ARM: kprobes: Add test cases for stack consuming instructions

These have extra 'checker' functions associated with them so lets make
sure those get covered by testing. As they may create uninitialised
space on the stack we also update the test code to ensure such space is
consistent between test runs. This is done by disabling interrupts in
setup_test_context().
Signed-off-by: Jon Medhurst <tixy@linaro.org>

arch/arm/probes/kprobes/test-arm.c

@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <asm/system_info.h>
 #include <asm/opcodes.h>
+#include <asm/probes.h>
 
 #include "test-core.h"
 
@@ -478,6 +479,7 @@ void kprobe_arm_test_cases(void)
 	TEST_RPR(  "strh	r",0, VAL1,", [r",1, 48,", -r",2, 24,"]")
 	TEST_RPR(  "streqh	r",14,VAL2,", [r",11,0, ", r",12, 48,"]")
 	TEST_UNSUPPORTED(  "streqh	r14, [r13, r12]")
+	TEST_UNSUPPORTED(  "streqh	r14, [r12, r13]")
 	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,"")
@@ -502,6 +504,9 @@ void kprobe_arm_test_cases(void)
 	TEST_RP(   "strplh	r",12,VAL2,", [r",11,24,", #-4]!")
 	TEST_RP(   "strh	r",2, VAL1,", [r",3, 24,"], #48")
 	TEST_RP(   "strh	r",10,VAL2,", [r",9, 64,"], #-48")
+	TEST_RP(   "strh	r",3, VAL1,", [r",13,TEST_MEMORY_SIZE,", #-"__stringify(MAX_STACK_SIZE)"]!")
+	TEST_UNSUPPORTED("strh r3, [r13, #-"__stringify(MAX_STACK_SIZE)"-8]!")
+	TEST_RP(   "strh	r",4, VAL1,", [r",14,TEST_MEMORY_SIZE,", #-"__stringify(MAX_STACK_SIZE)"-8]!")
 	TEST_UNSUPPORTED(__inst_arm(0xe1efc3b0) "	@ strh r12, [pc, #48]!")
 	TEST_UNSUPPORTED(__inst_arm(0xe0c9f3b0) "	@ strh pc, [r9], #48")
 
@@ -568,6 +573,7 @@ void kprobe_arm_test_cases(void)
 	TEST_RPR(  "strd	r",0, VAL1,", [r",1, 48,", -r",2,24,"]")
 	TEST_RPR(  "strccd	r",8, VAL2,", [r",11,0, ", r",12,48,"]")
 	TEST_UNSUPPORTED(  "strccd r8, [r13, r12]")
+	TEST_UNSUPPORTED(  "strccd r8, [r12, r13]")
 	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,"")
@@ -591,6 +597,9 @@ void kprobe_arm_test_cases(void)
 	TEST_RP(   "strvcd	r",12,VAL2,", [r",11,24,", #-16]!")
 	TEST_RP(   "strd	r",2, VAL1,", [r",4, 24,"], #48")
 	TEST_RP(   "strd	r",10,VAL2,", [r",9, 64,"], #-48")
+	TEST_RP(   "strd	r",6, VAL1,", [r",13,TEST_MEMORY_SIZE,", #-"__stringify(MAX_STACK_SIZE)"]!")
+	TEST_UNSUPPORTED("strd r6, [r13, #-"__stringify(MAX_STACK_SIZE)"-8]!")
+	TEST_RP(   "strd	r",4, VAL1,", [r",12,TEST_MEMORY_SIZE,", #-"__stringify(MAX_STACK_SIZE)"-8]!")
 	TEST_UNSUPPORTED(__inst_arm(0xe1efc3f0) "	@ strd r12, [pc, #48]!")
 
 	TEST_P(	   "ldrd	r0, [r",0, 24,", #-8]")
@@ -639,16 +648,20 @@ void kprobe_arm_test_cases(void)
 	TEST_RP( "str"byte"	r",12,VAL2,", [r",11,24,", #-4]!")		\
 	TEST_RP( "str"byte"	r",2, VAL1,", [r",3, 24,"], #48")		\
 	TEST_RP( "str"byte"	r",10,VAL2,", [r",9, 64,"], #-48")		\
+	TEST_RP( "str"byte"	r",3, VAL1,", [r",13,TEST_MEMORY_SIZE,", #-"__stringify(MAX_STACK_SIZE)"]!") \
+	TEST_UNSUPPORTED("str"byte" r3, [r13, #-"__stringify(MAX_STACK_SIZE)"-8]!")				\
+	TEST_RP( "str"byte"	r",4, VAL1,", [r",10,TEST_MEMORY_SIZE,", #-"__stringify(MAX_STACK_SIZE)"-8]!") \
 	TEST_RPR("str"byte"	r",0, VAL1,", [r",1, 48,", -r",2, 24,"]")	\
 	TEST_RPR("str"byte"	r",14,VAL2,", [r",11,0, ", r",12, 48,"]")	\
-	TEST_UNSUPPORTED("str"byte" r14, [r13, r12]")	\
+	TEST_UNSUPPORTED("str"byte" r14, [r13, r12]")				\
+	TEST_UNSUPPORTED("str"byte" r14, [r12, r13]")				\
 	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",11,0, ", r",12, 32,", lsr #2]")\
-	TEST_UNSUPPORTED("str"byte"	r14, [r13, r12, 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]")			\

