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notiMessage/magisk-modules/tng_exit_guard/jni/main.cpp
mars 818b2f4f51 fix(tng): 防止 SIGABRT 跳 LR 死循环,改 pc+4 与 streak freeze
吞 ABRT 时若跳回近距 LR 会瞬间再 abort 刷屏;改为优先 pc+4,同 tid+pc 超阈值后冻结工作线程,主线程仅 bail。
2026-08-03 10:26:48 +08:00

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/*
* TNG eWallet — Zygisk companion.
*
* stable: PLT + ABRT/SIGTRAP swallow + exit_group seccomp@400ms.
* Promon worker SIGSEGV (libtngdigital_ewallet.so null deref): LR-return skip (cap N).
* pc==lr 循环 SEGV 也 skiplibc++abi __cxa_guard_acquire → SIGABRT 吞掉。
*/
#include <android/log.h>
#include <errno.h>
#include <linux/audit.h>
#include <linux/filter.h>
#include <linux/seccomp.h>
#include <pthread.h>
#include <signal.h>
#include <stddef.h>
#include <sys/mman.h>
#include <sys/prctl.h>
#include <sys/syscall.h>
#include <sys/sysmacros.h>
#include <ucontext.h>
#include <unistd.h>
#include <atomic>
#include <cstdint>
#include <cstdio>
#include <cstring>
#include "zygisk.hpp"
#define SC_RET_ALLOW 0x7fff0000U
#define SC_RET_ERRNO_EPERM (0x00050000U | 1U)
#define LOG_TAG "TngExitGuard"
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__)
static constexpr const char *kTargetPkg = "my.com.tngdigital.ewallet";
static constexpr const char *kPromonSo = "libtngdigital_ewallet.so";
static bool g_enabled = false;
static std::atomic<int> g_seccomp_ok{0};
static std::atomic<int> g_stack_chk{0};
static std::atomic<int> g_promon_segv{0};
static std::atomic<uintptr_t> g_promon_start{0};
static std::atomic<uintptr_t> g_promon_end{0};
/* 隔离进程 :goacqowmmt 会循环 SEGVcap=16 打满后 freeze 反拖累主进程 */
static constexpr int kMaxPromonSegvSkip = 0; /* 0 = unlimited LR-return skip */
static std::atomic<int> g_soft_sig_logged{0};
static void freeze_forever() {
for (;;) pause();
}
static void refresh_promon_so_range() {
FILE *fp = fopen("/proc/self/maps", "r");
if (!fp) return;
char line[1024];
uintptr_t start = 0, end = 0;
while (fgets(line, sizeof(line), fp)) {
unsigned long s = 0, e = 0;
char path[512] = {};
int n = sscanf(line, "%lx-%lx %*s %*s %*s %*s %511[^\n]", &s, &e, path);
if (n < 3) continue;
char *p = path;
while (*p == ' ') ++p;
if (strstr(p, kPromonSo) == nullptr) continue;
if (start == 0 || s < start) start = s;
if (e > end) end = e;
}
fclose(fp);
if (start != 0 && end > start) {
g_promon_start.store(start);
g_promon_end.store(end);
}
}
static bool pc_in_promon_so(uintptr_t pc) {
uintptr_t start = g_promon_start.load();
uintptr_t end = g_promon_end.load();
return start != 0 && pc >= start && pc < end;
}
static void promon_segv_handler(int sig, siginfo_t *info, void *ctx) {
(void)sig;
(void)info;
ucontext_t *uc = reinterpret_cast<ucontext_t *>(ctx);
#if defined(__aarch64__)
uintptr_t pc = uc->uc_mcontext.pc;
uintptr_t lr = uc->uc_mcontext.regs[30];
#else
uintptr_t pc = 0;
uintptr_t lr = 0;
#endif
refresh_promon_so_range();
/* Promon 典型 pc==lr 自旋 null derefmaps 尚未刷新时也按此 skip */
if (pc != 0 && pc == lr) {
int n = ++g_promon_segv;
if (n <= 3 || n % 50 == 0) {
LOGI("promon pc==lr SIGSEGV tid=%d pc=%lx n=%d — skip to pc+4",
(int)gettid(), (unsigned long)pc, n);
}
uc->uc_mcontext.pc = pc + 4;
return;
}
if (pc_in_promon_so(pc) || pc_in_promon_so(lr)) {
int n = ++g_promon_segv;
