Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932511AbWCAGaK (ORCPT ); Wed, 1 Mar 2006 01:30:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932513AbWCAGaJ (ORCPT ); Wed, 1 Mar 2006 01:30:09 -0500 Received: from fmr17.intel.com ([134.134.136.16]:10443 "EHLO orsfmr002.jf.intel.com") by vger.kernel.org with ESMTP id S932511AbWCAGaI (ORCPT ); Wed, 1 Mar 2006 01:30:08 -0500 Message-ID: <44053DC6.6060209@linux.intel.com> Date: Wed, 01 Mar 2006 14:23:02 +0800 From: bibo mao User-Agent: Thunderbird 1.5 (X11/20051201) MIME-Version: 1.0 To: prasanna@in.ibm.com CC: "bibo,mao" , Andrew Morton , linux-kernel@vger.kernel.org, Ananth N Mavinakayanahalli , "Keshavamurthy, Anil S" , hiramatu@sdl.hitachi.co.jp Subject: Re: [PATCH]kprobe handler discard user space trap References: <4403FA60.6060701@intel.com> <20060228113431.GG10512@in.ibm.com> In-Reply-To: <20060228113431.GG10512@in.ibm.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4952 Lines: 126 This patch removes code in kprobe_handler() function which calculates user space int3 trap address in i386 architecture. And this patch is based on kprobe-handler-discard-user-space-trap.patch, against 2.6.16-rc5-mm1. Signed-off-by: bibo mao --- a/arch/i386/kernel/kprobes.c 2006-03-01 12:48:54.000000000 +0800 +++ b/arch/i386/kernel/kprobes.c 2006-03-01 14:08:12.000000000 +0800 @@ -203,7 +203,7 @@ static int __kprobes kprobe_handler(stru { struct kprobe *p; int ret = 0; - kprobe_opcode_t *addr = NULL; + kprobe_opcode_t *addr = (kprobe_opcode_t *)(regs->eip - sizeof(kprobe_opcode_t)); unsigned long *lp; struct kprobe_ctlblk *kcb; #ifdef CONFIG_PREEMPT @@ -217,17 +217,6 @@ static int __kprobes kprobe_handler(stru preempt_disable(); kcb = get_kprobe_ctlblk(); - /* Check if the application is using LDT entry for its code segment and - * calculate the address by reading the base address from the LDT entry. - */ - if ((regs->xcs & 4) && (current->mm)) { - lp = (unsigned long *) ((unsigned long)((regs->xcs >> 3) * 8) - + (char *) current->mm->context.ldt); - addr = (kprobe_opcode_t *) (get_desc_base(lp) + regs->eip - - sizeof(kprobe_opcode_t)); - } else { - addr = (kprobe_opcode_t *)(regs->eip - sizeof(kprobe_opcode_t)); - } /* Check we're not actually recursing */ if (kprobe_running()) { p = get_kprobe(addr); Prasanna S Panchamukhi wrote: > On Tue, Feb 28, 2006 at 03:23:12PM +0800, bibo,mao wrote: >> Currently kprobe handler traps only happen in kernel space, so function >> kprobe_exceptions_notify should skip traps which happen in user space. >> This patch modifies this, and it is based on 2.6.16-rc4. > > You need to remove the code which calculates the > user space address in kprobe_handler() and also you need > to remove the code that checks for VM86 in i386, since > your patch check if user/vm86 at the top level. > > Thanks > Prasanna > >> Signed-off-by: bibo mao >> >> diff -Nruap a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c >> --- a/arch/i386/kernel/kprobes.c 2006-02-25 17:08:52.000000000 +0800 >> +++ b/arch/i386/kernel/kprobes.c 2006-03-01 10:37:50.000000000 +0800 >> @@ -463,6 +463,9 @@ int __kprobes kprobe_exceptions_notify(s >> struct die_args *args = (struct die_args *)data; >> int ret = NOTIFY_DONE; >> >> + if (user_mode(args->regs)) >> + return ret; >> + >> switch (val) { >> case DIE_INT3: >> if (kprobe_handler(args->regs)) >> diff -Nruap a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c >> --- a/arch/ia64/kernel/kprobes.c 2006-02-25 17:08:53.000000000 +0800 >> +++ b/arch/ia64/kernel/kprobes.c 2006-03-01 10:39:15.000000000 +0800 >> @@ -740,6 +740,9 @@ int __kprobes kprobe_exceptions_notify(s >> struct die_args *args = (struct die_args *)data; >> int ret = NOTIFY_DONE; >> >> + if (user_mode(args->regs)) >> + return ret; >> + >> switch(val) { >> case DIE_BREAK: >> /* err is break number from ia64_bad_break() */ >> diff -Nruap a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c >> --- a/arch/powerpc/kernel/kprobes.c 2006-02-25 17:08:52.000000000 +0800 >> +++ b/arch/powerpc/kernel/kprobes.c 2006-03-01 10:39:53.000000000 +0800 >> @@ -397,6 +397,9 @@ int __kprobes kprobe_exceptions_notify(s >> struct die_args *args = (struct die_args *)data; >> int ret = NOTIFY_DONE; >> >> + if (user_mode(args->regs)) >> + return ret; >> + >> switch (val) { >> case DIE_BPT: >> if (kprobe_handler(args->regs)) >> diff -Nruap a/arch/sparc64/kernel/kprobes.c b/arch/sparc64/kernel/kprobes.c >> --- a/arch/sparc64/kernel/kprobes.c 2006-02-25 17:08:52.000000000 +0800 >> +++ b/arch/sparc64/kernel/kprobes.c 2006-03-01 10:40:16.000000000 +0800 >> @@ -324,6 +324,9 @@ int __kprobes kprobe_exceptions_notify(s >> struct die_args *args = (struct die_args *)data; >> int ret = NOTIFY_DONE; >> >> + if (user_mode(args->regs)) >> + return ret; >> + >> switch (val) { >> case DIE_DEBUG: >> if (kprobe_handler(args->regs)) >> diff -Nruap a/arch/x86_64/kernel/kprobes.c b/arch/x86_64/kernel/kprobes.c >> --- a/arch/x86_64/kernel/kprobes.c 2006-02-25 17:08:52.000000000 +0800 >> +++ b/arch/x86_64/kernel/kprobes.c 2006-03-01 10:38:48.000000000 +0800 >> @@ -601,6 +601,9 @@ int __kprobes kprobe_exceptions_notify(s >> struct die_args *args = (struct die_args *)data; >> int ret = NOTIFY_DONE; >> >> + if (user_mode(args->regs)) >> + return ret; >> + >> switch (val) { >> case DIE_INT3: >> if (kprobe_handler(args->regs)) > - 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/