job control: sessions and process groups

kernel-src/arch/x86-64/syscall.asm

@@ -52,6 +52,11 @@ extern syscall_newthread
 extern syscall_threadexit
 extern syscall_futex
 extern syscall_gettid
+extern syscall_getppid
+extern syscall_getpgid
+extern syscall_getsid
+extern syscall_setsid
+extern syscall_setpgid
 syscalltab:
 dq syscall_print
 dq syscall_mmap
@@ -106,7 +111,12 @@ dq syscall_newthread
 dq syscall_threadexit
 dq syscall_futex
 dq syscall_gettid
-syscallcount equ 53
+dq syscall_getppid
+dq syscall_getpgid
+dq syscall_getsid
+dq syscall_setsid
+dq syscall_setpgid
+syscallcount equ 58
 section .text
 global arch_syscall_entry
 ; on entry:

kernel-src/arch/x86-64/syscalllog.c

@@ -4,7 +4,7 @@
 
 #ifdef SYSCALL_LOGGING
 
-#define SYSCALL_COUNT 53
+#define SYSCALL_COUNT 58
 #define LOGSTR(x) arch_e9_puts(x)
 
 static char *name[] = {
@@ -60,7 +60,12 @@ static char *name[] = {
 	"newthread",
 	"threadexit",
 	"futex",
-	"gettid"
+	"gettid",
+	"getppid",
+	"getpgid",
+	"getsid",
+	"setsid",
+	"setpgid"
 };
 
 static char *args[] = {
@@ -116,7 +121,12 @@ static char *args[] = {
 	"entry %p stack %p", // newthread
 	"N/A", // threadexit
 	"futex %p op %d value %d timespec %p", // futex
-	"N/A" // gettid
+	"N/A", // gettid
+	"N/A", // getppid
+	"pid %d", // getpgid
+	"pid %d", // getsid
+	"N/A", // setsid
+	"pid %d pgid %d", // setpgid
 };
 
 #endif
@@ -129,7 +139,6 @@ __attribute__((no_caller_saved_registers)) void arch_syscall_log(int syscall, ui
 
 	thread_t *thread = _cpu()->thread;
 	proc_t *proc = thread->proc;
-
 	snprintf(argbuff, 768, syscall < SYSCALL_COUNT ? args[syscall] : "N/A", a1, a2, a3, a4, a5, a6);
 	snprintf(printbuff, 1024, "\e[92msyscall: pid %d tid %d: %s: %s (%lu free pages)\n\e[0m", proc->pid, thread->tid, syscall < SYSCALL_COUNT ? name[syscall] : "invalid syscall", argbuff, freepagecount);
 

kernel-src/include/kernel/jobctl.h

@@ -0,0 +1,17 @@
+#ifndef _JOBCTL_H
+#define _JOBCTL_H
+
+#include <kernel/scheduler.h>
+
+int jobctl_newsession(proc_t *proc);
+int jobctl_newgroup(proc_t *proc);
+int jobctl_changegroup(proc_t *proc, proc_t *group);
+void jobctl_detach(proc_t *);
+void jobctl_addproc(proc_t *parent, proc_t *proc);
+void jobctl_procremove(proc_t *proc);
+pid_t jobctl_getpgid(proc_t *proc);
+pid_t jobctl_getsid(proc_t *proc);
+void jobctl_setctty(proc_t *proc, void *ctty);
+void *jobctl_getctty(proc_t *proc);
+
+#endif

kernel-src/include/kernel/scheduler.h

@@ -74,6 +74,29 @@ typedef struct proc_t {
 	semaphore_t waitsem;
 	spinlock_t exiting;
 	bool nomorethreads;
+
+	spinlock_t jobctllock;
+	struct {
+		// NULL if this process is leader
+		struct proc_t *leader;
+
+		// these are only applicable if the process is leader
+		struct proc_t *foreground; // process group leader, NULL if self
+		void *controllingtty;
+		int processcount; // refcount
+	} session;
+
+	struct {
+		// NULL if this process is leader
+		struct proc_t *leader;
+		// linked list
+		struct proc_t *nextmember;
+		struct proc_t *previousmember;
+
+		// these are only applicable if the process is leader
+		spinlock_t lock; // protects the linked list
+		int processcount; // refcount
+	} pgrp;
 } proc_t;
 
