Commit 0b68c02c authored by Ramon Nou's avatar Ramon Nou
Browse files

fix(client): avoid SIGTRAP by routing post-shutdown syscalls to passthrough hook

parent 8f53e3d3

src/client/intercept.cpp

+22 −9
Changes for src/client/intercept.cpp: 22 added lines, 9 removed lines.
Original line number Diff line number Diff line
@@ -1439,11 +1439,30 @@ internal_hook_guard_wrapper(long syscall_number, long arg0, long arg1, 
 * being called inside a signal handler might easily forward a mock fd to the

 * kernel.

 */

static int

passthrough_hook_wrapper(long syscall_number, long arg0, long arg1, long arg2,

                         long arg3, long arg4, long arg5,

                         long* syscall_return_value) {

    (void)syscall_number;

    (void)arg0;

    (void)arg1;

    (void)arg2;

    (void)arg3;

    (void)arg4;

    (void)arg5;

    (void)syscall_return_value;

    return gkfs::syscall::forward_to_kernel;

}



int

hook_guard_wrapper(long syscall_number, long arg0, long arg1, long arg2,

                   long arg3, long arg4, long arg5,

                   long* syscall_return_value) {



    if(!CTX || !CTX->interception_enabled()) {

        return gkfs::syscall::forward_to_kernel;

    }



    pthread_once(&key_once_control, make_key); // Ensure the key is created

    if(pthread_getspecific(reentrance_guard_key) != NULL) {

        // While handling an application syscall, nested syscalls originate
@@ -1457,11 +1476,6 @@ hook_guard_wrapper(long syscall_number, long arg0, long arg1, long arg2, 
            reentrance_guard_key,

            reinterpret_cast<void*>(1)); // cppcheck-suppress intToPointerCast



    if(!CTX->interception_enabled()) {

        pthread_setspecific(reentrance_guard_key, NULL);

        return gkfs::syscall::forward_to_kernel;

    }



#ifdef SYS_socketcall

    if(syscall_number == SYS_socketcall)

        syscall_number = socketcall_wrapper(syscall_number, arg0, arg1, arg2,
@@ -1506,12 +1520,11 @@ start_interception() { 


void

stop_interception() {

    assert(CTX->interception_enabled());



    LOG(DEBUG, "Disabling syscall interception for client process");



    // Reset callback function pointer

    intercept_hook_point = nullptr;

    // Reset callback function pointer to passthrough so that subsequent syscalls

    // (during exit/shutdown/atexit) are forwarded to kernel instead of triggering SIGTRAP.

    intercept_hook_point = passthrough_hook_wrapper;

    intercept_hook_point_post_kernel = nullptr;

    intercept_hook_point_clone_child = nullptr;

    intercept_hook_point_clone_parent = nullptr;