version 1.1.1.2, 2012/05/29 12:26:49
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version 1.1.1.3, 2012/10/09 09:29:52
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Line 73 struct sigforward {
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Line 73 struct sigforward {
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}; |
}; |
TQ_DECLARE(sigforward) |
TQ_DECLARE(sigforward) |
static struct sigforward_list sigfwd_list; |
static struct sigforward_list sigfwd_list; |
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static pid_t ppgrp = -1; |
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volatile pid_t cmnd_pid = -1; |
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static int handle_signals(int sv[2], pid_t child, int log_io, |
static int handle_signals(int sv[2], pid_t child, int log_io, |
struct command_status *cstat); |
struct command_status *cstat); |
static void forward_signals(int fd); |
static void forward_signals(int fd); |
static void schedule_signal(int signo); |
static void schedule_signal(int signo); |
#ifdef SA_SIGINFO |
#ifdef SA_SIGINFO |
static void handler_nofwd(int s, siginfo_t *info, void *context); | static void handler_user_only(int s, siginfo_t *info, void *context); |
#endif |
#endif |
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/* |
/* |
Line 90 static int fork_cmnd(struct command_details *details,
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Line 93 static int fork_cmnd(struct command_details *details,
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{ |
{ |
struct command_status cstat; |
struct command_status cstat; |
sigaction_t sa; |
sigaction_t sa; |
pid_t child; |
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debug_decl(fork_cmnd, SUDO_DEBUG_EXEC) |
debug_decl(fork_cmnd, SUDO_DEBUG_EXEC) |
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ppgrp = getpgrp(); /* parent's process group */ |
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/* |
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* Handle suspend/restore of sudo and the command. |
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* In most cases, the command will be in the same process group as |
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* sudo and job control will "just work". However, if the command |
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* changes its process group ID and does not change it back (or is |
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* kill by SIGSTOP which is not catchable), we need to resume the |
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* command manually. Also, if SIGTSTP is sent directly to sudo, |
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* we need to suspend the command, and then suspend ourself, restoring |
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* the default SIGTSTP handler temporarily. |
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* |
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* XXX - currently we send SIGCONT upon resume in some cases where |
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* we don't need to (e.g. command pgrp == parent pgrp). |
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*/ |
zero_bytes(&sa, sizeof(sa)); |
zero_bytes(&sa, sizeof(sa)); |
sigemptyset(&sa.sa_mask); |
sigemptyset(&sa.sa_mask); |
sa.sa_flags = SA_INTERRUPT; /* do not restart syscalls */ |
sa.sa_flags = SA_INTERRUPT; /* do not restart syscalls */ |
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#ifdef SA_SIGINFO |
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sa.sa_flags |= SA_SIGINFO; |
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sa.sa_sigaction = handler; |
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#else |
sa.sa_handler = handler; |
sa.sa_handler = handler; |
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#endif |
sigaction(SIGCONT, &sa, NULL); |
sigaction(SIGCONT, &sa, NULL); |
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#ifdef SA_SIGINFO |
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sa.sa_sigaction = handler_user_only; |
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#endif |
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sigaction(SIGTSTP, &sa, NULL); |
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/* |
/* |
* The policy plugin's session init must be run before we fork |
* The policy plugin's session init must be run before we fork |
Line 106 static int fork_cmnd(struct command_details *details,
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Line 132 static int fork_cmnd(struct command_details *details,
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if (policy_init_session(details) != true) |
if (policy_init_session(details) != true) |
errorx(1, _("policy plugin failed session initialization")); |
errorx(1, _("policy plugin failed session initialization")); |
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child = sudo_debug_fork(); | cmnd_pid = sudo_debug_fork(); |
switch (child) { | switch (cmnd_pid) { |
case -1: |
case -1: |
error(1, _("unable to fork")); |
