Revise signal handling to work with GNO.

This involved using signal() rather than sigaction(), which GNO doesn't have. signal() doesn't have the signal-blocking feature of sigaction(), but I've tried to emulate it.
This commit is contained in:
Stephen Heumann 2014-11-04 10:45:28 -06:00
parent 036b92595c
commit cbdfea4c97
3 changed files with 67 additions and 68 deletions

View File

@ -448,7 +448,11 @@ extern char *mkdtemp(char *template) FAST_FUNC;
#endif
#ifndef HAVE_SIGHANDLER_T
# ifndef __GNO__
typedef void (*sighandler_t)(int);
# else
typedef void (*sighandler_t)(int, int);
# endif
#endif
#ifndef HAVE_STPCPY

View File

@ -14,17 +14,6 @@
/* All known arches use small ints for signals */
smallint bb_got_signal;
void record_signo(int signo)
{
bb_got_signal = signo;
}
/* Saves 2 bytes on x86! Oh my... */
int FAST_FUNC sigaction_set(int signum, const struct sigaction *act)
{
return sigaction(signum, act, NULL);
}
int FAST_FUNC sigprocmask_allsigs(int how)
{
sigset_t set;
@ -47,35 +36,6 @@ void FAST_FUNC bb_signals(int sigs, void (*f)(int))
}
}
void FAST_FUNC bb_signals_recursive_norestart(int sigs, void (*f)(int))
{
int sig_no = 0;
int bit = 1;
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = f;
/*sa.sa_flags = 0;*/
/*sigemptyset(&sa.sa_mask); - hope memset did it*/
while (sigs) {
if (sigs & bit) {
sigs -= bit;
sigaction_set(sig_no, &sa);
}
sig_no++;
bit <<= 1;
}
}
void FAST_FUNC sig_block(int sig)
{
sigset_t ss;
sigemptyset(&ss);
sigaddset(&ss, sig);
sigprocmask(SIG_BLOCK, &ss, NULL);
}
void FAST_FUNC sig_unblock(int sig)
{
sigset_t ss;
@ -84,13 +44,6 @@ void FAST_FUNC sig_unblock(int sig)
sigprocmask(SIG_UNBLOCK, &ss, NULL);
}
void FAST_FUNC wait_for_any_sig(void)
{
sigset_t ss;
sigemptyset(&ss);
sigsuspend(&ss);
}
/* Assuming the sig is fatal */
void FAST_FUNC kill_myself_with_sig(int sig)
{
@ -99,23 +52,3 @@ void FAST_FUNC kill_myself_with_sig(int sig)
raise(sig);
_exit(sig | 128); /* Should not reach it */
}
void FAST_FUNC signal_SA_RESTART_empty_mask(int sig, void (*handler)(int))
{
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
/*sigemptyset(&sa.sa_mask);*/
sa.sa_flags = SA_RESTART;
sa.sa_handler = handler;
sigaction_set(sig, &sa);
}
void FAST_FUNC signal_no_SA_RESTART_empty_mask(int sig, void (*handler)(int))
{
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
/*sigemptyset(&sa.sa_mask);*/
/*sa.sa_flags = 0;*/
sa.sa_handler = handler;
sigaction_set(sig, &sa);
}

View File

@ -826,19 +826,25 @@ struct globals {
unsigned long memleak_value;
int debug_indent;
#endif
#ifndef __GNO__
struct sigaction sa;
#endif
char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
};
#define G (*ptr_to_globals)
/* Not #defining name to G.name - this quickly gets unwieldy
* (too many defines). Also, I actually prefer to see when a variable
* is global, thus "G." prefix is a useful hint */
#define INIT_G() do { \
#ifndef __GNO__
# define INIT_G() do { \
SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
/* memset(&G.sa, 0, sizeof(G.sa)); */ \
sigfillset(&G.sa.sa_mask); \
G.sa.sa_flags = SA_RESTART; \
} while (0)
#else
# define INIT_G() SET_PTR_TO_GLOBALS(xzalloc(sizeof(G)))
#endif
/* Function prototypes for builtins */
@ -1478,8 +1484,28 @@ static void record_pending_signo(int sig)
#endif
}
#ifdef __GNO__
# pragma databank 1
static void record_pending_signo_wrapper_gno(int sig, int code)
{
/* Block all blockable signals now, to attempt to emulate the
* behavior if this handler had been installed by the original
* sigaction() call rather than GNO's signal().
*/
sigset_t new_mask, old_mask;
sigfillset(&new_mask);
sigprocmask(SIG_BLOCK, &new_mask, &old_mask);
record_pending_signo(sig);
sigprocmask(SIG_SETMASK, &old_mask, NULL);
}
# pragma databank 0
#endif
static sighandler_t install_sighandler(int sig, sighandler_t handler)
{
#ifndef __GNO__
struct sigaction old_sa;
/* We could use signal() to install handlers... almost:
@ -1494,6 +1520,10 @@ static sighandler_t install_sighandler(int sig, sighandler_t handler)
G.sa.sa_handler = handler;
sigaction(sig, &G.sa, &old_sa);
return old_sa.sa_handler;
#else
/* GNO doesn't have sigaction(), so we'll have to use signal(). */
return signal(sig, handler);
#endif
}
#if ENABLE_HUSH_JOB
@ -1527,6 +1557,26 @@ static void sigexit(int sig)
kill_myself_with_sig(sig); /* does not return */
}
# ifdef __GNO__
# pragma databank 1
static void sigexit_wrapper_gno(int sig, int code)
{
/* Block all blockable signals now, to attempt to emulate the
* behavior if this handler had been installed by the original
* sigaction() call rather than GNO's signal().
*/
sigset_t new_mask, old_mask;
sigfillset(&new_mask);
sigprocmask(SIG_BLOCK, &new_mask, &old_mask);
sigexit(sig);
// Shouldn't get here, but just in case...
sigprocmask(SIG_SETMASK, &old_mask, NULL);
}
# pragma databank 0
# endif
#else
# define disable_restore_tty_pgrp_on_exit() ((void)0)
@ -1543,12 +1593,20 @@ static sighandler_t pick_sighandler(unsigned sig)
#if ENABLE_HUSH_JOB
/* is sig fatal? */
if (G_fatal_sig_mask & sigmask)
# ifndef __GNO__
handler = sigexit;
# else
handler = sigexit_wrapper_gno;
# endif
else
#endif
/* sig has special handling? */
if (G.special_sig_mask & sigmask) {
#ifndef __GNO__
handler = record_pending_signo;
#else
handler = record_pending_signo_wrapper_gno;
#endif
/* TTIN/TTOU/TSTP can't be set to record_pending_signo
* in order to ignore them: they will be raised
* in an endless loop when we try to do some
@ -8632,7 +8690,11 @@ static int FAST_FUNC builtin_trap(char **argv)
continue;
if (new_cmd)
#ifndef __GNO__
handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
#else
handler = (new_cmd[0] ? record_pending_signo_wrapper_gno : SIG_IGN);
#endif
else
/* We are removing trap handler */
handler = pick_sighandler(sig);