X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?p=xscreensaver;a=blobdiff_plain;f=driver%2Fsubprocs.c;h=88270d6ca0ad448ba55f374d1110faa3fb02ed5c;hp=4d8332a6c0a4f777d4b4328bdfce7e3f8be27faa;hb=6b1c86cf395f59389e4ece4ea8f4bea2c332745b;hpb=258170f6204e23da06f272ffda1f4504b6ae2eaf diff --git a/driver/subprocs.c b/driver/subprocs.c index 4d8332a6..88270d6c 100644 --- a/driver/subprocs.c +++ b/driver/subprocs.c @@ -1,4 +1,5 @@ -/* xscreensaver, Copyright (c) 1991-1993 Jamie Zawinski +/* subprocs.c --- choosing, spawning, and killing screenhacks. + * xscreensaver, Copyright (c) 1991-2008 Jamie Zawinski * * Permission to use, copy, modify, distribute, and sell this software and its * documentation for any purpose is hereby granted without fee, provided that @@ -9,579 +10,1348 @@ * implied warranty. */ -#if __STDC__ -#include -#include -#include +#ifdef HAVE_CONFIG_H +# include "config.h" #endif +#include #include +#include #include /* not used for much... */ #ifndef ESRCH -#include +# include #endif #include /* sys/resource.h needs this for timeval */ -#include /* for setpriority() and PRIO_PROCESS */ -#include /* for waitpid() and associated macros */ -#include /* for the signal names */ +#include /* for PATH_MAX */ -extern char **environ; /* why isn't this in some header file? */ +#ifdef HAVE_SYS_WAIT_H +# include /* for waitpid() and associated macros */ +#endif -#ifndef NO_SETUID -#include /* for getpwnam() and struct passwd */ -#include /* for getgrgid() and struct group */ -#endif /* NO_SETUID */ +#ifdef HAVE_SETRLIMIT +# include /* for setrlimit() and RLIMIT_AS */ +#endif + +#ifdef VMS +# include +# include /* for close */ +# include /* for getpid */ +# define pid_t int +# define fork vfork +#endif /* VMS */ + +#include /* for the signal names */ #if !defined(SIGCHLD) && defined(SIGCLD) -#define SIGCHLD SIGCLD +# define SIGCHLD SIGCLD #endif -#if __STDC__ +#if 0 /* putenv() is declared in stdlib.h on modern linux systems. */ +#ifdef HAVE_PUTENV extern int putenv (/* const char * */); /* getenv() is in stdlib.h... */ -extern int kill (pid_t, int); /* signal() is in sys/signal.h... */ +#endif #endif -# if defined(SVR4) || defined(SYSV) -# undef PRIO_PROCESS -# define random() rand() -# else /* !totally-losing-SYSV */ -extern long random(); /* rand() is in stdlib.h... */ -# endif /* !totally-losing-SYSV */ +extern int kill (pid_t, int); /* signal() is in sys/signal.h... */ +/* This file doesn't need the Xt headers, so stub these types out... */ +#undef XtPointer +#define XtAppContext void* +#define XrmDatabase void* +#define XtIntervalId void* +#define XtPointer void* +#define Widget void* #include "xscreensaver.h" +#include "exec.h" +#include "yarandom.h" +#include "visual.h" /* for id_to_visual() */ -/* this must be `sh', not whatever $SHELL happens to be. */ -char *shell; -static pid_t pid = 0; -char **screenhacks; -int screenhacks_count; -int current_hack = -1; -char *demo_hack; -int next_mode_p = 0; -Bool locking_disabled_p = False; -char *nolock_reason = 0; -int nice_inferior = 0; +extern saver_info *global_si_kludge; /* I hate C so much... */ -extern Bool demo_mode_p; -static void -exec_screenhack (command) - char *command; +/* Used when printing error/debugging messages from signal handlers. + */ +static const char * +no_malloc_number_to_string (long num) { - char *tmp; - char buf [512]; - char *av [5]; - int ac = 0; + static char string[128] = ""; + int num_digits; + Bool negative_p = False; - /* Close this fork's version of the display's fd. It will open its own. */ - close (ConnectionNumber (dpy)); - - /* I don't believe what a sorry excuse for an operating system UNIX is! + num_digits = 0; - - I want to spawn a process. - - I want to know it's pid so that I can kill it. - - I would like to receive a message when it dies of natural causes. - - I want the spawned process to have user-specified arguments. + if (num == 0) + return "0"; - The *only way* to parse arguments the way the shells do is to run a - shell (or duplicate what they do, which would be a *lot* of code.) + if (num < 0) + { + negative_p = True; + num = -num; + } - The *only way* to know the pid of the process is to fork() and exec() - it in the spawned side of the fork. + while ((num > 0) && (num_digits < sizeof(string) - 1)) + { + int digit; + digit = (int) num % 10; + num_digits++; + string[sizeof(string) - 1 - num_digits] = digit + '0'; + num /= 10; + } - But if you're running a shell to parse your arguments, this gives you - the pid of the SHELL, not the pid of the PROCESS that you're actually - interested in, which is an *inferior* of the shell. This also means - that the SIGCHLD you get applies to the shell, not its inferior. + if (negative_p) + { + num_digits++; + string[sizeof(string) - 1 - num_digits] = '-'; + } - So, the only solution other than implementing an argument parser here - is to force the shell to exec() its inferior. What a fucking hack! - We prepend "exec " to the command string. - */ - tmp = command; - command = (char *) malloc (strlen (tmp) + 6); - memcpy (command, "exec ", 5); - memcpy (command + 5, tmp, strlen (tmp) + 1); - - /* Invoke the shell as "/bin/sh -c 'exec prog -arg -arg ...'" */ - av [ac++] = shell; - av [ac++] = "-c"; - av [ac++] = command; - av [ac++] = 0; - - if (verbose_p) - printf ("%s: spawning \"%s\" in pid %d.