udebug.c

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/*
 * udebug - debug ring buffer library
 *
 * Copyright (C) 2023 Felix Fietkau <nbd@nbd.name>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include <poll.h>
#include <time.h>
#include "udebug-priv.h"
#include "usock.h"
 
#define ALIGN(i, sz)    (((i) + (sz) - 1) & ~((sz) - 1))
 
#ifndef MAP_ANONYMOUS
#define MAP_ANONYMOUS MAP_ANON
#endif
 
#define UDEBUG_MIN_ALLOC_LEN    128
static struct blob_buf b;
static unsigned int page_size;
 
static void __randname(char *template)
{
        int i;
        struct timespec ts;
        unsigned long r;
 
        clock_gettime(CLOCK_REALTIME, &ts);
        r = ts.tv_sec + ts.tv_nsec;
        for (i=0; i<6; i++, r>>=5)
                template[i] = 'A'+(r&15)+(r&16)*2;
}
 
int udebug_id_cmp(const void *k1, const void *k2, void *ptr)
{
        uint32_t id1 = (uint32_t)(uintptr_t)k1, id2 = (uint32_t)(uintptr_t)k2;
        if (id1 < id2)
                return -1;
        else if (id1 > id2)
                return 1;
        return 0;
}
 
static inline int
shm_open_anon(char *name)
{
        char *template = name + strlen(name) - 6;
        int fd;
 
        if (template < name || memcmp(template, "XXXXXX", 6) != 0)
                return -1;
 
        for (int i = 0; i < 100; i++) {
                __randname(template);
                fd = shm_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
                if (fd >= 0) {
                        if (shm_unlink(name) < 0) {
                                close(fd);
                                continue;
                        }
                        return fd;
                }
 
                if (fd < 0 && errno != EEXIST)
                        return -1;
        }
 
        return -1;
}
 
static void __udebug_disconnect(struct udebug *ctx, bool reconnect)
{
        uloop_fd_delete(&ctx->fd);
        close(ctx->fd.fd);
        ctx->fd.fd = -1;
        ctx->poll_handle = -1;
        if (ctx->reconnect.cb && reconnect)
                uloop_timeout_set(&ctx->reconnect, 1);
}
 
uint64_t udebug_timestamp(void)
{
        struct timespec ts;
        uint64_t val;
 
        clock_gettime(CLOCK_REALTIME, &ts);
 
        val = ts.tv_sec;
        val *= UDEBUG_TS_SEC;
        val += ts.tv_nsec / 1000;
 
        return val;
}
 
static int
__udebug_buf_map(struct udebug_buf *buf, int fd)
{
        unsigned int pad = 0;
        void *ptr, *ptr2;
 
#ifdef mips
        pad = page_size;
#endif
        ptr = mmap(NULL, buf->head_size + 2 * buf->data_size + pad, PROT_NONE,
                   MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
        if (ptr == MAP_FAILED)
                return -1;
 
#ifdef mips
        ptr = (void *)ALIGN((unsigned long)ptr, page_size);
#endif
 
        ptr2 = mmap(ptr, buf->head_size + buf->data_size,
                    PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, fd, 0);
        if (ptr2 != ptr)
                goto err_unmap;
 
        ptr2 = mmap(ptr + buf->head_size + buf->data_size, buf->data_size,
                    PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, fd,
                    buf->head_size);
        if (ptr2 != ptr + buf->head_size + buf->data_size)
                goto err_unmap;
 
        buf->hdr = ptr;
        buf->data = ptr + buf->head_size;
        return 0;
 
err_unmap:
        munmap(ptr, buf->head_size + 2 * buf->data_size);
        return -1;
}
 
static int
writev_retry(int fd, struct iovec *iov, int iov_len, int sock_fd)
{
        uint8_t fd_buf[CMSG_SPACE(sizeof(int))] = { 0 };
        struct msghdr msghdr = { 0 };
        struct cmsghdr *cmsg;
        int len = 0;
        int *pfd;
 
        msghdr.msg_iov = iov,
        msghdr.msg_iovlen = iov_len,
        msghdr.msg_control = fd_buf;
        msghdr.msg_controllen = sizeof(fd_buf);
 
