lib: Add hexdump

Often during debugging session it's very interesting to see
what data we were dealing with. For example what we write or read
to/from memory or peripherals.

This change introduces functions that allow to dump binary
data with one simple function invocation like:
------------------->8----------------
print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, buf, len);
------------------->8----------------

which gives us the following:
------------------->8----------------
00000000: f2 b7 c9 88 62 61 75 64 72 61 74 65 3d 31 31 35  ....baudrate=115
00000010: 32 30 30 00 62 6f 6f 74 61 72 67 73 3d 63 6f 6e  200.bootargs=con
00000020: 73 6f 6c 65 3d 74 74 79 53 33 2c 31 31 35 32 30  sole=ttyS3,11520
00000030: 30 6e 38 00 62 6f 6f 74 64 65 6c 61 79 3d 33 00  0n8.bootdelay=3.
00000040: 62 6f 6f 74 66 69 6c 65 3d 75 49 6d 61 67 65 00  bootfile=uImage.
00000050: 66 64 74 63 6f 6e 74 72 6f 6c 61 64 64 72 3d 39  fdtcontroladdr=9
00000060: 66 66 62 31 62 61 30 00 6c 6f 61 64 61 64 64 72  ffb1ba0.loadaddr
00000070: 3d 30 78 38 32 30 30 30 30 30 30 00 73 74 64 65  =0x82000000.stde
00000080: 72 72 3d 73 65 72 69 61 6c 30 40 65 30 30 32 32  rr=serial0@e0022
00000090: 30 30 30 00 73 74 64 69 6e 3d 73 65 72 69 61 6c  000.stdin=serial
000000a0: 30 40 65 30 30 32 32 30 30 30 00 73 74 64 6f 75  [email protected]
000000b0: 74 3d 73 65 72 69 61 6c 30 40 65 30 30 32 32 30  t=serial0@e00220
000000c0: 30 30 00 00 00 00 00 00 00 00 00 00 00 00 00 00  00..............
...
------------------->8----------------

Source of hexdump.c was copied from Linux kernel v4.7-rc2.

Signed-off-by: Alexey Brodkin <[email protected]>
Cc: Anatolij Gustschin <[email protected]>
Cc: Mario Six <[email protected]>
Cc: Simon Glass <[email protected]>
Cc: Tom Rini <[email protected]>
Cc: Stefan Roese <[email protected]>

drivers/mtd/ubi/attach.c

@@ -789,7 +789,7 @@ static int check_corruption(struct ubi_device *ubi, struct ubi_vid_hdr *vid_hdr,
 	ubi_dump_vid_hdr(vid_hdr);
 	pr_err("hexdump of PEB %d offset %d, length %d",
 	       pnum, ubi->leb_start, ubi->leb_size);
-	ubi_dbg_print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+	ubi_dbg_print_hex_dump("", DUMP_PREFIX_OFFSET, 32, 1,
 			       ubi->peb_buf, ubi->leb_size, 1);
 	err = 1;
 

drivers/mtd/ubi/debug.c

@@ -5,6 +5,7 @@
  * Author: Artem Bityutskiy (Битюцкий Артём)
  */
 
+#include <hexdump.h>
 #include <ubi_uboot.h>
 #include "ubi.h"
 #ifndef __UBOOT__
@@ -39,7 +40,7 @@ void ubi_dump_flash(struct ubi_device *ubi, int pnum, int offset, int len)
 
 	ubi_msg(ubi, "dumping %d bytes of data from PEB %d, offset %d",
 		len, pnum, offset);
-	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
+	print_hex_dump("", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
 out:
 	vfree(buf);
 	return;
@@ -60,7 +61,7 @@ void ubi_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr)
 	pr_err("\timage_seq      %d\n", be32_to_cpu(ec_hdr->image_seq));
 	pr_err("\thdr_crc        %#08x\n", be32_to_cpu(ec_hdr->hdr_crc));
 	pr_err("erase counter header hexdump:\n");
-	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+	print_hex_dump("", DUMP_PREFIX_OFFSET, 32, 1,
 		       ec_hdr, UBI_EC_HDR_SIZE, 1);
 }
 
@@ -85,7 +86,7 @@ void ubi_dump_vid_hdr(const struct ubi_vid_hdr *vid_hdr)
 		(unsigned long long)be64_to_cpu(vid_hdr->sqnum));
 	pr_err("\thdr_crc   %08x\n", be32_to_cpu(vid_hdr->hdr_crc));
 	pr_err("Volume identifier header hexdump:\n");
-	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+	print_hex_dump("", DUMP_PREFIX_OFFSET, 32, 1,
 		       vid_hdr, UBI_VID_HDR_SIZE, 1);
 }
 

drivers/mtd/ubi/debug.h

@@ -16,6 +16,8 @@ void ubi_dump_vid_hdr(const struct ubi_vid_hdr *vid_hdr);
 #include <linux/random.h>
 #endif
 
