Merge branch 'master' of gitlab.cvh-server.de:cloepke/bs

20160425/.gitignore

+.chardev-1.ko.cmd
+.chardev-1.mod.o.cmd
+.chardev-1.o.cmd
+.chardev-1write.ko.cmd
+.chardev-1write.mod.o.cmd
+.chardev-1write.o.cmd
+.hellomod-1.ko.cmd
+.hellomod-1.mod.o.cmd
+.hellomod-1.o.cmd
+.tmp_versions/
+Module.symvers
+chardev-1.ko
+chardev-1.mod.c
+chardev-1.mod.o
+chardev-1.o
+chardev-1write.ko
+chardev-1write.mod.c
+chardev-1write.mod.o
+chardev-1write.o
+hellomod-1.ko
+hellomod-1.mod.c
+hellomod-1.mod.o
+hellomod-1.o
+modules.order
+

20160425/Makefile

 obj-m += hellomod-1.o
 obj-m += chardev-1.o
+obj-m += chardev-1write.o
 
 all:
 	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules

20160425/chardev-1write.c

+/*  Modified by:      Christian Löpke <christian.loepke@hs-bochum.de>
+ *  chardev-1write.c: Creates a char device that says Mr. Anderson or a 
+ *                    written name how many times he read from the dev
+ *                    file.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <asm/uaccess.h>	/* for put_user */
+
+/*  
+ *  Prototypes - this would normally go in a .h file
+ */
+int init_module(void);
+void cleanup_module(void);
+static int device_open(struct inode *, struct file *);
+static int device_release(struct inode *, struct file *);
+static ssize_t device_read(struct file *, char *, size_t, loff_t *);
+static ssize_t device_write(struct file *, const char *, size_t, loff_t *);
+
+#define SUCCESS 0
+#define DEVICE_NAME "chardev"	/* Dev name as it appears in /proc/devices   */
+#define BUF_LEN 80		/* Max length of the message from the device */
+#define USERBUF_LEN 20		/* Max length for user definable name */
+/* 
+ * Global variables are declared as static, so are global within the file. 
+ */
+
+static int Major;	    /* Major number assigned to our device driver */
+static int Device_Open = 0; /* Is device open?  
+			     * Used to prevent multiple access to device */
+static char msg[BUF_LEN];   /* The msg the device will give when asked */
+static char *msg_Ptr;	    /* The current char from msg we are writing */
+
+static char msg_username[USERBUF_LEN]; /* User definable name */
+static int told_you_counter = 0; /* Counts the outputs I've made */
+
+static struct file_operations fops = {
+	.read = device_read,
+	.write = device_write,
+	.open = device_open,
+	.release = device_release
+};
+
+/*
+ * This function is called when the module is loaded
+ */
+int init_module(void)
+{
+        Major = register_chrdev(0, DEVICE_NAME, &fops);
+
+	if (Major < 0) {
+	  printk(	KERN_ALERT 
+			"%s: Registering char device failed with %d\n", 
+			DEVICE_NAME,			
+			Major);
+	  return Major;
+	}
+
+	printk(	KERN_INFO "%s: I was assigned major number %d. To talk to\n",
+		DEVICE_NAME,		
+		Major);
+	printk(	KERN_INFO 
+		"%s: the driver, create a dev file with\n", DEVICE_NAME);
+	printk(	KERN_INFO "%s: 'mknod /dev/%s c %d 0'.\n",
+		DEVICE_NAME,
+		DEVICE_NAME,
+		Major);
+	printk(	KERN_INFO 
+		"%s: Try various minor numbers. Try to cat and echo to\n",
+		DEVICE_NAME);
+	printk(	KERN_INFO "%s: the device file.\n", DEVICE_NAME);
+	printk(	KERN_INFO 
+		"%s: Remove the device file and module when done.\n", 
+		DEVICE_NAME);
+
+	sprintf(msg_username, "Mr. Anderson"); //Setup initial username.
+	return SUCCESS;
+}
+
+/*