        cmsg = CMSG_FIRSTHDR(&msghdr);
        cmsg->cmsg_type = SCM_RIGHTS;
        cmsg->cmsg_level = SOL_SOCKET;
        cmsg->cmsg_len = CMSG_LEN(sizeof(int));
 
        pfd = (int *) CMSG_DATA(cmsg);
        msghdr.msg_controllen = cmsg->cmsg_len;
 
        do {
                ssize_t cur_len;
 
                if (sock_fd < 0) {
                        msghdr.msg_control = NULL;
                        msghdr.msg_controllen = 0;
                } else {
                        *pfd = sock_fd;
                }
 
                cur_len = sendmsg(fd, &msghdr, 0);
                if (cur_len < 0) {
                        struct pollfd pfd = {
                                .fd = fd,
                                .events = POLLOUT
                        };
 
                        switch(errno) {
                        case EAGAIN:
                                poll(&pfd, 1, -1);
                                break;
                        case EINTR:
                                break;
                        default:
                                return -1;
                        }
                        continue;
                }
 
                if (len > 0)
                        sock_fd = -1;
 
                len += cur_len;
                while (cur_len >= (ssize_t) iov->iov_len) {
                        cur_len -= iov->iov_len;
                        iov_len--;
                        iov++;
                        if (!iov_len)
                                return len;
                }
                iov->iov_base += cur_len;
                iov->iov_len -= cur_len;
                msghdr.msg_iov = iov;
                msghdr.msg_iovlen = iov_len;
        } while (1);
 
        /* Should never reach here */
        return -1;
}
 
static int
recv_retry(int fd, struct iovec *iov, bool wait, int *recv_fd)
{
        uint8_t fd_buf[CMSG_SPACE(sizeof(int))] = { 0 };
        struct msghdr msghdr = { 0 };
        struct cmsghdr *cmsg;
        int total = 0;
        int bytes;
        int *pfd;
 
        msghdr.msg_iov = iov,
        msghdr.msg_iovlen = 1,
        msghdr.msg_control = fd_buf;
        msghdr.msg_controllen = sizeof(fd_buf);
 
        cmsg = CMSG_FIRSTHDR(&msghdr);
        cmsg->cmsg_type = SCM_RIGHTS;
        cmsg->cmsg_level = SOL_SOCKET;
        cmsg->cmsg_len = CMSG_LEN(sizeof(int));
 
        pfd = (int *) CMSG_DATA(cmsg);
 
        while (iov->iov_len > 0) {
                if (recv_fd) {
                        msghdr.msg_control = fd_buf;
                        msghdr.msg_controllen = cmsg->cmsg_len;
                } else {
                        msghdr.msg_control = NULL;
                        msghdr.msg_controllen = 0;
                }
 
                *pfd = -1;
                bytes = recvmsg(fd, &msghdr, 0);
                if (!bytes)
                        return -2;
                if (bytes < 0) {
                        bytes = 0;
                        if (errno == EINTR)
                                continue;
 
                        if (errno != EAGAIN)
                                return -2;
                }
                if (!wait && !bytes)
                        return 0;
 
                if (recv_fd)
                        *recv_fd = *pfd;
                else if (*pfd >= 0)
                        close(*pfd);
 
                if (bytes > 0)
                        recv_fd = NULL;
 
                wait = true;
                iov->iov_len -= bytes;
                iov->iov_base += bytes;
                total += bytes;
 
                if (iov->iov_len > 0) {
                        struct pollfd pfd = {
                                .fd = fd,
                                .events = POLLIN
                        };
                        int ret;
                        do {
                                ret = poll(&pfd, 1, UDEBUG_TIMEOUT);
                        } while (ret < 0 && errno == EINTR);
 
