Added the devtrace module.

.gitignore

@@ -28,3 +28,4 @@ core
 # CVS default ignores end
 .depend
 iBCS
+devtrace

ChangeLog

@@ -1,3 +1,10 @@
+Tue Aug 23 17:21:45 BST 1994
+
+	* Added my device trace stub in case anyone needs to investigate
+	  and emulate some special device.
+	  -- Mike
+
+
 Wed Aug 17 14:06:34 BST 1994
 
 	* Added an extern definition of the formats list needed by

Makefile

@@ -1,7 +1,7 @@
 #
 # Makefile for the iBCS emulator files
 #
-# $Id: Makefile,v 1.21 1994/08/05 09:29:09 mike Exp $
+# $Id: Makefile,v 1.22 1994/08/25 07:50:36 mike Exp $
 # $Source: /nfs4/sophia/home/mjagdis/src/ibcs.cvs/ibcs/Makefile,v $
 #
 # Note! Dependencies are done automagically by 'make dep', which also
@@ -115,6 +115,9 @@ emulate2.o:	emulate.c
 		-DKVERSION=\"$(KVERSION)\" \
 		-c -o emulate2.o emulate.c
 
+devtrace: devtrace.c
+	$(CC) $(CFLAGS) -DKVERSION=\"$(KVERSION)\" -c -o devtrace devtrace.c
+
 clean:
 	rm -f core *.o *.a *.s .depend
 

README

@@ -107,7 +107,7 @@ INSTALLATION
    available on all major Linux archive sites.
 
 2. Apply the kernel patches if you are using a 1.0 kernel (read them
-   first - the patch file is annotated). Not patches are required for
+   first - the patch file is annotated). No patches are required for
    kernels 1.1.15 and later. If you are using an earlier 1.1 kernel
    you should upgrade it. The 1.1 series is a development kernel and
    liable to frequent bug fixes. Non-current releases of 1.1 will *not*
@@ -136,7 +136,7 @@ INSTALLATION
    Instructions on how to make the kernel are included in the README file
    in the Linux kernel source directory.
 
-4. Install the kernel. Use either LILO or a separate diskette.
+4. Install the kernel. Use either LILO or a seperate diskette.
 
 5. The interfaces to some subsystems occur at the device layer and thus
    you need to create some device files in order to use them:
@@ -266,6 +266,20 @@ and kill the tail:
 
 and examine the log.
 
+If the program is trying to access a device that doesn't exist and whose
+intended behaviour is not readily apparent (not all devices are devices,
+take a look at /dev/socksys which implements the socket system calls
+behind ioctls) you may wish to use the devtrace module. Firstly, if
+you aren't using a recent (1.1.45+?) kernel you will need to edit the
+file devtrace.c and define a fixed major number. Build the module
+using 'make devtrace' and load it with insmod. If you left the major
+number as zero look up the allocated number in /proc/devices then
+create whatever device nodes your program is trying to access. The
+devtrace module simply writes kernel syslog messages for all operations
+performed on it and pretends that everything succeeds. This will
+cause your program to die horribly but should leave you with enough
+information to find out what was expected of the real device.
+
 If you can fix the problem do so and post the fix to the IBCS2 mailing
 list, otherwise post the *relevant* details you have - parts of the log
 file, ioctl details, syscall details etc. Remember, it's better to post

