diff options
Diffstat (limited to 'login/utmp_file.c')
| -rw-r--r-- | login/utmp_file.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/login/utmp_file.c b/login/utmp_file.c index c0bd229952..9033f72a4e 100644 --- a/login/utmp_file.c +++ b/login/utmp_file.c @@ -22,6 +22,7 @@ #include <errno.h> #include <fcntl.h> #include <signal.h> +#include <stdbool.h> #include <stdio.h> #include <string.h> #include <unistd.h> @@ -244,12 +245,16 @@ getutent_r_file (struct utmp *buffer, struct utmp **result) static int -internal_getut_r (const struct utmp *id, struct utmp *buffer) +internal_getut_r (const struct utmp *id, struct utmp *buffer, + bool *lock_failed) { int result = -1; LOCK_FILE (file_fd, F_RDLCK) - LOCKING_FAILED (); + { + *lock_failed = true; + LOCKING_FAILED (); + } #if _HAVE_UT_TYPE - 0 if (id->ut_type == RUN_LVL || id->ut_type == BOOT_TIME @@ -320,7 +325,10 @@ getutid_r_file (const struct utmp *id, struct utmp *buffer, return -1; } - if (internal_getut_r (id, &last_entry) < 0) + /* We don't have to distinguish whether we can lock the file or + whether there is no entry. */ + bool lock_failed = false; + if (internal_getut_r (id, &last_entry, &lock_failed) < 0) { *result = NULL; return -1; @@ -410,7 +418,16 @@ pututline_file (const struct utmp *data) __utmp_equal (&last_entry, data))) found = 1; else - found = internal_getut_r (data, &buffer); + { + bool lock_failed = false; + found = internal_getut_r (data, &buffer, &lock_failed); + + if (__builtin_expect (lock_failed, false)) + { + __set_errno (EAGAIN); + return NULL; + } + } LOCK_FILE (file_fd, F_WRLCK) { |