Multithreaded kernel and improvement of signal handling.
Pardon the big ass-commit, this took months to develop and debug and the
refactoring got so far that a clean merge became impossible. The good news
is that this commit does quite a bit of cleaning up and generally improves
the kernel quality.
This makes the kernel fully pre-emptive and multithreaded. This was done
by rewriting the interrupt code, the scheduler, introducing new threading
primitives, and rewriting large parts of the kernel. During the past few
commits the kernel has had its device drivers thread secured; this commit
thread secures large parts of the core kernel. There still remains some
parts of the kernel that is _not_ thread secured, but this is not a problem
at this point. Each user-space thread has an associated kernel stack that
it uses when it goes into kernel mode. This stack is by default 8 KiB since
that value works for me and is also used by Linux. Strange things tends to
happen on x86 in case of a stack overflow - there is no ideal way to catch
such a situation right now.
The system call conventions were changed, too. The %edx register is now
used to provide the errno value of the call, instead of the kernel writing
it into a registered global variable. The system call code has also been
updated to better reflect the native calling conventions: not all registers
have to be preserved. This makes system calls faster and simplifies the
assembly. In the kernel, there is no longer the event.h header or the hacky
method of 'resuming system calls' that closely resembles cooperative
multitasking. If a system call wants to block, it should just block.
The signal handling was also improved significantly. At this point, signals
cannot interrupt kernel threads (but can always interrupt user-space threads
if enabled), which introduces some problems with how a SIGINT could
interrupt a blocking read, for instance. This commit introduces and uses a
number of new primitives such as kthread_lock_mutex_signal() that attempts
to get the lock but fails if a signal is pending. In this manner, the kernel
is safer as kernel threads cannot be shut down inconveniently, but in return
for complexity as blocking operations must check they if they should fail.
Process exiting has also been refactored significantly. The _exit(2) system
call sets the exit code and sends SIGKILL to all the threads in the process.
Once all the threads have cleaned themselves up and exited, a worker thread
calls the process's LastPrayer() method that unmaps memory, deletes the
address space, notifies the parent, etc. This provides a very robust way to
terminate processes as even half-constructed processes (during a failing fork
for instance) can be gracefully terminated.
I have introduced a number of kernel threads to help avoid threading problems
and simplify kernel design. For instance, there is now a functional generic
kernel worker thread that any kernel thread can schedule jobs for. Interrupt
handlers run with interrupts off (hence they cannot call kthread_ functions
as it may deadlock the system if another thread holds the lock) therefore
they cannot use the standard kernel worker threads. Instead, they use a
special purpose interrupt worker thread that works much like the generic one
expect that interrupt handlers can safely queue work with interrupts off.
Note that this also means that interrupt handlers cannot allocate memory or
print to the kernel log/screen as such mechanisms uses locks. I'll introduce
a lock free algorithm for such cases later on.
The boot process has also changed. The original kernel init thread in
kernel.cpp creates a new bootstrap thread and becomes the system idle thread.
Note that pid=0 now means the kernel, as there is no longer a system idle
process. The bootstrap thread launches all the kernel worker threads and then
creates a new process and loads /bin/init into it and then creates a thread
in pid=1, which starts the system. The bootstrap thread then quietly waits
for pid=1 to exit after which it shuts down/reboots/panics the system.
In general, the introduction of race conditions and dead locks have forced me
to revise a lot of the design and make sure it was thread secure. Since early
parts of the kernel was quite hacky, I had to refactor such code. So it seems
that the risk of dead locks forces me to write better code.
Note that a real preemptive multithreaded kernel simplifies the construction
of blocking system calls. My hope is that this will trigger a clean up of
the filesystem code that current is almost beyond repair.
Almost all of the kernel was modified during this refactoring. To the extent
possible, these changes have been backported to older non-multithreaded
kernel, but many changes were tightly coupled and went into this commit.
Of interest is the implementation of the kthread_ api based on the design
of pthreads; this library allows easy synchronization mechanisms and
includes C++-style scoped locks. This commit also introduces new worker
threads and tested mechanisms for interrupt handlers to schedule work in a
kernel worker thread.
