From e3228cf4544355f73437a2b9c6916be9cbafc201 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Wed, 28 Nov 2012 11:50:29 -0800 Subject: [PATCH] x86, 386 removal: Remove CONFIG_X86_POPAD_OK The check_popad() routine tested for a 386-specific bug, and never actually did anything useful with it anyway other than print a message. Signed-off-by: H. Peter Anvin Link: http://lkml.kernel.org/r/1354132230-21854-8-git-send-email-hpa@linux.intel.com --- arch/x86/Kconfig.cpu | 4 ---- arch/x86/kernel/cpu/bugs.c | 28 ---------------------------- 2 files changed, 32 deletions(-) diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu index 159ee9c824c..423db7189eb 100644 --- a/arch/x86/Kconfig.cpu +++ b/arch/x86/Kconfig.cpu @@ -325,10 +325,6 @@ config X86_INVD_BUG def_bool y depends on M486 -config X86_POPAD_OK - def_bool y - depends on X86_32 - config X86_ALIGNMENT_16 def_bool y depends on MWINCHIP3D || MWINCHIPC6 || MCYRIXIII || MELAN || MK6 || M586MMX || M586TSC || M586 || M486 || MVIAC3_2 || MGEODEGX1 diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 0cd07ccdf38..92dfec986a4 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -106,33 +106,6 @@ static void __init check_hlt(void) pr_cont("OK\n"); } -/* - * Most 386 processors have a bug where a POPAD can lock the - * machine even from user space. - */ - -static void __init check_popad(void) -{ -#ifndef CONFIG_X86_POPAD_OK - int res, inp = (int) &res; - - pr_info("Checking for popad bug... "); - __asm__ __volatile__( - "movl $12345678,%%eax; movl $0,%%edi; pusha; popa; movl (%%edx,%%edi),%%ecx " - : "=&a" (res) - : "d" (inp) - : "ecx", "edi"); - /* - * If this fails, it means that any user program may lock the - * CPU hard. Too bad. - */ - if (res != 12345678) - pr_cont("Buggy\n"); - else - pr_cont("OK\n"); -#endif -} - /* * Check whether we are able to run this kernel safely on SMP. * @@ -157,7 +130,6 @@ void __init check_bugs(void) #endif check_config(); check_hlt(); - check_popad(); init_utsname()->machine[1] = '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86); alternative_instructions(); -- 2.20.1