devtrace/devtrace.c

@@ -0,0 +1,158 @@
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/fcntl.h>
+#include <linux/major.h>
+#include <asm/segment.h>
+#define __KERNEL__ 1
+
+#include <linux/kernel.h>
+#include <linux/net.h>
+#include <linux/sched.h>
+#include <linux/signal.h>
+#include <linux/socket.h>
+#include <linux/utsname.h>
+#include <linux/time.h>
+#include <linux/termios.h>
+#include <linux/sys.h>
+#include <linux/config.h>
+
+#include <linux/module.h>
+
+
+/* Zero for auto allocation. The major number allocated can be found
+ * by looking in /proc/devices after the module is loaded. Auto
+ * allocation of major numbers is a fairly new kernel feature. If you
+ * aren't using a recent 1.1.x kernel you may have to set an explicit
+ * major number here.
+ */
+#define DEVTRACE_MAJOR	0
+
+
+char kernel_version[] = KVERSION;
+
+
+static int
+devtrace_lseek(struct inode *inode, struct file *file, off_t offset, int whence)
+{
+	printk(KERN_DEBUG "devtrace: [%d] %lx: lseek to 0x%08lx whence=%d\n",
+		current->pid, (unsigned long)file,
+		offset, whence);
+
+	/* Easy way out. Most devices we wish to trace are either
+	 * STREAMS devices or character devices which aren't seekable
+	 * anyway.
+	 */
+	return -ESPIPE;
+}
+
+
+static int
+devtrace_read(struct inode *inode, struct file *file, char *buf, int size)
+{
+	printk(KERN_DEBUG "devtrace: [%d] %lx: read %d bytes to 0x%lx\n",
+		current->pid, (unsigned long)file,
+		size, (unsigned long)buf);
+
+	return size;
+}
+
+
+static int
+devtrace_write(struct inode *inode, struct file *file, char *buf, int size)
+{
+	printk(KERN_DEBUG "devtrace: [%d] %lx: write %d bytes from 0x%lx\n",
+		current->pid, (unsigned long)file,
+		size, (unsigned long)buf);
+
+	return size;
+}
+
+
+static int
+devtrace_ioctl(struct inode *inode, struct file *file,
+		unsigned int cmd, unsigned long arg)
+{
+	static char *code[] = {
+		"",		"I_NREAD",	"I_PUSH",	"I_POP",
+		"I_LOOK",	"I_FLUSH",	"I_SRDOPT",	"I_GRDOPT",
+		"I_STR",	"I_SETSIG",	"I_GETSIG",	"I_FIND",
+		"I_LINK",	"I_UNLINK",	"I_PEEK",	"I_FDINSERT",
+		"I_SENDFD",	"I_RECVFD"
+	};
+
+	printk(KERN_DEBUG "devtrace: [%d] %lx: ioctl 0x%x (%s) with argument 0x%lx requested\n",
+		current->pid, (unsigned long)file,
+		cmd, (cmd & 0xff) <= 18 ? code[(cmd & 0xff)] : "????",
+		(unsigned long)arg);
+
+	return 0;
+}
+
+
+static int
+devtrace_open(struct inode *ino, struct file *filep)
+{
+	MOD_INC_USE_COUNT;
+
+	printk(KERN_DEBUG "devtrace: [%d] %lx opening\n",
+		current->pid, (unsigned long)filep);
+
+	return 0;
+}
+
+
+static void
+devtrace_close(struct inode *ino, struct file *filep)
+{
+	MOD_DEC_USE_COUNT;
+
+	printk(KERN_DEBUG "devtrace: [%d] %lx closed\n",
+		current->pid, (unsigned long)filep);
+}
+
+
+static struct file_operations devtrace_fops = {
+	devtrace_lseek,		/* lseek */
+	devtrace_read,		/* read */
+	devtrace_write,		/* write */
+	NULL,			/* readdir */
+	NULL,			/* select */
+	devtrace_ioctl,		/* ioctl */
+	NULL,			/* mmap */
+	devtrace_open,		/* open */
+	devtrace_close,		/* close */
+	NULL			/* fsync */
+};
+
+
+static int devtrace_major;
+
+
+int
+init_module(void)
+{
+	devtrace_major = register_chrdev(DEVTRACE_MAJOR, "devtrace", &devtrace_fops);
+	if (devtrace_major < 0) {
+		printk(KERN_INFO "iBCS: couldn't register devtrace on character major %d\n",
+			DEVTRACE_MAJOR);
+		return 1;
+	} else {
+		if (!devtrace_major)
+			devtrace_major = DEVTRACE_MAJOR;
+		printk(KERN_INFO "iBCS: devtrace registered on character major %d\n", devtrace_major);
+
+		return 0;
+	}
+}
+
+
+void
+cleanup_module(void)
+{
+	if (MOD_IN_USE)
+		printk(KERN_INFO "iBCS: devtrace module is in use, remove delayed\n");
+
+	if (devtrace_major > 0 && unregister_chrdev(devtrace_major, "devtrace") != 0)
+		printk(KERN_NOTICE "iBCS: couldn't unregister devtrace device!\n");
+}

iBCSemul/Makefile

@@ -1,7 +1,7 @@
 #
 # Makefile for the iBCS emulator files
 #
-# $Id: Makefile,v 1.21 1994/08/05 09:29:09 mike Exp $
+# $Id: Makefile,v 1.22 1994/08/25 07:50:36 mike Exp $
 # $Source: /nfs4/sophia/home/mjagdis/src/ibcs.cvs/ibcs/iBCSemul/Makefile,v $
 #
 # Note! Dependencies are done automagically by 'make dep', which also
@@ -115,6 +115,9 @@ emulate2.o:	emulate.c
 		-DKVERSION=\"$(KVERSION)\" \
 		-c -o emulate2.o emulate.c
 
+devtrace: devtrace.c
+	$(CC) $(CFLAGS) -DKVERSION=\"$(KVERSION)\" -c -o devtrace devtrace.c
+
 clean:
 	rm -f core *.o *.a *.s .depend