shithub: drawcpu

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ref: 8d93ccdbb2a2dee8d2eb1387da1b316fdf84b208
dir: /kern/syscall.c/
#include "u.h"
#include "lib.h"
#include "dat.h"
#include "fns.h"
#include "error.h"
#include "user.h"
#include "sys.h"

static u32int
arg(int n)
{
	/* no locking necessary, since we're on the stack */
	return *(u32int*) vaddrnol(up->R[13] + 4 + 4 * n, 4);
}

static u64int
argv(int n)
{
	return arg(n) | ((u64int)arg(n+1) << 32);
}

u32int
noteerr(u32int x, u32int y)
{
	if(((int)x) >= ((int)y))
		return x;
	rerrstr(up->errstr, ERRMAX);
	return x;
}

void
cherrstr(char *str, ...)
{
	va_list va;
	
	va_start(va, str);
	vsnprint(up->errstr, ERRMAX, str, va);
	va_end(va);
}

static void
_sysopen(void)
{
	u32int name, flags;
	char *namet;
	int fd, copied;
	
	name = arg(0);
	flags = arg(1);
	namet = copyifnec(name, -1, &copied);
	fd = open(namet, flags);
	if(copied)
		free(namet);
	if(fd < 0) {
		noteerr(0, 1);
		up->R[0] = fd;
		return;
	}
	up->R[0] = fd;
}

static void
_syscreate(void)
{
	u32int name, flags, perm;
	char *namet;
	int fd, copied;
	
	name = arg(0);
	flags = arg(1);
	perm = arg(2);
	namet = copyifnec(name, -1, &copied);
	fd = create(namet, flags, perm);
	if(copied)
		free(namet);
	if(fd < 0) {
		noteerr(0, 1);
		up->R[0] = fd;
		return;
	}
	up->R[0] = fd;
}

static void
_sysclose(void)
{
	u32int fd;
	
	fd = arg(0);
	up->R[0] = noteerr(close(fd), 0);
}

static void
_syspread(void)
{
	int buffered;
	u32int fd, size, buf;
	u64int off;
	void *targ;
	
	fd = arg(0);
	buf = arg(1);
	size = arg(2);
	off = argv(3);
	targ = bufifnec(buf, size, &buffered);
	up->R[0] = noteerr(pread(fd, targ, size, off), size);
	if(buffered)
		copyback(buf, up->R[0], targ);
}

static void
_syspwrite(void)
{
	u32int fd, size, buf;
	u64int off;
	int copied;
	void *buft;
	
	fd = arg(0);
	buf = arg(1);
	size = arg(2);
	off = argv(3);
	buft = copyifnec(buf, size, &copied);
	up->R[0] = noteerr(pwrite(fd, buft, size, off), size);
	if(copied)
		free(buft);
}

static void
_sysseek(void)
{
	u32int fd, type;
	vlong n, *ret;
	Segment *seg;
	
	ret = vaddr(arg(0), 8, &seg);
	fd = arg(1);
	n = argv(2);
	type = arg(4);
	*ret = seek(fd, n, type);
	if(*ret < 0) noteerr(0, 1);
	segunlock(seg);
}

static void
_sysfd2path(void)
{
	u32int fd, buf, nbuf;
	void *buft;
	int buffered;
	
	fd = arg(0);
	buf = arg(1);
	nbuf = arg(2);
	buft = bufifnec(buf, nbuf, &buffered);
	up->R[0] = noteerr(fd2path(fd, buft, nbuf), 0);
	if(buffered)
		copyback(buf, nbuf, buft);
}

static void
_sysstat(void)
{
	u32int name, edir, nedir;
	char *namet;
	void *edirt;
	int copied, buffered;
	
	name = arg(0);
	namet = copyifnec(name, -1, &copied);
	edir = arg(1);
	nedir = arg(2);
	edirt = bufifnec(edir, nedir, &buffered);
	up->R[0] = noteerr(sysstat(namet, edirt, nedir), nedir);
	if(copied)
		free(namet);
	if(buffered)
		copyback(edir, up->R[0], edirt);
}

static void
_sysfstat(void)
{
	u32int fd, edir, nedir;
	void *edirt;
	int buffered;
	
