diff options
Diffstat (limited to 'frida_mode/src/persistent/persistent_x86.c')
| -rw-r--r-- | frida_mode/src/persistent/persistent_x86.c | 40 |
1 files changed, 31 insertions, 9 deletions
diff --git a/frida_mode/src/persistent/persistent_x86.c b/frida_mode/src/persistent/persistent_x86.c index 0675edf4..7add6e99 100644 --- a/frida_mode/src/persistent/persistent_x86.c +++ b/frida_mode/src/persistent/persistent_x86.c @@ -39,6 +39,7 @@ struct x86_regs { typedef struct x86_regs arch_api_regs; static arch_api_regs saved_regs = {0}; +static gpointer saved_ret = NULL; gboolean persistent_is_supported(void) { @@ -117,7 +118,9 @@ static void instrument_persitent_restore_regs(GumX86Writer * cw, gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_EBP, GUM_REG_EAX, (0x4 * 6)); - /* Don't restore RIP or RSP */ + /* Don't restore RIP */ + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_ESP, GUM_REG_EAX, + (0x4 * 8)); /* Restore RBX, RAX & Flags */ gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_EBX, GUM_REG_EAX, @@ -184,6 +187,26 @@ static void persistent_prologue_hook(GumX86Writer *cw, struct x86_regs *regs) { } +static void instrument_persitent_save_ret(GumX86Writer *cw) { + + /* Stack usage by this function */ + gssize offset = (3 * 4); + + gum_x86_writer_put_pushfx(cw); + gum_x86_writer_put_push_reg(cw, GUM_REG_EAX); + gum_x86_writer_put_push_reg(cw, GUM_REG_EBX); + + gum_x86_writer_put_mov_reg_address(cw, GUM_REG_EAX, GUM_ADDRESS(&saved_ret)); + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_EBX, GUM_REG_ESP, + offset); + gum_x86_writer_put_mov_reg_ptr_reg(cw, GUM_REG_EAX, GUM_REG_EBX); + + gum_x86_writer_put_pop_reg(cw, GUM_REG_EBX); + gum_x86_writer_put_pop_reg(cw, GUM_REG_EAX); + gum_x86_writer_put_popfx(cw); + +} + void persistent_prologue(GumStalkerOutput *output) { /* @@ -210,11 +233,10 @@ void persistent_prologue(GumStalkerOutput *output) { gconstpointer loop = cw->code + 1; - /* Stack must be 16-byte aligned per ABI */ - instrument_persitent_save_regs(cw, &saved_regs); - /* Pop the return value */ - gum_x86_writer_put_lea_reg_reg_offset(cw, GUM_REG_ESP, GUM_REG_ESP, (4)); + gum_x86_writer_put_lea_reg_reg_offset(cw, GUM_REG_ESP, GUM_REG_ESP, 4); + + instrument_persitent_save_regs(cw, &saved_regs); /* loop: */ gum_x86_writer_put_label(cw, loop); @@ -244,6 +266,8 @@ void persistent_prologue(GumStalkerOutput *output) { /* original: */ gum_x86_writer_put_label(cw, original); + instrument_persitent_save_ret(cw); + if (persistent_debug) { gum_x86_writer_put_breakpoint(cw); } } @@ -254,10 +278,8 @@ void persistent_epilogue(GumStalkerOutput *output) { if (persistent_debug) { gum_x86_writer_put_breakpoint(cw); } - gum_x86_writer_put_lea_reg_reg_offset(cw, GUM_REG_ESP, GUM_REG_ESP, - persistent_ret_offset); - - gum_x86_writer_put_ret(cw); + gum_x86_writer_put_mov_reg_address(cw, GUM_REG_EAX, GUM_ADDRESS(&saved_ret)); + gum_x86_writer_put_jmp_reg_ptr(cw, GUM_REG_EAX); } |