2005-04-21 16:53:53 +02:00
|
|
|
/* SYSVR4 and ANSI compatible signal(2). */
|
|
|
|
|
|
|
|
|
|
#include <lib.h>
|
|
|
|
|
#define sigaction _sigaction
|
Merge of David's ptrace branch. Summary:
o Support for ptrace T_ATTACH/T_DETACH and T_SYSCALL
o PM signal handling logic should now work properly, even with debuggers
being present
o Asynchronous PM/VFS protocol, full IPC support for senda(), and
AMF_NOREPLY senda() flag
DETAILS
Process stop and delay call handling of PM:
o Added sys_runctl() kernel call with sys_stop() and sys_resume()
aliases, for PM to stop and resume a process
o Added exception for sending/syscall-traced processes to sys_runctl(),
and matching SIGKREADY pseudo-signal to PM
o Fixed PM signal logic to deal with requests from a process after
stopping it (so-called "delay calls"), using the SIGKREADY facility
o Fixed various PM panics due to race conditions with delay calls versus
VFS calls
o Removed special PRIO_STOP priority value
o Added SYS_LOCK RTS kernel flag, to stop an individual process from
running while modifying its process structure
Signal and debugger handling in PM:
o Fixed debugger signals being dropped if a second signal arrives when
the debugger has not retrieved the first one
o Fixed debugger signals being sent to the debugger more than once
o Fixed debugger signals unpausing process in VFS; removed PM_UNPAUSE_TR
protocol message
o Detached debugger signals from general signal logic and from being
blocked on VFS calls, meaning that even VFS can now be traced
o Fixed debugger being unable to receive more than one pending signal in
one process stop
o Fixed signal delivery being delayed needlessly when multiple signals
are pending
o Fixed wait test for tracer, which was returning for children that were
not waited for
o Removed second parallel pending call from PM to VFS for any process
o Fixed process becoming runnable between exec() and debugger trap
o Added support for notifying the debugger before the parent when a
debugged child exits
o Fixed debugger death causing child to remain stopped forever
o Fixed consistently incorrect use of _NSIG
Extensions to ptrace():
o Added T_ATTACH and T_DETACH ptrace request, to attach and detach a
debugger to and from a process
o Added T_SYSCALL ptrace request, to trace system calls
o Added T_SETOPT ptrace request, to set trace options
o Added TO_TRACEFORK trace option, to attach automatically to children
of a traced process
o Added TO_ALTEXEC trace option, to send SIGSTOP instead of SIGTRAP upon
a successful exec() of the tracee
o Extended T_GETUSER ptrace support to allow retrieving a process's priv
structure
o Removed T_STOP ptrace request again, as it does not help implementing
debuggers properly
o Added MINIX3-specific ptrace test (test42)
o Added proper manual page for ptrace(2)
Asynchronous PM/VFS interface:
o Fixed asynchronous messages not being checked when receive() is called
with an endpoint other than ANY
o Added AMF_NOREPLY senda() flag, preventing such messages from
satisfying the receive part of a sendrec()
o Added asynsend3() that takes optional flags; asynsend() is now a
#define passing in 0 as third parameter
o Made PM/VFS protocol asynchronous; reintroduced tell_fs()
o Made PM_BASE request/reply number range unique
o Hacked in a horrible temporary workaround into RS to deal with newly
revealed RS-PM-VFS race condition triangle until VFS is asynchronous
System signal handling:
o Fixed shutdown logic of device drivers; removed old SIGKSTOP signal
o Removed is-superuser check from PM's do_procstat() (aka getsigset())
o Added sigset macros to allow system processes to deal with the full
signal set, rather than just the POSIX subset
Miscellaneous PM fixes:
o Split do_getset into do_get and do_set, merging common code and making
structure clearer
o Fixed setpriority() being able to put to sleep processes using an
invalid parameter, or revive zombie processes
o Made find_proc() global; removed obsolete proc_from_pid()
o Cleanup here and there
Also included:
o Fixed false-positive boot order kernel warning
o Removed last traces of old NOTIFY_FROM code
THINGS OF POSSIBLE INTEREST
o It should now be possible to run PM at any priority, even lower than
user processes
o No assumptions are made about communication speed between PM and VFS,
although communication must be FIFO
o A debugger will now receive incoming debuggee signals at kill time
only; the process may not yet be fully stopped
o A first step has been made towards making the SYSTEM task preemptible
2009-09-30 11:57:22 +02:00
|
|
|
#define _SYSTEM 1
|
2005-04-21 16:53:53 +02:00
|
|
|
#include <signal.h>
|
|
|
|
|
|
|
|
|
|
PUBLIC sighandler_t signal(sig, disp)
|
|
|
|
|
int sig; /* signal number */
|
|
|
|
|
sighandler_t disp; /* signal handler, or SIG_DFL, or SIG_IGN */
|
|
|
|
|
{
|
|
|
|
|
struct sigaction sa, osa;
|
|
|
|
|
|
2009-11-28 14:20:50 +01:00
|
|
|
if (sig <= 0 || sig >= _NSIG || sig == SIGKILL) {
|
2005-04-21 16:53:53 +02:00
|
|
|
errno = EINVAL;
|
|
|
|
|
return(SIG_ERR);
|
|
|
|
|
}
|
|
|
|
|
sigemptyset(&sa.sa_mask);
|
|
|
|
|
|
|
|
|
|
#ifdef WANT_UNRELIABLE_SIGNALS
|
|
|
|
|
/* Allow the signal being handled to interrupt the signal handler. */
|
|
|
|
|
sa.sa_flags = SA_NODEFER;
|
|
|
|
|
|
|
|
|
|
/* When signal is caught, reset signal handler to SIG_DFL for all but
|
|
|
|
|
* SIGILL and SIGTRAP.
|
|
|
|
|
*/
|
|
|
|
|
if (sig != SIGILL && sig != SIGTRAP) sa.sa_flags |= SA_RESETHAND;
|
|
|
|
|
#else
|
|
|
|
|
sa.sa_flags = 0;
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
sa.sa_handler = disp;
|
|
|
|
|
if (sigaction(sig, &sa, &osa) < 0) return(SIG_ERR);
|
|
|
|
|
return(osa.sa_handler);
|
|
|
|
|
}
|