 #include <arch/cpu.h>

kernel-src/include/kernel/tty.h

@@ -5,6 +5,7 @@
 #include <termios.h>
 #include <kernel/poll.h>
 #include <ringbuffer.h>
+#include <kernel/vfs.h>
 
 #define DEVICE_BUFFER_SIZE 512
 #define READ_BUFFER_SIZE 4096
@@ -23,6 +24,7 @@ typedef struct {
 	ttydevicewritefn_t writetodevice;
 	int minor;
 	winsize_t winsize;
+	vnode_t *mastervnode;
 } tty_t;
 
 void tty_init();

kernel-src/include/kernel/vfs.h

@@ -55,6 +55,7 @@ typedef struct vfs_t {
 #define V_FFLAGS_NONBLOCKING 4
 #define V_FFLAGS_SHARED 8
 #define V_FFLAGS_EXEC 16
+#define V_FFLAGS_NOCTTY 32
 
 typedef struct vnode_t {
 	struct vops_t *ops;

kernel-src/io/tty.c

@@ -2,6 +2,7 @@
 #include <kernel/devfs.h>
 #include <logging.h>
 #include <kernel/alloc.h>
+#include <kernel/jobctl.h>
 
 #define TTY_MAX_COUNT 4096
 #define CONTROLLING_TTY_MINOR TTY_MAX_COUNT
@@ -237,6 +238,29 @@ static int isatty(int minor) {
 	return 0;
 }
 
+static int open(int minor, vnode_t **vnode, int flags) {
+	tty_t *tty = ttyget(minor);
+
+	if (minor == CONTROLLING_TTY_MINOR) {
+		// return controlling tty
+		tty_t *ctty = jobctl_getctty(_cpu()->thread->proc);
+
+		if (ctty == NULL) {
+			return ENXIO;
+		}
+
+		VOP_RELEASE(*vnode);
+		*vnode = (vnode_t *)(ctty->mastervnode);
+	} else if (tty == NULL) {
+		return ENODEV;
+	} else if ((flags & V_FFLAGS_NOCTTY) == 0) {
+		// set as controlling tty
+		jobctl_setctty(_cpu()->thread->proc, tty);
+	}
+
+	return 0;
+}
+
 static int allocminor(tty_t *tty) {
 	MUTEX_ACQUIRE(&listmutex, false);
 
@@ -264,7 +288,8 @@ static devops_t devops = {
 	.poll = poll,
 	.read = read,
 	.ioctl = ioctl,
-	.isatty = isatty
+	.isatty = isatty,
+	.open = open
 };
 
 tty_t *tty_create(char *name, ttydevicewritefn_t fn) {
@@ -310,6 +335,14 @@ tty_t *tty_create(char *name, ttydevicewritefn_t fn) {
 	tty->writetodevice = fn;
 	tty->minor = minor;
 
+	vnode_t *newnode;
+	__assert(devfs_getnode(NULL, DEV_MAJOR_TTY, minor, &newnode) == 0);
+
+	tty->mastervnode = (vnode_t *)((devnode_t *)newnode)->master;
+	VOP_HOLD(tty->mastervnode);
+
+	VOP_RELEASE(newnode);
+
 	return tty;
 	error:
 	if (tty->name)
@@ -322,6 +355,10 @@ tty_t *tty_create(char *name, ttydevicewritefn_t fn) {
 	return NULL;
 }
 
+void tty_unregister(char *name, tty_t *tty) {
+
+}
+
 void tty_destroy(char *name, tty_t *tty) {
 	
