From: Borislav Petkov <[email protected]> Keep the "nopti" for traditional reasons.
Requested-by: Linus Torvalds <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Andy Lutomirsky <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Greg KH <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Brian Gerst <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: Boris Ostrovsky <[email protected]> Cc: Juergen Gross <[email protected]> Cc: David Laight <[email protected]> Cc: Eduardo Valentin <[email protected]> Cc: [email protected] Cc: Will Deacon <[email protected]> Cc: [email protected] --- Documentation/admin-guide/kernel-parameters.txt | 6 ++++++ arch/x86/mm/pti.c | 18 ++++++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 5dfd26265484..520fdec15bbb 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3255,6 +3255,12 @@ pt. [PARIDE] See Documentation/blockdev/paride.txt. + pti= [X86_64] + Control user/kernel address space isolation: + on - enable + off - disable + auto - default setting + pty.legacy_count= [KNL] Number of legacy pty's. Overwrites compiled-in default number. diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index f48645d2f3fd..4afa16b444b2 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -51,15 +51,33 @@ void __init pti_check_boottime_disable(void) { bool enable = true; + char arg[5]; + + if (cmdline_find_option(boot_command_line, "pti", arg, sizeof(arg))) { + if (!strncmp(arg, "on", 2)) + goto enable; + + if (!strncmp(arg, "off", 3)) { + pr_info("disabled on command line.\n"); + return; + } + + if (!strncmp(arg, "auto", 4)) + goto skip; + } if (cmdline_find_option_bool(boot_command_line, "nopti")) { pr_info("disabled on command line.\n"); enable = false; } + +skip: if (hypervisor_is_type(X86_HYPER_XEN_PV)) { pr_info("disabled on XEN_PV.\n"); enable = false; } + +enable: if (enable) setup_force_cpu_bug(X86_BUG_CPU_SECURE_MODE_PTI); } -- 2.13.0