+#include <hexdump.h>
+
 #define ubi_assert(expr)  do {                                               \
 	if (unlikely(!(expr))) {                                             \
 		pr_crit("UBI assert failed in %s at %u (pid %d)\n",          \
@@ -24,8 +26,8 @@ void ubi_dump_vid_hdr(const struct ubi_vid_hdr *vid_hdr);
 	}                                                                    \
 } while (0)
 
-#define ubi_dbg_print_hex_dump(l, ps, pt, r, g, b, len, a)                   \
-		print_hex_dump(l, ps, pt, r, g, b, len, a)
+#define ubi_dbg_print_hex_dump(ps, pt, r, g, b, len, a)                      \
+		print_hex_dump(ps, pt, r, g, b, len, a)
 
 #define ubi_dbg_msg(type, fmt, ...) \
 	pr_debug("UBI DBG " type " (pid %d): " fmt "\n", current->pid,       \

drivers/mtd/ubi/io.c

@@ -78,6 +78,7 @@
 #include <linux/err.h>
 #include <linux/slab.h>
 #else
+#include <hexdump.h>
 #include <ubi_uboot.h>
 #endif
 
@@ -1353,11 +1354,11 @@ static int self_check_write(struct ubi_device *ubi, const void *buf, int pnum,
 		ubi_msg(ubi, "data differ at position %d", i);
 		ubi_msg(ubi, "hex dump of the original buffer from %d to %d",
 			i, i + dump_len);
-		print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+		print_hex_dump("", DUMP_PREFIX_OFFSET, 32, 1,
 			       buf + i, dump_len, 1);
 		ubi_msg(ubi, "hex dump of the read buffer from %d to %d",
 			i, i + dump_len);
-		print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+		print_hex_dump("", DUMP_PREFIX_OFFSET, 32, 1,
 			       buf1 + i, dump_len, 1);
 		dump_stack();
 		err = -EINVAL;
@@ -1419,7 +1420,7 @@ int ubi_self_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)
 fail:
 	ubi_err(ubi, "self-check failed for PEB %d", pnum);
 	ubi_msg(ubi, "hex dump of the %d-%d region", offset, offset + len);
-	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
+	print_hex_dump("", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
 	err = -EINVAL;
 error:
 	dump_stack();

drivers/usb/gadget/f_mass_storage.c

@@ -240,6 +240,7 @@
 /* #define DUMP_MSGS */
 
 #include <config.h>
+#include <hexdump.h>
 #include <malloc.h>
 #include <common.h>
 #include <console.h>

drivers/usb/gadget/storage_common.c

@@ -124,7 +124,7 @@
 # define dump_msg(fsg, label, buf, length) do {                         \
 	if (length < 512) {						\
 		DBG(fsg, "%s, length %u:\n", label, length);		\
-		print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET,	\
+		print_hex_dump("", DUMP_PREFIX_OFFSET,	\
 			       16, 1, buf, length, 0);			\
 	}								\
 } while (0)
@@ -139,7 +139,7 @@
 #  ifdef VERBOSE_DEBUG
 
 #    define dump_cdb(fsg)						\
-	print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE,	\
+	print_hex_dump("SCSI CDB: ", DUMP_PREFIX_NONE,	\
 		       16, 1, (fsg)->cmnd, (fsg)->cmnd_size, 0)		\
 
 #  else

examples/api/Makefile

@@ -32,6 +32,7 @@ OBJ-y += libgenwrap.o
 EXT_COBJ-y += lib/crc32.o
 EXT_COBJ-y += lib/ctype.o
 EXT_COBJ-y += lib/div64.o
+EXT_COBJ-y += lib/hexdump.o
 EXT_COBJ-y += lib/string.o
 EXT_COBJ-y += lib/time.o
 EXT_COBJ-y += lib/vsprintf.o

fs/ubifs/debug.c

@@ -15,6 +15,8 @@
  * various local functions of those subsystems.
  */
 
+#include <hexdump.h>
+
 #ifndef __UBOOT__
 #include <linux/module.h>
 #include <linux/debugfs.h>
@@ -307,7 +309,7 @@ void ubifs_dump_node(const struct ubifs_info *c, const void *node)
 	/* If the magic is incorrect, just hexdump the first bytes */
 	if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC) {
 		pr_err("Not a node, first %zu bytes:", UBIFS_CH_SZ);
-		print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 32, 1,
+		print_hex_dump("", DUMP_PREFIX_OFFSET, 32, 1,
 			       (void *)node, UBIFS_CH_SZ, 1);
 		return;
 	}
@@ -482,7 +484,7 @@ void ubifs_dump_node(const struct ubifs_info *c, const void *node)
 		       (int)le16_to_cpu(dn->compr_type));
 		pr_err("\tdata size      %d\n", dlen);
 		pr_err("\tdata:\n");
-		print_hex_dump(KERN_ERR, "\t", DUMP_PREFIX_OFFSET, 32, 1,
+		print_hex_dump("\t", DUMP_PREFIX_OFFSET, 32, 1,
 			       (void *)&dn->data, dlen, 0);
 		break;
 	}

