compat/backport-4.3.c

/*
 * Copyright (c) 2015  Hauke Mehrtens <hauke@hauke-m.de>
 *
 * Backport functionality introduced in Linux 4.3.
 *
 * 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.
 */

#include <linux/seq_file.h>
#include <linux/export.h>
#include <linux/printk.h>

static void seq_set_overflow(struct seq_file *m)
{
	m->count = m->size;
}

/* A complete analogue of print_hex_dump() */
void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
		  int rowsize, int groupsize, const void *buf, size_t len,
		  bool ascii)
{
	const u8 *ptr = buf;
	int i, linelen, remaining = len;
	int ret;

	if (rowsize != 16 && rowsize != 32)
		rowsize = 16;

	for (i = 0; i < len && !seq_has_overflowed(m); i += rowsize) {
		linelen = min(remaining, rowsize);
		remaining -= rowsize;

		switch (prefix_type) {
		case DUMP_PREFIX_ADDRESS:
			seq_printf(m, "%s%p: ", prefix_str, ptr + i);
			break;
		case DUMP_PREFIX_OFFSET:
			seq_printf(m, "%s%.8x: ", prefix_str, i);
			break;
		default:
			seq_printf(m, "%s", prefix_str);
			break;
		}

		ret = hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
					 m->buf + m->count, m->size - m->count,
					 ascii);
		if (ret >= m->size - m->count) {
			seq_set_overflow(m);
		} else {
			m->count += ret;
			seq_putc(m, '\n');
		}
	}
}
EXPORT_SYMBOL_GPL(seq_hex_dump);