Fix: possible null dereference
[lttng-tools.git] / src / bin / lttng-sessiond / kernel.c
index 2626e98b259f46eeebbeee69be8bc1935cb43dfa..4ee4bea64ff630abae9617624f86ce21cc87950d 100644 (file)
@@ -1,18 +1,8 @@
 /*
- * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License, version 2 only,
- * as published by the Free Software Foundation.
+ * SPDX-License-Identifier: GPL-2.0-only
  *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
 #define _LGPL_SOURCE
@@ -679,120 +669,281 @@ error:
        return ret;
 }
 
+static struct lttng_tracker_list *get_id_tracker_list(
+               struct ltt_kernel_session *session,
+               enum lttng_tracker_type tracker_type)
+{
+       switch (tracker_type) {
+       case LTTNG_TRACKER_PID:
+               return session->tracker_list_pid;
+       case LTTNG_TRACKER_VPID:
+               return session->tracker_list_vpid;
+       case LTTNG_TRACKER_UID:
+               return session->tracker_list_uid;
+       case LTTNG_TRACKER_VUID:
+               return session->tracker_list_vuid;
+       case LTTNG_TRACKER_GID:
+               return session->tracker_list_gid;
+       case LTTNG_TRACKER_VGID:
+               return session->tracker_list_vgid;
+       default:
+               return NULL;
+       }
+}
 
-int kernel_track_pid(struct ltt_kernel_session *session, int pid)
+int kernel_track_id(enum lttng_tracker_type tracker_type,
+               struct ltt_kernel_session *session,
+               const struct lttng_tracker_id *id)
 {
-       int ret;
+       int ret, value;
+       struct lttng_tracker_list *tracker_list;
+       struct lttng_tracker_ids *saved_ids;
 
-       DBG("Kernel track PID %d for session id %" PRIu64 ".",
-                       pid, session->id);
-       ret = kernctl_track_pid(session->fd, pid);
-       if (!ret) {
-               return LTTNG_OK;
+       ret = lttng_tracker_id_lookup_string(tracker_type, id, &value);
+       if (ret != LTTNG_OK) {
+               return ret;
        }
-       switch (-ret) {
-       case EINVAL:
+
+       tracker_list = get_id_tracker_list(session, tracker_type);
+       if (!tracker_list) {
                return LTTNG_ERR_INVALID;
-       case ENOMEM:
-               return LTTNG_ERR_NOMEM;
-       case EEXIST:
-               return LTTNG_ERR_PID_TRACKED;
-       default:
-               return LTTNG_ERR_UNK;
        }
-}
 
-int kernel_untrack_pid(struct ltt_kernel_session *session, int pid)
-{
-       int ret;
+       /* Save list for restore on error. */
+       ret = lttng_tracker_id_get_list(tracker_list, &saved_ids);
+       if (ret != LTTNG_OK) {
+               return LTTNG_ERR_INVALID;
+       }
 