+ * This function is called when the module is unloaded
+ */
+void cleanup_module(void)
+{
+	/* 
+	 * Unregister the device 
+	 */
+	unregister_chrdev(Major, DEVICE_NAME);
+}
+
+/*
+ * Methods
+ */
+
+/* 
+ * Called when a process tries to open the device file, like
+ * "cat /dev/mycharfile"
+ */
+static int device_open(struct inode *inode, struct file *file)
+{
+	if (Device_Open)
+		return -EBUSY;
+
+	Device_Open++;
+	sprintf(msg,
+		"I already told you %d times Hello world!, %s.\n",
+		told_you_counter++,
+		msg_username);
+	msg_Ptr = msg;
+	try_module_get(THIS_MODULE);
+
+	return SUCCESS; /* Device successfully opened */
+}
+
+/* 
+ * Called when a process closes the device file.
+ */
+static int device_release(struct inode *inode, struct file *file)
+{
+	Device_Open--;		/* We're now ready for our next caller */
+
+	/* 
+	 * Decrement the usage count, or else once you opened the file, you'll
+	 * never get get rid of the module. 
+	 */
+	module_put(THIS_MODULE);
+
+	return 0; /* Device sucessfully closed */
+}
+
+/* 
+ * Called when a process, which already opened the dev file, attempts to
+ * read from it.
+ */
+static ssize_t device_read(struct file *filp,	/* see include/linux/fs.h   */
+			   char *buffer,	/* buffer to fill with data */
+			   size_t length,	/* length of the buffer     */
+			   loff_t * offset)
+{
+	/*
+	 * Number of bytes actually written to the buffer 
+	 */
+	int bytes_read = 0;
+
+	/*
+	 * If we're at the end of the message, 
+	 * return 0 signifying end of file 
+	 */
+	if (*msg_Ptr == 0)
+		return 0;
+
+	/* 
+	 * Actually put the data into the buffer 
+	 */
+	while (length && *msg_Ptr) {
+
+		/* 
+		 * The buffer is in the user data segment, not the kernel 
+		 * segment so "*" assignment won't work.  We have to use 
+		 * put_user which copies data from the kernel data segment to
+		 * the user data segment. 
+		 */
+		put_user(*(msg_Ptr++), buffer++);
+
+		length--;
+		bytes_read++;
+	}
+
+	/* 
+	 * Most read functions return the number of bytes put into the buffer
+	 */
+	return bytes_read;
+}
+
+/*  
+ * Called when a process writes to dev file: echo "hi" > /dev/hello 
+ */
+static ssize_t
+device_write(struct file *filp, const char *buff, size_t len, loff_t * off)
+{
+	/* Since nobody wants to read I have to correct the already told you
+	   counter! */
+	told_you_counter--;
+	if(len >= USERBUF_LEN) {
+		printk(	KERN_WARNING 
+			"%s: Sorry, your input is too long. Max %d allowed!\n",
+			DEVICE_NAME,
+			USERBUF_LEN);	  
+		return -ENOMEM; //Return not enaugh memory
+	}
+	else {
+		int i;
+		for(i = 0; i < len; i++) {//Save the given string
+			if(get_user(msg_username[i], buff + i) < 0) { //If returning error code
+				printk(KERN_WARNING 
+					   "%s: This memory does not belong to you!\n",
+						DEVICE_NAME);
+				return -EFAULT; //Stop reading from userspace.
+			}			
+			//msg_username[i] = buff[i]; //Heres was the CRASH
+			//printk(KERN_INFO "Got %c at %d from %d bytes.\n", buff[i], i, len);
+		}
+		for(i = len; i < USERBUF_LEN; i++) //Zeroing the rest of mem
+			msg_username[i] = 0;
+		printk(KERN_INFO "%s: Successfully got %d bytes!\n",
+		       DEVICE_NAME, (int)len);
+		if(msg_username[len-1] == '\n') //Got new line terminator ?
+		  msg_username[len-1] = 0; //Then terminate it!
+		return len; //Emit successfully stored len bytes
+	}	
+}

