diff options
Diffstat (limited to 'sysdeps/unix/getlogin_r.c')
| -rw-r--r-- | sysdeps/unix/getlogin_r.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/sysdeps/unix/getlogin_r.c b/sysdeps/unix/getlogin_r.c index b50776859f..ba7badd054 100644 --- a/sysdeps/unix/getlogin_r.c +++ b/sysdeps/unix/getlogin_r.c @@ -25,6 +25,7 @@ #include <fcntl.h> #include <utmp.h> +#include "../login/utmp-private.h" /* Return at most NAME_LEN characters of the login name of the user in NAME. If it cannot be determined or some other error occurred, return the error @@ -37,7 +38,7 @@ getlogin_r (name, name_len) { char tty_pathname[2 + 2 * NAME_MAX]; char *real_tty_path = tty_pathname; - int result = 0; + int result; struct utmp *ut, line, buffer; /* Get name of tty connected to fd 0. Return if not a tty or @@ -56,10 +57,16 @@ getlogin_r (name, name_len) return result; real_tty_path += 5; /* Remove "/dev/". */ - - __setutent (); strncpy (line.ut_line, real_tty_path, sizeof line.ut_line); - if (__getutline_r (&line, &buffer, &ut) < 0) + + /* We don't use the normal entry points __setutent et al, because we + want setutent + getutline_r + endutent all to happen with the lock + held so that our search is thread-safe. */ + + __libc_lock_lock (__libc_utmp_lock); + (*__libc_utmp_jump_table->setutent) (); + result = (*__libc_utmp_jump_table->getutline_r) (&line, &buffer, &ut); + if (result < 0) { if (errno == ESRCH) /* The caller expects ENOENT if nothing is found. */ @@ -67,7 +74,11 @@ getlogin_r (name, name_len) else result = errno; } - else + (*__libc_utmp_jump_table->endutent) (); + __libc_utmp_jump_table = &__libc_utmp_unknown_functions; + __libc_lock_unlock (__libc_utmp_lock); + + if (result == 0) { size_t needed = strlen (ut->ut_user) + 1; @@ -82,7 +93,6 @@ getlogin_r (name, name_len) result = 0; } } - __endutent (); return result; } |