 }

kernel-src/sys/jobctl.c

@@ -0,0 +1,286 @@
+#include <kernel/jobctl.h>
+#include <kernel/interrupt.h>
+#include <kernel/tty.h>
+#include <errno.h>
+#include <logging.h>
+
+// assumes interrupts are disabled
+static void addtolist(proc_t *pgrp, proc_t *proc) {
+	spinlock_acquire(&pgrp->pgrp.lock);
+
+	proc->pgrp.nextmember = pgrp->pgrp.nextmember;
+	proc->pgrp.previousmember = NULL;
+	pgrp->pgrp.nextmember = proc;
+
+	if (proc->pgrp.nextmember)
+		proc->pgrp.nextmember->pgrp.previousmember = proc;
+
+	spinlock_release(&pgrp->pgrp.lock);
+}
+
+// assumes interrupts are disabled
+static void removefromlist(proc_t *pgrp, proc_t *proc) {
+	spinlock_acquire(&pgrp->pgrp.lock);
+
+	if (proc->pgrp.previousmember)
+		proc->pgrp.previousmember->pgrp.nextmember = proc->pgrp.nextmember;
+
+	if (proc->pgrp.nextmember)
+		proc->pgrp.nextmember->pgrp.previousmember = proc->pgrp.previousmember;
+
+	spinlock_release(&pgrp->pgrp.lock);
+}
+
+void jobctl_setctty(proc_t *proc, void *_ctty) {
+	tty_t *tty = _ctty;
+	__assert(tty);
+
+	bool intstatus = interrupt_set(false);
+	spinlock_acquire(&proc->jobctllock);
+
+	tty_t *unholdtty = NULL;
+
+	// if not the session leader
+	if (proc->session.leader)
+		goto leave;
+
+	if (tty == NULL && proc->session.controllingtty) {
+		unholdtty = proc->session.controllingtty;
+		proc->session.controllingtty = NULL;
+	}
+
+	if (tty && proc->session.controllingtty == NULL) {
+		VOP_HOLD(tty->mastervnode);
+		proc->session.controllingtty = tty;
+	}
+
+	leave:
+	spinlock_release(&proc->jobctllock);
+	interrupt_set(intstatus);
+
+	if (unholdtty) {
+		VOP_RELEASE(unholdtty->mastervnode);
+	}
+}
+
+void *jobctl_getctty(proc_t *proc) {
+	tty_t *tty = NULL;
+
+	bool intstatus = interrupt_set(false);
+	spinlock_acquire(&proc->jobctllock);
+
+	if (proc->session.leader) {
+		proc_t *session = proc->session.leader;
+		spinlock_acquire(&session->jobctllock);
+
+		tty = session->session.controllingtty;
+		if (tty) {
+			VOP_HOLD(tty->mastervnode);
+		}
+
+		spinlock_release(&session->jobctllock);
+	} else if (proc->session.controllingtty){
+		// is the session leader
+		tty = proc->session.controllingtty;
+		VOP_HOLD(tty->mastervnode);
+	}
+
+	spinlock_release(&proc->jobctllock);
+	interrupt_set(intstatus);
+	return tty;
+}
+
+pid_t jobctl_getpgid(proc_t *proc) {
+	bool intstatus = interrupt_set(false);
+	spinlock_acquire(&proc->jobctllock);
+
+	pid_t pid = proc->pgrp.leader ? proc->pgrp.leader->pid : proc->pid; 
+
+	spinlock_release(&proc->jobctllock);
+	interrupt_set(intstatus);
+
+	return pid;
+}
+
+pid_t jobctl_getsid(proc_t *proc) {
+	bool intstatus = interrupt_set(false);
+	spinlock_acquire(&proc->jobctllock);
+
+	pid_t pid = proc->session.leader ? proc->session.leader->pid : proc->pid;
+
+	spinlock_release(&proc->jobctllock);
+	interrupt_set(intstatus);
+
+	return pid;
+}
+
+int jobctl_newsession(proc_t *proc) {
+	// keep those saved so we don't unhold them with interrupts disabled,
+	// which would possibly call into the allocators without interrupts
+	proc_t *unholdpgrp = NULL;
+	proc_t *unholdsession = NULL;
+
+	int error = 0;
+	bool intstatus = interrupt_set(false);
+	spinlock_acquire(&proc->jobctllock);
+
+	// check if session/group leader
+	if (proc->pgrp.leader == NULL) {
+		error = EPERM;
+		goto leave;
+	}
+
+	unholdpgrp = proc->pgrp.leader;
+	unholdsession = proc->session.leader;
+
+	removefromlist(proc->pgrp.leader, proc);
+
+	proc->session.leader = NULL;
+	proc->session.foreground = NULL;
