Fixed bugs in the conversion of kvm to to use procfs in rev.1.3. All

are in kvm_uread():
- the setting of errno before checking it in the lseek() was lost.
- EOF handling was lost.  kvm_uread() retried forever on EOF.  EOF is
  not really an error, but report it one as in rev.1.2.
- reporting of errno after a read error was lost.

Fixed style bugs in rev.1.3 and rev.1.12.

Not fixed: errno is not reported after lseek() failures.

lib/libkvm/kvm_proc.c

@@ -686,30 +686,35 @@ kvm_uread(kd, p, uva, buf, len)
 	int fd;
 
 	if (!ISALIVE(kd)) {
-		_kvm_err(kd, kd->program, "cannot read user space from dead kernel");
-		return(0);
+		_kvm_err(kd, kd->program,
+		    "cannot read user space from dead kernel");
+		return (0);
 	}
 
-	cp = buf;
-
 	sprintf(procfile, "/proc/%d/mem", p->p_pid);
 	fd = open(procfile, O_RDONLY, 0);
-
 	if (fd < 0) {
 		_kvm_err(kd, kd->program, "cannot open %s", procfile);
 		close(fd);
 		return (0);
 	}
 
-
+	cp = buf;
 	while (len > 0) {
+		errno = 0;
 		if (lseek(fd, (off_t)uva, 0) == -1 && errno != 0) {
-			_kvm_err(kd, kd->program, "invalid address (%x) in %s", uva, procfile);
+			_kvm_err(kd, kd->program, "invalid address (%x) in %s",
+			    uva, procfile);
 			break;
 		}
 		amount = read(fd, cp, len);
 		if (amount < 0) {
-			_kvm_err(kd, kd->program, "error reading %s", procfile);
+			_kvm_syserr(kd, kd->program, "error reading %s",
+			    procfile);
+			break;
+		}
+		if (amount == 0) {
+			_kvm_err(kd, kd->program, "EOF reading %s", procfile);
 			break;
 		}
 		cp += amount;
@@ -718,5 +723,5 @@ kvm_uread(kd, p, uva, buf, len)
 	}
 
 	close(fd);
-	return (ssize_t)(cp - buf);
+	return ((ssize_t)(cp - buf));
 }