uintptr_t target = lr;
if (target == 0 || target == pc) {
target = pc + 4;
}
if (kMaxPromonSegvSkip <= 0 || n <= kMaxPromonSegvSkip) {
if (n <= 3 || n % 50 == 0) {
LOGI("promon SIGSEGV tid=%d pc=%lx lr=%lx n=%d — skip to %lx",
(int)gettid(), (unsigned long)pc, (unsigned long)lr, n,
(unsigned long)target);
}
uc->uc_mcontext.pc = target;
return;
}
LOGI("promon SIGSEGV tid=%d n=%d — cap hit, freeze", (int)gettid(), n);
freeze_forever();
}
signal(SIGSEGV, SIG_DFL);
raise(SIGSEGV);
}
static std::atomic<pid_t> g_main_tid{0};
static std::atomic<int> g_abrt_swallow{0};
static std::atomic<pid_t> g_abrt_last_tid{0};
static std::atomic<uintptr_t> g_abrt_last_pc{0};
static std::atomic<int> g_abrt_streak{0};
static constexpr int kMaxAbrtStreak = 3;
/** ABRT/TRAPpc+4 或远距 LR同 tid+pc 连触发则 freeze避免 LR 自旋死循环。 */
static void fatal_skip_handler(int sig, siginfo_t *info, void *ctx) {
(void)info;
ucontext_t *uc = reinterpret_cast<ucontext_t *>(ctx);
#if defined(__aarch64__)
uintptr_t pc = uc->uc_mcontext.pc;
uintptr_t lr = uc->uc_mcontext.regs[30];
pid_t tid = gettid();
if (sig == SIGABRT) {
int streak = 1;
if (g_abrt_last_tid.load() == tid && g_abrt_last_pc.load() == pc) {
streak = g_abrt_streak.fetch_add(1) + 1;
} else {
g_abrt_last_tid.store(tid);
g_abrt_last_pc.store(pc);
g_abrt_streak.store(1);
}
if (streak > kMaxAbrtStreak) {
if (tid == g_main_tid.load()) {
LOGI("ABRT main-thread streak cap tid=%d pc=%lx — pc+4 bail", (int)tid,
(unsigned long)pc);
uc->uc_mcontext.pc = pc + 4;
g_abrt_streak.store(0);
return;
}
LOGI("ABRT streak cap tid=%d pc=%lx n=%d — freeze thread", (int)tid,
(unsigned long)pc, streak);
freeze_forever();
}
uintptr_t delta = (pc > lr) ? (pc - lr) : (lr - pc);
uintptr_t target = pc + 4;
/* lr 距 pc 很近时仍在 abort/epilogue 内,跳 LR 会 instant 再 ABRT */
if (lr != 0 && delta > 64) {
target = lr;
}
int n = ++g_abrt_swallow;
if (n <= 3 || n % 100 == 0) {
LOGI("ABRT skip tid=%d pc=%lx lr=%lx streak=%d -> %lx", (int)tid,
(unsigned long)pc, (unsigned long)lr, streak,
(unsigned long)target);
}
uc->uc_mcontext.pc = target;
return;
}
if (sig == SIGTRAP) {
uintptr_t target = pc != 0 ? pc + 4 : lr;
LOGI("TRAP skip tid=%d pc=%lx -> %lx", (int)tid, (unsigned long)pc,
(unsigned long)target);
uc->uc_mcontext.pc = target;
return;
}
#endif
freeze_forever();
}
static void install_fatal_skip_handlers() {
struct sigaction sa {};
sa.sa_sigaction = fatal_skip_handler;
sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
sigemptyset(&sa.sa_mask);
sigaction(SIGABRT, &sa, nullptr);
sigaction(SIGTRAP, &sa, nullptr);
LOGI("fatal skip handlers (ABRT pc+4/streak-freeze + TRAP pc+4)");
}
static void install_promon_segv_handler() {
refresh_promon_so_range();
struct sigaction sa {};
sa.sa_sigaction = promon_segv_handler;
sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
sigemptyset(&sa.sa_mask);
if (sigaction(SIGSEGV, &sa, nullptr) != 0) {
LOGE("SIGSEGV handler install failed errno=%d", errno);
return;
}
LOGI("promon SIGSEGV handler armed range=%lx-%lx",
(unsigned long)g_promon_start.load(),
(unsigned long)g_promon_end.load());
}
static void install_soft_signals() {
struct sigaction sa {};
sa.sa_sigaction = fatal_skip_handler;
sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
sigemptyset(&sa.sa_mask);
