Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752474Ab1BEAeb (ORCPT ); Fri, 4 Feb 2011 19:34:31 -0500 Received: from hera.kernel.org ([140.211.167.34]:33231 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751085Ab1BEAe2 (ORCPT ); Fri, 4 Feb 2011 19:34:28 -0500 Date: Sat, 5 Feb 2011 00:34:06 GMT From: "tip-bot for H. Peter Anvin" Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, castet.matthieu@free.fr, kees.cook@canonical.com, tglx@linutronix.de, hpa@linux.intel.com Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, castet.matthieu@free.fr, kees.cook@canonical.com, tglx@linutronix.de, hpa@linux.intel.com In-Reply-To: <4D41E86D.8060205@free.fr> References: <4D41E86D.8060205@free.fr> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86-32: Make sure the stack is set up before we use it Message-ID: Git-Commit-ID: 990957d4076354d449921b598cc8de28764cf7ed X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Sat, 05 Feb 2011 00:34:07 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5849 Lines: 181 Commit-ID: 990957d4076354d449921b598cc8de28764cf7ed Gitweb: http://git.kernel.org/tip/990957d4076354d449921b598cc8de28764cf7ed Author: H. Peter Anvin AuthorDate: Fri, 4 Feb 2011 16:14:11 -0800 Committer: H. Peter Anvin CommitDate: Fri, 4 Feb 2011 16:27:21 -0800 x86-32: Make sure the stack is set up before we use it Since checkin ebba638ae723d8a8fc2f7abce5ec18b688b791d7 we call verify_cpu even in 32-bit mode. Unfortunately, calling a function means using the stack, and the stack pointer was not initialized in the 32-bit setup code! This code initializes the stack pointer, and simplifies the interface slightly since it is easier to rely on just a pointer value rather than a descriptor; we need to have different values for the segment register anyway. This retains start_stack as a virtual address, even though a physical address would be more convenient for 32 bits; the 64-bit code wants the other way around... Reported-by: Matthieu Castet LKML-Reference: <4D41E86D.8060205@free.fr> Cc: Kees Cook Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/smp.h | 5 +---- arch/x86/kernel/acpi/sleep.c | 2 +- arch/x86/kernel/head_32.S | 20 ++++++++++++-------- arch/x86/kernel/head_64.S | 1 - arch/x86/kernel/smpboot.c | 4 ++-- 5 files changed, 16 insertions(+), 16 deletions(-) diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index 4c2f63c..1f46951 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -40,10 +40,7 @@ DECLARE_EARLY_PER_CPU(u16, x86_cpu_to_apicid); DECLARE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid); /* Static state in head.S used to set up a CPU */ -extern struct { - void *sp; - unsigned short ss; -} stack_start; +extern unsigned long stack_start; /* Initial stack pointer address */ struct smp_ops { void (*smp_prepare_boot_cpu)(void); diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c index 69fd72a..4d9ebba 100644 --- a/arch/x86/kernel/acpi/sleep.c +++ b/arch/x86/kernel/acpi/sleep.c @@ -100,7 +100,7 @@ int acpi_save_state_mem(void) #else /* CONFIG_64BIT */ header->trampoline_segment = setup_trampoline() >> 4; #ifdef CONFIG_SMP - stack_start.sp = temp_stack + sizeof(temp_stack); + stack_start = (unsigned long)temp_stack + sizeof(temp_stack); early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(smp_processor_id()); initial_gs = per_cpu_offset(smp_processor_id()); diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index fc293dc..10a6381 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -85,6 +85,8 @@ RESERVE_BRK(pagetables, INIT_MAP_SIZE) */ __HEAD ENTRY(startup_32) + movl pa(stack_start),%ecx + /* test KEEP_SEGMENTS flag to see if the bootloader is asking us to not reload segments */ testb $(1<<6), BP_loadflags(%esi) @@ -99,7 +101,9 @@ ENTRY(startup_32) movl %eax,%es movl %eax,%fs movl %eax,%gs + movl %eax,%ss 2: + leal -__PAGE_OFFSET(%ecx),%esp /* * Clear BSS first so that there are no surprises... @@ -145,8 +149,6 @@ ENTRY(startup_32) * _brk_end is set up to point to the first "safe" location. * Mappings are created both at virtual address 0 (identity mapping) * and PAGE_OFFSET for up to _end. - * - * Note that the stack is not yet set up! */ #ifdef CONFIG_X86_PAE @@ -282,6 +284,9 @@ ENTRY(startup_32_smp) movl %eax,%es movl %eax,%fs movl %eax,%gs + movl pa(stack_start),%ecx + movl %eax,%ss + leal -__PAGE_OFFSET(%ecx),%esp #endif /* CONFIG_SMP */ default_entry: @@ -347,8 +352,8 @@ default_entry: movl %eax,%cr0 /* ..and set paging (PG) bit */ ljmp $__BOOT_CS,$1f /* Clear prefetch and normalize %eip */ 1: - /* Set up the stack pointer */ - lss stack_start,%esp + /* Shift the stack pointer to a virtual address */ + addl $__PAGE_OFFSET, %esp /* * Initialize eflags. Some BIOS's leave bits like NT set. This would @@ -475,7 +480,6 @@ is386: movl $2,%ecx # set MP movb $1, ready cmpb $0,%cl # the first CPU calls start_kernel je 1f - movl (stack_start), %esp 1: #endif /* CONFIG_SMP */ jmp *(initial_code) @@ -670,15 +674,15 @@ ENTRY(initial_page_table) #endif .data +.balign 4 ENTRY(stack_start) .long init_thread_union+THREAD_SIZE - .long __BOOT_DS - -ready: .byte 0 early_recursion_flag: .long 0 +ready: .byte 0 + int_msg: .asciz "Unknown interrupt or fault at: %p %p %p\n" diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 239046b..1ee8493 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -264,7 +264,6 @@ ENTRY(secondary_startup_64) ENTRY(stack_start) .quad init_thread_union+THREAD_SIZE-8 - .word 0 __FINITDATA bad_address: diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 0cbe8c0..03273b6 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -638,7 +638,7 @@ wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip) * target processor state. */ startup_ipi_hook(phys_apicid, (unsigned long) start_secondary, - (unsigned long)stack_start.sp); + stack_start); /* * Run STARTUP IPI loop. @@ -785,7 +785,7 @@ do_rest: #endif early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu); initial_code = (unsigned long)start_secondary; - stack_start.sp = (void *) c_idle.idle->thread.sp; + stack_start = c_idle.idle->thread.sp; /* start_ip had better be page-aligned! */ start_ip = setup_trampoline(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/