                        if (!(pfd.revents & POLLIN))
                                return -1;
                }
        }
 
        return total;
}
 
static void
udebug_send_msg(struct udebug *ctx, struct udebug_client_msg *msg,
                struct blob_attr *meta, int fd)
{
        struct iovec iov[2] = {
                { .iov_base = msg, .iov_len = sizeof(*msg) },
                {}
        };
 
        if (!meta) {
                blob_buf_init(&b, 0);
                meta = b.head;
        }
 
        iov[1].iov_base = meta;
        iov[1].iov_len = blob_pad_len(meta);
        writev_retry(ctx->fd.fd, iov, ARRAY_SIZE(iov), fd);
}
 
static bool
udebug_recv_msg(struct udebug *ctx, struct udebug_client_msg *msg, int *fd,
                bool wait)
{
        struct iovec iov = {
                .iov_base = msg,
                .iov_len = sizeof(*msg)
        };
        int ret;
 
        ret = recv_retry(ctx->fd.fd, &iov, wait, fd);
        if (ret == -2)
                __udebug_disconnect(ctx, true);
 
        return ret == sizeof(*msg);
}
 
static struct udebug_client_msg *
__udebug_poll(struct udebug *ctx, int *fd, bool wait)
{
        static struct udebug_client_msg msg = {};
 
        while (udebug_recv_msg(ctx, &msg, fd, wait)) {
                struct udebug_remote_buf *rb;
                void *key;
 
                if (msg.type != CL_MSG_RING_NOTIFY)
                        return &msg;
 
                if (fd && *fd >= 0)
                        close(*fd);
 
                if (!ctx->notify_cb)
                        continue;
 
                key = (void *)(uintptr_t)msg.id;
                rb = avl_find_element(&ctx->remote_rings, key, rb, node);
                if (!rb || !rb->poll)
                        continue;
 
                if (ctx->poll_handle >= 0)
                        __atomic_fetch_or(&rb->buf.hdr->notify,
                                          1UL << ctx->poll_handle,
                                          __ATOMIC_RELAXED);
                ctx->notify_cb(ctx, rb);
        }
 
        return NULL;
}
 
static struct udebug_client_msg *
udebug_wait_for_response(struct udebug *ctx, struct udebug_client_msg *msg, int *rfd)
{
        int type = msg->type;
        int fd = -1;
 
        do {
                if (fd >= 0)
                        close(fd);
                fd = -1;
                msg = __udebug_poll(ctx, &fd, true);
        } while (msg && msg->type != type);
        if (!msg)
                return NULL;
 
        if (rfd)
                *rfd = fd;
        else if (fd >= 0)
                close(fd);
 
        return msg;
}
 
static void
udebug_buf_msg(struct udebug_buf *buf, enum udebug_client_msg_type type)
{
        struct udebug_client_msg msg = {
                .type = type,
                .id = buf->id,
        };
 
        udebug_send_msg(buf->ctx, &msg, NULL, -1);
        udebug_wait_for_response(buf->ctx, &msg, NULL);
}
 
static size_t __udebug_headsize(unsigned int ring_size)
{
        ring_size *= sizeof(struct udebug_ptr);
        return ALIGN(sizeof(struct udebug_hdr) + ring_size, page_size);
}
 
static void udebug_init_page_size(void)
{
        if (page_size)
                return;
        page_size = sysconf(_SC_PAGESIZE);
#ifdef mips
        /* leave extra alignment room to account for data cache aliases */
        if (page_size < 32 * 1024)
                page_size = 32 * 1024;
#endif
}
 
int udebug_buf_open(struct udebug_buf *buf, int fd, uint32_t ring_size, uint32_t data_size)
{
        udebug_init_page_size();
        INIT_LIST_HEAD(&buf->list);
        buf->ring_size = ring_size;
        buf->head_size = __udebug_headsize(ring_size);
        buf->data_size = data_size;
 
        if (buf->ring_size > (1U << 24) || buf->data_size > (1U << 29))
                return -1;
 
        if (__udebug_buf_map(buf, fd))
                return -1;
 
        if (buf->ring_size != buf->hdr->ring_size ||
                buf->data_size != buf->hdr->data_size) {
                munmap(buf->hdr, buf->head_size + 2 * buf->data_size);
                buf->hdr = NULL;
                return -1;
        }
 
        buf->fd = fd;
 
