ARM: kprobes: Add BLX macro
This is for use by inline assembler which will be added to kprobes-arm.c
It saves memory when used on newer ARM architectures and also provides
correct interworking should ARM probes be required on Thumb kernels in
the future.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
diff --git a/arch/arm/kernel/kprobes-arm.c b/arch/arm/kernel/kprobes-arm.c
index ea96214..80a9411 100644
--- a/arch/arm/kernel/kprobes-arm.c
+++ b/arch/arm/kernel/kprobes-arm.c
@@ -67,6 +67,13 @@
#define branch_displacement(insn) sign_extend(((insn) & 0xffffff) << 2, 25)
+#if __LINUX_ARM_ARCH__ >= 6
+#define BLX(reg) "blx "reg" \n\t"
+#else
+#define BLX(reg) "mov lr, pc \n\t" \
+ "mov pc, "reg" \n\t"
+#endif
+
#define is_r15(insn, bitpos) (((insn) & (0xf << bitpos)) == (0xf << bitpos))
#define PSR_fs (PSR_f|PSR_s)