	fd = arg(0);
	edir = arg(1);
	nedir = arg(2);
	edirt = bufifnec(edir, nedir, &buffered);
	up->R[0] = noteerr(sysfstat(fd, edirt, nedir), nedir);
	if(buffered)
		copyback(edir, up->R[0], edirt);
}

static void
_syswstat(void)
{
	u32int name, edir, nedir;
	char *namet;
	void *edirt;
	int copied, copied2;
	
	name = arg(0);
	namet = copyifnec(name, -1, &copied);
	edir = arg(1);
	nedir = arg(2);
	edirt = copyifnec(edir, nedir, &copied2);
	up->R[0] = noteerr(syswstat(namet, edirt, nedir), nedir);
	if(copied)
		free(namet);
	if(copied2)
		free(edirt);
}

static void
_sysfwstat(void)
{
	u32int fd, edir, nedir;
	void *edirt;
	int copied;
	
	fd = arg(0);
	edir = arg(1);
	nedir = arg(2);
	edirt = copyifnec(edir, nedir, &copied);
	up->R[0] = noteerr(sysfwstat(fd, edirt, nedir), nedir);
	if(copied)
		free(edirt);
}

// TODO: This may be better done as a longjmp back
static void
_sysexits(void)
{
	if(arg(0) == 0)
		exits(nil);
	else
		exits(vaddrnol(arg(0), 0));
}

static void
_sysbrk(void)
{
	ulong v;
	Segment *s;
	
	v = arg(0);
	v = v + 7 & -8;
	if(v >= up->S[SEGSTACK]->start)
		fprint(2, "bss > stack, wtf?");
	if(v < up->S[SEGBSS]->start)
		fprint(2, "bss length < 0, wtf?");
	s = up->S[SEGBSS];
	wlock(&s->rw);
	s->dref = realloc(s->dref, v - s->start + sizeof(Ref));
	if(s->dref == nil)
		fprint(2, "error reallocating");
	s->data = s->dref + 1;
	if(s->size < v - s->start)
		memset((char*)s->data + s->size, 0, v - s->start - s->size);
	s->size = v - s->start;
	up->R[0] = 0;
	wunlock(&s->rw);
}

static void
_syserrstr(void)
{
	char buf[ERRMAX], *srct;
	u32int src, len;
	int copied;
	
	src = arg(0);
	len = arg(1);
	srct = copyifnec(src, len, &copied);
	strcpy(buf, up->errstr);
	utfecpy(up->errstr, up->errstr + ERRMAX, srct);
	utfecpy(srct, srct + len, buf);
	if(copied)
		copyback(src, len, srct);
	up->R[0] = 0;
}

static void
_syschdir(void)
{
	u32int dir;
	char *dirt;
	int copied;
	
	dir = arg(0);
	dirt = copyifnec(dir, -1, &copied);
	up->R[0] = noteerr(syschdir(dirt), 0);
	if(copied)
		free(dirt);
}

static void
_sysnotify(void)
{
	u32int handler;
	
	handler = arg(0);
	up->notehandler = handler;
	up->R[0] = 0;
}

static void
_sysnoted(void)
{
	u32int v;
	
	v = arg(0);
	if(up->innote)
		longjmp(up->notejmp, v + 1);
	cherrstr("the front fell off");
	up->R[0] = -1;
}


static void
_sysrfork(void)
{
	u32int flags;
	int rc, i;
	Segment *s, *t;
	Proc *p;
	int old;
	
	flags = arg(0);