\n", progname, command, getpid ()); + return string + sizeof(string) - 1 - num_digits; +} -#if defined(SYSV) || defined(__hpux) - { - int old_nice = nice (0); - int n = nice_inferior - old_nice; - errno = 0; - if (nice (n) == -1 && errno != 0) - { - sprintf (buf, "%s: %snice(%d) failed", progname, - (verbose_p ? "## " : ""), n); - perror (buf); - } - } -#else /* !SYSV */ -#ifdef PRIO_PROCESS - if (setpriority (PRIO_PROCESS, getpid(), nice_inferior) != 0) +/* Like write(), but runs strlen() on the arg to get the length. */ +static int +write_string (int fd, const char *str) +{ + return write (fd, str, strlen (str)); +} + +static int +write_long (int fd, long n) +{ + const char *str = no_malloc_number_to_string (n); + return write_string (fd, str); +} + + +/* RLIMIT_AS (called RLIMIT_VMEM on some systems) controls the maximum size + of a process's address space, i.e., the maximal brk(2) and mmap(2) values. + Setting this lets you put a cap on how much memory a process can allocate. + + Except the "and mmap()" part kinda makes this useless, since many GL + implementations end up using mmap() to pull the whole frame buffer into + memory (or something along those lines) making it appear processes are + using hundreds of megabytes when in fact they're using very little, and + we end up capping their mallocs prematurely. YAY! + */ +#if defined(RLIMIT_VMEM) && !defined(RLIMIT_AS) +# define RLIMIT_AS RLIMIT_VMEM +#endif + +static void +limit_subproc_memory (int address_space_limit, Bool verbose_p) +{ + +/* This has caused way more problems than it has solved... + Let's just completely ignore the "memoryLimit" option now. + */ +#undef HAVE_SETRLIMIT + +#if defined(HAVE_SETRLIMIT) && defined(RLIMIT_AS) + struct rlimit r; + + if (address_space_limit < 10 * 1024) /* let's not be crazy */ + return; + + if (getrlimit (RLIMIT_AS, &r) != 0) { - sprintf (buf, "%s: %ssetpriority(PRIO_PROCESS, %d, %d) failed", - progname, (verbose_p ? "## " : ""), getpid(), nice_inferior); + char buf [512]; + sprintf (buf, "%s: getrlimit(RLIMIT_AS) failed", blurb()); perror (buf); + return; } -#else /* !PRIO_PROCESS */ - if (nice_inferior != 0) - fprintf (stderr, - "%s: %sdon't know how to change process priority on this system.\n", - progname, (verbose_p ? "## " : "")); -#endif /* !PRIO_PROCESS */ -#endif /* !SYSV */ - /* Now overlay the current process with /bin/sh running the command. - If this returns, it's an error. - */ - execve (av [0], av, environ); + r.rlim_cur = address_space_limit; - sprintf (buf, "%s: %sexecve() failed", progname, (verbose_p ? "## " : "")); - perror (buf); - exit (1); /* Note this this only exits a child fork. */ + if (setrlimit (RLIMIT_AS, &r) != 0) + { + char buf [512]; + sprintf (buf, "%s: setrlimit(RLIMIT_AS, {%lu, %lu}) failed", + blurb(), r.rlim_cur, r.rlim_max); + perror (buf); + return; + } + + if (verbose_p) + { + int i = address_space_limit; + char buf[100]; + if (i >= (1<<30) && i == ((i >> 30) << 30)) + sprintf(buf, "%dG", i >> 30); + else if (i >= (1<<20) && i == ((i >> 20) << 20)) + sprintf(buf, "%dM", i >> 20); + else if (i >= (1<<10) && i == ((i >> 10) << 10)) + sprintf(buf, "%dK", i >> 10); + else + sprintf(buf, "%d bytes", i); + + fprintf (stderr, "%s: limited pid %lu address space to %s.\n", + blurb(), (unsigned long) getpid (), buf); + } + +#endif /* HAVE_SETRLIMIT && RLIMIT_AS */ } -/* to avoid a race between the main thread and the SIGCHLD handler */ -static int killing = 0; -static Bool suspending = False; + +/* Management of child processes, and de-zombification. + */ + +enum job_status { + job_running, /* the process is still alive */ + job_stopped, /* we have sent it a STOP signal */ + job_killed, /* we have sent it a TERM signal */ + job_dead /* we have wait()ed for it, and it's dead -- this state only + occurs so that we can avoid calling free() from a signal + handler. Shortly after going into this state, the list + element will be removed. */ +}; + +struct screenhack_job { + char *name; + pid_t pid; + int screen; + enum job_status status; + struct screenhack_job *next; +}; + +static struct screenhack_job *jobs = 0; + +/* for debugging -- nothing calls this, but it's useful to invoke from gdb. + */ +void show_job_list (void); + +void +show_job_list (void) +{ + struct screenhack_job *job; + fprintf(stderr, "%s: job list:\n", blurb()); + for (job = jobs; job; job = job->next) + fprintf (stderr, " %5ld: %2d: (%s) %s\n", + (long) job->pid, + job->screen, + (job->status == job_running ? "running" : + job->status == job_stopped ? "stopped" : + job->status == job_killed ? " killed" : + job->status == job_dead ? " dead" : " ???"), + job->name); + fprintf (stderr, "\n"); +} + + +static void clean_job_list (void); + +static struct screenhack_job * +make_job (pid_t pid, int screen, const char *cmd) +{ + struct screenhack_job *job = (struct screenhack_job *) malloc (sizeof(*job)); + + static char name [1024]; + const char *in = cmd; + char *out = name; + int got_eq = 0; + int first = 1; + + clean_job_list(); + + AGAIN: + while (isspace(*in)) in++; /* skip whitespace */ + while (!isspace(*in) && *in != ':') { + if (*in == '=') got_eq = 1; + *out++ = *in++; /* snarf first token */ + } + + if (got_eq) /* if the first token was FOO=bar */ + { /* then get the next token instead. */ + got_eq = 0; + out = name; + first = 0; + goto AGAIN; + } + + while (isspace(*in)) in++; /* skip whitespace */ + *out = 0; + + job->name = strdup(name); + job->pid = pid; + job->screen = screen; + job->status = job_running; + job->next = jobs; + jobs = job; + + return jobs; +} -static char *current_hack_name P((void)); static void -await_child_death (killed) - Bool killed; +free_job (struct screenhack_job *job) { - Bool suspended_p = False; - int status; - pid_t kid; - killing = 1; - if (! pid) + if (!job) return; - - do + else if (job == jobs) + jobs = jobs->next; + else { - kid = waitpid (pid, &status, WUNTRACED); + struct screenhack_job *job2, *prev; + for (prev = 0, job2 = jobs; + job2; + prev = job2, job2 = job2->next) + if (job2 == job) + { + prev->next = job->next; + break; + } } - while (kid == -1 && errno == EINTR); + free(job->name); + free(job); +} - if (kid == pid) + +/* Cleans out dead jobs from the jobs list -- this must only be called + from the main thread, not from a signal handler. + */ +static void +clean_job_list (void) +{ + struct screenhack_job *job, *prev, *next; + for (prev = 0, job = jobs, next = (job ? job->next : 0); + job; + prev = job, job = next, next = (job ? job->next : 0)) { - if (WIFEXITED (status)) - { - int exit_status = WEXITSTATUS (status); - if (exit_status & 0x80) - exit_status |= ~0xFF; - if (exit_status != 0 && verbose_p) - printf ("%s: child pid %d (%s) exited abnormally (code %d).