[PATCH] ARM: kprobes: Eliminate test code's use of BX instruction on ARMv4 CPUs
Jon Medhurst (Tixy)
tixy at linaro.org
Mon Jan 19 09:18:50 PST 2015
Non-T variants of ARMv4 CPUs don't support the BX instruction so
eliminate it use.
Signed-off-by: Jon Medhurst <tixy at linaro.org>
---
This patch applies on top on my kprobe-opt branch [1] for which I plan on
sending a pull request for shortly.
[1] git://git.linaro.org/people/tixy/kernel.git kprobe-opt
arch/arm/probes/kprobes/test-arm.c | 2 ++
arch/arm/probes/kprobes/test-core.c | 10 +++++++---
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/arm/probes/kprobes/test-arm.c b/arch/arm/probes/kprobes/test-arm.c
index e72b07e..5c6e37e 100644
--- a/arch/arm/probes/kprobes/test-arm.c
+++ b/arch/arm/probes/kprobes/test-arm.c
@@ -215,9 +215,11 @@ void kprobe_arm_test_cases(void)
TEST_UNSUPPORTED("msr cpsr_f, lr")
TEST_UNSUPPORTED("msr spsr, r0")
+#if (__LINUX_ARM_ARCH__ >= 5) || defined(CONFIG_CPU_32v4T)
TEST_BF_R("bx r",0,2f,"")
TEST_BB_R("bx r",7,2f,"")
TEST_BF_R("bxeq r",14,2f,"")
+#endif
#if __LINUX_ARM_ARCH__ >= 5
TEST_R("clz r0, r",0, 0x0,"")
diff --git a/arch/arm/probes/kprobes/test-core.c b/arch/arm/probes/kprobes/test-core.c
index e495127..9775de2 100644
--- a/arch/arm/probes/kprobes/test-core.c
+++ b/arch/arm/probes/kprobes/test-core.c
@@ -236,6 +236,8 @@ static int tests_failed;
#ifndef CONFIG_THUMB2_KERNEL
+#define RET(reg) "mov pc, "#reg
+
long arm_func(long r0, long r1);
static void __used __naked __arm_kprobes_test_func(void)
@@ -245,7 +247,7 @@ static void __used __naked __arm_kprobes_test_func(void)
".type arm_func, %%function \n\t"
"arm_func: \n\t"
"adds r0, r0, r1 \n\t"
- "bx lr \n\t"
+ "mov pc, lr \n\t"
".code "NORMAL_ISA /* Back to Thumb if necessary */
: : : "r0", "r1", "cc"
);
@@ -253,6 +255,8 @@ static void __used __naked __arm_kprobes_test_func(void)
#else /* CONFIG_THUMB2_KERNEL */
+#define RET(reg) "bx "#reg
+
long thumb16_func(long r0, long r1);
long thumb32even_func(long r0, long r1);
long thumb32odd_func(long r0, long r1);
@@ -494,7 +498,7 @@ static void __naked benchmark_nop(void)
{
__asm__ __volatile__ (
"nop \n\t"
- "bx lr"
+ RET(lr)" \n\t"
);
}
@@ -977,7 +981,7 @@ void __naked __kprobes_test_case_start(void)
"bic r0, lr, #1 @ r0 = inline data \n\t"
"mov r1, sp \n\t"
"bl kprobes_test_case_start \n\t"
- "bx r0 \n\t"
+ RET(r0)" \n\t"
);
}
--
2.1.4
More information about the linux-arm-kernel
mailing list