sigaction(SIGABRT, &sa, nullptr);
sigaction(SIGTRAP, &sa, nullptr);
if (g_soft_sig_logged.fetch_add(1) == 0) {
LOGI("soft signals (ABRT streak-freeze + TRAP pc+4)");
}
}
#if defined(__aarch64__)
#define _BPFI(code, jt, jf, k) \
((struct sock_filter){(unsigned short)(code), (jt), (jf), (unsigned int)(k)})
static int install_seccomp_exit_group_only() {
struct sock_filter filter[] = {
_BPFI(BPF_LD | BPF_W | BPF_ABS, 0, 0, offsetof(struct seccomp_data, arch)),
_BPFI(BPF_JMP | BPF_JEQ | BPF_K, 1, 0, AUDIT_ARCH_AARCH64),
_BPFI(BPF_RET | BPF_K, 0, 0, SC_RET_ALLOW),
_BPFI(BPF_LD | BPF_W | BPF_ABS, 0, 0, offsetof(struct seccomp_data, nr)),
_BPFI(BPF_JMP | BPF_JEQ | BPF_K, 0, 1, 94),
_BPFI(BPF_RET | BPF_K, 0, 0, SC_RET_ERRNO_EPERM),
_BPFI(BPF_RET | BPF_K, 0, 0, SC_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)(sizeof(filter) / sizeof(filter[0])),
.filter = filter,
};
prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
long rc = syscall(__NR_seccomp, SECCOMP_SET_MODE_FILTER,
SECCOMP_FILTER_FLAG_TSYNC, &prog);
if (rc != 0) {
rc = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
if (rc != 0) {
LOGE("seccomp failed errno=%d", errno);
return -1;
}
LOGI("seccomp exit_group via prctl");
} else {
LOGI("seccomp exit_group via TSYNC");
}
g_seccomp_ok.store(1);
return 0;
}
#else
static int install_seccomp_exit_group_only() { return -1; }
#endif
using exit_fn = void (*)(int);
using kill_fn = int (*)(pid_t, int);
using tgkill_fn = int (*)(int, int, int);
using raise_fn = int (*)(int);
using pthread_kill_fn = int (*)(pthread_t, int);
static exit_fn orig_exit = nullptr;
static exit_fn orig__exit = nullptr;
static void (*orig_abort)() = nullptr;
static void (*orig_stack_chk_fail)() = nullptr;
static kill_fn orig_kill = nullptr;
static tgkill_fn orig_tgkill = nullptr;
static raise_fn orig_raise = nullptr;
static pthread_kill_fn orig_pthread_kill = nullptr;
static bool deadly(int sig) {
return sig == SIGKILL || sig == SIGABRT || sig == SIGTERM ||
sig == SIGTRAP || sig == SIGILL ||
sig == 9 || sig == 6 || sig == 5 || sig == 4 || sig == 15;
}
static void hooked_exit(int code) { LOGI("blocked exit(%d)", code); }
static void hooked__exit(int code) { LOGI("blocked _exit(%d)", code); }
static void hooked_abort() {
LOGI("blocked abort() tid=%d", (int)gettid());
}
static void hooked_stack_chk_fail() {
int n = ++g_stack_chk;
LOGI("blocked __stack_chk_fail tid=%d n=%d", (int)gettid(), n);
}
static int hooked_raise(int sig) {
if (deadly(sig)) {
LOGI("blocked raise(%d)", sig);
return 0;
}
return orig_raise ? orig_raise(sig) : -1;
}
static int hooked_kill(pid_t pid, int sig) {
if (deadly(sig)) {
LOGI("blocked kill(%d,%d)", (int)pid, sig);
return 0;
}
return orig_kill ? orig_kill(pid, sig) : -1;
}
static int hooked_tgkill(int tgid, int tid, int sig) {
if (deadly(sig)) {
LOGI("blocked tgkill(%d,%d,%d)", tgid, tid, sig);
return 0;
}
return orig_tgkill ? orig_tgkill(tgid, tid, sig) : -1;
}
static int hooked_pthread_kill(pthread_t thread, int sig) {
if (deadly(sig)) {
LOGI("blocked pthread_kill(sig=%d)", sig);
return 0;
}
return orig_pthread_kill ? orig_pthread_kill(thread, sig) : -1;
}
static bool find_libc(dev_t *dev, ino_t *ino) {
FILE *fp = fopen("/proc/self/maps", "r");
if (!fp) return false;