\n", - progname, pid, current_hack_name (), exit_status); - else if (verbose_p) - printf ("%s: child pid %d (%s) exited normally.\n", - progname, pid, current_hack_name ()); - } - else if (WIFSIGNALED (status)) + if (job->status == job_dead) { - if (!killed || WTERMSIG (status) != SIGTERM) - fprintf (stderr, - "%s: %schild pid %d (%s) terminated with signal %d!\n", - progname, (verbose_p ? "## " : ""), - pid, current_hack_name (), WTERMSIG (status)); - else if (verbose_p) - printf ("%s: child pid %d (%s) terminated with SIGTERM.\n", - progname, pid, current_hack_name ()); + if (prev) + prev->next = next; + free_job (job); + job = prev; } - else if (suspending) - { - suspended_p = True; - suspending = False; /* complain if it happens twice */ - } - else if (WIFSTOPPED (status)) + } +} + + +static struct screenhack_job * +find_job (pid_t pid) +{ + struct screenhack_job *job; + for (job = jobs; job; job = job->next) + if (job->pid == pid) + return job; + return 0; +} + +static void await_dying_children (saver_info *si); +#ifndef VMS +static void describe_dead_child (saver_info *, pid_t, int wait_status); +#endif + + +/* Semaphore to temporarily turn the SIGCHLD handler into a no-op. + Don't alter this directly -- use block_sigchld() / unblock_sigchld(). + */ +static int block_sigchld_handler = 0; + + +#ifdef HAVE_SIGACTION + sigset_t +#else /* !HAVE_SIGACTION */ + int +#endif /* !HAVE_SIGACTION */ +block_sigchld (void) +{ +#ifdef HAVE_SIGACTION + struct sigaction sa; + sigset_t child_set; + + memset (&sa, 0, sizeof (sa)); + sa.sa_handler = SIG_IGN; + sigaction (SIGPIPE, &sa, NULL); + + sigemptyset (&child_set); + sigaddset (&child_set, SIGCHLD); + sigprocmask (SIG_BLOCK, &child_set, 0); + +#else /* !HAVE_SIGACTION */ + signal (SIGPIPE, SIG_IGN); +#endif /* !HAVE_SIGACTION */ + + block_sigchld_handler++; + +#ifdef HAVE_SIGACTION + return child_set; +#else /* !HAVE_SIGACTION */ + return 0; +#endif /* !HAVE_SIGACTION */ +} + +void +unblock_sigchld (void) +{ +#ifdef HAVE_SIGACTION + struct sigaction sa; + sigset_t child_set; + + memset(&sa, 0, sizeof (sa)); + sa.sa_handler = SIG_DFL; + sigaction(SIGPIPE, &sa, NULL); + + sigemptyset(&child_set); + sigaddset(&child_set, SIGCHLD); + sigprocmask(SIG_UNBLOCK, &child_set, 0); + +#else /* !HAVE_SIGACTION */ + signal(SIGPIPE, SIG_DFL); +#endif /* !HAVE_SIGACTION */ + + block_sigchld_handler--; +} + +static int +kill_job (saver_info *si, pid_t pid, int signal) +{ + saver_preferences *p = &si->prefs; + struct screenhack_job *job; + int status = -1; + + clean_job_list(); + + if (block_sigchld_handler) + /* This function should not be called from the signal handler. */ + abort(); + + block_sigchld(); /* we control the horizontal... */ + + job = find_job (pid); + if (!job || + !job->pid || + job->status == job_killed) + { + if (p->verbose_p) + fprintf (stderr, "%s: no child %ld to signal!\n", + blurb(), (long) pid); + goto DONE; + } + + switch (signal) { + case SIGTERM: job->status = job_killed; break; +#ifdef SIGSTOP + /* #### there must be a way to do this on VMS... */ + case SIGSTOP: job->status = job_stopped; break; + case SIGCONT: job->status = job_running; break; +#endif /* SIGSTOP */ + default: abort(); + } + + if (p->verbose_p) + fprintf (stderr, "%s: %d: %s pid %lu (%s)\n", + blurb(), job->screen, + (job->status == job_killed ? "killing" : + job->status == job_stopped ? "suspending" : "resuming"), + (unsigned long) job->pid, + job->name); + + status = kill (job->pid, signal); + + if (p->verbose_p && status < 0) + { + if (errno == ESRCH) + fprintf (stderr, + "%s: %d: child process %lu (%s) was already dead.\n", + blurb(), job->screen, (unsigned long) job->pid, job->name); + else { - suspended_p = True; - fprintf (stderr, "%s: %schild pid %d (%s) stopped with signal %d!\n", - progname, (verbose_p ? "## " : ""), pid, - current_hack_name (), WSTOPSIG (status)); + char buf [1024]; + sprintf (buf, "%s: %d: couldn't kill child process %lu (%s)", + blurb(), job->screen, (unsigned long) job->pid, job->name); + perror (buf); } + } + + await_dying_children (si); + + DONE: + unblock_sigchld(); + if (block_sigchld_handler < 0) + abort(); + + clean_job_list(); + return status; +} + + +#ifdef SIGCHLD +static RETSIGTYPE +sigchld_handler (int sig) +{ + saver_info *si = global_si_kludge; /* I hate C so much... */ + + if (si->prefs.debug_p) + { + /* Don't call fprintf() from signal handlers, as it might malloc. + fprintf(stderr, "%s: got SIGCHLD%s\n", blurb(), + (block_sigchld_handler ? " (blocked)" : "")); + */ + write_string (STDERR_FILENO, blurb()); + write_string (STDERR_FILENO, ": got SIGCHLD"); + + if (block_sigchld_handler) + write_string (STDERR_FILENO, " (blocked)\n"); else - fprintf (stderr, "%s: %schild pid %d (%s) died in a mysterious way!", - progname, (verbose_p ? "## " : ""), pid, current_hack_name()); + write_string (STDERR_FILENO, "\n"); } - else if (kid <= 0) - fprintf (stderr, "%s: %swaitpid(%d, ...) says there are no kids? (%d)\n", - progname, (verbose_p ? "## " : ""), pid, kid); - else - fprintf (stderr, "%s: %swaitpid(%d, ...) says proc %d died, not %d?