Re: [PATCH] hexdump: Add ability to do endian conversions in print_hex_dump functions
From: Andy Shevchenko
Date: Wed Dec 09 2015 - 17:11:57 EST
On Wed, Dec 9, 2015 at 11:59 PM, Joe Perches <joe@xxxxxxxxxxx> wrote:
> There are use cases for dumping buffers with specific endian types
> for 2, 4, and 8 byte variables in arrays.
>
> Add an enum for DUMP_TYPE_(LE|BE|CPU) to enable emitting them as such.
>
> Rename groupsize to groupflags in the functions and add documentation
> to the kernel-doc to describe the use of the DUMP_TYPE_ enum.
One comment below and my tag
Acked-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
>
> Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
> ---
> include/linux/printk.h | 23 +++++++++++++++--------
> lib/hexdump.c | 49 ++++++++++++++++++++++++++++++++++++++-----------
> 2 files changed, 53 insertions(+), 19 deletions(-)
>
> diff --git a/include/linux/printk.h b/include/linux/printk.h
> index 9729565..aac2943 100644
> --- a/include/linux/printk.h
> +++ b/include/linux/printk.h
> @@ -424,12 +424,19 @@ enum {
> DUMP_PREFIX_ADDRESS,
> DUMP_PREFIX_OFFSET
> };
> +
> +enum {
> + DUMP_TYPE_CPU = 0,
> + DUMP_TYPE_LE = BIT(30),
> + DUMP_TYPE_BE = BIT(31)
> +};
> +
> extern int hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
> - int groupsize, char *linebuf, size_t linebuflen,
> + int groupflags, char *linebuf, size_t linebuflen,
> bool ascii);
> #ifdef CONFIG_PRINTK
> extern void print_hex_dump(const char *level, const char *prefix_str,
> - int prefix_type, int rowsize, int groupsize,
> + int prefix_type, int rowsize, int groupflags,
> const void *buf, size_t len, bool ascii);
> #if defined(CONFIG_DYNAMIC_DEBUG)
> #define print_hex_dump_bytes(prefix_str, prefix_type, buf, len) \
> @@ -440,7 +447,7 @@ extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
> #endif /* defined(CONFIG_DYNAMIC_DEBUG) */
> #else
> static inline void print_hex_dump(const char *level, const char *prefix_str,
> - int prefix_type, int rowsize, int groupsize,
> + int prefix_type, int rowsize, int groupflags,
> const void *buf, size_t len, bool ascii)
> {
> }
> @@ -453,17 +460,17 @@ static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
>
> #if defined(CONFIG_DYNAMIC_DEBUG)
> #define print_hex_dump_debug(prefix_str, prefix_type, rowsize, \
> - groupsize, buf, len, ascii) \
> + groupflags, buf, len, ascii) \
> dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
> - groupsize, buf, len, ascii)
> + groupflags, buf, len, ascii)
> #elif defined(DEBUG)
> #define print_hex_dump_debug(prefix_str, prefix_type, rowsize, \
> - groupsize, buf, len, ascii) \
> + groupflags, buf, len, ascii) \
> print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize, \
> - groupsize, buf, len, ascii)
> + groupflags, buf, len, ascii)
> #else
> static inline void print_hex_dump_debug(const char *prefix_str, int prefix_type,
> - int rowsize, int groupsize,
> + int rowsize, int groupflags,
> const void *buf, size_t len, bool ascii)
> {
> }
> diff --git a/lib/hexdump.c b/lib/hexdump.c
> index 992457b..f44608e 100644
> --- a/lib/hexdump.c
> +++ b/lib/hexdump.c
> @@ -80,7 +80,9 @@ EXPORT_SYMBOL(bin2hex);
> * @buf: data blob to dump
> * @len: number of bytes in the @buf
> * @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)
> + * @groupflags: number of bytes to print at a time (1, 2, 4, 8; default = 1)
> + * use a bitwise OR with %DUMP_TYPE_BE or %DUMP_TYPE_LE for endian conversions
> + * of @buf, otherwise %DUMP_TYPE_CPU is used
> * @linebuf: where to put the converted data
> * @linebuflen: total size of @linebuf, including space for terminating NUL
> * @ascii: include ASCII after the hex output
> @@ -105,7 +107,7 @@ EXPORT_SYMBOL(bin2hex);
> * (excluding the terminating NUL) which would have been written to the final
> * string if enough space had been available.
