ARM: kprobes: Add Thumb instruction decoding stubs

[firefly-linux-kernel-4.4.55.git] / arch / arm / kernel / kprobes.c

diff --git a/arch/arm/kernel/kprobes.c b/arch/arm/kernel/kprobes.c
index 0e47d3d674277c137aabd1c4abab135e0dc13455..0df2d6d57c04036b753df962e5e2787ded45425f 100644 (file)
--- a/arch/arm/kernel/kprobes.c
+++ b/arch/arm/kernel/kprobes.c
@@ -51,16 +51,32 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
        kprobe_opcode_t insn;
        kprobe_opcode_t tmp_insn[MAX_INSN_SIZE];
        unsigned long addr = (unsigned long)p->addr;
+       kprobe_decode_insn_t *decode_insn;
        int is;
 
-       if (addr & 0x3 || in_exception_text(addr))
+       if (in_exception_text(addr))
                return -EINVAL;
 
+#ifdef CONFIG_THUMB2_KERNEL
+       addr &= ~1; /* Bit 0 would normally be set to indicate Thumb code */
+       insn = ((u16 *)addr)[0];
+       if (is_wide_instruction(insn)) {
+               insn <<= 16;
+               insn |= ((u16 *)addr)[1];
+               decode_insn = thumb32_kprobe_decode_insn;
+       } else
+               decode_insn = thumb16_kprobe_decode_insn;
+#else /* !CONFIG_THUMB2_KERNEL */
+       if (addr & 0x3)
+               return -EINVAL;
        insn = *p->addr;
+       decode_insn = arm_kprobe_decode_insn;
+#endif
+
        p->opcode = insn;
        p->ainsn.insn = tmp_insn;
 
-       switch (arm_kprobe_decode_insn(insn, &p->ainsn)) {
+       switch ((*decode_insn)(insn, &p->ainsn)) {
        case INSN_REJECTED:     /* not supported */
                return -EINVAL;