\n", - progname, (verbose_p ? "## " : ""), pid, kid, pid); - killing = 0; - if (suspended_p != True) - pid = 0; + + if (block_sigchld_handler < 0) + abort(); + else if (block_sigchld_handler == 0) + { + block_sigchld(); + await_dying_children (si); + unblock_sigchld(); + } + + init_sigchld(); } +#endif /* SIGCHLD */ + + +#ifndef VMS -static char * -current_hack_name () +static void +await_dying_children (saver_info *si) { - static char chn [1024]; - char *hack = (demo_mode_p ? demo_hack : screenhacks [current_hack]); - int i; - for (i = 0; hack [i] != 0 && hack [i] != ' ' && hack [i] != '\t'; i++) - chn [i] = hack [i]; - chn [i] = 0; - return chn; + while (1) + { + int wait_status = 0; + pid_t kid; + + errno = 0; + kid = waitpid (-1, &wait_status, WNOHANG|WUNTRACED); + + if (si->prefs.debug_p) + { + if (kid < 0 && errno) + { + /* Don't call fprintf() from signal handlers, as it might malloc. + fprintf (stderr, "%s: waitpid(-1) ==> %ld (%d)\n", blurb(), + (long) kid, errno); + */ + write_string (STDERR_FILENO, blurb()); + write_string (STDERR_FILENO, ": waitpid(-1) ==> "); + write_long (STDERR_FILENO, (long) kid); + write_string (STDERR_FILENO, " ("); + write_long (STDERR_FILENO, (long) errno); + write_string (STDERR_FILENO, ")\n"); + } + else + { + /* Don't call fprintf() from signal handlers, as it might malloc. + fprintf (stderr, "%s: waitpid(-1) ==> %ld\n", blurb(), + (long) kid); + */ + write_string (STDERR_FILENO, blurb()); + write_string (STDERR_FILENO, ": waitpid(-1) ==> "); + write_long (STDERR_FILENO, (long) kid); + write_string (STDERR_FILENO, "\n"); + } + } + + /* 0 means no more children to reap. + -1 means error -- except "interrupted system call" isn't a "real" + error, so if we get that, we should just try again. */ + if (kid == 0 || + (kid < 0 && errno != EINTR)) + break; + + describe_dead_child (si, kid, wait_status); + } } -#ifdef SIGCHLD + static void -sigchld_handler (sig) - int sig; +describe_dead_child (saver_info *si, pid_t kid, int wait_status) { - if (killing) - return; - if (! pid) - abort (); - await_child_death (False); + int i; + saver_preferences *p = &si->prefs; + struct screenhack_job *job = find_job (kid); + const char *name = job ? job->name : ""; + int screen_no = job ? job->screen : 0; + + if (WIFEXITED (wait_status)) + { + int exit_status = WEXITSTATUS (wait_status); + + /* Treat exit code as a signed 8-bit quantity. */ + if (exit_status & 0x80) exit_status |= ~0xFF; + + /* One might assume that exiting with non-0 means something went wrong. + But that loser xswarm exits with the code that it was killed with, so + it *always* exits abnormally. Treat abnormal exits as "normal" (don't + mention them) if we've just killed the subprocess. But mention them + if they happen on their own. + */ + if (!job || + (exit_status != 0 && + (p->verbose_p || job->status != job_killed))) + { + /* Don't call fprintf() from signal handlers, as it might malloc. + fprintf (stderr, + "%s: %d: child pid %lu (%s) exited abnormally (code %d).\n", + blurb(), screen_no, (unsigned long) kid, name, exit_status); + */ + write_string (STDERR_FILENO, blurb()); + write_string (STDERR_FILENO, ": "); + write_long (STDERR_FILENO, (long) screen_no); + write_string (STDERR_FILENO, ": child pid "); + write_long (STDERR_FILENO, (long) kid); + write_string (STDERR_FILENO, " ("); + write_string (STDERR_FILENO, name); + write_string (STDERR_FILENO, ") exited abnormally (code "); + write_long (STDERR_FILENO, (long) exit_status); + write_string (STDERR_FILENO, ").\n"); + } + else if (p->verbose_p) + { + /* Don't call fprintf() from signal handlers, as it might malloc. + fprintf (stderr, "%s: %d: child pid %lu (%s) exited normally.\n", + blurb(), screen_no, (unsigned long) kid, name); + */ + write_string (STDERR_FILENO, blurb()); + write_string (STDERR_FILENO, ": "); + write_long (STDERR_FILENO, (long) screen_no); + write_string (STDERR_FILENO, ": child pid "); + write_long (STDERR_FILENO, (long) kid); + write_string (STDERR_FILENO, " ("); + write_string (STDERR_FILENO, name); + write_string (STDERR_FILENO, ") exited normally.\n"); + } + + if (job) + job->status = job_dead; + } + else if (WIFSIGNALED (wait_status)) + { + if (p->verbose_p || + !job || + job->status != job_killed || + WTERMSIG (wait_status) != SIGTERM) + { + /* Don't call fprintf() from signal handlers, as it might malloc. + fprintf (stderr, "%s: %d: child pid %lu (%s) terminated with %s.\n", + blurb(), screen_no, (unsigned long) kid, name, + signal_name (WTERMSIG(wait_status))); + */ + write_string (STDERR_FILENO, blurb()); + write_string (STDERR_FILENO, ": "); + write_long (STDERR_FILENO, (long) screen_no); + write_string (STDERR_FILENO, ": child pid "); + write_long (STDERR_FILENO, (long) kid); + write_string (STDERR_FILENO, " ("); + write_string (STDERR_FILENO, name); + write_string (STDERR_FILENO, ") terminated with signal "); + write_long (STDERR_FILENO, WTERMSIG(wait_status)); + write_string (STDERR_FILENO, ".\n"); + } + + if (job) + job->status = job_dead; + } + else if (WIFSTOPPED (wait_status)) + { + if (p->verbose_p) + { + /* Don't call fprintf() from signal handlers, as it might malloc. + fprintf (stderr, "%s: child pid %lu (%s) stopped with %s.\n", + blurb(), (unsigned long) kid, name, + signal_name (WSTOPSIG (wait_status))); + */ + write_string (STDERR_FILENO, blurb()); + write_string (STDERR_FILENO, ": "); + write_long (STDERR_FILENO, (long) screen_no); + write_string (STDERR_FILENO, ": child pid "); + write_long (STDERR_FILENO, (long) kid); + write_string (STDERR_FILENO, " ("); + write_string (STDERR_FILENO, name); + write_string (STDERR_FILENO, ") stopped with signal "); + write_long (STDERR_FILENO, WSTOPSIG(wait_status)); + write_string (STDERR_FILENO, ".