ARM: kprobes: Add load_write_pc()
This writes a value to PC which was obtained as the result of a
LDR or LDM instruction. For ARMv5T and later this must perform
interworking.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
diff --git a/arch/arm/kernel/kprobes.h b/arch/arm/kernel/kprobes.h
index 12627a3..5d6bf0d 100644
--- a/arch/arm/kernel/kprobes.h
+++ b/arch/arm/kernel/kprobes.h
@@ -109,6 +109,30 @@
regs->ARM_pc = pcv;
}
+
+#if __LINUX_ARM_ARCH__ >= 6
+
+/* Kernels built for >= ARMv6 should never run on <= ARMv5 hardware, so... */
+#define load_write_pc_interworks true
+#define test_load_write_pc_interworking()
+
+#else /* __LINUX_ARM_ARCH__ < 6 */
+
+/* We need run-time testing to determine if load_write_pc() should interwork. */
+extern bool load_write_pc_interworks;
+void __init test_load_write_pc_interworking(void);
+
+#endif
+
+static inline void __kprobes load_write_pc(long pcv, struct pt_regs *regs)
+{
+ if (load_write_pc_interworks)
+ bx_write_pc(pcv, regs);
+ else
+ regs->ARM_pc = pcv;
+}
+
+
void __kprobes kprobe_simulate_nop(struct kprobe *p, struct pt_regs *regs);
void __kprobes kprobe_emulate_none(struct kprobe *p, struct pt_regs *regs);