error(1, _("unable to fork")); |
break; |
break; |
Line 150 static int fork_cmnd(struct command_details *details,
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Line 176 static int fork_cmnd(struct command_details *details,
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sudo_debug_exit_int(__func__, __FILE__, __LINE__, sudo_debug_subsys, 1); |
sudo_debug_exit_int(__func__, __FILE__, __LINE__, sudo_debug_subsys, 1); |
_exit(1); |
_exit(1); |
} |
} |
debug_return_int(child); | sudo_debug_printf(SUDO_DEBUG_INFO, "executed %s, pid %d", details->command, |
| (int)cmnd_pid); |
| debug_return_int(cmnd_pid); |
} |
} |
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static struct signal_state { |
static struct signal_state { |
Line 216 sudo_execute(struct command_details *details, struct c
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Line 244 sudo_execute(struct command_details *details, struct c
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bool log_io = false; |
bool log_io = false; |
fd_set *fdsr, *fdsw; |
fd_set *fdsr, *fdsw; |
sigaction_t sa; |
sigaction_t sa; |
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sigset_t omask; |
pid_t child; |
pid_t child; |
debug_decl(sudo_execute, SUDO_DEBUG_EXEC) |
debug_decl(sudo_execute, SUDO_DEBUG_EXEC) |
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Line 273 sudo_execute(struct command_details *details, struct c
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Line 302 sudo_execute(struct command_details *details, struct c
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* Note: HP-UX select() will not be interrupted if SA_RESTART set. |
* Note: HP-UX select() will not be interrupted if SA_RESTART set. |
*/ |
*/ |
sa.sa_flags = SA_INTERRUPT; /* do not restart syscalls */ |
sa.sa_flags = SA_INTERRUPT; /* do not restart syscalls */ |
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#ifdef SA_SIGINFO |
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sa.sa_flags |= SA_SIGINFO; |
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sa.sa_sigaction = handler; |
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#else |
sa.sa_handler = handler; |
sa.sa_handler = handler; |
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#endif |
sigaction(SIGALRM, &sa, NULL); |
sigaction(SIGALRM, &sa, NULL); |
sigaction(SIGCHLD, &sa, NULL); |
sigaction(SIGCHLD, &sa, NULL); |
sigaction(SIGPIPE, &sa, NULL); |
sigaction(SIGPIPE, &sa, NULL); |
Line 291 sudo_execute(struct command_details *details, struct c
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Line 325 sudo_execute(struct command_details *details, struct c
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#ifdef SA_SIGINFO |
#ifdef SA_SIGINFO |
if (!log_io) { |
if (!log_io) { |
sa.sa_flags |= SA_SIGINFO; |
sa.sa_flags |= SA_SIGINFO; |
sa.sa_sigaction = handler_nofwd; | sa.sa_sigaction = handler_user_only; |
} |
} |
#endif |
#endif |
sigaction(SIGHUP, &sa, NULL); |
sigaction(SIGHUP, &sa, NULL); |
Line 306 sudo_execute(struct command_details *details, struct c
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Line 340 sudo_execute(struct command_details *details, struct c
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* to and from pty. Adjusts maxfd as needed. |
* to and from pty. Adjusts maxfd as needed. |
*/ |
*/ |
if (log_io) |
if (log_io) |
child = fork_pty(details, sv, &maxfd); | child = fork_pty(details, sv, &maxfd, &omask); |
else |
else |
child = fork_cmnd(details, sv); |
child = fork_cmnd(details, sv); |
close(sv[1]); |
close(sv[1]); |
Line 399 sudo_execute(struct command_details *details, struct c
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Line 433 sudo_execute(struct command_details *details, struct c
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break; |
break; |
} |
} |
} |
} |
if (cstat->type == CMD_WSTATUS) { | if (cstat->type == CMD_PID) { |
| /* |
| * Once we know the command's pid we can unblock |
| * signals which ere blocked in fork_pty(). This |
| * avoids a race between exec of the command and |
| * receipt of a fatal signal from it. |
| */ |
| cmnd_pid = cstat->val; |
| sudo_debug_printf(SUDO_DEBUG_INFO, "executed %s, pid %d", |
| details->command, (int)cmnd_pid); |
| if (log_io) |
| sigprocmask(SIG_SETMASK, &omask, NULL); |
| } else if (cstat->type == CMD_WSTATUS) { |
if (WIFSTOPPED(cstat->val)) { |
if (WIFSTOPPED(cstat->val)) { |
/* Suspend parent and tell child how to resume on return. */ |
/* Suspend parent and tell child how to resume on return. */ |
sudo_debug_printf(SUDO_DEBUG_INFO, |
sudo_debug_printf(SUDO_DEBUG_INFO, |
Line 460 do_tty_io:
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Line 506 do_tty_io:
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static int |
static int |
handle_signals(int sv[2], pid_t child, int log_io, struct command_status *cstat) |
handle_signals(int sv[2], pid_t child, int log_io, struct command_status *cstat) |
{ |
{ |
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char signame[SIG2STR_MAX]; |
unsigned char signo; |
unsigned char signo; |
ssize_t nread; |
ssize_t nread; |