\n"); + } + + if (job) + job->status = job_stopped; + } + else + { + /* Don't call fprintf() from signal handlers, as it might malloc. + fprintf (stderr, "%s: child pid %lu (%s) died in a mysterious way!", + blurb(), (unsigned long) kid, name); + */ + write_string (STDERR_FILENO, blurb()); + write_string (STDERR_FILENO, ": "); + write_long (STDERR_FILENO, (long) screen_no); + write_string (STDERR_FILENO, ": child pid "); + write_long (STDERR_FILENO, (long) kid); + write_string (STDERR_FILENO, " ("); + write_string (STDERR_FILENO, name); + write_string (STDERR_FILENO, ") died in a mysterious way!"); + if (job) + job->status = job_dead; + } + + /* Clear out the pid so that screenhack_running_p() knows it's dead. + */ + if (!job || job->status == job_dead) + for (i = 0; i < si->nscreens; i++) + { + saver_screen_info *ssi = &si->screens[i]; + if (kid == ssi->pid) + ssi->pid = 0; + } } -#endif + +#else /* VMS */ +static void await_dying_children (saver_info *si) { return; } +#endif /* VMS */ void -init_sigchld () +init_sigchld (void) { #ifdef SIGCHLD - if (((int) signal (SIGCHLD, sigchld_handler)) == -1) + +# ifdef HAVE_SIGACTION /* Thanks to Tom Kelly */ + + static Bool sigchld_initialized_p = 0; + if (!sigchld_initialized_p) + { + struct sigaction action, old; + + action.sa_handler = sigchld_handler; + sigemptyset(&action.sa_mask); + action.sa_flags = 0; + + if (sigaction(SIGCHLD, &action, &old) < 0) + { + char buf [255]; + sprintf (buf, "%s: couldn't catch SIGCHLD", blurb()); + perror (buf); + } + sigchld_initialized_p = True; + } + +# else /* !HAVE_SIGACTION */ + + if (((long) signal (SIGCHLD, sigchld_handler)) == -1L) { char buf [255]; - sprintf (buf, "%s: %scouldn't catch SIGCHLD", progname, - (verbose_p ? "## " : "")); + sprintf (buf, "%s: couldn't catch SIGCHLD", blurb()); perror (buf); } -#endif +# endif /* !HAVE_SIGACTION */ +#endif /* SIGCHLD */ } -extern void raise_window P((Bool inhibit_fade, Bool between_hacks_p)); -void -spawn_screenhack (first_time_p) - Bool first_time_p; + + +static Bool +select_visual_of_hack (saver_screen_info *ssi, screenhack *hack) +{ + saver_info *si = ssi->global; + saver_preferences *p = &si->prefs; + Bool selected; + + if (hack->visual && *hack->visual) + selected = select_visual(ssi, hack->visual); + else + selected = select_visual(ssi, 0); + + if (!selected && (p->verbose_p || si->demoing_p)) + fprintf (stderr, + (si->demoing_p + ? "%s: warning, no \"%s\" visual for \"%s\".\n" + : "%s: no \"%s\" visual; skipping \"%s\".\n"), + blurb(), + (hack->visual && *hack->visual ? hack->visual : "???"), + hack->command); + + return selected; +} + + +static void +print_path_error (const char *program) +{ + char buf [512]; + char *cmd = strdup (program); + char *token = strchr (cmd, ' '); + + if (token) *token = 0; + sprintf (buf, "%s: could not execute \"%.100s\"", blurb(), cmd); + free (cmd); + perror (buf); + + if (errno == ENOENT && + (token = getenv("PATH"))) + { +# ifndef PATH_MAX +# ifdef MAXPATHLEN +# define PATH_MAX MAXPATHLEN +# else +# define PATH_MAX 2048 +# endif +# endif + char path[PATH_MAX]; + fprintf (stderr, "\n"); + *path = 0; +# if defined(HAVE_GETCWD) + if (! getcwd (path, sizeof(path))) + *path = 0; +# elif defined(HAVE_GETWD) + getwd (path); +# endif + if (*path) + fprintf (stderr, " Current directory is: %s\n", path); + fprintf (stderr, " PATH is:\n"); + token = strtok (strdup(token), ":"); + while (token) + { + fprintf (stderr, " %s\n", token); + token = strtok(0, ":"); + } + fprintf (stderr, "\n"); + } +} + + +/* Executes the command in another process. + Command may be any single command acceptable to /bin/sh. + It may include wildcards, but no semicolons. + If successful, the pid of the other process is returned. + Otherwise, -1 is returned and an error may have been + printed to stderr. + */ +pid_t +fork_and_exec (saver_screen_info *ssi, const char *command) +{ + saver_info *si = ssi->global; + saver_preferences *p = &si->prefs; + pid_t forked; + + switch ((int) (forked = fork ())) + { + case -1: + { + char buf [255]; + sprintf (buf, "%s: couldn't fork", blurb()); + perror (buf); + break; + } + + case 0: + close (ConnectionNumber (si->dpy)); /* close display fd */ + limit_subproc_memory (p->inferior_memory_limit, p->verbose_p); + hack_subproc_environment (ssi); /* set $DISPLAY */ + + if (p->verbose_p) + fprintf (stderr, "%s: %d: spawning \"%s\" in pid %lu.\n", + blurb(), ssi->number, command, + (unsigned long) getpid ()); + + exec_command (p->shell, command, p->nice_inferior); + + /* If that returned, we were unable to exec the subprocess. + Print an error message, if desired. + */ + if (! p->ignore_uninstalled_p) + print_path_error (command); + + exit (1); /* exits child fork */ + break; + + default: /* parent */ + (void) make_job (forked, ssi->number, command); + break; + } + + return forked; +} + + +static void +spawn_screenhack_1 (saver_screen_info *ssi, Bool first_time_p) { - raise_window (first_time_p, True); - XFlush (dpy); + saver_info *si = ssi->global; + saver_preferences *p = &si->prefs; + raise_window (si, first_time_p, True, False); + XFlush (si->dpy); - if (screenhacks_count || demo_mode_p) + if (p->screenhacks_count) { - char *hack; + screenhack *hack; pid_t forked; char buf [255]; - int new_hack; - if (demo_mode_p) + int new_hack = -1; + int retry_count = 0; + Bool force = False; + + AGAIN: + + if (p->screenhacks_count < 1) + { + /* No hacks at all */ + new_hack = -1; + } + else if (p->screenhacks_count == 1) + { + /* Exactly one hack in the list */ + new_hack = 0; + } + else if (si->selection_mode == -1) + { + /* Select the next hack, wrapping. */ + new_hack = (ssi->current_hack + 1) % p->screenhacks_count; + } + else if (si->selection_mode == -2) + { + /* Select the previous hack, wrapping. */ + if (ssi->current_hack < 0) + new_hack = p->screenhacks_count - 1; + else + new_hack = ((ssi->current_hack + p->screenhacks_count - 1) + % p->screenhacks_count); + } + else if (si->selection_mode > 0) { - hack = demo_hack; + /* Select a specific hack, by number (via the ACTIVATE command.) */ + new_hack = ((si->selection_mode - 1) % p->screenhacks_count); + force = True; } - else + else if (p->mode == ONE_HACK && + p->selected_hack >= 0) { - if (screenhacks_count == 1) - new_hack = 0; - else if (next_mode_p == 1) - new_hack = (current_hack + 1) % screenhacks_count, - next_mode_p = 0; - else if (next_mode_p == 2) + /* Select a specific hack, by number (via "One Saver" mode.) */ + new_hack = p->selected_hack; + force = True; + } + else if (p->mode == BLANK_ONLY || p->mode == DONT_BLANK) + { + new_hack = -1; + } + else if (p->mode == RANDOM_HACKS_SAME && + ssi->number != 0) + { + /* Use the same hack that's running on screen 0. + (Assumes this function was called on screen 0 first.) + */ + new_hack = si->screens[0].current_hack; + } + else /* (p->mode == RANDOM_HACKS) */ + { + /* Select a random hack (but not the one we just ran.) */ + while ((new_hack = random () % p->screenhacks_count) + == ssi->current_hack) + ; + } + + if (new_hack < 0) /* don't run a hack */ + { + ssi->current_hack = -1; + if (si->selection_mode < 0) + si->selection_mode = 0; + return; + } + + ssi->current_hack = new_hack; + hack = p->screenhacks[ssi->current_hack]; + + /* If the hack is disabled, or there is no visual for this hack, + then try again (move forward, or backward, or re-randomize.) + Unless this hack was specified explicitly, in which case, + use it regardless. + */ + if (force) + select_visual_of_hack (ssi, hack); + + if (!force && + (!hack->enabled_p || + !on_path_p (hack->command) || + !select_visual_of_hack (ssi, hack))) + { + if (++retry_count > (p->screenhacks_count*4)) { - new_hack = ((current_hack + screenhacks_count - 1) - % screenhacks_count); - next_mode_p = 0; + /* Uh, oops. Odds are, there are no suitable visuals, + and we're looping. Give up. (This is totally lame, + what we should do is make a list of suitable hacks at + the beginning, then only loop over them.) + */ + if (p->verbose_p) + fprintf(stderr, + "%s: %d: no programs enabled, or no suitable visuals.\n", + blurb(), ssi->number); + return; } else - while ((new_hack = random () % screenhacks_count) == current_hack) - ; - current_hack = new_hack; - hack = screenhacks[current_hack]; + goto AGAIN; } - switch (forked = fork ()) + /* Turn off "next" and "prev" modes now, but "demo" mode is only + turned off by explicit action. + */ + if (si->selection_mode < 0) + si->selection_mode = 0; + + forked = fork_and_exec (ssi, hack->command); + switch ((int) forked) { - case -1: - sprintf (buf, "%s: %scouldn't fork", - progname, (verbose_p ? "## " : "")); + case -1: /* fork failed */ + case 0: /* child fork (can't happen) */ + sprintf (buf, "%s: couldn't fork", blurb()); perror (buf); - restore_real_vroot (); - exit (1); - case 0: - exec_screenhack (hack); /* this does not return */ + restore_real_vroot (si); + saver_exit (si, 1, "couldn't fork"); break; + default: - pid = forked; + ssi->pid = forked; break; } } } + void -kill_screenhack () +spawn_screenhack (saver_info *si, Bool first_time_p) { - killing = 1; - if (! pid) - return; - if (kill (pid, SIGTERM) < 0) + if (monitor_powered_on_p (si)) { - if (errno == ESRCH) - { - /* Sometimes we don't get a SIGCHLD at all! WTF? - It's a race condition. It looks to me like what's happening is - something like: a subprocess dies of natural causes. There is a - small window between when the process dies and when the SIGCHLD - is (would have been) delivered. If we happen to try to kill() - the process during that time, the kill() fails, because the - process is already dead. But! no SIGCHLD is delivered (perhaps - because the failed kill() has reset some state in the kernel?) - Anyway, if kill() says "No such process", then we have to wait() - for it anyway, because the process has already become a zombie. - I love Unix. - */ - await_child_death (False); - } - else - { - char buf [255]; - sprintf (buf, "%s: %scouldn't kill child process %d", progname, - (verbose_p ? "## " : ""), pid); - perror (buf); - } + int i; + for (i = 0; i < si->nscreens; i++) + { + saver_screen_info *ssi = &si->screens[i]; + spawn_screenhack_1 (ssi, first_time_p); + } } - else + else if (si->prefs.verbose_p) + fprintf (stderr, + "%s: X says monitor has powered down; " + "not launching a hack.\n", blurb()); + + store_saver_status (si); /* store current hack numbers */ +} + + +void +kill_screenhack (saver_info *si) +{ + int i; + for (i = 0; i < si->nscreens; i++) { - if (verbose_p) - printf ("%s: killing pid %d.\n", progname, pid); - await_child_death (True); + saver_screen_info *ssi = &si->screens[i]; + if (ssi->pid) + kill_job (si, ssi->pid, SIGTERM); + ssi->pid = 0; } } void -suspend_screenhack (suspend_p) - Bool suspend_p; +suspend_screenhack (saver_info *si, Bool suspend_p) { - - suspending = suspend_p; - if (! pid) - ; - else if (kill (pid, (suspend_p ? SIGSTOP : SIGCONT)) < 0) +#ifdef SIGSTOP /* older VMS doesn't have it... */ + int i; + for (i = 0; i < si->nscreens; i++) { - char buf [255]; - sprintf (buf, "%s: %scouldn't %s child process %d", progname, - (verbose_p ? "## " : ""), - (suspend_p ? "suspend" : "resume"), - pid); - perror (buf); + saver_screen_info *ssi = &si->screens[i]; + if (ssi->pid) + kill_job (si, ssi->pid, (suspend_p ? SIGSTOP : SIGCONT)); } - else if (verbose_p) - printf ("%s: %s pid %d.