[PATCH] lib/hexdump

[Randy Dunlap <randy.dunlap@oracle.com>]

From: Randy Dunlap <randy.dunlap@oracle.com>

Based on ace_dump_mem() from Grant Likely for the Xilinx 
SystemACE CompactFlash interface.

Add hex_dumper() to lib/hexdump.c and linux/kernel.h.

This patch adds the function 'hex_dumper' which can be used to perform a 
hex + ASCII dump of data to syslog, in an easily viewable format, thus
providing a common text hex dump format.

It does not provide a hexdump_to_buffer() function.
if someone needs that, we'll have to add it.

Example usage:
	hex_dumper(KERN_DEBUG, data, length);

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
---

 include/linux/kernel.h |    1 
 lib/Makefile           |    2 -
 lib/hexdump.c          |   51 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+), 1 deletion(-)

--- linux-2.6.21-git4.orig/include/linux/kernel.h
+++ linux-2.6.21-git4/include/linux/kernel.h
@@ -201,6 +201,7 @@ extern enum system_states {
 #define TAINT_USER			(1<<6)
 
 extern void dump_stack(void);
+extern void hex_dumper(const char *level, void *base, int len);
 
 #ifdef DEBUG
 /* If you are writing a driver, please use dev_dbg instead */
--- linux-2.6.21-git4.orig/lib/Makefile
+++ linux-2.6.21-git4/lib/Makefile
@@ -5,7 +5,7 @@
 lib-y := ctype.o string.o vsprintf.o cmdline.o \
 	 rbtree.o radix-tree.o dump_stack.o \
 	 idr.o int_sqrt.o bitmap.o extable.o prio_tree.o \
-	 sha1.o irq_regs.o reciprocal_div.o
+	 sha1.o irq_regs.o reciprocal_div.o hexdump.o
 
 lib-$(CONFIG_MMU) += ioremap.o
 lib-$(CONFIG_SMP) += cpumask.o
--- /dev/null
+++ linux-2.6.21-git4/lib/hexdump.c
@@ -0,0 +1,51 @@
+/*
+ * lib/hexdump.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation. See README and COPYING for
+ * more details.
+ */
+
+#include <linux/types.h>
+#include <linux/ctype.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+/**
+ * hex_dumper - print a text hex dump to syslog for a binary blob of data
+ * @level: kernel log level (e.g. KERN_DEBUG)
+ * @buf: data blob to dump
+ * @len: number of bytes in the @buf
+ *
+ * Given a buffer of u8 data, hex_dumper() will print a hex + ASCII dump
+ * to the kernel log at the specified kernel log level.
+ *
+ * E.g.:
+ *	hex_dumper(KERN_DEBUG, frame->data, frame->len);
+ *
+ * Prints the offsets of the block of memory, not addresses:
+ * 0009ab42: 40414243 44454647 48494a4b 4c4d4e4f-@ABCDEFG HIJKLMNO
+ */
+void hex_dumper(const char *level, void *base, int len)
+{
+	const u8 *ptr = base;
+	int i, j;
+
+	for (i = 0; i < len; i += 16) {
+		printk("%s%.8x:", level, i);
+		for (j = 0; (j < 16) && (i + j) < len; j++) {
+			if (!(j % 4))
+				printk(" ");
+			printk("%.2x", ptr[i + j]);
+		}
+		printk("-");
+		for (j = 0; (j < 16) && (i + j) < len; j++) {
+			printk("%c", isprint(ptr[i + j]) ? ptr[i + j] : '.');
+			if (j == 7)
+				printk(" ");
+		}
+		printk("\n");
+	}
+}
+EXPORT_SYMBOL(hex_dumper);