kprobes: implementation instruction B(ARM) in uprobes

diff --git a/kprobe/arch/asm-arm/dbi_kprobes.c b/kprobe/arch/asm-arm/dbi_kprobes.c
index 1169e43..033809f 100644 (file)
--- a/kprobe/arch/asm-arm/dbi_kprobes.c
+++ b/kprobe/arch/asm-arm/dbi_kprobes.c
@@ -83,6 +83,11 @@ EXPORT_SYMBOL_GPL (swap_sum_hit);
 #define sign_extend(x, signbit) ((x) | (0 - ((x) & (1 << (signbit)))))
 #define branch_displacement(insn) sign_extend(((insn) & 0xffffff) << 2, 25)
 
+static kprobe_opcode_t get_addr_b(kprobe_opcode_t insn, kprobe_opcode_t addr)
+{
+       // real position less then PC by 8
+       return (kprobe_opcode_t)((long)addr + 8 + branch_displacement(insn));
+}
 
 unsigned int arr_traps_template[] = {
                0xe1a0c00d,    // mov          ip, sp
@@ -412,7 +417,6 @@ int arch_check_insn_arm (struct arch_specific_insn *ainsn)
                ARM_INSN_MATCH (AUNDEF, ainsn->insn_arm[0]) ||
                ARM_INSN_MATCH (SWI, ainsn->insn_arm[0]) ||
                ARM_INSN_MATCH (BREAK, ainsn->insn_arm[0]) ||
-               ARM_INSN_MATCH (B, ainsn->insn_arm[0]) ||
                ARM_INSN_MATCH (BL, ainsn->insn_arm[0]) ||
                ARM_INSN_MATCH (BLX1, ainsn->insn_arm[0]) ||
                ARM_INSN_MATCH (BLX2, ainsn->insn_arm[0]) ||
@@ -836,6 +840,16 @@ int arch_copy_trampoline_arm_uprobe (struct kprobe *p, struct task_struct *task,
        }
        insns[UPROBES_TRAMP_RET_BREAK_IDX] = BREAKPOINT_INSTRUCTION;
        insns[7] = (kprobe_opcode_t) (p->addr + 1);
+
+       // B
+       if(ARM_INSN_MATCH (B, ainsn.insn_arm[0]))
+       {
+               memcpy (insns, pc_dep_insn_execbuf, sizeof (insns));
+               insns[UPROBES_TRAMP_RET_BREAK_IDX] = BREAKPOINT_INSTRUCTION;
+               insns[6] = (kprobe_opcode_t) (p->addr + 2);
+               insns[7] = get_addr_b(p->opcode, p->addr);
+       }
+
        DBPRINTF ("arch_prepare_uprobe: to %p - %lx %lx %lx %lx %lx %lx %lx %lx %lx",
                        p->ainsn.insn_arm, insns[0], insns[1], insns[2], insns[3], insns[4],
                        insns[5], insns[6], insns[7], insns[8]);