From 353cade3149c27b53260932ee3ff1ebde405976d Mon Sep 17 00:00:00 2001 From: Piotr Maziarz Date: Thu, 7 Nov 2019 13:45:37 +0100 Subject: [PATCH] seq_buf: Add printing formatted hex dumps Provided function is an analogue of print_hex_dump(). Implementing this function in seq_buf allows using for multiple purposes (e.g. for tracing) and therefore prevents from code duplication in every layer that uses seq_buf. print_hex_dump() is an essential part of logging data to dmesg. Adding similar capability for other purposes is beneficial to all users. Example usage: seq_buf_hex_dump(seq, "", DUMP_PREFIX_OFFSET, 16, 4, buf, ARRAY_SIZE(buf), true); Example output: 00000000: 00000000 ffffff10 ffffff32 ffff3210 ........2....2.. 00000010: ffff3210 83d00437 c0700000 00000000 .2..7.....p..... 00000020: 02010004 0000000f 0000000f 00004002 .............@.. 00000030: 00000fff 00000000 ........ Link: http://lkml.kernel.org/r/1573130738-29390-1-git-send-email-piotrx.maziarz@linux.intel.com Signed-off-by: Piotr Maziarz Signed-off-by: Cezary Rojewski Signed-off-by: Steven Rostedt (VMware) --- include/linux/seq_buf.h | 3 ++ lib/seq_buf.c | 62 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 65 insertions(+) diff --git a/include/linux/seq_buf.h b/include/linux/seq_buf.h index aa5deb041c25..fb0205d87d3c 100644 --- a/include/linux/seq_buf.h +++ b/include/linux/seq_buf.h @@ -125,6 +125,9 @@ extern int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len); extern int seq_buf_putmem_hex(struct seq_buf *s, const void *mem, unsigned int len); extern int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc); +extern int seq_buf_hex_dump(struct seq_buf *s, const char *prefix_str, + int prefix_type, int rowsize, int groupsize, + const void *buf, size_t len, bool ascii); #ifdef CONFIG_BINARY_PRINTF extern int diff --git a/lib/seq_buf.c b/lib/seq_buf.c index bd807f545a9d..4e865d42ab03 100644 --- a/lib/seq_buf.c +++ b/lib/seq_buf.c @@ -328,3 +328,65 @@ int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, int cnt) s->readpos += cnt; return cnt; } + +/** + * seq_buf_hex_dump - print formatted hex dump into the sequence buffer + * @s: seq_buf descriptor + * @prefix_str: string to prefix each line with; + * caller supplies trailing spaces for alignment if desired + * @prefix_type: controls whether prefix of an offset, address, or none + * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE) + * @rowsize: number of bytes to print per line; must be 16 or 32 + * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1) + * @buf: data blob to dump + * @len: number of bytes in the @buf + * @ascii: include ASCII after the hex output + * + * Function is an analogue of print_hex_dump() and thus has similar interface. + * + * linebuf size is maximal length for one line. + * 32 * 3 - maximum bytes per line, each printed into 2 chars + 1 for + * separating space + * 2 - spaces separating hex dump and ascii representation + * 32 - ascii representation + * 1 - terminating '\0' + * + * Returns zero on success, -1 on overflow + */ +int seq_buf_hex_dump(struct seq_buf *s, 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; + unsigned char linebuf[32 * 3 + 2 + 32 + 1]; + int ret; + + if (rowsize != 16 && rowsize != 32) + rowsize = 16; + + for (i = 0; i < len; i += rowsize) { + linelen = min(remaining, rowsize); + remaining -= rowsize; + + hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, + linebuf, sizeof(linebuf), ascii); + + switch (prefix_type) { + case DUMP_PREFIX_ADDRESS: + ret = seq_buf_printf(s, "%s%p: %s\n", + prefix_str, ptr + i, linebuf); + break; + case DUMP_PREFIX_OFFSET: + ret = seq_buf_printf(s, "%s%.8x: %s\n", + prefix_str, i, linebuf); + break; + default: + ret = seq_buf_printf(s, "%s%s\n", prefix_str, linebuf); + break; + } + if (ret) + return ret; + } + return 0; +}