	if((flags & (RFFDG | RFCFDG)) == (RFFDG | RFCFDG) ||
	   (flags & (RFNAMEG | RFCNAMEG)) == (RFNAMEG | RFCNAMEG) ||
	   (flags & (RFENVG | RFCENVG)) == (RFENVG | RFCENVG)) {
		up->R[0] = -1;
		cherrstr("bad arg in syscall");
		return;
	}
	if((flags & RFPROC) == 0) {
		if(flags & RFFDG) {
			old = up->fd;
			up->fd = copyfd(up->fd);
			fddecref(old);
		}
		if(flags & RFCFDG) {
			old = up->fd;
			//up->fd = newfd();
			fddecref(old);
		}
		up->R[0] = noteerr(rfork(flags), 0);
		return;
	}
	//incref(&nproc);
	p = emallocz(sizeof(Proc));
	memcpy(p, up, sizeof(Proc));
	for(i = 0; i < SEGNUM; i++) {
		s = p->S[i];
		if(s == nil)
			continue;
		if((flags & RFMEM) == 0 && i != SEGTEXT || i == SEGSTACK) {
			t = emallocz(sizeof(Segment));
			incref(t);
			t->size = s->size;
			t->start = s->start;
			t->dref = emalloc(sizeof(Ref) + s->size);
			memset(t->dref, 0, sizeof(Ref));
			incref(t->dref);
			t->data = t->dref + 1;
			memcpy(t->data, s->data, s->size);
			p->S[i] = t;
		} else {
			incref(s->dref);
			incref(s);
		}
	}
	
	if(flags & RFFDG)
		p->fd = copyfd(up->fd);
	//else if(flags & RFCFDG)
	//	p->fd = newfd();
	//else
	//	incref(up->fd);

	//incref(up->path);
	rc = rfork(RFMEM | flags);
	if(rc < 0) /* this should NEVER happen */
		sysfatal("rfork failed wtf: %r");
	if(rc == 0) {
	//	up = p;
		//atexit(cleanup);
		up->pid = getpid();
		inittos();
	//	addproc(P);
	}
	up->R[0] = rc;
}
   

static void
_sysexec(void)
{
	u32int name, argv, *argvt;
	char *namet, **argvv;
	int i, argc, rc;
	Segment *seg1, *seg2;
	
	name = arg(0);
	argv = arg(1);
	namet = strdup(vaddr(name, 0, &seg1));
	segunlock(seg1);
	argvt = vaddr(argv, 0, &seg1);
	for(argc = 0; argvt[argc]; argc++)
		;
	argvv = emalloc(sizeof(char *) * argc);
	for(i = 0; i < argc; i++) {
		argvv[i] = strdup(vaddr(argvt[i], 0, &seg2));
		segunlock(seg2);
	}
	segunlock(seg1);
	rc = loadtext(namet, argc, argvv);
	for(i = 0; i < argc; i++)
		free(argvv[i]);
	free(argvv);
	if(rc < 0)
		up->R[0] = noteerr(rc, 0);
	free(namet);
}

static void
_sysawait(void)
{
	u32int s, n;
	void *st;
	int buffered;
	
	s = arg(0);
	n = arg(1);
	st = bufifnec(s, n, &buffered);
	up->R[0] = noteerr(await(st, n), 0);
	if(buffered)
		copyback(s, up->R[0], st);
}

static void
_syspipe(void)
{
	u32int fd, *fdt;
	int buffered;
	
	fd = arg(0);
	fdt = bufifnec(fd, 8, &buffered);
	up->R[0] = noteerr(syspipe((int *) fdt), 0);
	if(buffered)
		copyback(fd, 8, fdt);
}

static void
_sysdup(void)
{
	u32int oldfd, newfd;
	
	oldfd = arg(0);
	newfd = arg(1);
	up->R[0] = noteerr(dup2(oldfd, newfd), 0);
}

static void
_syssleep(void)
{
	u32int n;
	
	n = arg(0);
	osmsleep(n);
	up->R[0] = 0;
}

static void
_sysrendezvous(void)
{
	u32int tag, value;
	
	tag = arg(0);
	value = arg(1);
	up->R[0] = (u32int) (uintptr)sysrendezvous((void *)tag, (void *)value);
	if(up->R[0] == ~0)
		noteerr(0, 1);
}

static void
_sysmount(void)
{
	u32int fd, afd, old, flag, aname;
	char *oldt, *anamet;
	int copiedold, copiedaname;
	
	fd = arg(0);
	afd = arg(1);
	old = arg(2);
	flag = arg(3);
	aname = arg(4);
	oldt = copyifnec(old, -1, &copiedold);
	if(aname) {
		anamet = copyifnec(aname, -1, &copiedaname);
	} else {
		anamet = nil;
		copiedaname = 0;
	}
	up->R[0] = noteerr(sysmount(fd, afd, oldt, flag, anamet), 0);
	if(copiedold)
		free(oldt);
	if(copiedaname)
		free(anamet);
}