        return 0;
}
 
int udebug_buf_init(struct udebug_buf *buf, size_t entries, size_t size)
{
        char filename[] = "/udebug.XXXXXX";
        unsigned int order = 12;
        uint8_t ring_order = 5;
        size_t head_size;
        int fd;
 
        udebug_init_page_size();
        INIT_LIST_HEAD(&buf->list);
        if (size < page_size)
                size = page_size;
        while(size > 1U << order)
                order++;
        size = 1 << order;
        while (entries > 1U << ring_order)
                ring_order++;
        entries = 1 << ring_order;
 
        if (size > (1U << 29) || entries > (1U << 24))
                return -1;
 
        head_size = __udebug_headsize(entries);
        while (ALIGN(sizeof(*buf->hdr) + (entries * 2) * sizeof(struct udebug_ptr), page_size) == head_size)
                entries *= 2;
 
        fd = shm_open_anon(filename);
        if (fd < 0)
                return -1;
 
        if (ftruncate(fd, head_size + size) < 0)
                goto err_close;
 
        buf->head_size = head_size;
        buf->data_size = size;
        buf->ring_size = entries;
 
        if (__udebug_buf_map(buf, fd))
                goto err_close;
 
        buf->fd = fd;
        buf->hdr->ring_size = entries;
        buf->hdr->data_size = size;
 
        /* ensure hdr changes are visible */
        __sync_synchronize();
 
        return 0;
 
err_close:
        close(fd);
        return -1;
}
 
static void *udebug_buf_alloc(struct udebug_buf *buf, uint32_t ofs, uint32_t len)
{
        struct udebug_hdr *hdr = buf->hdr;
 
        hdr->data_used = u32_max(hdr->data_used, ofs + len + 1);
 
        /* ensure that data_used update is visible before clobbering data */
        __sync_synchronize();
 
        return udebug_buf_ptr(buf, ofs);
}
 
uint64_t udebug_buf_flags(struct udebug_buf *buf)
{
        struct udebug_hdr *hdr = buf->hdr;
        uint64_t flags;
 
        if (!hdr)
                return 0;
 
        flags = hdr->flags[0];
        if (sizeof(flags) != sizeof(uintptr_t))
                flags |= ((uint64_t)hdr->flags[1]) << 32;
 
        return flags;
}
 
void udebug_entry_init_ts(struct udebug_buf *buf, uint64_t timestamp)
{
        struct udebug_hdr *hdr = buf->hdr;
        struct udebug_ptr *ptr;
 
        if (!hdr)
                return;
 
        ptr = udebug_ring_ptr(hdr, hdr->head);
        ptr->start = hdr->data_head;
        ptr->len = 0;
        ptr->timestamp = timestamp;
}
 
void *udebug_entry_append(struct udebug_buf *buf, const void *data, uint32_t len)
{
        struct udebug_hdr *hdr = buf->hdr;
        struct udebug_ptr *ptr;
        uint32_t ofs;
        void *ret;
 
        if (!hdr)
                return NULL;
 
        ptr = udebug_ring_ptr(hdr, hdr->head);
        ofs = ptr->start + ptr->len;
        if (ptr->len + len > buf->data_size / 2)
                return NULL;
 
        ret = udebug_buf_alloc(buf, ofs, len);
        if (data)
                memcpy(ret, data, len);
        ptr->len += len;
 
        return ret;
}
 
uint16_t udebug_entry_trim(struct udebug_buf *buf, uint16_t len)
{
        struct udebug_hdr *hdr = buf->hdr;
        struct udebug_ptr *ptr;
 
        if (!hdr)
                return 0;
 
        ptr = udebug_ring_ptr(hdr, hdr->head);
        if (len)
                ptr->len -= len;
 
        return ptr->len;
}
 
void udebug_entry_set_length(struct udebug_buf *buf, uint16_t len)
{
        struct udebug_hdr *hdr = buf->hdr;
        struct udebug_ptr *ptr;
 
        if (!hdr)
                return;
 
        ptr = udebug_ring_ptr(hdr, hdr->head);
        ptr->len = len;
}
 
int udebug_entry_printf(struct udebug_buf *buf, const char *fmt, ...)
{
        va_list ap;
        size_t ret;
 