A lot of code have been rewritten from scratch and has become a lot more
stable and correct.
Share and enjoy!
2012-08-01 11:30:34 -04:00
|
|
|
/*******************************************************************************
|
2011-09-15 16:38:40 -04:00
|
|
|
|
2013-10-13 17:49:34 -04:00
|
|
|
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013.
|
2011-09-15 16:38:40 -04:00
|
|
|
|
2013-07-10 09:26:01 -04:00
|
|
|
This file is part of the Sortix C Library.
|
2011-09-15 16:38:40 -04:00
|
|
|
|
2013-07-10 09:26:01 -04:00
|
|
|
The Sortix C Library is free software: you can redistribute it and/or modify
|
|
|
|
|
it under the terms of the GNU Lesser General Public License as published by
|
|
|
|
|
the Free Software Foundation, either version 3 of the License, or (at your
|
|
|
|
|
option) any later version.
|
2011-09-15 16:38:40 -04:00
|
|
|
|
2013-07-10 09:26:01 -04:00
|
|
|
The Sortix C Library is distributed in the hope that it will be useful, but
|
|
|
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
|
|
|
|
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
|
|
|
|
|
License for more details.
|
2011-09-15 16:38:40 -04:00
|
|
|
|
2013-07-10 09:26:01 -04:00
|
|
|
You should have received a copy of the GNU Lesser General Public License
|
|
|
|
|
along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
|
2011-09-15 16:38:40 -04:00
|
|
|
|
2013-07-10 09:26:01 -04:00
|
|
|
signal.h
|
|
|
|
|
Signals.
|
2011-09-15 16:38:40 -04:00
|
|
|
|
Multithreaded kernel and improvement of signal handling.
Pardon the big ass-commit, this took months to develop and debug and the
refactoring got so far that a clean merge became impossible. The good news
is that this commit does quite a bit of cleaning up and generally improves
the kernel quality.
This makes the kernel fully pre-emptive and multithreaded. This was done
by rewriting the interrupt code, the scheduler, introducing new threading
primitives, and rewriting large parts of the kernel. During the past few
commits the kernel has had its device drivers thread secured; this commit
thread secures large parts of the core kernel. There still remains some
parts of the kernel that is _not_ thread secured, but this is not a problem
at this point. Each user-space thread has an associated kernel stack that
it uses when it goes into kernel mode. This stack is by default 8 KiB since
that value works for me and is also used by Linux. Strange things tends to
happen on x86 in case of a stack overflow - there is no ideal way to catch
such a situation right now.
The system call conventions were changed, too. The %edx register is now
used to provide the errno value of the call, instead of the kernel writing
it into a registered global variable. The system call code has also been
updated to better reflect the native calling conventions: not all registers
have to be preserved. This makes system calls faster and simplifies the
assembly. In the kernel, there is no longer the event.h header or the hacky
method of 'resuming system calls' that closely resembles cooperative
multitasking. If a system call wants to block, it should just block.
The signal handling was also improved significantly. At this point, signals
cannot interrupt kernel threads (but can always interrupt user-space threads
if enabled), which introduces some problems with how a SIGINT could
interrupt a blocking read, for instance. This commit introduces and uses a
number of new primitives such as kthread_lock_mutex_signal() that attempts
to get the lock but fails if a signal is pending. In this manner, the kernel
is safer as kernel threads cannot be shut down inconveniently, but in return
for complexity as blocking operations must check they if they should fail.
Process exiting has also been refactored significantly. The _exit(2) system
call sets the exit code and sends SIGKILL to all the threads in the process.
Once all the threads have cleaned themselves up and exited, a worker thread
calls the process's LastPrayer() method that unmaps memory, deletes the
address space, notifies the parent, etc. This provides a very robust way to
terminate processes as even half-constructed processes (during a failing fork
for instance) can be gracefully terminated.