-       DBG("Kernel untrack PID %d for session id %" PRIu64 ".",
-                       pid, session->id);
-       ret = kernctl_untrack_pid(session->fd, pid);
-       if (!ret) {
-               return LTTNG_OK;
+       /* Add to list. */
+       ret = lttng_tracker_list_add(tracker_list, id);
+       if (ret != LTTNG_OK) {
+               goto end;
+       }
+
+       switch (tracker_type) {
+       case LTTNG_TRACKER_PID:
+               DBG("Kernel track PID %d for session id %" PRIu64 ".", value,
+                               session->id);
+               ret = kernctl_track_pid(session->fd, value);
+               if (!ret) {
+                       ret = LTTNG_OK;
+                       goto end;
+               }
+               break;
+       case LTTNG_TRACKER_VPID:
+               DBG("Kernel track VPID %d for session id %" PRIu64 ".", value,
+                               session->id);
+               ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VPID, value);
+               if (!ret) {
+                       ret = LTTNG_OK;
+                       goto end;
+               }
+               break;
+       case LTTNG_TRACKER_UID:
+               DBG("Kernel track UID %d for session id %" PRIu64 ".", value,
+                               session->id);
+               ret = kernctl_track_id(session->fd, LTTNG_TRACKER_UID, value);
+               if (!ret) {
+                       ret = LTTNG_OK;
+                       goto end;
+               }
+               break;
+       case LTTNG_TRACKER_GID:
+               DBG("Kernel track GID %d for session id %" PRIu64 ".", value,
+                               session->id);
+               ret = kernctl_track_id(session->fd, LTTNG_TRACKER_GID, value);
+               if (!ret) {
+                       ret = LTTNG_OK;
+                       goto end;
+               }
+               break;
+       case LTTNG_TRACKER_VUID:
+               DBG("Kernel track VUID %d for session id %" PRIu64 ".", value,
+                               session->id);
+               ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VUID, value);
+               if (!ret) {
+                       ret = LTTNG_OK;
+                       goto end;
+               }
+               break;
+       case LTTNG_TRACKER_VGID:
+               DBG("Kernel track VGID %d for session id %" PRIu64 ".", value,
+                               session->id);
+               ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VGID, value);
+               if (!ret) {
+                       ret = LTTNG_OK;
+                       goto end;
+               }
+               break;
+       default:
+               ret = -EINVAL;
+               break;
        }
+
+       /* Error handling. */
        switch (-ret) {
        case EINVAL:
-               return LTTNG_ERR_INVALID;
+               ret = LTTNG_ERR_INVALID;
+               break;
        case ENOMEM:
-               return LTTNG_ERR_NOMEM;
-       case ENOENT:
-               return LTTNG_ERR_PID_NOT_TRACKED;
+               ret = LTTNG_ERR_NOMEM;
+               break;
+       case EEXIST:
+               ret = LTTNG_ERR_ID_TRACKED;
+               break;
        default:
-               return LTTNG_ERR_UNK;
+               ret = LTTNG_ERR_UNK;
+               break;
+       }
+
+       if (lttng_tracker_id_set_list(tracker_list, saved_ids) != LTTNG_OK) {
+               ERR("Error on tracker add error handling.\n");
        }
+end:
+       lttng_tracker_ids_destroy(saved_ids);
+       return ret;
 }
 
-ssize_t kernel_list_tracker_pids(struct ltt_kernel_session *session,
-               int **_pids)
+int kernel_untrack_id(enum lttng_tracker_type tracker_type,
+               struct ltt_kernel_session *session,
+               const struct lttng_tracker_id *id)
 {
-       int fd, ret;
-       int pid;
-       ssize_t nbmem, count = 0;
-       FILE *fp;
-       int *pids;
+       int ret, value;
+       struct lttng_tracker_list *tracker_list;
+       struct lttng_tracker_ids *saved_ids;
 
-       fd = kernctl_list_tracker_pids(session->fd);
-       if (fd < 0) {
-               PERROR("kernel tracker pids list");
-               goto error;
+       ret = lttng_tracker_id_lookup_string(tracker_type, id, &value);
+       if (ret != LTTNG_OK) {
+               return ret;
        }
 
-       fp = fdopen(fd, "r");
-       if (fp == NULL) {
-               PERROR("kernel tracker pids list fdopen");
-               goto error_fp;
+       tracker_list = get_id_tracker_list(session, tracker_type);
+       if (!tracker_list) {
+               return LTTNG_ERR_INVALID;
        }
-
-       nbmem = KERNEL_TRACKER_PIDS_INIT_LIST_SIZE;
-       pids = zmalloc(sizeof(*pids) * nbmem);
-       if (pids == NULL) {
-               PERROR("alloc list pids");
-               count = -ENOMEM;
+       /* Save list for restore on error. */
+       ret = lttng_tracker_id_get_list(tracker_list, &saved_ids);
+       if (ret != LTTNG_OK) {
+               return LTTNG_ERR_INVALID;
+       }
+       /* Remove from list. */
+       ret = lttng_tracker_list_remove(tracker_list, id);
+       if (ret != LTTNG_OK) {
                goto end;
        }
 
