#define _GNU_SOURCE

#include <linux/prctl.h>
#include <pthread.h>
#include <sys/prctl.h>
#include <time.h>

/*
 * Wine's Win16 process is re-parented during startup, so Linux's default Yama
 * policy rejects a later same-user debugger attach.  This preload helper only
 * relaxes that relationship check for the process into which it is loaded.
 * Normal uid-based ptrace permission checks still apply.
 */
static void apply_ptrace_policy(void)
{
    (void)prctl(PR_SET_DUMPABLE, 1, 0, 0, 0);
    (void)prctl(PR_SET_PTRACER, PR_SET_PTRACER_ANY, 0, 0, 0);
}

static void *reapply_ptrace_policy(void *unused)
{
    const struct timespec interval = {.tv_sec = 0, .tv_nsec = 250000000};
    (void)unused;

    /* Wine adjusts process policy during bootstrap; outlast those updates. */
    for (unsigned int attempt = 0; attempt < 20; attempt++) {
        (void)nanosleep(&interval, NULL);
        apply_ptrace_policy();
    }
    return NULL;
}

__attribute__((constructor)) static void allow_same_user_debugger(void)
{
    pthread_t worker;

    apply_ptrace_policy();
    if (pthread_create(&worker, NULL, reapply_ptrace_policy, NULL) == 0) {
        (void)pthread_detach(worker);
    }
}