int status; |
int status; |
Line 485 handle_signals(int sv[2], pid_t child, int log_io, str
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Line 532 handle_signals(int sv[2], pid_t child, int log_io, str
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cstat->val = errno; |
cstat->val = errno; |
debug_return_int(-1); |
debug_return_int(-1); |
} |
} |
sudo_debug_printf(SUDO_DEBUG_DIAG, "received signal %d", signo); | if (sig2str(signo, signame) == -1) |
| snprintf(signame, sizeof(signame), "%d", signo); |
| sudo_debug_printf(SUDO_DEBUG_DIAG, "received SIG%s", signame); |
if (signo == SIGCHLD) { |
if (signo == SIGCHLD) { |
/* |
/* |
* If logging I/O, child is the intermediate process, |
* If logging I/O, child is the intermediate process, |
Line 508 handle_signals(int sv[2], pid_t child, int log_io, str
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Line 557 handle_signals(int sv[2], pid_t child, int log_io, str
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if (WIFSTOPPED(status)) { |
if (WIFSTOPPED(status)) { |
/* |
/* |
* Save the controlling terminal's process group |
* Save the controlling terminal's process group |
* so we can restore it after we resume. | * so we can restore it after we resume, if needed. |
| * Most well-behaved shells change the pgrp back to |
| * its original value before suspending so we must |
| * not try to restore in that case, lest we race with |
| * the child upon resume, potentially stopping sudo |
| * with SIGTTOU while the command continues to run. |
*/ |
*/ |
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sigaction_t sa, osa; |
pid_t saved_pgrp = (pid_t)-1; |
pid_t saved_pgrp = (pid_t)-1; |
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int signo = WSTOPSIG(status); |
int fd = open(_PATH_TTY, O_RDWR|O_NOCTTY, 0); |
int fd = open(_PATH_TTY, O_RDWR|O_NOCTTY, 0); |
if (fd != -1) | if (fd != -1) { |
saved_pgrp = tcgetpgrp(fd); | if ((saved_pgrp = tcgetpgrp(fd)) == ppgrp) |
if (kill(getpid(), WSTOPSIG(status)) != 0) { | saved_pgrp = -1; |
warning("kill(%d, %d)", (int)getpid(), | |
WSTOPSIG(status)); | |
} |
} |
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if (signo == SIGTSTP) { |
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zero_bytes(&sa, sizeof(sa)); |
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sigemptyset(&sa.sa_mask); |
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sa.sa_handler = SIG_DFL; |
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sigaction(SIGTSTP, &sa, &osa); |
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} |
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if (kill(getpid(), signo) != 0) |
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warning("kill(%d, SIG%s)", (int)getpid(), signame); |
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if (signo == SIGTSTP) |
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sigaction(SIGTSTP, &osa, NULL); |
if (fd != -1) { |
if (fd != -1) { |
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/* |
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* Restore command's process group if different. |
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* Otherwise, we cannot resume some shells. |
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*/ |
if (saved_pgrp != (pid_t)-1) |
if (saved_pgrp != (pid_t)-1) |
(void)tcsetpgrp(fd, saved_pgrp); |
(void)tcsetpgrp(fd, saved_pgrp); |
close(fd); |
close(fd); |
Line 538 handle_signals(int sv[2], pid_t child, int log_io, str
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Line 606 handle_signals(int sv[2], pid_t child, int log_io, str
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} else { |
} else { |
/* Nothing listening on sv[0], send directly. */ |
/* Nothing listening on sv[0], send directly. */ |
if (signo == SIGALRM) |
if (signo == SIGALRM) |
terminate_child(child, false); | terminate_command(child, false); |
else if (kill(child, signo) != 0) |
else if (kill(child, signo) != 0) |
warning("kill(%d, %d)", (int)child, signo); | warning("kill(%d, SIG%s)", (int)child, signame); |
} |
} |
} |
} |
} |
} |
Line 553 handle_signals(int sv[2], pid_t child, int log_io, str
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Line 621 handle_signals(int sv[2], pid_t child, int log_io, str
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static void |
static void |
forward_signals(int sock) |
forward_signals(int sock) |
{ |
{ |
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char signame[SIG2STR_MAX]; |
struct sigforward *sigfwd; |
struct sigforward *sigfwd; |
struct command_status cstat; |
struct command_status cstat; |
ssize_t nsent; |
ssize_t nsent; |
Line 560 forward_signals(int sock)
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Line 629 forward_signals(int sock)
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while (!tq_empty(&sigfwd_list)) { |
while (!tq_empty(&sigfwd_list)) { |
sigfwd = tq_first(&sigfwd_list); |
sigfwd = tq_first(&sigfwd_list); |
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if (sig2str(sigfwd->signo, signame) == -1) |