-       while (fscanf(fp, "process { pid = %u; };\n", &pid) == 1) {
-               if (count >= nbmem) {
-                       int *new_pids;
-                       size_t new_nbmem;
-
-                       new_nbmem = nbmem << 1;
-                       DBG("Reallocating pids list from %zu to %zu entries",
-                                       nbmem, new_nbmem);
-                       new_pids = realloc(pids, new_nbmem * sizeof(*new_pids));
-                       if (new_pids == NULL) {
-                               PERROR("realloc list events");
-                               free(pids);
-                               count = -ENOMEM;
-                               goto end;
-                       }
-                       /* Zero the new memory */
-                       memset(new_pids + nbmem, 0,
-                               (new_nbmem - nbmem) * sizeof(*new_pids));
-                       nbmem = new_nbmem;
-                       pids = new_pids;
+       switch (tracker_type) {
+       case LTTNG_TRACKER_PID:
+               DBG("Kernel untrack PID %d for session id %" PRIu64 ".", value,
+                               session->id);
+               ret = kernctl_untrack_pid(session->fd, value);
+               if (!ret) {
+                       ret = LTTNG_OK;
+                       goto end;
+               }
+               break;
+       case LTTNG_TRACKER_VPID:
+               DBG("Kernel untrack VPID %d for session id %" PRIu64 ".", value,
+                               session->id);
+               ret = kernctl_untrack_id(
+                               session->fd, LTTNG_TRACKER_VPID, value);
+               if (!ret) {
+                       ret = LTTNG_OK;
+                       goto end;
+               }
+               break;
+       case LTTNG_TRACKER_UID:
+               DBG("Kernel untrack UID %d for session id %" PRIu64 ".", value,
+                               session->id);
+               ret = kernctl_untrack_id(session->fd, LTTNG_TRACKER_UID, value);
+               if (!ret) {
+                       ret = LTTNG_OK;
+                       goto end;
+               }
+               break;
+       case LTTNG_TRACKER_GID:
+               DBG("Kernel untrack GID %d for session id %" PRIu64 ".", value,
+                               session->id);
+               ret = kernctl_untrack_id(session->fd, LTTNG_TRACKER_GID, value);
+               if (!ret) {
+                       ret = LTTNG_OK;
+                       goto end;
                }
-               pids[count++] = pid;
+               break;
+       case LTTNG_TRACKER_VUID:
+               DBG("Kernel untrack VUID %d for session id %" PRIu64 ".", value,
+                               session->id);
+               ret = kernctl_untrack_id(
+                               session->fd, LTTNG_TRACKER_VUID, value);
+               if (!ret) {
+                       ret = LTTNG_OK;
+                       goto end;
+               }
+               break;
+       case LTTNG_TRACKER_VGID:
+               DBG("Kernel untrack VGID %d for session id %" PRIu64 ".", value,
+                               session->id);
+               ret = kernctl_untrack_id(
+                               session->fd, LTTNG_TRACKER_VGID, value);
+               if (!ret) {
+                       ret = LTTNG_OK;
+                       goto end;
+               }
+               break;
+       default:
+               ret = -EINVAL;
+               break;
        }
 
-       *_pids = pids;
-       DBG("Kernel list tracker pids done (%zd pids)", count);
+       /* Error handling. */
+       switch (-ret) {
+       case EINVAL:
+               ret = LTTNG_ERR_INVALID;
+               break;
+       case ENOMEM:
+               ret = LTTNG_ERR_NOMEM;
+               break;
+       case EEXIST:
+               ret = LTTNG_ERR_ID_TRACKED;
+               break;
+       default:
+               ret = LTTNG_ERR_UNK;
+               break;
+       }
+
+       if (lttng_tracker_id_set_list(tracker_list, saved_ids) != LTTNG_OK) {
+               ERR("Error on tracker remove error handling.\n");
+       }
 end:
-       ret = fclose(fp);       /* closes both fp and fd */
-       if (ret) {
-               PERROR("fclose");
+       lttng_tracker_ids_destroy(saved_ids);
+       return ret;
+}
+
+/*
+ * Called with session lock held.
+ */
+int kernel_list_tracker_ids(enum lttng_tracker_type tracker_type,
+               struct ltt_kernel_session *session,
+               struct lttng_tracker_ids **_ids)
+{
+       int ret = 0;
+       struct lttng_tracker_list *tracker_list;
+
+       tracker_list = get_id_tracker_list(session, tracker_type);
+       if (!tracker_list) {
+               ret = -LTTNG_ERR_INVALID;
+               goto end;
        }
-       return count;
 
-error_fp:
-       ret = close(fd);
-       if (ret) {
-               PERROR("close");
+       ret = lttng_tracker_id_get_list(tracker_list, _ids);
+       if (ret != LTTNG_OK) {
+               ret = -LTTNG_ERR_INVALID;
+               goto end;
        }
-error:
-       return -1;
+
+end:
+       return ret;
 }
 
 /*
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