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Fix unblocking of signals in interactive mode

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In interactive mode (-I2), those signals that were blocked at startup
will remain blocked for the whole period of strace execution.

* strace.c (empty_set): Rename to start_set.  All users changed.
(init): Initialize start_set and blocked_set to the set of currently
blocked signals.
(startup_attach, trace): Use SIG_SETMASK instead of SIG_BLOCK.
* NEWS: Mention this change.
This commit is contained in:
Дмитрий Левин 2017-05-27 10:00:43 +00:00
parent ab2efa7a54
commit f83b49b03a
2 changed files with 24 additions and 17 deletions
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4
NEWS
View File

@ -1,6 +1,10 @@
Noteworthy changes in release ?.?? (????-??-??)
===============================================
* Bug fixes
* In interactive mode (-I2), those signals that were blocked at startup
will remain blocked for the whole period of strace execution.
Noteworthy changes in release 4.17 (2017-05-24)
===============================================

37
strace.c
View File

@ -158,7 +158,7 @@ unsigned os_release; /* generated from uname()'s u.release */
static void detach(struct tcb *tcp);
static void cleanup(void);
static void interrupt(int sig);
static sigset_t empty_set, blocked_set;
static sigset_t start_set, blocked_set;
#ifdef HAVE_SIG_ATOMIC_T
static volatile sig_atomic_t interrupted;
@ -1128,7 +1128,7 @@ startup_attach(void)
* We rely on cleanup() from this point on.
*/
if (interactive)
sigprocmask(SIG_BLOCK, &blocked_set, NULL);
sigprocmask(SIG_SETMASK, &blocked_set, NULL);
if (daemonized_tracer) {
pid_t pid = fork();
@ -1170,10 +1170,10 @@ startup_attach(void)
attach_tcb(tcp);
if (interactive) {
sigprocmask(SIG_SETMASK, &empty_set, NULL);
sigprocmask(SIG_SETMASK, &start_set, NULL);
if (interrupted)
goto ret;
sigprocmask(SIG_BLOCK, &blocked_set, NULL);
sigprocmask(SIG_SETMASK, &blocked_set, NULL);
}
} /* for each tcbtab[] */
@ -1188,7 +1188,7 @@ startup_attach(void)
ret:
if (interactive)
sigprocmask(SIG_SETMASK, &empty_set, NULL);
sigprocmask(SIG_SETMASK, &start_set, NULL);
}
/* Stack-o-phobic exec helper, in the hope to work around
@ -1885,6 +1885,15 @@ init(int argc, char *argv[])
if (!outfname || outfname[0] == '|' || outfname[0] == '!') {
setvbuf(shared_log, NULL, _IOLBF, 0);
}
/*
* argv[0] -pPID -oFILE Default interactive setting
* yes * 0 INTR_WHILE_WAIT
* no 1 0 INTR_WHILE_WAIT
* yes * 1 INTR_NEVER
* no 1 1 INTR_WHILE_WAIT
*/
if (outfname && argv[0]) {
if (!opt_intr)
opt_intr = INTR_NEVER;
@ -1894,17 +1903,11 @@ init(int argc, char *argv[])
if (!opt_intr)
opt_intr = INTR_WHILE_WAIT;
/* argv[0] -pPID -oFILE Default interactive setting
* yes * 0 INTR_WHILE_WAIT
* no 1 0 INTR_WHILE_WAIT
* yes * 1 INTR_NEVER
* no 1 1 INTR_WHILE_WAIT
*/
sigprocmask(SIG_SETMASK, NULL, &start_set);
memcpy(&blocked_set, &start_set, sizeof(blocked_set));
sigemptyset(&empty_set);
sigemptyset(&blocked_set);
/* startup_child() must be called before the signal handlers get
/*
* startup_child() must be called before the signal handlers get
* installed below as they are inherited into the spawned process.
* Also we do not need to be protected by them as during interruption
* in the startup_child() mode we kill the spawned process anyway.
@ -2289,11 +2292,11 @@ trace(void)
}
if (interactive)
sigprocmask(SIG_SETMASK, &empty_set, NULL);
sigprocmask(SIG_SETMASK, &start_set, NULL);
pid = wait4(-1, &status, __WALL, (cflag ? &ru : NULL));
wait_errno = errno;
if (interactive)
sigprocmask(SIG_BLOCK, &blocked_set, NULL);
sigprocmask(SIG_SETMASK, &blocked_set, NULL);
if (pid < 0) {
if (wait_errno == EINTR)