fbbb7 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -287,6 +287,16 @@ static void __init pti_clone_user_shared(void) pti_clone_p4d(CPU_ENTRY_AREA_BASE); } +/* + * 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. */ @@ -308,4 +318,5 @@ void __init pti_init(void) pti_clone_user_shared(); pti_clone_entry_text(); + pti_setup_espfix64(); } -- 2.39.5