I have introduced a number of kernel threads to help avoid threading problems
and simplify kernel design. For instance, there is now a functional generic
kernel worker thread that any kernel thread can schedule jobs for. Interrupt
handlers run with interrupts off (hence they cannot call kthread_ functions
as it may deadlock the system if another thread holds the lock) therefore
they cannot use the standard kernel worker threads. Instead, they use a
special purpose interrupt worker thread that works much like the generic one
expect that interrupt handlers can safely queue work with interrupts off.
Note that this also means that interrupt handlers cannot allocate memory or
print to the kernel log/screen as such mechanisms uses locks. I'll introduce
a lock free algorithm for such cases later on.
The boot process has also changed. The original kernel init thread in
kernel.cpp creates a new bootstrap thread and becomes the system idle thread.
Note that pid=0 now means the kernel, as there is no longer a system idle
process. The bootstrap thread launches all the kernel worker threads and then
creates a new process and loads /bin/init into it and then creates a thread
in pid=1, which starts the system. The bootstrap thread then quietly waits
for pid=1 to exit after which it shuts down/reboots/panics the system.
In general, the introduction of race conditions and dead locks have forced me
to revise a lot of the design and make sure it was thread secure. Since early
parts of the kernel was quite hacky, I had to refactor such code. So it seems
that the risk of dead locks forces me to write better code.
Note that a real preemptive multithreaded kernel simplifies the construction
of blocking system calls. My hope is that this will trigger a clean up of
the filesystem code that current is almost beyond repair.
Almost all of the kernel was modified during this refactoring. To the extent
possible, these changes have been backported to older non-multithreaded
kernel, but many changes were tightly coupled and went into this commit.
Of interest is the implementation of the kthread_ api based on the design
of pthreads; this library allows easy synchronization mechanisms and
includes C++-style scoped locks. This commit also introduces new worker
threads and tested mechanisms for interrupt handlers to schedule work in a
kernel worker thread.
A lot of code have been rewritten from scratch and has become a lot more
stable and correct.
Share and enjoy!
2012-08-01 11:30:34 -04:00
|
|
|
*******************************************************************************/
|
2011-09-15 16:38:40 -04:00
|
|
|
|
2013-10-13 17:49:34 -04:00
|
|
|
#ifndef INCLUDE_SIGNAL_H
|
|
|
|
|
#define INCLUDE_SIGNAL_H
|
2011-09-15 16:38:40 -04:00
|
|
|
|
|
|
|
|
#include <features.h>
|
Multithreaded kernel and improvement of signal handling.
Pardon the big ass-commit, this took months to develop and debug and the
refactoring got so far that a clean merge became impossible. The good news
is that this commit does quite a bit of cleaning up and generally improves
the kernel quality.
This makes the kernel fully pre-emptive and multithreaded. This was done
by rewriting the interrupt code, the scheduler, introducing new threading
primitives, and rewriting large parts of the kernel. During the past few
commits the kernel has had its device drivers thread secured; this commit
thread secures large parts of the core kernel. There still remains some
parts of the kernel that is _not_ thread secured, but this is not a problem
at this point. Each user-space thread has an associated kernel stack that
it uses when it goes into kernel mode. This stack is by default 8 KiB since
that value works for me and is also used by Linux. Strange things tends to
happen on x86 in case of a stack overflow - there is no ideal way to catch
such a situation right now.
The system call conventions were changed, too. The %edx register is now
used to provide the errno value of the call, instead of the kernel writing
it into a registered global variable. The system call code has also been
updated to better reflect the native calling conventions: not all registers
have to be preserved. This makes system calls faster and simplifies the
assembly. In the kernel, there is no longer the event.h header or the hacky
method of 'resuming system calls' that closely resembles cooperative
multitasking. If a system call wants to block, it should just block.
The signal handling was also improved significantly. At this point, signals
cannot interrupt kernel threads (but can always interrupt user-space threads
if enabled), which introduces some problems with how a SIGINT could
interrupt a blocking read, for instance. This commit introduces and uses a
number of new primitives such as kthread_lock_mutex_signal() that attempts
to get the lock but fails if a signal is pending. In this manner, the kernel
is safer as kernel threads cannot be shut down inconveniently, but in return
for complexity as blocking operations must check they if they should fail.
