Implement PID tracker content listing

[lttng-tools.git] / src / bin / lttng-sessiond / kernel.c

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index 4bb418949d3ea330b60397ed2352f5541c7fcbdc..59d86f45ae1b399866d8656228cedb9c49ce5a37 100644 (file)
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -381,6 +381,77 @@ int kernel_untrack_pid(struct ltt_kernel_session *session, int pid)
        return kernctl_untrack_pid(session->fd, pid);
 }
 
+ssize_t kernel_list_tracker_pids(struct ltt_kernel_session *session,
+               int **_pids)
+{
+       int fd, ret;
+       int pid;
+       ssize_t nbmem, count = 0;
+       FILE *fp;
+       int *pids;
+
+       fd = kernctl_list_tracker_pids(session->fd);
+       if (fd < 0) {
+               PERROR("kernel tracker pids list");
+               goto error;
+       }
+
+       fp = fdopen(fd, "r");
+       if (fp == NULL) {
+               PERROR("kernel tracker pids list fdopen");
+               goto error_fp;
+       }
+
+       nbmem = KERNEL_TRACKER_PIDS_INIT_LIST_SIZE;
+       pids = zmalloc(sizeof(*pids) * nbmem);
+       if (pids == NULL) {
+               PERROR("alloc list pids");
+               count = -ENOMEM;
+               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;
+               }
+               pids[count++] = pid;
+       }
+
+       *_pids = pids;
+       DBG("Kernel list tracker pids done (%zd pids)", count);
+end:
+       ret = fclose(fp);       /* closes both fp and fd */
+       if (ret) {
+               PERROR("fclose");
+       }
+       return count;
+
+error_fp:
+       ret = close(fd);
+       if (ret) {
+               PERROR("close");
+       }
+error:
+       return -1;
+}
+
 /*
  * Create kernel metadata, open from the kernel tracer and add it to the
  * kernel session.