> */
> -int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
> +int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupflags,
> char *linebuf, size_t linebuflen, bool ascii)
> {
> const u8 *ptr = buf;
> @@ -114,6 +116,7 @@ int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
> int j, lx = 0;
> int ascii_column;
> int ret;
> + int groupsize = groupflags & ~(DUMP_TYPE_LE | DUMP_TYPE_BE);
>
> if (rowsize != 16 && rowsize != 32)
> rowsize = 16;
> @@ -138,9 +141,16 @@ int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
> const u64 *ptr8 = buf;
>
> for (j = 0; j < ngroups; j++) {
> + u64 val;
> +
> + if (groupflags & DUMP_TYPE_LE)
> + val = get_unaligned_le64(ptr8 + j);
> + else if (groupflags & DUMP_TYPE_BE)
> + val = get_unaligned_be64(ptr8 + j);
> + else
> + val = get_unaligned(ptr8 + j);
> ret = snprintf(linebuf + lx, linebuflen - lx,
> - "%s%16.16llx", j ? " " : "",
> - get_unaligned(ptr8 + j));
> + "%s%16.16llx", j ? " " : "", val);
> if (ret >= linebuflen - lx)
> goto overflow1;
> lx += ret;
> @@ -149,9 +159,16 @@ int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
> const u32 *ptr4 = buf;
>
> for (j = 0; j < ngroups; j++) {
> + u32 val;
> +
> + if (groupflags & DUMP_TYPE_LE)
> + val = get_unaligned_le32(ptr4 + j);
> + else if (groupflags & DUMP_TYPE_BE)
> + val = get_unaligned_be32(ptr4 + j);
> + else
> + val = get_unaligned(ptr4 + j);
> ret = snprintf(linebuf + lx, linebuflen - lx,
> - "%s%8.8x", j ? " " : "",
> - get_unaligned(ptr4 + j));
> + "%s%8.8x", j ? " " : "", val);
> if (ret >= linebuflen - lx)
> goto overflow1;
> lx += ret;
> @@ -160,9 +177,16 @@ int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
> const u16 *ptr2 = buf;
>
> for (j = 0; j < ngroups; j++) {
> + u16 val;
> +
> + if (groupflags & DUMP_TYPE_LE)
> + val = get_unaligned_le16(ptr2 + j);
> + else if (groupflags & DUMP_TYPE_BE)
> + val = get_unaligned_be16(ptr2 + j);
> + else
> + val = get_unaligned(ptr2 + j);
> ret = snprintf(linebuf + lx, linebuflen - lx,
> - "%s%4.4x", j ? " " : "",
> - get_unaligned(ptr2 + j));
> + "%s%4.4x", j ? " " : "", val);
> if (ret >= linebuflen - lx)
> goto overflow1;
> lx += ret;
> @@ -216,7 +240,10 @@ EXPORT_SYMBOL(hex_dump_to_buffer);
> * @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)
> + * @groupflags: number of bytes to print at a time (1, 2, 4, 8; default = 1)
> + * @groupflags: number of bytes to print at a time (1, 2, 4, 8; default = 1)
Duplicate.
> + * use a bitwise OR with %DUMP_TYPE_BE or %DUMP_TYPE_LE for endian conversions
> + * of @buf, otherwise %DUMP_TYPE_CPU is used
> * @buf: data blob to dump
> * @len: number of bytes in the @buf
> * @ascii: include ASCII after the hex output
> @@ -240,7 +267,7 @@ EXPORT_SYMBOL(hex_dump_to_buffer);
> * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c pqrstuvwxyz{|}~.
> */
> void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
> - int rowsize, int groupsize,
> + int rowsize, int groupflags,
> const void *buf, size_t len, bool ascii)
> {
> const u8 *ptr = buf;
> @@ -254,7 +281,7 @@ void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
> linelen = min(remaining, rowsize);
> remaining -= rowsize;
>
> - hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
> + hex_dump_to_buffer(ptr + i, linelen, rowsize, groupflags,
> linebuf, sizeof(linebuf), ascii);
>
> switch (prefix_type) {
> --
> 2.6.3.368.gf34be46
>
--
With Best Regards,
Andy Shevchenko
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/