missing: define kernel internal limit TASK_COMM_LEN in userspace too

We already use it at two places, and we are about to add one too.
Arbitrary literally hardcoded limits suck.
This commit is contained in:
Lennart Poettering 2018-06-01 21:43:43 +02:00
parent e225e5c3c6
commit 92f14395cd
3 changed files with 9 additions and 2 deletions

View File

@ -1407,4 +1407,11 @@ struct statx {
#define AT_STATX_DONT_SYNC 0x4000
#endif
/* The maximum thread/process name length including trailing NUL byte. This mimics the kernel definition of the same
* name, which we need in userspace at various places but is not defined in userspace currently, neither under this
* name nor any other. */
#ifndef TASK_COMM_LEN
#define TASK_COMM_LEN 16
#endif
#include "missing_syscall.h"

View File

@ -296,7 +296,7 @@ int rename_process(const char name[]) {
* 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 > 15) /* Linux process names can be 15 chars at max */
if (l >= TASK_COMM_LEN) /* Linux process names can be 15 chars at max */
truncated = true;
/* Second step, change glibc's ID of the process name. */

View File

@ -366,7 +366,7 @@ static void test_rename_process_now(const char *p, int ret) {
assert_se(get_process_comm(0, &comm) >= 0);
log_info("comm = <%s>", comm);
assert_se(strneq(comm, p, 15));
assert_se(strneq(comm, p, TASK_COMM_LEN-1));
assert_se(get_process_cmdline(0, 0, false, &cmdline) >= 0);
/* we cannot expect cmdline to be renamed properly without privileges */