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#include <unistd.h>
#include "frida-gum.h"
#include "config.h"
#include "debug.h"
#include "instrument.h"
#include "persistent.h"
#include "util.h"
#if defined(__aarch64__)
struct arm64_regs {
uint64_t x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10;
union {
uint64_t x11;
uint32_t fp_32;
};
union {
uint64_t x12;
uint32_t ip_32;
};
union {
uint64_t x13;
uint32_t sp_32;
};
union {
uint64_t x14;
uint32_t lr_32;
};
union {
uint64_t x15;
uint32_t pc_32;
};
union {
uint64_t x16;
uint64_t ip0;
};
union {
uint64_t x17;
uint64_t ip1;
};
uint64_t x18, x19, x20, x21, x22, x23, x24, x25, x26, x27, x28;
union {
uint64_t x29;
uint64_t fp;
};
union {
uint64_t x30;
uint64_t lr;
};
union {
uint64_t x31;
uint64_t sp;
};
// the zero register is not saved here ofc
uint64_t pc;
uint32_t cpsr;
uint8_t vfp_zregs[32][16 * 16];
uint8_t vfp_pregs[17][32];
uint32_t vfp_xregs[16];
};
typedef struct arm64_regs arch_api_regs;
static arch_api_regs saved_regs = {0};
static gpointer saved_lr = NULL;
gboolean persistent_is_supported(void) {
return true;
}
static void instrument_persitent_save_regs(GumArm64Writer * cw,
struct arm64_regs *regs) {
GumAddress regs_address = GUM_ADDRESS(regs);
const guint32 mrs_x1_nzcv = 0xd53b4201;
gum_arm64_writer_put_stp_reg_reg_reg_offset(
cw, ARM64_REG_X0, ARM64_REG_X1, ARM64_REG_SP, -(16 + GUM_RED_ZONE_SIZE),
GUM_INDEX_PRE_ADJUST);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X2, ARM64_REG_X3,
ARM64_REG_SP, -(16),
GUM_INDEX_PRE_ADJUST);
gum_arm64_writer_put_instruction(cw, mrs_x1_nzcv);
gum_arm64_writer_put_ldr_reg_address(cw, ARM64_REG_X0,
GUM_ADDRESS(regs_address));
/* Skip x0 & x1 we'll do that later */
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X2, ARM64_REG_X3,
ARM64_REG_X0, (16 * 1),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X4, ARM64_REG_X5,
ARM64_REG_X0, (16 * 2),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X6, ARM64_REG_X7,
ARM64_REG_X0, (16 * 3),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X8, ARM64_REG_X9,
ARM64_REG_X0, (16 * 4),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X10, ARM64_REG_X11,
ARM64_REG_X0, (16 * 5),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X12, ARM64_REG_X13,
ARM64_REG_X0, (16 * 6),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X14, ARM64_REG_X15,
ARM64_REG_X0, (16 * 7),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X16, ARM64_REG_X17,
ARM64_REG_X0, (16 * 8),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X18, ARM64_REG_X19,
ARM64_REG_X0, (16 * 9),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X20, ARM64_REG_X21,
ARM64_REG_X0, (16 * 10),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X22, ARM64_REG_X23,
ARM64_REG_X0, (16 * 11),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X24, ARM64_REG_X25,
ARM64_REG_X0, (16 * 12),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X26, ARM64_REG_X27,
ARM64_REG_X0, (16 * 13),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X28, ARM64_REG_X29,
ARM64_REG_X0, (16 * 14),
GUM_INDEX_SIGNED_OFFSET);
/* LR & Adjusted SP */
gum_arm64_writer_put_add_reg_reg_imm(cw, ARM64_REG_X2, ARM64_REG_SP,
(GUM_RED_ZONE_SIZE + 32));
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X30, ARM64_REG_X2,
ARM64_REG_X0, (16 * 15),
GUM_INDEX_SIGNED_OFFSET);
/* PC & CPSR */
gum_arm64_writer_put_ldr_reg_address(cw, ARM64_REG_X2,
GUM_ADDRESS(persistent_start));
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X2, ARM64_REG_X1,
ARM64_REG_X0, (16 * 16),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_Q0, ARM64_REG_Q1,
ARM64_REG_X0, (16 * 17),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_Q2, ARM64_REG_Q3,
ARM64_REG_X0, (16 * 18),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_Q4, ARM64_REG_Q5,