fs/ubifs/scan.c

@@ -16,6 +16,7 @@
  */
 
 #ifdef __UBOOT__
+#include <hexdump.h>
 #include <linux/err.h>
 #endif
 #include "ubifs.h"
@@ -236,7 +237,7 @@ void ubifs_scanned_corruption(const struct ubifs_info *c, int lnum, int offs,
 	if (len > 8192)
 		len = 8192;
 	ubifs_err(c, "first %d bytes from LEB %d:%d", len, lnum, offs);
-	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4, buf, len, 1);
+	print_hex_dump("", DUMP_PREFIX_OFFSET, 32, 4, buf, len, 1);
 }
 
 /**

include/hexdump.h

@@ -0,0 +1,91 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2018 Synopsys, Inc. All rights reserved.
+ *
+ */
+
+#ifndef HEXDUMP_H
+#define HEXDUMP_H
+
+#include <linux/ctype.h>
+#include <linux/types.h>
+
+enum {
+	DUMP_PREFIX_NONE,
+	DUMP_PREFIX_ADDRESS,
+	DUMP_PREFIX_OFFSET
+};
+
+extern const char hex_asc[];
+#define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
+#define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
+
+static inline char *hex_byte_pack(char *buf, u8 byte)
+{
+	*buf++ = hex_asc_hi(byte);
+	*buf++ = hex_asc_lo(byte);
+	return buf;
+}
+
+/**
+ * hex_to_bin - convert a hex digit to its real value
+ * @ch: ascii character represents hex digit
+ *
+ * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad
+ * input.
+ */
+static inline int hex_to_bin(char ch)
+{
+	if ((ch >= '0') && (ch <= '9'))
+		return ch - '0';
+	ch = tolower(ch);
+	if ((ch >= 'a') && (ch <= 'f'))
+		return ch - 'a' + 10;
+	return -1;
+}
+
+/**
+ * hex2bin - convert an ascii hexadecimal string to its binary representation
+ * @dst: binary result
+ * @src: ascii hexadecimal string
+ * @count: result length
+ *
+ * Return 0 on success, -1 in case of bad input.
+ */
+static inline int hex2bin(u8 *dst, const char *src, size_t count)
+{
+	while (count--) {
+		int hi = hex_to_bin(*src++);
+		int lo = hex_to_bin(*src++);
+
+		if ((hi < 0) || (lo < 0))
+			return -1;
+
+		*dst++ = (hi << 4) | lo;
+	}
+	return 0;
+}
+
+/**
+ * bin2hex - convert binary data to an ascii hexadecimal string
+ * @dst: ascii hexadecimal result
+ * @src: binary data
+ * @count: binary data length
+ */
+static inline char *bin2hex(char *dst, const void *src, size_t count)
+{
+	const unsigned char *_src = src;
+
+	while (count--)
+		dst = hex_byte_pack(dst, *_src++);
+	return dst;
+}
+
+int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
+		       char *linebuf, size_t linebuflen, bool ascii);
+void print_hex_dump(const char *prefix_str, int prefix_type, int rowsize,
+		    int groupsize, const void *buf, size_t len, bool ascii);
+void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
+			  const void *buf, size_t len);
+
+#endif /* HEXDUMP_H */

include/linux/compat.h

@@ -193,7 +193,6 @@ typedef unsigned long blkcnt_t;
 #define init_waitqueue_head(...)	do { } while (0)
 #define wait_event_interruptible(...)	0
 #define wake_up_interruptible(...)	do { } while (0)
-#define print_hex_dump(...)		do { } while (0)
 #define dump_stack(...)			do { } while (0)
 
 #define task_pid_nr(x)			0

lib/Kconfig

@@ -285,6 +285,11 @@ config ERRNO_STR
 	  - if errno is null or positive number - a pointer to "Success" message
 	  - if errno is negative - a pointer to errno related message
 
+config HEXDUMP
+	bool "Enable hexdump"
+	help
+	  This enables functions for printing dumps of binary data.
+
 config OF_LIBFDT
 	bool "Enable the FDT library"
 	default y if OF_CONTROL

lib/Makefile

@@ -86,6 +86,7 @@ obj-$(CONFIG_REGEX) += slre.o
 obj-y += string.o
 obj-y += tables_csum.o
 obj-y += time.o
+obj-y += hexdump.o
 obj-$(CONFIG_TRACE) += trace.o
 obj-$(CONFIG_LIB_UUID) += uuid.o
 obj-$(CONFIG_LIB_RAND) += rand.o