From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752183AbaJYSx2 (ORCPT ); Sat, 25 Oct 2014 14:53:28 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:47852 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750947AbaJYSx0 (ORCPT ); Sat, 25 Oct 2014 14:53:26 -0400 From: Wang Nan To: , CC: , , , , , , , , , , Subject: [PATCH 4/4] ARM: kprobes: disallow probing stack consuming instructions Date: Sat, 25 Oct 2014 14:42:53 +0800 Message-ID: <1414219373-20070-5-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1414219373-20070-1-git-send-email-wangnan0@huawei.com> References: <1414219373-20070-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.197.247] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020202.544B46E0.0121,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 76036ec598f800814f8cc8e2b69bbf95 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch prohibit probing instructions for which the stack requirement are unable to be determined statically. Some test cases are found not work again after the modification, this patch also removes them. Signed-off-by: Wang Nan --- arch/arm/kernel/kprobes-test-arm.c | 16 ++++++++++------ arch/arm/kernel/kprobes.c | 8 ++++++++ 2 files changed, 18 insertions(+), 6 deletions(-) diff --git a/arch/arm/kernel/kprobes-test-arm.c b/arch/arm/kernel/kprobes-test-arm.c index 264c064..59f9b25 100644 --- a/arch/arm/kernel/kprobes-test-arm.c +++ b/arch/arm/kernel/kprobes-test-arm.c @@ -476,7 +476,8 @@ void kprobe_arm_test_cases(void) TEST_GROUP("Extra load/store instructions") TEST_RPR( "strh r",0, VAL1,", [r",1, 48,", -r",2, 24,"]") - TEST_RPR( "streqh r",14,VAL2,", [r",13,0, ", r",12, 48,"]") + TEST_RPR( "streqh r",14,VAL2,", [r",11,0, ", r",12, 48,"]") + TEST_UNSUPPORTED( "streqh r14, [r13, r12]") TEST_RPR( "strh r",1, VAL1,", [r",2, 24,", r",3, 48,"]!") TEST_RPR( "strneh r",12,VAL2,", [r",11,48,", -r",10,24,"]!") TEST_RPR( "strh r",2, VAL1,", [r",3, 24,"], r",4, 48,"") @@ -565,7 +566,8 @@ void kprobe_arm_test_cases(void) #if __LINUX_ARM_ARCH__ >= 5 TEST_RPR( "strd r",0, VAL1,", [r",1, 48,", -r",2,24,"]") - TEST_RPR( "strccd r",8, VAL2,", [r",13,0, ", r",12,48,"]") + TEST_RPR( "strccd r",8, VAL2,", [r",11,0, ", r",12,48,"]") + TEST_UNSUPPORTED( "strccd r8, [r13, r12]") TEST_RPR( "strd r",4, VAL1,", [r",2, 24,", r",3, 48,"]!") TEST_RPR( "strcsd r",12,VAL2,", [r",11,48,", -r",10,24,"]!") TEST_RPR( "strd r",2, VAL1,", [r",5, 24,"], r",4,48,"") @@ -639,13 +641,15 @@ void kprobe_arm_test_cases(void) TEST_RP( "str"byte" r",2, VAL1,", [r",3, 24,"], #48") \ TEST_RP( "str"byte" r",10,VAL2,", [r",9, 64,"], #-48") \ TEST_RPR("str"byte" r",0, VAL1,", [r",1, 48,", -r",2, 24,"]") \ - TEST_RPR("str"byte" r",14,VAL2,", [r",13,0, ", r",12, 48,"]") \ + TEST_RPR("str"byte" r",14,VAL2,", [r",11,0, ", r",12, 48,"]") \ + TEST_UNSUPPORTED("str"byte" r14, [r13, r12]") \ TEST_RPR("str"byte" r",1, VAL1,", [r",2, 24,", r",3, 48,"]!") \ TEST_RPR("str"byte" r",12,VAL2,", [r",11,48,", -r",10,24,"]!") \ TEST_RPR("str"byte" r",2, VAL1,", [r",3, 24,"], r",4, 48,"") \ TEST_RPR("str"byte" r",10,VAL2,", [r",9, 48,"], -r",11,24,"") \ TEST_RPR("str"byte" r",0, VAL1,", [r",1, 24,", r",2, 32,", asl #1]")\ - TEST_RPR("str"byte" r",14,VAL2,", [r",13,0, ", r",12, 32,", lsr #2]")\ + TEST_RPR("str"byte" r",14,VAL2,", [r",11,0, ", r",12, 32,", lsr #2]")\ + TEST_UNSUPPORTED("str"byte" r14, [r13, r12, lsr #2]")\ TEST_RPR("str"byte" r",1, VAL1,", [r",2, 24,", r",3, 32,", asr #3]!")\ TEST_RPR("str"byte" r",12,VAL2,", [r",11,24,", r",10, 4,", ror #31]!")\ TEST_P( "ldr"byte" r0, [r",0, 24,", #-2]") \ @@ -669,12 +673,12 @@ void kprobe_arm_test_cases(void) LOAD_STORE("") TEST_P( "str pc, [r",0,0,", #15*4]") - TEST_R( "str pc, [sp, r",2,15*4,"]") + TEST_UNSUPPORTED( "str pc, [sp, r2]") TEST_BF( "ldr pc, [sp, #15*4]") TEST_BF_R("ldr pc, [sp, r",2,15*4,"]") TEST_P( "str sp, [r",0,0,", #13*4]") - TEST_R( "str sp, [sp, r",2,13*4,"]") + TEST_UNSUPPORTED( "str sp, [sp, r2]") TEST_BF( "ldr sp, [sp, #13*4]") TEST_BF_R("ldr sp, [sp, r",2,13*4,"]") diff --git a/arch/arm/kernel/kprobes.c b/arch/arm/kernel/kprobes.c index 618531d..59f5e64 100644 --- a/arch/arm/kernel/kprobes.c +++ b/arch/arm/kernel/kprobes.c @@ -124,6 +124,14 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) break; } + /* + * Unable to instrument insn like 'str r0, [sp, +/-r1]'. + * __und_svc protects 64 bytes stack, so instrumenting insn + * likes 'str r0, [sp, #-68]' should be prohibited. + */ + if ((p->ainsn.stack_space < 0) || (p->ainsn.stack_space > 64)) + return -EINVAL; + return 0; } -- 1.8.4