Process exiting has also been refactored significantly. The _exit(2) system
call sets the exit code and sends SIGKILL to all the threads in the process.
Once all the threads have cleaned themselves up and exited, a worker thread
calls the process's LastPrayer() method that unmaps memory, deletes the
address space, notifies the parent, etc. This provides a very robust way to
terminate processes as even half-constructed processes (during a failing fork
for instance) can be gracefully terminated.
I have introduced a number of kernel threads to help avoid threading problems
and simplify kernel design. For instance, there is now a functional generic
kernel worker thread that any kernel thread can schedule jobs for. Interrupt
handlers run with interrupts off (hence they cannot call kthread_ functions
as it may deadlock the system if another thread holds the lock) therefore
they cannot use the standard kernel worker threads. Instead, they use a
special purpose interrupt worker thread that works much like the generic one
expect that interrupt handlers can safely queue work with interrupts off.
Note that this also means that interrupt handlers cannot allocate memory or
print to the kernel log/screen as such mechanisms uses locks. I'll introduce
a lock free algorithm for such cases later on.
The boot process has also changed. The original kernel init thread in
kernel.cpp creates a new bootstrap thread and becomes the system idle thread.
Note that pid=0 now means the kernel, as there is no longer a system idle
process. The bootstrap thread launches all the kernel worker threads and then
creates a new process and loads /bin/init into it and then creates a thread
in pid=1, which starts the system. The bootstrap thread then quietly waits
for pid=1 to exit after which it shuts down/reboots/panics the system.
In general, the introduction of race conditions and dead locks have forced me
to revise a lot of the design and make sure it was thread secure. Since early
parts of the kernel was quite hacky, I had to refactor such code. So it seems
that the risk of dead locks forces me to write better code.
Note that a real preemptive multithreaded kernel simplifies the construction
of blocking system calls. My hope is that this will trigger a clean up of
the filesystem code that current is almost beyond repair.
Almost all of the kernel was modified during this refactoring. To the extent
possible, these changes have been backported to older non-multithreaded
kernel, but many changes were tightly coupled and went into this commit.
Of interest is the implementation of the kthread_ api based on the design
of pthreads; this library allows easy synchronization mechanisms and
includes C++-style scoped locks. This commit also introduces new worker
threads and tested mechanisms for interrupt handlers to schedule work in a
kernel worker thread.
A lot of code have been rewritten from scratch and has become a lot more
stable and correct.
Share and enjoy!
2012-08-01 11:30:34 -04:00
|
|
|
#include <sortix/signal.h>
|
2013-10-13 17:49:34 -04:00
|
|
|
|
|
|
|
|
__BEGIN_DECLS
|
|
|
|
|
|
|
|
|
|
@include(uid_t.h)
|
|
|
|
|
@include(pid_t.h)
|
|
|
|
|
@include(size_t.h)
|
|
|
|
|
/* TODO: POSIX says this header declares struct timespec, but not time_t... */
|
|
|
|
|
@include(time_t.h)
|
|
|
|
|
/* TODO: pthread_t */
|
|
|
|
|
/* TODO: pthread_attr_t */
|
|
|
|
|
|
|
|
|
|
__END_DECLS
|
|
|
|
|
|
2013-01-08 09:09:56 -05:00
|
|
|
#include <sortix/sigset.h>
|
2013-10-13 17:49:34 -04:00
|
|
|
#include <sortix/timespec.h>
|
2011-09-15 16:38:40 -04:00
|
|
|
|
|
|
|
|
__BEGIN_DECLS
|
|
|
|
|
|
