On Thu, Nov 6, 2014 at 4:53 AM, Ben Hutchings <b...@decadent.org.uk> wrote:
> --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -2455,6 +2455,14 @@ config X86_X32 > elf32_x86_64 support enabled to compile a kernel with this > option set. > > +config X86_X32_DISABLED > + bool "x32 ABI disabled by default" > + depends on X86_X32 > + default n > + help > + Disable the x32 ABI unless explicitly enabled using the > + kernel paramter "syscall.x32=y". parameter > diff --git a/arch/x86/kernel/syscall_64.c b/arch/x86/kernel/syscall_64.c > index 4ac730b..7a6e66f 100644 > --- a/arch/x86/kernel/syscall_64.c > +++ b/arch/x86/kernel/syscall_64.c > +static int __init x32_enable(void) > +{ > + BUG_ON(system_call_fast_compare_end - system_call_fast_compare != 10); > + BUG_ON(system_call_trace_compare_end - system_call_trace_compare != > 10); > + BUG_ON(system_call_mask_compare_end - system_call_mask_compare != 10); BUILD_BUG_ON > + > + if (x32_enabled) { > + text_poke_early(system_call_fast_compare, > + system_call_mask_compare, 10); > + text_poke_early(system_call_trace_compare, > + system_call_mask_compare, 10); > +#ifdef CONFIG_X86_X32_DISABLED > + pr_info("Enabled x32 syscalls\n"); > +#endif I don't think it hurts to print this unconditionally. > + } > +#ifndef CONFIG_X86_X32_DISABLED > + else > + pr_info("Disabled x32 syscalls\n"); > +#endif > + > + return 0; > +} > +late_initcall(x32_enable); > + > +#endif Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/