char line[1024];
bool ok = false;
while (fgets(line, sizeof(line), fp)) {
uintptr_t start = 0, end = 0;
char perms[8] = {};
unsigned long long offset = 0;
char deststr[32] = {};
unsigned long inode = 0;
char path[512] = {};
int n = sscanf(line, "%lx-%lx %7s %llx %31s %lu %511[^\n]",
&start, &end, perms, &offset, deststr, &inode, path);
if (n < 7 || inode == 0) continue;
char *p = path;
while (*p == ' ') ++p;
if (strstr(p, "libc.so") == nullptr) continue;
unsigned maj = 0, min = 0;
if (sscanf(deststr, "%x:%x", &maj, &min) != 2) continue;
*dev = makedev(maj, min);
*ino = inode;
ok = true;
break;
}
fclose(fp);
return ok;
}
static void install_plt(zygisk::Api *api) {
if (!api) return;
dev_t dev = 0;
ino_t ino = 0;
if (!find_libc(&dev, &ino)) return;
api->pltHookRegister(dev, ino, "exit", (void *)hooked_exit, (void **)&orig_exit);
api->pltHookRegister(dev, ino, "_exit", (void *)hooked__exit, (void **)&orig__exit);
api->pltHookRegister(dev, ino, "abort", (void *)hooked_abort, (void **)&orig_abort);
api->pltHookRegister(dev, ino, "__stack_chk_fail",
(void *)hooked_stack_chk_fail, (void **)&orig_stack_chk_fail);
api->pltHookRegister(dev, ino, "raise", (void *)hooked_raise, (void **)&orig_raise);
api->pltHookRegister(dev, ino, "kill", (void *)hooked_kill, (void **)&orig_kill);
api->pltHookRegister(dev, ino, "tgkill", (void *)hooked_tgkill, (void **)&orig_tgkill);
api->pltHookRegister(dev, ino, "pthread_kill",
(void *)hooked_pthread_kill, (void **)&orig_pthread_kill);
bool ok = api->pltHookCommit();
LOGI("PLT commit=%d", ok ? 1 : 0);
}
static void *phase_thread(void *) {
install_promon_segv_handler();
usleep(400 * 1000);
install_seccomp_exit_group_only();
LOGI("seccomp armed @400ms ok=%d", g_seccomp_ok.load());
for (int i = 0; i < 40; i++) {
usleep(1000 * 1000);
install_soft_signals();
if (i % 5 == 0) refresh_promon_so_range();
}
LOGI("phase done seccomp=%d stack_chk=%d promon_segv=%d",
g_seccomp_ok.load(), g_stack_chk.load(), g_promon_segv.load());
return nullptr;
}
static void install_all(zygisk::Api *api) {
g_main_tid.store(gettid());
LOGI("install pid=%d main_tid=%d (PLT+ABRT-streak-freeze+TRAP+pc==lr-SEGV+exit_group@400ms)",
getpid(), (int)g_main_tid.load());
install_fatal_skip_handlers();
install_soft_signals();
install_plt(api);
pthread_t th;
if (pthread_create(&th, nullptr, phase_thread, nullptr) == 0) {
pthread_detach(th);
}
LOGI("ready");
}
class TngExitGuardModule : public zygisk::ModuleBase {
public:
void onLoad(zygisk::Api *api, JNIEnv *env) override {
this->api = api;
this->env = env;
}
void preAppSpecialize(zygisk::AppSpecializeArgs *args) override {
const char *nice = nullptr;
if (args->nice_name) {
nice = env->GetStringUTFChars(args->nice_name, nullptr);
}
bool match = nice && (
std::strncmp(nice, kTargetPkg, std::strlen(kTargetPkg)) == 0);
if (nice) env->ReleaseStringUTFChars(args->nice_name, nice);
g_enabled = match;
if (!match) {
api->setOption(zygisk::Option::DLCLOSE_MODULE_LIBRARY);
return;
}
LOGI("preAppSpecialize matched");
}
void postAppSpecialize(const zygisk::AppSpecializeArgs *args) override {
(void)args;
if (!g_enabled) return;
install_all(api);
}
private:
zygisk::Api *api = nullptr;
JNIEnv *env = nullptr;
};
REGISTER_ZYGISK_MODULE(TngExitGuardModule)