From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161115AbWHJKgn (ORCPT ); Thu, 10 Aug 2006 06:36:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161146AbWHJKgn (ORCPT ); Thu, 10 Aug 2006 06:36:43 -0400 Received: from ns.oss.ntt.co.jp ([222.151.198.98]:2187 "EHLO serv1.oss.ntt.co.jp") by vger.kernel.org with ESMTP id S1161115AbWHJKgm (ORCPT ); Thu, 10 Aug 2006 06:36:42 -0400 Subject: [PATCH 1/2] i386: Disallow kprobes on NMI handlers From: Fernando Luis =?ISO-8859-1?Q?V=E1zquez?= Cao To: Andi Kleen Cc: prasanna@in.ibm.com, akpm@osdl.org, linux-kernel@vger.kernel.org Content-Type: text/plain Organization: =?UTF-8?Q?NTT=E3=82=AA=E3=83=BC=E3=83=97=E3=83=B3=E3=82=BD=E3=83=BC?= =?UTF-8?Q?=E3=82=B9=E3=82=BD=E3=83=95=E3=83=88=E3=82=A6=E3=82=A7?= =?UTF-8?Q?=E3=82=A2=E3=82=BB=E3=83=B3=E3=82=BF?= Date: Thu, 10 Aug 2006 19:36:39 +0900 Message-Id: <1155206199.3001.40.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org A kprobe executes IRET early and that could cause NMI recursion and stack corruption. Note: This problem was originally identified and solved by Andi Kleen in the x86_64 architecture. This patch is an adaption of his patch for i386. Signed-off-by: Fernando Vazquez --- diff -urNp linux-2.6.18-rc4-orig/arch/i386/kernel/entry.S linux-2.6.18-rc4/arch/i386/kernel/entry.S --- linux-2.6.18-rc4-orig/arch/i386/kernel/entry.S 2006-08-10 17:24:14.000000000 +0900 +++ linux-2.6.18-rc4/arch/i386/kernel/entry.S 2006-08-10 17:31:55.000000000 +0900 @@ -725,7 +725,7 @@ debug_stack_correct: * check whether we got an NMI on the debug path where the debug * fault happened on the sysenter path. */ -ENTRY(nmi) +KPROBE_ENTRY(nmi) RING0_INT_FRAME pushl %eax CFI_ADJUST_CFA_OFFSET 4 diff -urNp linux-2.6.18-rc4-orig/arch/i386/kernel/nmi.c linux-2.6.18-rc4/arch/i386/kernel/nmi.c --- linux-2.6.18-rc4-orig/arch/i386/kernel/nmi.c 2006-08-10 17:24:15.000000000 +0900 +++ linux-2.6.18-rc4/arch/i386/kernel/nmi.c 2006-08-10 17:40:22.000000000 +0900 @@ -579,7 +579,7 @@ EXPORT_SYMBOL(touch_nmi_watchdog); extern void die_nmi(struct pt_regs *, const char *msg); -void nmi_watchdog_tick (struct pt_regs * regs) +void __kprobes nmi_watchdog_tick (struct pt_regs * regs) { /* diff -urNp linux-2.6.18-rc4-orig/arch/i386/kernel/traps.c linux-2.6.18-rc4/arch/i386/kernel/traps.c --- linux-2.6.18-rc4-orig/arch/i386/kernel/traps.c 2006-08-10 17:24:16.000000000 +0900 +++ linux-2.6.18-rc4/arch/i386/kernel/traps.c 2006-08-10 18:16:12.000000000 +0900 @@ -626,7 +626,8 @@ gp_in_kernel: } } -static void mem_parity_error(unsigned char reason, struct pt_regs * regs) +static __kprobes void +mem_parity_error(unsigned char reason, struct pt_regs * regs) { printk(KERN_EMERG "Uhhuh. NMI received. Dazed and confused, but trying " "to continue\n"); @@ -637,7 +638,8 @@ static void mem_parity_error(unsigned ch clear_mem_error(reason); } -static void io_check_error(unsigned char reason, struct pt_regs * regs) +static __kprobes void +io_check_error(unsigned char reason, struct pt_regs * regs) { unsigned long i; @@ -653,7 +655,8 @@ static void io_check_error(unsigned char outb(reason, 0x61); } -static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs) +static __kprobes void +unknown_nmi_error(unsigned char reason, struct pt_regs * regs) { #ifdef CONFIG_MCA /* Might actually be able to figure out what the guilty party @@ -671,7 +674,7 @@ static void unknown_nmi_error(unsigned c static DEFINE_SPINLOCK(nmi_print_lock); -void die_nmi (struct pt_regs *regs, const char *msg) +void __kprobes die_nmi(struct pt_regs *regs, const char *msg) { if (notify_die(DIE_NMIWATCHDOG, msg, regs, 0, 2, SIGINT) == NOTIFY_STOP) @@ -703,7 +706,7 @@ void die_nmi (struct pt_regs *regs, cons do_exit(SIGSEGV); } -static void default_do_nmi(struct pt_regs * regs) +static __kprobes void default_do_nmi(struct pt_regs * regs) { unsigned char reason = 0; @@ -741,14 +744,14 @@ static void default_do_nmi(struct pt_reg reassert_nmi(); } -static int dummy_nmi_callback(struct pt_regs * regs, int cpu) +static __kprobes int dummy_nmi_callback(struct pt_regs * regs, int cpu) { return 0; } static nmi_callback_t nmi_callback = dummy_nmi_callback; -fastcall void do_nmi(struct pt_regs * regs, long error_code) +fastcall __kprobes void do_nmi(struct pt_regs * regs, long error_code) { int cpu;