4.14-stable review patch. If anyone has any objections, please let me know.
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From: Andy Lutomirski luto@kernel.org
commit 4b6bbe95b87966ba08999574db65c93c5e925a36 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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(); }