+	proc->session.controllingtty = NULL;
+
+	proc->pgrp.leader = NULL;
+	proc->pgrp.nextmember = NULL;
+	proc->pgrp.previousmember = NULL;
+
+	leave:
+	spinlock_release(&proc->jobctllock);
+	interrupt_set(intstatus);
+
+	if (unholdpgrp) {
+		PROC_RELEASE(unholdpgrp);
+		PROC_RELEASE(unholdsession);
+	}
+
+	return error;
+}
+
+int jobctl_newgroup(proc_t *proc) {
+	// keep it saved so we don't unhold it with interrupts disabled,
+	// which would possibly call into the allocators without interrupts
+	proc_t *unholdpgrp = NULL;
+
+	int error = 0;
+	bool intstatus = interrupt_set(false);
+	spinlock_acquire(&proc->jobctllock);
+
+	// check if session/group leader
+	if (proc->pgrp.leader == NULL) {
+		error = EPERM;
+		goto leave;
+	}
+
+	unholdpgrp = proc->pgrp.leader;
+
+	removefromlist(proc->pgrp.leader, proc);
+
+	proc->pgrp.leader = NULL;
+	proc->pgrp.nextmember = NULL;
+	proc->pgrp.previousmember = NULL;
+
+	leave:
+	spinlock_release(&proc->jobctllock);
+	interrupt_set(intstatus);
+
+	if (unholdpgrp) {
+		PROC_RELEASE(unholdpgrp);
+	}
+
+	return error;
+}
+
+int jobctl_changegroup(proc_t *proc, proc_t *group) {
+	// keep it saved so we don't unhold it with interrupts disabled,
+	// which would possibly call into the allocators without interrupts
+	proc_t *unholdpgrp = NULL;
+
+	int error = 0;
+	bool intstatus = interrupt_set(false);
+	spinlock_acquire(&proc->jobctllock);
+
+	// check if session/group leader
+	if (proc->pgrp.leader == NULL) {
+		error = EPERM;
+		goto leave;
+	}
+
+	removefromlist(proc->pgrp.leader, proc);
+	unholdpgrp = proc->pgrp.leader;
+	proc->pgrp.leader = group;
+	addtolist(group, proc);
+
+	leave:
+	spinlock_release(&proc->jobctllock);
+	interrupt_set(intstatus);
+
+	if (unholdpgrp) {
+		PROC_RELEASE(unholdpgrp);
+	}
+
+	return error;
+}
+
+void jobctl_detach(proc_t *proc) {
+	// called on process exit (when the last userland thread is exiting)
+	proc_t *unholdpgrp = NULL;
+	proc_t *unholdsession = NULL;
+	bool intstatus = interrupt_set(false);
+	spinlock_acquire(&proc->jobctllock);
+
+	if (proc->pgrp.leader) {
+		unholdpgrp = proc->pgrp.leader;
+		removefromlist(proc->pgrp.leader, proc);
+		proc->pgrp.leader = NULL;
+	}
+
+	if (proc->session.leader) {
+		unholdsession = proc->session.leader;
+		proc->session.leader = NULL;
+	}
+
+	spinlock_release(&proc->jobctllock);
+	interrupt_set(intstatus);
+
+	if (unholdpgrp) {
+		PROC_RELEASE(unholdpgrp);
+	}
+
+	if (unholdsession) {
+		PROC_RELEASE(unholdsession);
+	}
+}
+
+void jobctl_addproc(proc_t *parent, proc_t *proc) {
+	// called when a new process is being created (such as by fork)
+
+	bool intstatus = interrupt_set(false);
+	spinlock_acquire(&parent->jobctllock);
+	spinlock_acquire(&proc->jobctllock);
+
+	proc->session.leader = parent->session.leader ? parent->session.leader : parent;
+	proc->pgrp.leader = parent->pgrp.leader ? parent->pgrp.leader : parent;
+
+	PROC_HOLD(proc->session.leader);
+	PROC_HOLD(proc->pgrp.leader);
+
+	addtolist(proc->pgrp.leader, proc);
+
+	spinlock_release(&proc->jobctllock);
+	spinlock_release(&parent->jobctllock);
+	interrupt_set(intstatus);
+}
+
+void jobctl_procremove(proc_t *proc) {
+	// called after all refcounts to a proc are released
+	// cleans up session stuff
+
+	if (proc->session.leader != NULL)
+		return;
+
+	if (proc->session.foreground) {
+		PROC_RELEASE(proc->session.foreground);
+	}
+
+	tty_t *tty = proc->session.controllingtty;
+	VOP_RELEASE(tty->mastervnode);
+}