\n", progname, - (suspend_p ? "suspending" : "resuming"), pid); +#endif /* SIGSTOP */ } - -/* Restarting the xscreensaver process from scratch. */ - -static char **saved_argv; +/* Called when we're exiting abnormally, to kill off the subproc. */ void -save_argv (argc, argv) - int argc; - char **argv; +emergency_kill_subproc (saver_info *si) { - saved_argv = (char **) malloc ((argc + 2) * sizeof (char *)); - saved_argv [argc] = 0; - while (argc--) + int i; +#ifdef SIGCHLD + signal (SIGCHLD, SIG_IGN); +#endif /* SIGCHLD */ + + for (i = 0; i < si->nscreens; i++) { - int i = strlen (argv [argc]) + 1; - saved_argv [argc] = (char *) malloc (i); - memcpy (saved_argv [argc], argv [argc], i); + saver_screen_info *ssi = &si->screens[i]; + if (ssi->pid) + { + kill_job (si, ssi->pid, SIGTERM); + ssi->pid = 0; + } } } -void -restart_process () +Bool +screenhack_running_p (saver_info *si) { - XCloseDisplay (dpy); - fflush (stdout); - fflush (stderr); - execvp (saved_argv [0], saved_argv); - fprintf (stderr, "%s: %scould not restart process: %s (%d)\n", - progname, (verbose_p ? "## " : ""), - (errno == E2BIG ? "arglist too big" : - errno == EACCES ? "could not execute" : - errno == EFAULT ? "memory fault" : - errno == EIO ? "I/O error" : - errno == ENAMETOOLONG ? "name too long" : - errno == ELOOP ? "too many symbolic links" : - errno == ENOENT ? "file no longer exists" : - errno == ENOTDIR ? "directory no longer exists" : - errno == ENOEXEC ? "bad executable file" : - errno == ENOMEM ? "out of memory" : - "execvp() returned unknown error code"), - errno); - exit (1); + Bool any_running_p = False; + int i; + for (i = 0; i < si->nscreens; i++) + { + saver_screen_info *ssi = &si->screens[i]; + if (ssi->pid) any_running_p = True; + } + return any_running_p; } + +/* Environment variables. */ + + +/* Modifies $PATH in the current environment, so that if DEFAULT_PATH_PREFIX + is defined, the xscreensaver daemon will search that directory for hacks. + */ void -demo_mode_restart_process () +hack_environment (saver_info *si) { - int i; - for (i = 0; saved_argv [i]; i++); - /* add the -demo switch; save_argv() left room for this. */ - saved_argv [i] = "-demo"; - saved_argv [i+1] = 0; - restart_process (); +#if defined(HAVE_PUTENV) && defined(DEFAULT_PATH_PREFIX) + static const char *def_path = DEFAULT_PATH_PREFIX; + if (def_path && *def_path) + { + const char *opath = getenv("PATH"); + char *npath = (char *) malloc(strlen(def_path) + strlen(opath) + 20); + strcpy (npath, "PATH="); + strcat (npath, def_path); + strcat (npath, ":"); + strcat (npath, opath); + + if (putenv (npath)) + abort (); + + /* don't free (npath) -- some implementations of putenv (BSD 4.4, + glibc 2.0) copy the argument, but some (libc4,5, glibc 2.1.2) + do not. So we must leak it (and/or the previous setting). Yay. + */ + } +#endif /* HAVE_PUTENV && DEFAULT_PATH_PREFIX */ } + void -hack_environment () +hack_subproc_environment (saver_screen_info *ssi) { /* Store $DISPLAY into the environment, so that the $DISPLAY variable that - the spawned processes inherit is the same as the value of -display passed - in on our command line (which is not necessarily the same as what our - $DISPLAY variable is.) + the spawned processes inherit is correct. First, it must be on the same + host and display as the value of -display passed in on our command line + (which is not necessarily the same as what our $DISPLAY variable is.) + Second, the screen number in the $DISPLAY passed to the subprocess should + be the screen on which this particular hack is running -- not the display + specification which the driver itself is using, since the driver ignores + its screen number and manages all existing screens. + + Likewise, store a window ID in $XSCREENSAVER_WINDOW -- this will allow + us to (eventually) run multiple hacks in Xinerama mode, where each hack + has the same $DISPLAY but a different piece of glass. */ - char *s, buf [2048]; - int i; - sprintf (buf, "DISPLAY=%s", DisplayString (dpy)); - i = strlen (buf); - s = (char *) malloc (i+1); - strncpy (s, buf, i+1); - if (putenv (s)) + saver_info *si = ssi->global; + const char *odpy = DisplayString (si->dpy); + char *ndpy = (char *) malloc (strlen(odpy) + 20); + char *nssw = (char *) malloc (40); + char *s, *c; + + strcpy (ndpy, "DISPLAY="); + s = ndpy + strlen(ndpy); + strcpy (s, odpy); + + /* We have to find the last colon since it is the boundary between + hostname & screen - IPv6 numeric format addresses may have many + colons before that point, and DECnet addresses always have two colons */ + c = strrchr(s,':'); /* skip to last colon */ + if (c != NULL) s = c+1; + while (isdigit(*s)) s++; /* skip over dpy number */ + while (*s == '.') s++; /* skip over dot */ + if (s[-1] != '.') *s++ = '.'; /* put on a dot */ + sprintf(s, "%d", ssi->real_screen_number); /* put on screen number */ + + sprintf (nssw, "XSCREENSAVER_WINDOW=0x%lX", + (unsigned long) ssi->screensaver_window); + + /* Allegedly, BSD 4.3 didn't have putenv(), but nobody runs such systems + any more, right? It's not Posix, but everyone seems to have it. */ +#ifdef HAVE_PUTENV + if (putenv (ndpy)) + abort (); + if (putenv (nssw)) abort (); + + /* don't free ndpy/nssw -- some implementations of putenv (BSD 4.4, + glibc 2.0) copy the argument, but some (libc4,5, glibc 2.1.2) + do not. So we must leak it (and/or the previous setting). Yay. + */ +#endif /* HAVE_PUTENV */ } -/* Change the uid/gid of the screensaver process, so that it is safe for it - to run setuid root (which it needs to do on some systems to read the - encrypted passwords from the passwd file.) - - hack_uid() is run before opening the X connection, so that XAuth works. - hack_uid_warn() is called after the connection is opened and the command - line arguments are parsed, so that the messages from hack_uid() get - printed after we know whether we're in `verbose' mode. - */ +/* GL crap */ -#ifndef NO_SETUID +Visual * +get_best_gl_visual (saver_screen_info *ssi) +{ + saver_info *si = ssi->global; + pid_t