ARM64_REG_X0, (16 * 19),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_Q6, ARM64_REG_Q7,
ARM64_REG_X0, (16 * 20),
GUM_INDEX_SIGNED_OFFSET);
/* x0 & x1 */
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X2, ARM64_REG_X3,
ARM64_REG_SP, 16,
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_stp_reg_reg_reg_offset(cw, ARM64_REG_X2, ARM64_REG_X3,
ARM64_REG_X0, (16 * 0),
GUM_INDEX_SIGNED_OFFSET);
/* Pop the saved values */
gum_arm64_writer_put_ldp_reg_reg_reg_offset(
cw, ARM64_REG_X2, ARM64_REG_X3, ARM64_REG_SP, 16, GUM_INDEX_POST_ADJUST);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(
cw, ARM64_REG_X0, ARM64_REG_X1, ARM64_REG_SP, 16 + GUM_RED_ZONE_SIZE,
GUM_INDEX_POST_ADJUST);
}
static void instrument_persitent_restore_regs(GumArm64Writer * cw,
struct arm64_regs *regs) {
GumAddress regs_address = GUM_ADDRESS(regs);
const guint32 msr_nzcv_x1 = 0xd51b4201;
gum_arm64_writer_put_ldr_reg_address(cw, ARM64_REG_X0,
GUM_ADDRESS(regs_address));
/* Skip x0 - x3 we'll do that last */
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X4, ARM64_REG_X5,
ARM64_REG_X0, (16 * 2),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X6, ARM64_REG_X7,
ARM64_REG_X0, (16 * 3),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X8, ARM64_REG_X9,
ARM64_REG_X0, (16 * 4),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X10, ARM64_REG_X11,
ARM64_REG_X0, (16 * 5),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X12, ARM64_REG_X13,
ARM64_REG_X0, (16 * 6),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X14, ARM64_REG_X15,
ARM64_REG_X0, (16 * 7),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X16, ARM64_REG_X17,
ARM64_REG_X0, (16 * 8),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X18, ARM64_REG_X19,
ARM64_REG_X0, (16 * 9),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X20, ARM64_REG_X21,
ARM64_REG_X0, (16 * 10),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X22, ARM64_REG_X23,
ARM64_REG_X0, (16 * 11),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X24, ARM64_REG_X25,
ARM64_REG_X0, (16 * 12),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X26, ARM64_REG_X27,
ARM64_REG_X0, (16 * 13),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X28, ARM64_REG_X29,
ARM64_REG_X0, (16 * 14),
GUM_INDEX_SIGNED_OFFSET);
/* Don't restore RIP or RSP, use x1-x3 as clobber */
/* LR & Adjusted SP (clobber x1) */
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X30, ARM64_REG_X1,
ARM64_REG_X0, (16 * 15),
GUM_INDEX_SIGNED_OFFSET);
/* PC (x2) & CPSR (x1) */
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X2, ARM64_REG_X1,
ARM64_REG_X0, (16 * 16),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_instruction(cw, msr_nzcv_x1);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_Q0, ARM64_REG_Q1,
ARM64_REG_X0, (16 * 17),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_Q2, ARM64_REG_Q3,
ARM64_REG_X0, (16 * 18),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_Q4, ARM64_REG_Q5,
ARM64_REG_X0, (16 * 19),
GUM_INDEX_SIGNED_OFFSET);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_Q6, ARM64_REG_Q7,
ARM64_REG_X0, (16 * 20),
GUM_INDEX_SIGNED_OFFSET);
/* x2 & x3 */
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X2, ARM64_REG_X3,
ARM64_REG_X0, (16 * 1),
GUM_INDEX_SIGNED_OFFSET);
/* x0 & x1 */
gum_arm64_writer_put_ldp_reg_reg_reg_offset(cw, ARM64_REG_X0, ARM64_REG_X1,
ARM64_REG_X0, (16 * 0),
GUM_INDEX_SIGNED_OFFSET);
}
static void instrument_exit(GumArm64Writer *cw) {
gum_arm64_writer_put_mov_reg_reg(cw, ARM64_REG_X0, ARM64_REG_XZR);
gum_arm64_writer_put_call_address_with_arguments(
cw, GUM_ADDRESS(_exit), 1, GUM_ARG_REGISTER, ARM64_REG_X0);
}
static int instrument_afl_persistent_loop_func(void) {
