return 0;
}
-int rename_process(const char name[]) {
- static size_t mm_size = 0;
- static char *mm = NULL;
- bool truncated = false;
- size_t l;
-
- /* This is a like a poor man's setproctitle(). It changes the comm field, argv[0], and also the glibc's
- * internally used name of the process. For the first one a limit of 16 chars applies; to the second one in
- * many cases one of 10 (i.e. length of "/sbin/init") — however if we have CAP_SYS_RESOURCES it is unbounded;
- * to the third one 7 (i.e. the length of "systemd". If you pass a longer string it will likely be
- * truncated.
- *
- * Returns 0 if a name was set but truncated, > 0 if it was set but not truncated. */
-
- if (isempty(name))
- return -EINVAL; /* let's not confuse users unnecessarily with an empty name */
-
- if (!is_main_thread())
- return -EPERM; /* Let's not allow setting the process name from other threads than the main one, as we
- * cache things without locking, and we make assumptions that PR_SET_NAME sets the
- * process name that isn't correct on any other threads */
-
- l = strlen(name);
-
- /* First step, change the comm field. The main thread's comm is identical to the process comm. This means we
- * can use PR_SET_NAME, which sets the thread name for the calling thread. */
- if (prctl(PR_SET_NAME, name) < 0)
- log_debug_errno(errno, "PR_SET_NAME failed: %m");
- if (l >= TASK_COMM_LEN) /* Linux userspace process names can be 15 chars at max */
- truncated = true;
-
- /* Second step, change glibc's ID of the process name. */
- if (program_invocation_name) {
- size_t k;
-
- k = strlen(program_invocation_name);
- strncpy(program_invocation_name, name, k);
- if (l > k)
- truncated = true;
- }
-
- /* Third step, completely replace the argv[] array the kernel maintains for us. This requires privileges, but
- * has the advantage that the argv[] array is exactly what we want it to be, and not filled up with zeros at
- * the end. This is the best option for changing /proc/self/cmdline. */
-
+static int update_argv(const char name[], size_t l) {
/* Let's not bother with this if we don't have euid == 0. Strictly speaking we should check for the
* CAP_SYS_RESOURCE capability which is independent of the euid. In our own code the capability generally is
* present only for euid == 0, hence let's use this as quick bypass check, to avoid calling mmap() if
* PR_SET_MM_ARG_{START,END} fails with EPERM later on anyway. After all geteuid() is dead cheap to call, but
* mmap() is not. */
if (geteuid() != 0)
- log_debug("Skipping PR_SET_MM, as we don't have privileges.");
- else if (mm_size < l+1) {
+ return log_debug_errno(SYNTHETIC_ERRNO(EPERM),
+ "Skipping PR_SET_MM, as we don't have privileges.");
+
+ static size_t mm_size = 0;
+ static char *mm = NULL;
+ int r;
+
+ if (mm_size < l+1) {
size_t nn_size;
char *nn;
nn_size = PAGE_ALIGN(l+1);
nn = mmap(NULL, nn_size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
- if (nn == MAP_FAILED) {
- log_debug_errno(errno, "mmap() failed: %m");
- goto use_saved_argv;
- }
+ if (nn == MAP_FAILED)
+ return log_debug_errno(errno, "mmap() failed: %m");
strncpy(nn, name, nn_size);
log_debug_errno(errno, "PR_SET_MM_ARG_START failed, attempting PR_SET_MM_ARG_END hack: %m");
if (prctl(PR_SET_MM, PR_SET_MM_ARG_END, (unsigned long) nn + l + 1, 0, 0) < 0) {
- log_debug_errno(errno, "PR_SET_MM_ARG_END hack failed, proceeding without: %m");
+ r = log_debug_errno(errno, "PR_SET_MM_ARG_END hack failed, proceeding without: %m");
(void) munmap(nn, nn_size);
- goto use_saved_argv;
+ return r;
}
- if (prctl(PR_SET_MM, PR_SET_MM_ARG_START, (unsigned long) nn, 0, 0) < 0) {
- log_debug_errno(errno, "PR_SET_MM_ARG_START still failed, proceeding without: %m");
- goto use_saved_argv;
- }
+ if (prctl(PR_SET_MM, PR_SET_MM_ARG_START, (unsigned long) nn, 0, 0) < 0)
+ return log_debug_errno(errno, "PR_SET_MM_ARG_START still failed, proceeding without: %m");
} else {
/* And update the end pointer to the new end, too. If this fails, we don't really know what
* to do, it's pretty unlikely that we can rollback, hence we'll just accept the failure,
log_debug_errno(errno, "PR_SET_MM_ARG_END failed, proceeding without: %m");
}
-use_saved_argv:
+ return 0;
+}
+
+int rename_process(const char name[]) {
+ bool truncated = false;
+
+ /* This is a like a poor man's setproctitle(). It changes the comm field, argv[0], and also the glibc's
+ * internally used name of the process. For the first one a limit of 16 chars applies; to the second one in
+ * many cases one of 10 (i.e. length of "/sbin/init") — however if we have CAP_SYS_RESOURCES it is unbounded;
+ * to the third one 7 (i.e. the length of "systemd". If you pass a longer string it will likely be
+ * truncated.
+ *
+ * Returns 0 if a name was set but truncated, > 0 if it was set but not truncated. */
+
+ if (isempty(name))
+ return -EINVAL; /* let's not confuse users unnecessarily with an empty name */
+
+ if (!is_main_thread())
+ return -EPERM; /* Let's not allow setting the process name from other threads than the main one, as we
+ * cache things without locking, and we make assumptions that PR_SET_NAME sets the
+ * process name that isn't correct on any other threads */
+
+ size_t l = strlen(name);
+
+ /* First step, change the comm field. The main thread's comm is identical to the process comm. This means we
+ * can use PR_SET_NAME, which sets the thread name for the calling thread. */
+ if (prctl(PR_SET_NAME, name) < 0)
+ log_debug_errno(errno, "PR_SET_NAME failed: %m");
+ if (l >= TASK_COMM_LEN) /* Linux userspace process names can be 15 chars at max */
+ truncated = true;
+
+ /* Second step, change glibc's ID of the process name. */
+ if (program_invocation_name) {
+ size_t k;
+
+ k = strlen(program_invocation_name);
+ strncpy(program_invocation_name, name, k);
+ if (l > k)
+ truncated = true;
+ }
+
+ /* Third step, completely replace the argv[] array the kernel maintains for us. This requires privileges, but
+ * has the advantage that the argv[] array is exactly what we want it to be, and not filled up with zeros at
+ * the end. This is the best option for changing /proc/self/cmdline. */
+ (void) update_argv(name, l);
+
/* Fourth step: in all cases we'll also update the original argv[], so that our own code gets it right too if
* it still looks here */
-
if (saved_argc > 0) {
- int i;
-
if (saved_argv[0]) {
size_t k;
truncated = true;
}
- for (i = 1; i < saved_argc; i++) {
+ for (int i = 1; i < saved_argc; i++) {
if (!saved_argv[i])
break;
projects / thirdparty / systemd.git / commitdiff