forked; + int fds [2]; + int in, out; + char buf[1024]; -static int hack_uid_errno; -static char hack_uid_buf [255], *hack_uid_error; + char *av[10]; + int ac = 0; -void -hack_uid () -{ - /* If we've been run as setuid or setgid to someone else (most likely root) - turn off the extra permissions so that random user-specified programs - don't get special privileges. (On some systems it might be necessary - to install this as setuid root in order to read the passwd file to - implement lock-mode...) - */ - setgid (getgid ()); - setuid (getuid ()); - - hack_uid_errno = 0; - hack_uid_error = 0; - - /* If we're being run as root (as from xdm) then switch the user id - to something safe. */ - if (getuid () == 0) - { - struct passwd *p; - /* Locking can't work when running as root, because we have no way of - knowing what the user id of the logged in user is (so we don't know - whose password to prompt for.) - */ - locking_disabled_p = True; - nolock_reason = "running as root"; - p = getpwnam ("nobody"); - if (! p) p = getpwnam ("daemon"); - if (! p) p = getpwnam ("bin"); - if (! p) p = getpwnam ("sys"); - if (! p) - { - hack_uid_error = "couldn't find safe uid; running as root."; - hack_uid_errno = -1; - } - else - { - struct group *g = getgrgid (p->pw_gid); - hack_uid_error = hack_uid_buf; - sprintf (hack_uid_error, "changing uid/gid to %s/%s (%d/%d).", - p->pw_name, (g ? g->gr_name : "???"), p->pw_uid, p->pw_gid); - - /* Change the gid to be a safe one. If we can't do that, then - print a warning. We change the gid before the uid so that we - change the gid while still root. */ - if (setgid (p->pw_gid) != 0) - { - hack_uid_errno = errno; - sprintf (hack_uid_error, "couldn't set gid to %s (%d)", - (g ? g->gr_name : "???"), p->pw_gid); - } + av[ac++] = "xscreensaver-gl-helper"; + av[ac] = 0; - /* Now change the uid to be a safe one. */ - if (setuid (p->pw_uid) != 0) - { - hack_uid_errno = errno; - sprintf (hack_uid_error, "couldn't set uid to %s (%d)", - p->pw_name, p->pw_uid); - } - } + if (pipe (fds)) + { + perror ("error creating pipe:"); + return 0; + } + + in = fds [0]; + out = fds [1]; + + switch ((int) (forked = fork ())) + { + case -1: + { + sprintf (buf, "%s: couldn't fork", blurb()); + perror (buf); + saver_exit (si, 1, 0); + } + case 0: + { + int stdout_fd = 1; + + close (in); /* don't need this one */ + close (ConnectionNumber (si->dpy)); /* close display fd */ + + if (dup2 (out, stdout_fd) < 0) /* pipe stdout */ + { + perror ("could not dup() a new stdout:"); + return 0; + } + hack_subproc_environment (ssi); /* set $DISPLAY */ + + execvp (av[0], av); /* shouldn't return. */ + + if (errno != ENOENT /* || si->prefs.verbose_p */ ) + { + /* Ignore "no such file or directory" errors. + Issue all other exec errors, though. */ + sprintf (buf, "%s: running %s", blurb(), av[0]); + perror (buf); + } + exit (1); /* exits fork */ + break; + } + default: + { + int result = 0; + int wait_status = 0; + + FILE *f = fdopen (in, "r"); + unsigned long v = 0; + char c; + + close (out); /* don't need this one */ + + *buf = 0; + if (! fgets (buf, sizeof(buf)-1, f)) + *buf = 0; + fclose (f); + + /* Wait for the child to die. */ + waitpid (-1, &wait_status, 0); + + if (1 == sscanf (buf, "0x%lx %c", &v, &c)) + result = (int) v; + + if (result == 0) + { + if (si->prefs.verbose_p) + { + int L = strlen(buf); + fprintf (stderr, "%s: %s did not report a GL visual!\n", + blurb(), av[0]); + + if (L && buf[L-1] == '\n') + buf[--L] = 0; + if (*buf) + fprintf (stderr, "%s: %s said: \"%s\"\n", + blurb(), av[0], buf); + } + return 0; + } + else + { + Visual *v = id_to_visual (ssi->screen, result); + if (si->prefs.verbose_p) + fprintf (stderr, "%s: %d: %s: GL visual is 0x%X%s.\n", + blurb(), ssi->number, + av[0], result, + (v == ssi->default_visual ? " (default)" : "")); + return v; + } + } } -#ifndef NO_LOCKING - else /* disable locking if already being run as "someone else" */ - { - struct passwd *p = getpwuid (getuid ()); - if (!p || - !strcmp (p->pw_name, "root") || - !strcmp (p->pw_name, "nobody") || - !strcmp (p->pw_name, "daemon") || - !strcmp (p->pw_name, "bin") || - !strcmp (p->pw_name, "sys")) - { - locking_disabled_p = True; - nolock_reason = hack_uid_buf; - sprintf (nolock_reason, "running as %s", p->pw_name); - } - } -#endif /* NO_LOCKING */ + + abort(); } + + +/* Restarting the xscreensaver process from scratch. */ + +static char **saved_argv; + void -hack_uid_warn () +save_argv (int argc, char **argv) { - if (! hack_uid_error) - ; - else if (hack_uid_errno == 0) + saved_argv = (char **) calloc (argc+2, sizeof (char *)); + saved_argv [argc] = 0; + while (argc--) { - if (verbose_p) - printf ("%s: %s\n", progname, hack_uid_error); + int i = strlen (argv [argc]) + 1; + saved_argv [argc] = (char *) malloc (i); + memcpy (saved_argv [argc], argv [argc], i); } - else +} + + +/* Re-execs the process with the arguments in saved_argv. Does not return. + */ +void +restart_process (saver_info *si) +{ + fflush (stdout); + fflush (stderr); + shutdown_stderr (si); + if (si->prefs.verbose_p) { - char buf [255]; - sprintf (buf, "%s: %s%s", progname, (verbose_p ? "## " : ""), - hack_uid_error); - if (hack_uid_errno == -1) - fprintf (stderr, "%s\n", buf); - else - { - errno = hack_uid_errno; - perror (buf); - } + int i; + fprintf (stderr, "%s: re-executing", blurb()); + for (i = 0; saved_argv[i]; i++) + fprintf (stderr, " %s", saved_argv[i]); + fprintf (stderr, "\n"); } -} + describe_uids (si, stderr); + fprintf (stderr, "\n"); -#endif /* !NO_SETUID */ + fflush (stdout); + fflush (stderr); + execvp (saved_argv [0], saved_argv); /* shouldn't return */ + { + char buf [512]; + sprintf (buf, "%s: could not restart process", blurb()); + perror(buf); + fflush(stderr); + abort(); + } +}