int ret = __afl_persistent_loop(persistent_count);
previous_pc = 0;
return ret;
}
static void instrument_afl_persistent_loop(GumArm64Writer *cw) {
gum_arm64_writer_put_sub_reg_reg_imm(cw, ARM64_REG_SP, ARM64_REG_SP,
GUM_RED_ZONE_SIZE);
gum_arm64_writer_put_call_address_with_arguments(
cw, GUM_ADDRESS(instrument_afl_persistent_loop_func), 0);
gum_arm64_writer_put_add_reg_reg_imm(cw, ARM64_REG_SP, ARM64_REG_SP,
GUM_RED_ZONE_SIZE);
}
static void persistent_prologue_hook(GumArm64Writer * cw,
struct arm64_regs *regs) {
if (hook == NULL) return;
gum_arm64_writer_put_sub_reg_reg_imm(cw, ARM64_REG_SP, ARM64_REG_SP,
GUM_RED_ZONE_SIZE);
gum_arm64_writer_put_ldr_reg_address(cw, ARM64_REG_X3,
GUM_ADDRESS(&__afl_fuzz_len));
gum_arm64_writer_put_ldr_reg_reg_offset(cw, ARM64_REG_X3, ARM64_REG_X3, 0);
gum_arm64_writer_put_ldr_reg_reg_offset(cw, ARM64_REG_X3, ARM64_REG_X3, 0);
gum_arm64_writer_put_and_reg_reg_imm(cw, ARM64_REG_X3, ARM64_REG_X3,
G_MAXULONG);
gum_arm64_writer_put_ldr_reg_address(cw, ARM64_REG_X2,
GUM_ADDRESS(&__afl_fuzz_ptr));
gum_arm64_writer_put_ldr_reg_reg_offset(cw, ARM64_REG_X2, ARM64_REG_X2, 0);
gum_arm64_writer_put_call_address_with_arguments(
cw, GUM_ADDRESS(hook), 4, GUM_ARG_ADDRESS, GUM_ADDRESS(regs),
GUM_ARG_ADDRESS, GUM_ADDRESS(0), GUM_ARG_REGISTER, ARM64_REG_X2,
GUM_ARG_REGISTER, ARM64_REG_X3);
gum_arm64_writer_put_add_reg_reg_imm(cw, ARM64_REG_SP, ARM64_REG_SP,
GUM_RED_ZONE_SIZE);
}
static void instrument_persitent_save_lr(GumArm64Writer *cw) {
gum_arm64_writer_put_stp_reg_reg_reg_offset(
cw, ARM64_REG_X0, ARM64_REG_X1, ARM64_REG_SP, -(16 + GUM_RED_ZONE_SIZE),
GUM_INDEX_PRE_ADJUST);
gum_arm64_writer_put_ldr_reg_address(cw, ARM64_REG_X0,
GUM_ADDRESS(&saved_lr));
gum_arm64_writer_put_str_reg_reg_offset(cw, ARM64_REG_LR, ARM64_REG_X0, 0);
gum_arm64_writer_put_ldp_reg_reg_reg_offset(
cw, ARM64_REG_X0, ARM64_REG_X1, ARM64_REG_SP, 16 + GUM_RED_ZONE_SIZE,
GUM_INDEX_POST_ADJUST);
}
void persistent_prologue(GumStalkerOutput *output) {
/*
* SAVE REGS
* SAVE RET
* POP RET
* loop:
* CALL instrument_afl_persistent_loop
* TEST EAX, EAX
* JZ end:
* call hook (optionally)
* RESTORE REGS
* call original
* jmp loop:
*
* end:
* JMP SAVED RET
*
* original:
* INSTRUMENTED PERSISTENT FUNC
*/
GumArm64Writer *cw = output->writer.arm64;
gconstpointer loop = cw->code + 1;
/* Stack must be 16-byte aligned per ABI */
instrument_persitent_save_regs(cw, &saved_regs);
/* loop: */
gum_arm64_writer_put_label(cw, loop);
/* call instrument_prologue_func */
instrument_afl_persistent_loop(cw);
/* jz done */
gconstpointer done = cw->code + 1;
gum_arm64_writer_put_cmp_reg_reg(cw, ARM64_REG_X0, ARM64_REG_XZR);
gum_arm64_writer_put_b_cond_label(cw, ARM64_CC_EQ, done);
/* Optionally call the persistent hook */
persistent_prologue_hook(cw, &saved_regs);
instrument_persitent_restore_regs(cw, &saved_regs);
gconstpointer original = cw->code + 1;
/* call original */
gum_arm64_writer_put_bl_label(cw, original);
/* jmp loop */
gum_arm64_writer_put_b_label(cw, loop);
/* done: */
gum_arm64_writer_put_label(cw, done);
instrument_exit(cw);
/* original: */
gum_arm64_writer_put_label(cw, original);
instrument_persitent_save_lr(cw);
if (persistent_debug) { gum_arm64_writer_put_brk_imm(cw, 0); }
}
void persistent_epilogue(GumStalkerOutput *output) {
GumArm64Writer *cw = output->writer.arm64;
if (persistent_debug) { gum_arm64_writer_put_brk_imm(cw, 0); }
gum_arm64_writer_put_add_reg_reg_imm(cw, ARM64_REG_SP, ARM64_REG_SP,
persistent_ret_offset);
gum_arm64_writer_put_ldr_reg_address(cw, ARM64_REG_X0,
GUM_ADDRESS(&saved_lr));
gum_arm64_writer_put_ldr_reg_reg_offset(cw, ARM64_REG_X0, ARM64_REG_X0, 0);
gum_arm64_writer_put_br_reg(cw, ARM64_REG_X0);
}
#endif
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