2013-10-13 17:49:34 -04:00
|
|
|
/* TODO: Should this be volatile? It isn't on Linux. */
|
2013-01-14 08:41:44 -05:00
|
|
|
typedef int sig_atomic_t;
|
2011-09-15 16:38:40 -04:00
|
|
|
|
|
|
|
|
typedef void (*sighandler_t)(int);
|
|
|
|
|
|
2013-10-13 17:49:34 -04:00
|
|
|
void SIG_DFL(int);
|
|
|
|
|
void SIG_IGN(int);
|
|
|
|
|
void SIG_ERR(int);
|
|
|
|
|
|
|
|
|
|
#define SIG_DFL SIG_DFL
|
|
|
|
|
#define SIG_IGN SIG_IGN
|
|
|
|
|
#define SIG_ERR SIG_ERR
|
|
|
|
|
/* TODO: POSIX specifies a obsolecent SIG_HOLD here. */
|
|
|
|
|
|
|
|
|
|
union sigval
|
|
|
|
|
{
|
|
|
|
|
int sival_int;
|
|
|
|
|
void* sival_ptr;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
struct sigevent
|
|
|
|
|
{
|
|
|
|
|
int sigev_notify;
|
|
|
|
|
int sigev_signo;
|
|
|
|
|
union sigval sigev_value;
|
|
|
|
|
void (*sigev_notify_function)(union sigval);
|
|
|
|
|
/*pthread_attr_t* sigev_notify_attributes;*/
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
#define SIGEV_NONE 0
|
|
|
|
|
#define SIGEV_SIGNAL 1
|
|
|
|
|
#define SIGEV_THREAD 2
|
|
|
|
|
|
|
|
|
|
/* TODO: SIGRTMIN */
|
|
|
|
|
/* TODO: SIGRTMAX */
|
|
|
|
|
|
|
|
|
|
typedef struct
|
|
|
|
|
{
|
|
|
|
|
int si_signo;
|
|
|
|
|
int si_code;
|
|
|
|
|
int si_errno;
|
|
|
|
|
pid_t si_pid;
|
|
|
|
|
uid_t si_uid;
|
|
|
|
|
void* si_addr;
|
|
|
|
|
int si_status;
|
|
|
|
|
union sigval si_value;
|
|
|
|
|
} siginfo_t;
|
|
|
|
|
|
|
|
|
|
#define ILL_ILLOPC 1
|
|
|
|
|
#define ILL_ILLOPN 2
|
|
|
|
|
#define ILL_ILLADR 3
|
|
|
|
|
#define ILL_ILLTRP 4
|
|
|
|
|
#define ILL_PRVOPC 5
|
|
|
|
|
#define ILL_PRVREG 6
|
|
|
|
|
#define ILL_COPROC 7
|
|
|
|
|
#define ILL_BADSTK 8
|
|
|
|
|
#define FPE_INTDIV 9
|
|
|
|
|
#define FPE_INTOVF 10
|
|
|
|
|
#define FPE_FLTDIV 11
|
|
|
|
|
#define FPE_FLTOVF 12
|
|
|
|
|
#define FPE_FLTUND 13
|
|
|
|
|
#define FPE_FLTRES 14
|
|
|
|
|
#define FPE_FLTINV 15
|
|
|
|
|
#define FPE_FLTSUB 16
|
|
|
|
|
#define SEGV_MAPERR 17
|
|
|
|
|
#define SEGV_ACCERR 18
|
|
|
|
|
#define BUS_ADRALN 19
|
|
|
|
|
#define BUS_ADRERR 20
|
|
|
|
|
#define BUS_OBJERR 21
|
|
|
|
|
#define TRAP_BRKPT 22
|
|
|
|
|
#define TRAP_TRACE 23
|
|
|
|
|
#define CLD_EXITED 24
|
|
|
|
|
#define CLD_KILLED 25
|
|
|
|
|
#define CLD_DUMPED 26
|
|
|
|
|
#define CLD_TRAPPED 27
|
|
|
|
|
#define CLD_STOPPED 29
|
|
|
|
|
#define CLD_CONTINUED 30
|
|
|
|
|
#define SI_USER 31
|
|
|
|
|
#define SI_QUEUE 32
|
|
|
|
|
#define SI_TIMER 33
|
|
|
|
|
#define SI_ASYNCIO 34
|
|
|
|
|
#define SI_MSGQ 35
|
|
|
|
|
|
|
|
|
|
struct sigaction
|
|
|
|
|
{
|
|
|
|
|
void (*sa_handler)(int);
|
|
|
|
|
void (*sa_sigaction)(int, siginfo_t*, void*);
|
|
|
|
|
sigset_t sa_mask;
|
|
|
|
|
int sa_flags;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
#define SA_NOCLDSTOP (1<<0)
|
|
|
|
|
#define SA_ONSTACK (1<<1)
|
|
|
|
|
#define SA_RESETHAND (1<<2)
|
|
|
|
|
#define SA_RESTART (1<<3)
|
|
|
|
|
#define SA_SIGINFO (1<<4)
|
|
|
|
|
#define SA_NOCLDWAIT (1<<5)
|
|
|
|
|
#define SA_NODEFER (1<<6)
|
|
|
|
|
#define SS_ONSTACK (1<<7)
|
|
|
|
|
#define SS_DISABLE (1<<8)
|
|
|
|
|
/* TODO: MINSIGSTKSZ */
|
|
|
|
|
/* TODO: SIGSTKSZ */
|
|
|
|
|
|
|
|
|
|
/* TODO: mcontext_t */
|
|
|
|
|
typedef int mcontext_t;
|
|
|
|
|
|
|
|
|
|
typedef struct
|
|
|
|
|
{
|
|
|
|
|
void* ss_sp;
|
|
|
|
|
size_t ss_size;
|
|
|
|
|
int ss_flags;
|
|
|
|
|
} stack_t;
|
|
|
|
|
|
|
|
|
|
typedef struct __ucontext ucontext_t;
|
|
|
|
|
struct __ucontext
|
|
|
|
|
{
|
|
|
|
|
ucontext_t* uc_link;
|
|
|
|
|
sigset_t uc_sigmask;
|
|
|
|
|
stack_t uc_stack;
|
|
|
|
|
mcontext_t uc_mcontext;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
int kill(pid_t, int);