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snprintf(signame, sizeof(signame), "%d", sigfwd->signo); |
sudo_debug_printf(SUDO_DEBUG_INFO, |
sudo_debug_printf(SUDO_DEBUG_INFO, |
"sending signal %d to child over backchannel", sigfwd->signo); | "sending SIG%s to child over backchannel", signame); |
cstat.type = CMD_SIGNO; |
cstat.type = CMD_SIGNO; |
cstat.val = sigfwd->signo; |
cstat.val = sigfwd->signo; |
do { |
do { |
Line 594 static void
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Line 665 static void
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schedule_signal(int signo) |
schedule_signal(int signo) |
{ |
{ |
struct sigforward *sigfwd; |
struct sigforward *sigfwd; |
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char signame[SIG2STR_MAX]; |
debug_decl(schedule_signal, SUDO_DEBUG_EXEC) |
debug_decl(schedule_signal, SUDO_DEBUG_EXEC) |
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sudo_debug_printf(SUDO_DEBUG_DIAG, "forwarding signal %d to child", signo); | if (sig2str(signo, signame) == -1) |
| snprintf(signame, sizeof(signame), "%d", signo); |
| sudo_debug_printf(SUDO_DEBUG_DIAG, "forwarding SIG%s to child", signame); |
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sigfwd = ecalloc(1, sizeof(*sigfwd)); |
sigfwd = ecalloc(1, sizeof(*sigfwd)); |
sigfwd->prev = sigfwd; |
sigfwd->prev = sigfwd; |
Line 611 schedule_signal(int signo)
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Line 685 schedule_signal(int signo)
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* Generic handler for signals passed from parent -> child. |
* Generic handler for signals passed from parent -> child. |
* The other end of signal_pipe is checked in the main event loop. |
* The other end of signal_pipe is checked in the main event loop. |
*/ |
*/ |
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#ifdef SA_SIGINFO |
void |
void |
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handler(int s, siginfo_t *info, void *context) |
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{ |
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unsigned char signo = (unsigned char)s; |
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/* |
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* If the signal came from the command we ran, just ignore |
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* it since we don't want the child to indirectly kill itself. |
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* This can happen with, e.g. BSD-derived versions of reboot |
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* that call kill(-1, SIGTERM) to kill all other processes. |
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*/ |
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if (info != NULL && info->si_code == SI_USER && info->si_pid == cmnd_pid) |
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return; |
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/* |
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* The pipe is non-blocking, if we overflow the kernel's pipe |
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* buffer we drop the signal. This is not a problem in practice. |
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*/ |
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ignore_result(write(signal_pipe[1], &signo, sizeof(signo))); |
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} |
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#else |
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void |
handler(int s) |
handler(int s) |
{ |
{ |
unsigned char signo = (unsigned char)s; |
unsigned char signo = (unsigned char)s; |
Line 622 handler(int s)
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Line 718 handler(int s)
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*/ |
*/ |
ignore_result(write(signal_pipe[1], &signo, sizeof(signo))); |
ignore_result(write(signal_pipe[1], &signo, sizeof(signo))); |
} |
} |
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#endif |
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#ifdef SA_SIGINFO |
#ifdef SA_SIGINFO |
/* |
/* |
Line 631 handler(int s)
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Line 728 handler(int s)
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* signals that are generated by the kernel. |
* signals that are generated by the kernel. |
*/ |
*/ |
static void |
static void |
handler_nofwd(int s, siginfo_t *info, void *context) | handler_user_only(int s, siginfo_t *info, void *context) |
{ |
{ |
unsigned char signo = (unsigned char)s; |
unsigned char signo = (unsigned char)s; |
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/* Only forward user-generated signals. */ |
/* Only forward user-generated signals. */ |
if (info == NULL || info->si_code <= 0) { | if (info != NULL && info->si_code == SI_USER) { |
/* |
/* |
* The pipe is non-blocking, if we overflow the kernel's pipe |
* The pipe is non-blocking, if we overflow the kernel's pipe |
* buffer we drop the signal. This is not a problem in practice. |
* buffer we drop the signal. This is not a problem in practice. |