20160425/dmesgCrash.log

+Mai 08 20:02:22 archtux kernel: BUG: unable to handle kernel paging 
+request at 0000000000ba9810
+Mai 08 20:02:22 archtux kernel: IP: [<ffffffffa05d6138>] 
+device_write+0xa8/0xd0 [chardev_1write]
+Mai 08 20:02:22 archtux kernel: PGD 251819067 PUD 251b40067 PMD 
+2518e4067 PTE 800000022be53067
+Mai 08 20:02:22 archtux kernel: Oops: 0001 [#4] PREEMPT SMP 
+Mai 08 20:02:22 archtux kernel: Modules linked in: chardev_1write(PO) 
+ctr ccm fuse snd_hda_codec_hdmi snd_hda_codec_realtek 
+snd_hda_codec_generic joydev mousedev arc4 iwlmvm snd_soc_skl 
+snd_soc_skl_ipc i915 snd_soc_sst_ipc snd_soc_sst_dsp snd_hda_ext_core 
+snd_soc_sst_match snd_soc_core snd_compress mac80211 snd_pcm_dmaengine 
+ac97_bus drm_kms_helper intel_rapl x86_pkg_temp_thermal snd_hda_intel 
+snd_hda_codec intel_powerclamp coretemp snd_hda_core iwlwifi uvcvideo 
+videobuf2_vmalloc videobuf2_memops snd_hwdep kvm_intel evdev drm 
+input_leds snd_pcm videobuf2_v4l2 cfg80211 intel_gtt led_class 
+syscopyarea sysfillrect snd_timer sysimgblt kvm fb_sys_fops snd 
+irqbypass mac_hid mei_me videobuf2_core pcspkr i2c_algo_bit shpchp 
+soundcore mei serio_raw psmouse videodev btusb hci_uart btrtl btbcm 
+btqca btintel media i2c_i801 thermal
+Mai 08 20:02:22 archtux kernel:  bluetooth battery video 
+pinctrl_sunrisepoint pinctrl_intel rfkill tpm_tis i2c_hid hid 
+intel_lpss_acpi intel_lpss tpm fjes processor acpi_pad button ac 
+sch_fq_codel ip_tables x_tables sha256_ssse3 sha256_generic hmac drbg 
+ansi_cprng algif_skcipher af_alg dm_crypt dm_mod sd_mod atkbd libps2 
+crct10dif_pclmul crc32_pclmul crc32c_intel ahci ghash_clmulni_intel 
+libahci libata xhci_pci aesni_intel xhci_hcd aes_x86_64 lrw gf128mul 
+glue_helper ablk_helper cryptd usbcore scsi_mod usb_common i8042 serio 
+ext4 crc16 mbcache jbd2 [last unloaded: chardev_1write]
+Mai 08 20:02:22 archtux kernel: CPU: 2 PID: 3447 Comm: bash Tainted: P      
+D    O    4.5.2-1-ARCH #1
+Mai 08 20:02:22 archtux kernel: Hardware name: Intel Corporation Skylake 
+Platform/U931, BIOS 5.11 04/08/2016
+Mai 08 20:02:22 archtux kernel: task: ffff8802671b0000 ti: 
+ffff8802597e0000 task.ti: ffff8802597e0000
+Mai 08 20:02:22 archtux kernel: RIP: 0010:[<ffffffffa05d6138>]  
+[<ffffffffa05d6138>] device_write+0xa8/0xd0 [chardev_1write]
+Mai 08 20:02:22 archtux kernel: RSP: 0018:ffff8802597e3e10  EFLAGS: 
+00010246
+Mai 08 20:02:22 archtux kernel: RAX: 0000000000000000 RBX: 
+0000000000000005 RCX: ffff8802597e3f18
+Mai 08 20:02:22 archtux kernel: RDX: 0000000000000005 RSI: 
+0000000000ba9810 RDI: ffff880246f4c900
+Mai 08 20:02:22 archtux kernel: RBP: ffff8802597e3e38 R08: 
+0000000000ba9815 R09: 00007ffffffff000
+Mai 08 20:02:22 archtux kernel: R10: 0000000000000004 R11: 
+0000000000000246 R12: 0000000000ba9810
+Mai 08 20:02:22 archtux kernel: R13: 0000000000000000 R14: 
+ffffffffa05d7090 R15: 0000000000000005
+Mai 08 20:02:22 archtux kernel: FS:  00007f1037d52700(0000) 
+GS:ffff880273d00000(0000) knlGS:0000000000000000
+Mai 08 20:02:22 archtux kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 
+0000000080050033
+Mai 08 20:02:22 archtux kernel: CR2: 0000000000ba9810 CR3: 
+0000000268c22000 CR4: 00000000003406e0
+Mai 08 20:02:22 archtux kernel: Stack:
+Mai 08 20:02:22 archtux kernel:  ffff880246f4c900 ffff8802597e3f18 
+0000000000ba9810 ffff8802597e3f18
+Mai 08 20:02:22 archtux kernel:  0000000000000000 ffff8802597e3ec0 
+ffffffff811ecde7 00000000354527a1
+Mai 08 20:02:22 archtux kernel:  00000000354527a1 000000000000000a 
+000000000000000a 0000000000000400
+Mai 08 20:02:22 archtux kernel: Call Trace:
+Mai 08 20:02:22 archtux kernel:  [<ffffffff811ecde7>] 
+__vfs_write+0x37/0x100
+Mai 08 20:02:22 archtux kernel:  [<ffffffff811edc97>] 
+vfs_write+0xa7/0x1a0
+Mai 08 20:02:22 archtux kernel:  [<ffffffff811eebe5>] 
+SyS_write+0x55/0xc0
+Mai 08 20:02:22 archtux kernel:  [<ffffffff8120ab43>] ? 
+__close_fd+0xa3/0xd0
+Mai 08 20:02:22 archtux kernel:  [<ffffffff815b0b6e>] 
+entry_SYSCALL_64_fastpath+0x12/0x6d
+Mai 08 20:02:22 archtux kernel: Code: 04 72 5d a0 48 c7 c7 58 70 5d a0 
+e8 a0 01 b9 e0 48 c7 c0 f4 ff ff ff eb cc 49 89 f4 41 89 d7 31 c0 45 31 
+ed 49 c7 c6 90 70 5d a0 <41> 0f be 34 04 44 89 ea 44 89 f9 41 83 c5 01 
+4c 89 f7 e8 6e 01 
+Mai 08 20:02:22 archtux kernel: RIP  [<ffffffffa05d6138>] 
+device_write+0xa8/0xd0 [chardev_1write]
+Mai 08 20:02:22 archtux kernel:  RSP <ffff8802597e3e10>
+Mai 08 20:02:22 archtux kernel: CR2: 0000000000ba9810
+Mai 08 20:02:22 archtux kernel: ---[ end trace 2e7525e9567b5a55 ]---
+