kernel-src/sys/scheduler.c

@@ -10,6 +10,7 @@
 #include <kernel/file.h>
 #include <semaphore.h>
 #include <kernel/devfs.h>
+#include <kernel/jobctl.h>
 
 #define QUANTUM_US 100000
 #define SCHEDULER_STACK_SIZE PAGE_SIZE
@@ -55,6 +56,8 @@ proc_t *sched_newproc() {
 	proc->fdfirst = 3;
 	SPINLOCK_INIT(proc->fdlock);
 	SEMAPHORE_INIT(&proc->waitsem, 0);
+	SPINLOCK_INIT(proc->jobctllock);
+	SPINLOCK_INIT(proc->pgrp.lock);
 
 	proc->fd = alloc(sizeof(fd_t) * 3);
 	if (proc->fd == NULL) {
@@ -242,6 +245,8 @@ void sched_procexit() {
 	// which hold a reference. it won't now since its a zombie, which is why it will be held
 	PROC_HOLD(proc);
 
+	jobctl_detach(proc);
+
 	// close fds
 	for (int fd = 0; fd < proc->fdcount; ++fd)
 		fd_close(fd);
@@ -606,11 +611,11 @@ void sched_runinit() {
 
 	vnode_t *consolenode;
 	__assert(devfs_getbyname("console", &consolenode) == 0);
-	__assert(VOP_OPEN(&consolenode, V_FFLAGS_READ, &proc->cred) == 0)
+	__assert(VOP_OPEN(&consolenode, V_FFLAGS_READ | V_FFLAGS_NOCTTY, &proc->cred) == 0)
 	VOP_HOLD(consolenode);
-	__assert(VOP_OPEN(&consolenode, V_FFLAGS_WRITE, &proc->cred) == 0)
+	__assert(VOP_OPEN(&consolenode, V_FFLAGS_WRITE | V_FFLAGS_NOCTTY, &proc->cred) == 0)
 	VOP_HOLD(consolenode);
-	__assert(VOP_OPEN(&consolenode, V_FFLAGS_WRITE, &proc->cred) == 0)
+	__assert(VOP_OPEN(&consolenode, V_FFLAGS_WRITE | V_FFLAGS_NOCTTY, &proc->cred) == 0)
 
 	file_t *stdin = fd_allocate();
 	file_t *stdout = fd_allocate();

kernel-src/sys/syscalls/fork.c

@@ -3,8 +3,8 @@
 #include <errno.h>
 #include <kernel/file.h>
 #include <kernel/interrupt.h>
+#include <kernel/jobctl.h>
 
-#include <logging.h>
 syscallret_t syscall_fork(context_t *ctx) {
 	syscallret_t ret = {
 		.ret = -1,
@@ -53,6 +53,7 @@ syscallret_t syscall_fork(context_t *ctx) {
 
 	CTX_RET(&nthread->context) = 0;
 	CTX_ERRNO(&nthread->context) = 0;
+	jobctl_addproc(proc, nproc);
 
 	ret.ret = nproc->pid;
 

kernel-src/sys/syscalls/getpid.c

@@ -1,5 +1,7 @@
 #include <kernel/syscalls.h>
 #include <arch/cpu.h>
+#include <kernel/jobctl.h>
+#include <logging.h>
 
 syscallret_t syscall_getpid(context_t *ctx) {
 	syscallret_t ret = {
@@ -8,3 +10,31 @@ syscallret_t syscall_getpid(context_t *ctx) {
 	};
 	return ret;
 }
+
+syscallret_t syscall_getppid(context_t *ctx) {
+	syscallret_t ret = {
+		.ret = _cpu()->thread->proc->parent ? _cpu()->thread->proc->parent->pid : 1,
+		.errno = 0
+	};
+	return ret;
+}
+
+syscallret_t syscall_getpgid(context_t *ctx, pid_t pid) {
+	syscallret_t ret = {
+		.errno = 0
+	};
+
+	__assert(pid == 0);
+	ret.ret = jobctl_getpgid(_cpu()->thread->proc);
+	return ret;
+}
+
+syscallret_t syscall_getsid(context_t *ctx, pid_t pid) {
+	syscallret_t ret = {
+		.errno = 0
+	};
+
+	__assert(pid == 0);
+	ret.ret = jobctl_getsid(_cpu()->thread->proc);
+	return ret;
+}