        va_start(ap, fmt);
        ret = udebug_entry_vprintf(buf, fmt, ap);
        va_end(ap);
 
        return ret;
}
 
int udebug_entry_vprintf(struct udebug_buf *buf, const char *fmt, va_list ap)
{
        struct udebug_hdr *hdr = buf->hdr;
        struct udebug_ptr *ptr;
        uint32_t ofs;
        uint32_t len;
        va_list ap2;
        char *str;
 
        if (!hdr)
                return -1;
 
        ptr = udebug_ring_ptr(hdr, hdr->head);
        ofs = ptr->start + ptr->len;
        if (ptr->len > buf->data_size / 2)
                return -1;
 
        str = udebug_buf_alloc(buf, ofs, UDEBUG_MIN_ALLOC_LEN);
        va_copy(ap2, ap);
        len = vsnprintf(str, UDEBUG_MIN_ALLOC_LEN, fmt, ap2);
        va_end(ap2);
        if (len <= UDEBUG_MIN_ALLOC_LEN)
                goto out;
 
        if (ptr->len + len > buf->data_size / 2)
                return -1;
 
        udebug_buf_alloc(buf, ofs, len + 1);
        len = vsnprintf(str, len, fmt, ap);
 
out:
        ptr->len += len;
        return 0;
}
 
void udebug_entry_add(struct udebug_buf *buf)
{
        struct udebug_hdr *hdr = buf->hdr;
        struct udebug_ptr *ptr;
        uint32_t notify;
        uint8_t *data;
 
        if (!hdr)
                return;
 
        ptr = udebug_ring_ptr(hdr, hdr->head);
 
        /* ensure strings are always 0-terminated */
        data = udebug_buf_ptr(buf, ptr->start + ptr->len);
        *data = 0;
        hdr->data_head = ptr->start + ptr->len + 1;
 
        /* ensure that all data changes are visible before advancing head */
        __sync_synchronize();
 
        u32_set(&hdr->head, u32_get(&hdr->head) + 1);
        if (!u32_get(&hdr->head))
                u32_set(&hdr->head_hi, u32_get(&hdr->head_hi) + 1);
 
        /* ensure that head change is visible */
        __sync_synchronize();
 
        notify = __atomic_exchange_n(&hdr->notify, 0, __ATOMIC_RELAXED);
        if (notify) {
                struct udebug_client_msg msg = {
                        .type = CL_MSG_RING_NOTIFY,
                        .id = buf->id,
                        .notify_mask = notify,
                };
                blob_buf_init(&b, 0);
 
                udebug_send_msg(buf->ctx, &msg, b.head, -1);
        }
}
void udebug_buf_free(struct udebug_buf *buf)
{
        struct udebug *ctx = buf->ctx;
 
        if (!list_empty(&buf->list) && buf->list.prev)
                list_del(&buf->list);
 
        if (ctx && ctx->fd.fd >= 0)
                udebug_buf_msg(buf, CL_MSG_RING_REMOVE);
 
        munmap(buf->hdr, buf->head_size + 2 * buf->data_size);
        close(buf->fd);
        memset(buf, 0, sizeof(*buf));
}
 
static void
__udebug_buf_add(struct udebug *ctx, struct udebug_buf *buf)
{
        struct udebug_client_msg msg = {
                .type = CL_MSG_RING_ADD,
                .id = buf->id,
                .ring_size = buf->hdr->ring_size,
                .data_size = buf->hdr->data_size,
        };
        const struct udebug_buf_meta *meta = buf->meta;
        void *c;
 
        blob_buf_init(&b, 0);
        blobmsg_add_string(&b, "name", meta->name);
        c = blobmsg_open_array(&b, "flags");
        for (size_t i = 0; i < meta->n_flags; i++) {
                const struct udebug_buf_flag *flag = &meta->flags[i];
                void *e = blobmsg_open_array(&b, NULL);
                blobmsg_add_string(&b, NULL, flag->name);
                blobmsg_add_u64(&b, NULL, flag->mask);
                blobmsg_close_array(&b, e);
        }
        blobmsg_close_array(&b, c);
 