|
|
|
|
|
int killpg(pid_t, int);
|
|
|
|
|
void psiginfo(const siginfo_t*, const char*);
|
|
|
|
|
void psignal(int, const char*);
|
|
|
|
|
int pthread_sigmask(int, const sigset_t* __restrict, sigset_t* __restrict);
|
2012-05-28 17:10:55 -04:00
|
|
|
int raise(int sig);
|
2013-10-13 17:49:34 -04:00
|
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int sigaction(int, const struct sigaction* __restrict, struct sigaction* __restrict);
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int sigaddset(sigset_t*, int);
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int sigaltstack(const stack_t* __restrict, stack_t* __restrict);
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2013-07-27 10:28:58 -04:00
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int sigandset(sigset_t*, const sigset_t*, const sigset_t*);
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2013-10-13 17:49:34 -04:00
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int sigdelset(sigset_t*, int);
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int sigemptyset(sigset_t*);
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int sigfillset(sigset_t*);
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/* TODO: sighold (obsolescent XSI). */
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/* TODO: sigignore (obsolescent XSI). */
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/* TODO: siginterrupt (obsolescent XSI). */
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2013-07-27 10:28:58 -04:00
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int sigisemptyset(const sigset_t*);
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2013-10-13 17:49:34 -04:00
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int sigismember(const sigset_t*, int);
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sighandler_t signal(int, sighandler_t);
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2013-07-27 10:28:58 -04:00
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int signotset(sigset_t*, const sigset_t*);
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int sigorset(sigset_t*, const sigset_t*, const sigset_t*);
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2013-10-13 17:49:34 -04:00
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/* TODO: sigpause (obsolescent XSI). */
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int sigpending(sigset_t*);
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int sigprocmask(int, const sigset_t* __restrict, sigset_t* __restrict);
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int sigqueue(pid_t, int, const union sigval);
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/* TODO: sigrelse (obsolescent XSI). */
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/* TODO: sigset (obsolescent XSI). */
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int sigsuspend(const sigset_t*);
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int sigtimedwait(const sigset_t* __restrict, siginfo_t* __restrict,
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const struct timespec* __restrict);
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int sigwait(const sigset_t* __restrict, int* __restrict);
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int sigwaitinfo(const sigset_t* __restrict, siginfo_t* vrestrict);
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2011-09-15 16:38:40 -04:00
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__END_DECLS
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#endif
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