From a0266c214fab21371a499e6ab1c9385cc6589189 Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Mon, 5 Jan 2015 19:29:25 +0800 Subject: ARM: kprobes: disallow probing stack consuming instructions This patch prohibits probing instructions for which the stack requirements 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 Reviewed-by: Jon Medhurst Signed-off-by: Jon Medhurst --- arch/arm/probes/kprobes/core.c | 9 +++++++++ arch/arm/probes/kprobes/test-arm.c | 16 ++++++++++------ 2 files changed, 19 insertions(+), 6 deletions(-) (limited to 'arch/arm/probes') diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c index 74f3dc3ac212..3a58db4cc1c6 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -115,6 +115,15 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) break; } + /* + * Never instrument insn like 'str r0, [sp, +/-r1]'. Also, insn likes + * 'str r0, [sp, #-68]' should also be prohibited. + * See __und_svc. + */ + if ((p->ainsn.stack_space < 0) || + (p->ainsn.stack_space > MAX_STACK_SIZE)) + return -EINVAL; + return 0; } diff --git a/arch/arm/probes/kprobes/test-arm.c b/arch/arm/probes/kprobes/test-arm.c index d9a1255f3043..fdeb300b0fc8 100644 --- a/arch/arm/probes/kprobes/test-arm.c +++ b/arch/arm/probes/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,"") @@ -638,13 +640,15 @@ 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]") \ @@ -668,12 +672,12 @@ 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,"]") -- cgit