        udebug_send_msg(ctx, &msg, b.head, buf->fd);
        udebug_wait_for_response(ctx, &msg, NULL);
}
 
int udebug_buf_add(struct udebug *ctx, struct udebug_buf *buf,
                   const struct udebug_buf_meta *meta)
{
        if (!buf->hdr)
                return -1;
 
        list_add_tail(&buf->list, &ctx->local_rings);
        buf->ctx = ctx;
        buf->meta = meta;
        buf->id = ctx->next_id++;
        buf->hdr->format = meta->format;
        buf->hdr->sub_format = meta->sub_format;
 
        if (ctx->fd.fd >= 0)
                __udebug_buf_add(ctx, buf);
 
        return 0;
}
 
void udebug_init(struct udebug *ctx)
{
        INIT_LIST_HEAD(&ctx->local_rings);
        avl_init(&ctx->remote_rings, udebug_id_cmp, true, NULL);
        ctx->fd.fd = -1;
        ctx->poll_handle = -1;
}
 
static void udebug_reconnect_cb(struct uloop_timeout *t)
{
        struct udebug *ctx = container_of(t, struct udebug, reconnect);
 
        if (udebug_connect(ctx, ctx->socket_path) < 0) {
                uloop_timeout_set(&ctx->reconnect, 1000);
                return;
        }
 
        udebug_add_uloop(ctx);
}
 
void udebug_auto_connect(struct udebug *ctx, const char *path)
{
        free(ctx->socket_path);
        ctx->reconnect.cb = udebug_reconnect_cb;
        ctx->socket_path = path ? strdup(path) : NULL;
        if (ctx->fd.fd >= 0)
                return;
 
        udebug_reconnect_cb(&ctx->reconnect);
}
 
int udebug_connect(struct udebug *ctx, const char *path)
{
        struct udebug_remote_buf *rb;
        struct udebug_buf *buf;
 
        if (ctx->fd.fd >= 0)
                close(ctx->fd.fd);
        ctx->fd.fd = -1;
 
        if (!path)
                path = UDEBUG_SOCK_NAME;
 
        ctx->fd.fd = usock(USOCK_UNIX, path, NULL);
        if (ctx->fd.fd < 0)
                return -1;
 
        list_for_each_entry(buf, &ctx->local_rings, list)
                __udebug_buf_add(ctx, buf);
 
        avl_for_each_element(&ctx->remote_rings, rb, node) {
                if (!rb->poll)
                        continue;
 
                rb->poll = false;
                udebug_remote_buf_set_poll(ctx, rb, true);
        }
 
        return 0;
}
 
void udebug_poll(struct udebug *ctx)
{
        while (__udebug_poll(ctx, NULL, false));
}
 
struct udebug_client_msg *
udebug_send_and_wait(struct udebug *ctx, struct udebug_client_msg *msg, int *rfd)
{
        udebug_send_msg(ctx, msg, NULL, -1);
 
        return udebug_wait_for_response(ctx, msg, rfd);
}
 
static void udebug_fd_cb(struct uloop_fd *fd, unsigned int events)
{
        struct udebug *ctx = container_of(fd, struct udebug, fd);
 
        if (fd->eof)
                __udebug_disconnect(ctx, true);
 
        udebug_poll(ctx);
}
 
void udebug_add_uloop(struct udebug *ctx)
{
        if (ctx->fd.registered)
                return;
 
        ctx->fd.cb = udebug_fd_cb;
        uloop_fd_add(&ctx->fd, ULOOP_READ);
}
 
void udebug_free(struct udebug *ctx)
{
        struct udebug_remote_buf *rb, *tmp;
        struct udebug_buf *buf;
 
        free(ctx->socket_path);
        ctx->socket_path = NULL;
 
        __udebug_disconnect(ctx, false);
        uloop_timeout_cancel(&ctx->reconnect);
 
        while (!list_empty(&ctx->local_rings)) {
                buf = list_first_entry(&ctx->local_rings, struct udebug_buf, list);
                udebug_buf_free(buf);
        }
 
        avl_for_each_element_safe(&ctx->remote_rings, rb, node, tmp)
                udebug_remote_buf_unmap(ctx, rb);
}