static void
_sysbind(void)
{
	u32int name, old, flags;
	char *namet, *oldt;
	int copiedname, copiedold;
	
	name = arg(0);
	old = arg(1);
	flags = arg(2);
	namet = copyifnec(name, -1, &copiedname);
	oldt = copyifnec(old, -1, &copiedold);
	up->R[0] = noteerr(sysbind(namet, oldt, flags), 0);
	if(copiedname)
		free(namet);
	if(copiedold)
		free(oldt);
}

static void
_sysunmount(void)
{
	u32int name, old;
	char *namet, *oldt;
	int copiedname, copiedold;
	
	name = arg(0);
	old = arg(1);
	oldt = copyifnec(old, -1, &copiedold);
	if(name == 0) {
		namet = nil;
		copiedname = 0;
		up->R[0] = noteerr(sysunmount(nil, oldt), 0);
	} else {
		namet = copyifnec(name, -1, &copiedname);
		up->R[0] = noteerr(sysunmount(namet, oldt), 0);
	}
	if(copiedold)
		free(oldt);
	if(copiedname)
		free(namet);
}

static void
_sysremove(void)
{
	u32int file;
	char *filet;
	int copied;
	
	file = arg(0);
	filet = copyifnec(file, -1, &copied);
	up->R[0] = noteerr(sysremove(filet), 0);
	if(copied)
		free(filet);
}

static void
_sysalarm(void)
{
	u32int msec;
	
	msec = arg(0);
	up->R[0] = alarm(msec);
}

static void
_syssemacquire(void)
{
	u32int addr, block;
	long *addrt;

	addr = arg(0);
	block = arg(1);
	addrt = vaddrnol(addr, 4);
	// Still need semaphores
	up->R[0] = noteerr(semacquire(addrt, block), 0);
}

static void
_syssemrelease(void)
{
	u32int addr, count;
	long *addrt;
	Segment *seg;

	addr = arg(0);
	count = arg(1);
	addrt = vaddr(addr, 4, &seg);
	// Still need semaphores
	up->R[0] = noteerr(semrelease(addrt, count), 0);
	segunlock(seg);
}

void
_syscall(void)
{
	u32int n;
	static void (*calls[])(void) = {
		[EXITS] 		= _sysexits,
		[CLOSE] 		= _sysclose,
		[OPEN] 			= _sysopen,
		[CREATE] 		= _syscreate,
		[PREAD] 		= _syspread,
		[PWRITE] 		= _syspwrite,
		[BRK_] 			= _sysbrk,
		[ERRSTR] 		= _syserrstr,
		[STAT] 			= _sysstat,
		[FSTAT] 		= _sysfstat,
		[WSTAT] 		= _syswstat,
		[FWSTAT] 		= _sysfwstat,
		[SEEK] 			= _sysseek,
		[CHDIR]		 	= _syschdir,
		[FD2PATH] 		= _sysfd2path,
		[NOTIFY] 		= _sysnotify,
		[NOTED] 		= _sysnoted,
		[RFORK] 		= _sysrfork,
		[EXEC]	 		= _sysexec,
		[AWAIT] 		= _sysawait,
		[PIPE] 			= _syspipe,
		[SLEEP] 		= _syssleep,
		[RENDEZVOUS] 	= _sysrendezvous,
		[BIND] 			= _sysbind,
		[UNMOUNT] 		= _sysunmount,
		[DUP] 			= _sysdup,
		[MOUNT] 		= _sysmount,
		[REMOVE] 		= _sysremove,
		[ALARM] 		= _sysalarm,
		[SEMACQUIRE] 	= _syssemacquire,
		[SEMRELEASE] 	= _syssemrelease,
	};
	
	n = up->R[0];
	if(n >= nelem(calls) || calls[n] == nil)
		fprint(2, "no such syscall %d @ %#ux", n, up->R[15] - 4);
	calls[n]();
}