kernel-src/sys/syscalls/setpid.c

@@ -0,0 +1,21 @@
+#include <kernel/syscalls.h>
+#include <kernel/jobctl.h>
+#include <logging.h>
+
+syscallret_t syscall_setsid(context_t *) {
+	syscallret_t ret;
+
+	ret.errno = jobctl_newsession(_cpu()->thread->proc);
+	ret.ret = ret.errno ? -1 : _cpu()->thread->proc->pid;
+	return ret;
+}
+
+syscallret_t syscall_setpgid(context_t *, pid_t pid, pid_t pgid) {
+	syscallret_t ret;
+	__assert(pid == 0 || pid == _cpu()->thread->proc->pid);
+	__assert(pgid == 0 || pgid == _cpu()->thread->proc->pid);
+
+	ret.errno = jobctl_newgroup(_cpu()->thread->proc);
+	ret.ret = ret.errno ? -1 : _cpu()->thread->proc->pid;
+	return ret;
+}

patches/mlibc/jinx-working-patch.patch

@@ -188,10 +188,10 @@ index 0000000..e5b087a
 +
 diff --git mlibc-workdir/sysdeps/astral/generic/generic.cpp mlibc-workdir/sysdeps/astral/generic/generic.cpp
 new file mode 100644
-index 0000000..00537fa
+index 0000000..d2ec1c5
 --- /dev/null
 +++ mlibc-workdir/sysdeps/astral/generic/generic.cpp
-@@ -0,0 +1,599 @@
+@@ -0,0 +1,618 @@
 +#include <bits/ensure.h>
 +#include <mlibc/debug.hpp>
 +#include <mlibc/all-sysdeps.hpp>
@@ -276,13 +276,20 @@ index 0000000..00537fa
 +	}
 +	
 +	pid_t sys_getppid() {
-+		// TODO UNSTUB
++		long ret;
-+		return 1;
++		syscall(SYSCALL_GETPPID, &ret);
++		return ret;
++	}
++
++	int sys_getsid(pid_t pid, pid_t *pgid) {
++		long ret;
++		long error = syscall(SYSCALL_GETSID, &ret, pid);
++		return 0;
 +	}
 +
 +	int sys_getpgid(pid_t pid, pid_t *pgid) {
-+		// TODO UNSTUB
++		long ret;
-+		*pgid = 1;
++		long error = syscall(SYSCALL_GETPGID, &ret, pid);
 +		return 0;
 +	}
 +
@@ -327,6 +334,18 @@ index 0000000..00537fa
 +		return 0;
 +	}
 +
++	int sys_setpgid(pid_t pid, pid_t pgid) {
++		long ret;
++		return syscall(SYSCALL_SETPGID, &ret, pid, pgid);
++	}
++
++	int sys_setsid(pid_t *out) {
++		long ret;
++		long error = syscall(SYSCALL_SETSID, &ret);
++		*out = ret;
++		return error;
++	}
++
 +	int sys_futex_tid() {
 +		long ret;
 +		syscall(SYSCALL_GETTID, &ret);
@@ -810,10 +829,10 @@ index 0000000..990eca0
 +#endif
 diff --git mlibc-workdir/sysdeps/astral/include/astral/syscall.h mlibc-workdir/sysdeps/astral/include/astral/syscall.h
 new file mode 100644
-index 0000000..c57a0fa
+index 0000000..859c459
 --- /dev/null
 +++ mlibc-workdir/sysdeps/astral/include/astral/syscall.h
-@@ -0,0 +1,76 @@
+@@ -0,0 +1,81 @@
 +#ifndef _SYSCALL_H_INCLUDE
 +#define _SYSCALL_H_INCLUDE
 +
@@ -870,6 +889,11 @@ index 0000000..c57a0fa
 +#define SYSCALL_THREADEXIT 50
 +#define SYSCALL_FUTEX 51
 +#define SYSCALL_GETTID 52
++#define SYSCALL_GETPPID 53
++#define SYSCALL_GETPGID 54
++#define SYSCALL_GETSID 55
++#define SYSCALL_SETSID 56
++#define SYSCALL_SETPGID 57
 +
 +#include <stddef.h>
 +#include <stdint.h>