- if ((ip = namei(uchar, 0)) == NULL)
- return;
- bno = 0;
- bp = 0;
- if(access(ip, IEXEC))
- goto bad;
- if((ip->i_mode & IFMT) != IFREG ||
- (ip->i_mode & (IEXEC|(IEXEC>>3)|(IEXEC>>6))) == 0) {
- u.u_error = EACCES;
- goto bad;
- }
- /*
- * Collect arguments on "file" in swap space.
- */
- na = 0;
- ne = 0;
- nc = 0;
- uap = (struct execa *)u.u_ap;
- if ((bno = malloc(argmap, ctod(clrnd((int) btoc(NCARGS))))) == 0) {
- swkill(u.u_procp, "exece");
- goto bad;
- }
- if (bno % CLSIZE)
- panic("execa malloc");
- if (uap->argp) for (;;) {
- ap = NULL;
- if (uap->argp) {
- ap = fuword((caddr_t)uap->argp);
- uap->argp++;
- }
- if (ap==NULL && uap->envp) {
- uap->argp = NULL;
- if ((ap = fuword((caddr_t)uap->envp)) == NULL)
- break;
- uap->envp++;
- ne++;
- }
- if (ap==NULL)
- break;
- na++;
- if(ap == -1)
- u.u_error = EFAULT;
- do {
- if (nc >= NCARGS-1)
- u.u_error = E2BIG;
- if ((c = fubyte((caddr_t)ap++)) < 0)
- u.u_error = EFAULT;
- if (u.u_error) {
- if (bp)
- brelse(bp);
- bp = 0;
- goto badarg;
- }
- if ((nc&BMASK) == 0) {
- if (bp)
- bdwrite(bp);
- bp = getblk(argdev,
- (daddr_t)(dbtofsb(bno)+(nc>>BSHIFT)));
- cp = bp->b_un.b_addr;
- }
- nc++;
- *cp++ = c;
- } while (c>0);
- }
- if (bp)
- bdwrite(bp);
- bp = 0;
- nc = (nc + NBPW-1) & ~(NBPW-1);
- if (getxfile(ip, nc) || u.u_error) {
-badarg:
- for (c = 0; c < nc; c += BSIZE)
- if (bp = baddr(argdev, dbtofsb(bno)+(c>>BSHIFT))) {
- bp->b_flags |= B_AGE; /* throw away */
- bp->b_flags &= ~B_DELWRI; /* cancel io */
- brelse(bp);
- bp = 0;
- }
- goto bad;
- }
-
- /*
- * copy back arglist
- */
-
- ucp = USRSTACK - nc - NBPW;
- ap = ucp - na*NBPW - 3*NBPW;
- u.u_ar0[SP] = ap;
- (void) suword((caddr_t)ap, na-ne);
- nc = 0;
- for (;;) {
- ap += NBPW;
- if (na==ne) {
- (void) suword((caddr_t)ap, 0);
- ap += NBPW;
- }
- if (--na < 0)
- break;
- (void) suword((caddr_t)ap, ucp);
- do {
- if ((nc&BMASK) == 0) {
- if (bp)
- brelse(bp);
- bp = bread(argdev,
- (daddr_t)(dbtofsb(bno)+(nc>>BSHIFT)));
- bp->b_flags |= B_AGE; /* throw away */
- bp->b_flags &= ~B_DELWRI; /* cancel io */
- cp = bp->b_un.b_addr;
- }
- (void) subyte((caddr_t)ucp++, (c = *cp++));
- nc++;
- } while(c&0377);
- }
- (void) suword((caddr_t)ap, 0);
- (void) suword((caddr_t)ucp, 0);
- setregs();
-bad:
- if (bp)
- brelse(bp);
- if (bno)
- mfree(argmap, ctod(clrnd((int) btoc(NCARGS))), bno);
- iput(ip);