diff options
| -rw-r--r-- | login-utils/last.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/login-utils/last.c b/login-utils/last.c index 5550dcb3f..e4a849776 100644 --- a/login-utils/last.c +++ b/login-utils/last.c @@ -31,6 +31,7 @@ #include <stdio.h> #include <ctype.h> #include <utmp.h> +#include <pwd.h> #include <stdlib.h> #include <unistd.h> #include <string.h> @@ -572,6 +573,26 @@ static void __attribute__((__noreturn__)) usage(FILE *out) exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS); } +static int is_phantom(struct utmp *ut) +{ + struct passwd *pw; + char path[32]; + FILE *f; + unsigned int loginuid, ret = 0; + + pw = getpwnam(ut->ut_name); + if (!pw) + return 1; + sprintf(path, "/proc/%u/loginuid", ut->ut_pid); + if (!(f = fopen(path, "r"))) + return 1; + if (fscanf(f, "%u", &loginuid) != 1) + ret = 1; + fclose(f); + if (!ret && pw->pw_uid != loginuid) + return 1; + return ret; +} static void process_wtmp_file(const struct last_control *ctl) { @@ -766,9 +787,7 @@ static void process_wtmp_file(const struct last_control *ctl) if (!lastboot) { c = R_NOW; /* Is process still alive? */ - if (ut.ut_pid > 0 && - kill(ut.ut_pid, 0) != 0 && - errno == ESRCH) + if (is_phantom(&ut)) c = R_PHANTOM; } else c = whydown; |