arch/arm/probes/kprobes/test-core.c

@@ -1196,6 +1196,13 @@ static void setup_test_context(struct pt_regs *regs)
 			regs->uregs[arg->reg] =
 				(unsigned long)current_stack + arg->val;
 			memory_needs_checking = true;
+			/*
+			 * Test memory at an address below SP is in danger of
+			 * being altered by an interrupt occurring and pushing
+			 * data onto the stack. Disable interrupts to stop this.
+			 */
+			if (arg->reg == 13)
+				regs->ARM_cpsr |= PSR_I_BIT;
 			break;
 		}
 		case ARG_TYPE_MEM: {
@@ -1272,6 +1279,8 @@ test_after_pre_handler(struct kprobe *p, struct pt_regs *regs)
 
 	/* Undo any changes done to SP by the test case */
 	regs->ARM_sp = (unsigned long)current_stack;
+	/* Enable interrupts in case setup_test_context disabled them */
+	regs->ARM_cpsr &= ~PSR_I_BIT;
 
 	container_of(p, struct test_probe, kprobe)->hit = test_instance;
 	return 0;

arch/arm/probes/kprobes/test-thumb.c

@@ -11,6 +11,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <asm/opcodes.h>
+#include <asm/probes.h>
 
 #include "test-core.h"
 
@@ -416,6 +417,9 @@ void kprobe_thumb32_test_cases(void)
 	TEST_RR( "strd	r",14,VAL2,", r",12,VAL1,", [sp, #16]!")
 	TEST_RRP("strd	r",1, VAL1,", r",0, VAL2,", [r",7, 24,"], #16")
 	TEST_RR( "strd	r",7, VAL2,", r",8, VAL1,", [sp], #-16")
+	TEST_RRP("strd	r",6, VAL1,", r",7, VAL2,", [r",13, TEST_MEMORY_SIZE,", #-"__stringify(MAX_STACK_SIZE)"]!")
+	TEST_UNSUPPORTED("strd r6, r7, [r13, #-"__stringify(MAX_STACK_SIZE)"-8]!")
+	TEST_RRP("strd	r",4, VAL1,", r",5, VAL2,", [r",14, TEST_MEMORY_SIZE,", #-"__stringify(MAX_STACK_SIZE)"-8]!")
 	TEST_UNSUPPORTED(__inst_thumb32(0xe9efec04) "	@ strd	r14, r12, [pc, #16]!")
 	TEST_UNSUPPORTED(__inst_thumb32(0xe8efec04) "	@ strd	r14, r12, [pc], #16")
 
@@ -821,14 +825,22 @@ CONDITION_INSTRUCTIONS(22,
 	TEST_RP( "str"size"	r",14,VAL2,", [r",1, 256,  ", #-128]!")		\
 	TEST_RPR("str"size".w	r",0, VAL1,", [r",1, 0,", r",2, 4,"]")		\
 	TEST_RPR("str"size"	r",14,VAL2,", [r",10,0,", r",11,4,", lsl #1]")	\
+	TEST_UNSUPPORTED("str"size"	r0, [r13, r1]")				\
 	TEST_R(  "str"size".w	r",7, VAL1,", [sp, #24]")			\
 	TEST_RP( "str"size".w	r",0, VAL2,", [r",0,0, "]")			\
+	TEST_RP( "str"size"	r",6, VAL1,", [r",13, TEST_MEMORY_SIZE,", #-"__stringify(MAX_STACK_SIZE)"]!") \
+	TEST_UNSUPPORTED("str"size"	r6, [r13, #-"__stringify(MAX_STACK_SIZE)"-8]!")			\
+	TEST_RP( "str"size"	r",4, VAL2,", [r",12, TEST_MEMORY_SIZE,", #-"__stringify(MAX_STACK_SIZE)"-8]!") \
 	TEST_UNSUPPORTED("str"size"t	r0, [r1, #4]")
 
 	SINGLE_STORE("b")
 	SINGLE_STORE("h")
 	SINGLE_STORE("")
 
+	TEST_UNSUPPORTED(__inst_thumb32(0xf801000d) "	@ strb	r0, [r1, r13]")
+	TEST_UNSUPPORTED(__inst_thumb32(0xf821000d) "	@ strh	r0, [r1, r13]")
+	TEST_UNSUPPORTED(__inst_thumb32(0xf841000d) "	@ str	r0, [r1, r13]")
+
 	TEST("str	sp, [sp]")
 	TEST_UNSUPPORTED(__inst_thumb32(0xf8cfe000) "	@ str	r14, [pc]")
 	TEST_UNSUPPORTED(__inst_thumb32(0xf8cef000) "	@ str	pc, [r14]")