diff --git a/qmeventd/qmeventd.c b/qmeventd/qmeventd.c index a843da5f..921c0dca 100644 --- a/qmeventd/qmeventd.c +++ b/qmeventd/qmeventd.c @@ -75,14 +75,13 @@ get_pid_from_fd(int fd) } /* - * reads the vmid from /proc//cmdline - * after the '-id' argument + * parses the vmid from the qemu.slice entry of /proc//cgroup */ static unsigned long get_vmid_from_pid(pid_t pid) { char filename[32] = { 0 }; - int len = snprintf(filename, sizeof(filename), "/proc/%d/cmdline", pid); + int len = snprintf(filename, sizeof(filename), "/proc/%d/cgroup", pid); if (len < 0) { fprintf(stderr, "error during snprintf for %d: %s\n", pid, strerror(errno)); @@ -99,41 +98,52 @@ get_vmid_from_pid(pid_t pid) } unsigned long vmid = 0; - ssize_t rc = 0; char *buf = NULL; size_t buflen = 0; - while ((rc = getdelim(&buf, &buflen, '\0', fp)) >= 0) { - if (!strcmp(buf, "-id")) { - break; + + while (getline(&buf, &buflen, fp) >= 0) { + char *cgroup_path = strrchr(buf, ':'); + if (!cgroup_path) { + fprintf(stderr, "unexpected cgroup entry %s\n", buf); + goto ret; } - } + cgroup_path++; - if (rc < 0) { - goto err; - } + if (strncmp(cgroup_path, "/qemu.slice", 11)) { + continue; + } - if (getdelim(&buf, &buflen, '\0', fp) >= 0) { - if (buf[0] == '-' || buf[0] == '\0') { - fprintf(stderr, "invalid vmid %s\n", buf); + char *vmid_start = strrchr(buf, '/'); + if (!vmid_start) { + fprintf(stderr, "unexpected cgroup entry %s\n", buf); + goto ret; + } + vmid_start++; + + if (vmid_start[0] == '-' || vmid_start[0] == '\0') { + fprintf(stderr, "invalid vmid in cgroup entry %s\n", buf); goto ret; } errno = 0; char *endptr = NULL; - vmid = strtoul(buf, &endptr, 10); + vmid = strtoul(vmid_start, &endptr, 10); if (errno != 0) { + fprintf(stderr, "error parsing vmid for %d: %s\n", pid, strerror(errno)); vmid = 0; - goto err; - } else if (*endptr != '\0') { - fprintf(stderr, "invalid vmid %s\n", buf); + } else if (*endptr != '.') { + fprintf(stderr, "unexpected cgroup entry %s\n", buf); vmid = 0; } goto ret; } -err: - fprintf(stderr, "error parsing vmid for %d: %s\n", pid, strerror(errno)); + if (errno) { + fprintf(stderr, "error parsing vmid for %d: %s\n", pid, strerror(errno)); + } else { + fprintf(stderr, "error parsing vmid for %d: no qemu.slice cgroup entry\n", pid); + } ret: free(buf);